Carbon Offset Cost Calculator — Tonnes to Price by Project Type
Estimate the budget to retire a given tonnage of carbon credits across a portfolio of project types, using your own sourced price bands — because voluntary-market prices vary by an order of magnitude with project mechanism, durability, and integrity.
You supply the price; the tool does the portfolio arithmetic. Voluntary carbon credit prices are not a published, standardised dataset — they are negotiated, quality-stratified, and opaque. This calculator therefore prices your portfolio from bands you supply: a low, central, and high price per tonne for each project type, from your own quotes or a market report you cite, and it computes the total budget and its uncertainty range. The single exception is direct air capture, where published pricing is defensible enough that the tool offers an indicative reference band (in USD) as an editable starting point — you can overtype it, and it is withdrawn in any other currency.
Core formula: total cost = Σ (tonnesi × pricei) × (1 + overhead%), summed across each project row. The tonnes for each row are the total tonnage to neutralise, multiplied by that row’s allocation share. The overhead percentage is a single optional adder for buffer-pool contributions, retirement fees, or broker margin — it defaults to zero.
Three prices, not one. Each row takes a low, central, and high price, producing a budget range rather than a false-precision point estimate. On a market where the same nominal tonne trades from a few pounds to several hundred, a range is the honest output. The blended price per tonne — total central cost ÷ total tonnes — is reported so portfolios of different mixes can be compared on a like basis.
Two axes drive the price: mechanism and durability. Each project type is classified as avoidance (the project prevents an emission that would otherwise occur) or removal (the project takes CO2 out of the atmosphere), and carries a durability score from 0 (no storage) to 3 (durable for a thousand years or more). Removal and durability both command a premium, which is why a durable engineered removal can cost fifty times an avoidance credit.
Currency is a display label only. Pick GBP, USD, or EUR; the tool does not convert. Enter every price band in that one currency. The one MasterBrain reference band — direct air capture — is quoted in USD, so it is offered only when you select USD and withdrawn otherwise, never converted.
What this tool is not. It is a budgeting estimator, not an accounting tool and not purchasing advice. Retiring credits does not reduce your reported GHG inventory, and this tool makes no neutrality claim. Price is not a proxy for quality — additionality, permanence, and verification must be assessed separately (see the ICVCM Core Carbon Principles). Full method: carbon offset pricing methodology.
Amount unit for the tonnage above (1 kt = 1,000 t). Neutralisation is a last step — reduce first, offset the residual.
Prices are your own inputs — enter a band (low / central / high) per project. A single row = one project; multiple rows = a blended portfolio (allocations normalise to 100%).
Enter your tonnage and a price band per project to estimate cost
Results appear instantly. A cost range, a spend-by-project split, a cost-vs-quality frontier, a portfolio breakdown, and the full audit trail appear after calculation. This is a budgeting estimate — not purchasing advice.
This is an indicative budgeting and due-diligence estimate, not purchasing or investment advice. GreenCalculus does not supply, broker, price, endorse, or verify carbon credits, and does not link to sellers or registries. All prices are your own inputs — the result is only as accurate as the bands you enter. Voluntary carbon market prices are wide, volatile, and vary by vintage, registry, co-benefit, and volume; a quote dates quickly, so treat the range as a planning envelope and re-confirm current pricing before committing. Price is not a proxy for quality: cheap avoidance credits (unbundled renewables, some REDD+ and cookstove projects) have faced the strongest additionality and integrity scrutiny, while durable removals cost more because permanence and verification cost more. Offsetting is a last step — prioritise reducing emissions within your value chain first (SBTi / GHG Protocol), and treat neutralisation of the residual as beyond-value-chain mitigation. Confirm any purchase against independent quality assessment (e.g. ICVCM Core Carbon Principles) and your own procurement due diligence.
A carbon credit is sold by the tonne, and a tonne is a tonne — so it is tempting to think one credit is much like another. It is not. The same nominal tonne of CO2e trades for under £10 as an avoided-deforestation credit and over £500 as direct air capture, and the gap is not arbitrary: it tracks whether the project removes carbon or merely avoids an emission, how long the carbon stays put, and whether the claim survives scrutiny.
Pricing an offset portfolio is not a lookup — it is a set of decisions about quality, and the price is where those decisions show up.
Carbon offset cost = tonnes × price per tonne, summed across project types. Prices range from under £10/t for avoidance credits to £300–700/t for durable engineered removal, so the project mix drives the budget far more than the tonnage.
What this calculator prices — and what it can’t promise
This calculator estimates the budget to retire a chosen tonnage of voluntary carbon credits across a mix of project types. It answers a procurement question — what will this offset portfolio cost, and how wide is the uncertainty — using price bands you supply. It deliberately does not answer two questions it is often mistaken for: it does not reduce your carbon inventory, and it does not tell you a credit is good.
Retiring a carbon credit does not lower your reported emissions. A GHG inventory records the tonnes your organisation emitted; a retired credit is a separate transaction recorded outside the inventory, and under the GHG Protocol and SBTi it neutralises a residual after reductions, not instead of them. This tool prices that residual purchase — it makes no accounting or neutrality claim.
Price is not a quality guarantee
The single most important thing to understand before pricing offsets is that price and quality are correlated but not equivalent. A higher price often signals a more durable, more rigorously verified credit — but it can also reflect scarcity, hype, or a premium co-benefit story, and a low price does not automatically mean a weak credit. The calculator prices what you tell it; it cannot assess whether the underlying credit is additional, permanent, or free of double-counting. Those are separate judgements, covered in the quality and integrity section, and they are where the real work of credible offsetting lives.
On the voluntary market the price is the most visible quality signal — but it is a signal, not a certificate. Read it as a starting hypothesis to verify, never as verification itself.
How the calculation works — tonnes to cost
The arithmetic is deliberately simple; the judgement is all in the inputs. Each row of the portfolio contributes its tonnage times its price, and the rows sum to a portfolio total with an optional overhead adder.
Total cost = Σ (tonnesi × pricei) × (1 + overhead%)
where tonnesi = total tonnage × allocation sharei
| Step | What happens |
|---|---|
| 1 — Set the tonnage | Enter the total tCO2e to neutralise (typically the residual after reductions). |
| 2 — Allocate across project types | Split the tonnage into rows by allocation share (e.g. 50% afforestation, 30% biochar, 20% direct air capture). Shares sum to 100%. |
| 3 — Enter three prices per row | A low, central, and high price per tonne for each project type, in one currency, from your own sourcing. |
| 4 — Add overhead (optional) | A single percentage for buffer-pool, retirement, or broker costs. Defaults to zero. |
| 5 — Read the range | The tool returns a low–central–high total, a blended price per tonne, and the removal and durability share of spend. |
Because currency is a display label with no conversion, every price band must be entered in the same currency. The blended price per tonne — total central cost divided by total tonnes — is the figure to compare portfolios on: two portfolios buying the same tonnage can differ several-fold in blended price purely on their project mix.
Enter three genuinely different prices, not the same number three times. The low–high spread is the point: on a market this opaque, a single-point budget is false precision. If you only have one quote, set the low and high a sensible margin either side of it to carry the uncertainty forward into the total, rather than presenting a spuriously exact figure to a budget holder.
What drives the price — mechanism, durability, and more
Five attributes explain most of the price variation between credits. The first two — mechanism and durability — are the axes this calculator classifies each project type on; the other three shift a price within a type’s range.
Mechanism: avoidance vs removal
An avoidance credit pays for an emission that does not happen — protecting a forest that would have been cleared, or replacing a polluting cookstove. A removal credit pays to take CO2 out of the atmosphere and store it. Removals are scarcer and generally cost more, and the science of net zero increasingly treats durable removals as the only credits that can neutralise residual emissions at the target date.
Durability: how long the carbon stays put
Durability is scored from 0 (no storage — an avoided emission) to 3 (locked away for a thousand years or more, as in geological storage). A tree can burn and a soil can be tilled, so nature-based storage sits mid-scale; mineralised or geologically stored carbon sits at the top. The durability premium is steep: the most durable removals are the most expensive credits on the market.
Within a project type, three further attributes move the price:
- Vintage — the year the reduction or removal occurred. Older vintages often trade at a discount; buyers increasingly prefer recent vintages closer to the retirement year.
- Geography and co-benefits — credits carrying verified community, biodiversity, or development co-benefits command a premium over bare-carbon credits, as do projects in higher-cost or higher-integrity jurisdictions.
- Certification and rating — the registry (Verra VCS, Gold Standard) and any independent rating shift price, and credits assessed against the ICVCM Core Carbon Principles increasingly attract a quality premium.
Do not price a portfolio from a single market-average headline number. “The average voluntary credit costs £X” collapses a distribution that spans two orders of magnitude, and any real portfolio sits somewhere specific within it depending on its mechanism and durability mix. Price each project type on its own band; the blended figure falls out of the mix, it is not an input.
The ten project types priced in this calculator
The calculator classifies ten project archetypes on the two axes above — a taxonomy read live from MasterBrain, each type carrying its mechanism, durability score, and an integrity flag. The table shows the mechanism and durability the tool assigns to each; with one exception it does not show prices, because prices are yours to source — the ordering below is by durability, which is the strongest single predictor of where in the price range a type falls. The exception is direct air capture, for which the tool carries an indicative USD reference band, covered under sourcing a price.
| Project type | Mechanism | Durability | Where it typically sits on price |
|---|---|---|---|
| Unbundled renewable energy | Avoidance | No storage (0) | Lowest — abundant supply, contested additionality |
| Improved cookstoves | Avoidance | No storage (0) | Low — strong co-benefits can lift it |
| REDD+ / avoided deforestation | Avoidance | Reversible, decades (1) | Low–moderate — reversal and baseline risk |
| Afforestation / reforestation (ARR) | Removal | Reversible, decades (1) | Moderate — a nature-based removal |
| Blue carbon / mangrove | Removal | Reversible, decades (1) | Moderate — high co-benefit premium |
| Soil carbon | Removal | Reversible, decades (1) | Moderate — measurement and reversal risk |
| Biochar | Removal | Durable, centuries (2) | High — a durable removal |
| Enhanced rock weathering | Removal | Durable, >1000 yr (3) | Highest tier — durable engineered removal |
| BECCS | Removal | Durable, >1000 yr (3) | Highest tier — durable engineered removal |
| Direct air capture (DACCS) | Removal | Durable, ~1000 yr (3) | Highest — the durability benchmark |
“Engineered” is not a separate mechanism — biochar, enhanced weathering, BECCS, and direct air capture are all removals, and what sets them apart is their durability score, not their category. The calculator prices on mechanism and durability precisely because those two axes, not a nature-vs-tech label, are what the price and the net-zero science actually track. For the sequestration side of nature-based removal, see the forestry removals calculator.
Sourcing and sanity-checking a price
Because the tool prices almost every project type from bands you supply — the direct-air-capture reference band below is the one exception — the quality of your result depends on the prices you feed it. There is no single authoritative price for a voluntary credit, so the task is to triangulate a defensible band and carry its uncertainty forward.
Get a direct quote
The most reliable price is a quote for the specific credits you intend to retire — from a project developer, a broker, or a marketplace, for a stated project, vintage, and volume. A quote reflects the actual trade you would make, including any volume effect, in a way a market average never can.
Cite a market report
Where you have no quote, a dated price assessment from a recognised market-data provider gives a defensible band by project category. Record the source and the date — voluntary prices move, and a figure without a date is not auditable. Treat the report’s category average as a central estimate and set your low and high around it.
Sanity-check against durability
Before accepting a price, check it against the type’s durability. A durable engineered removal quoted at avoidance-credit prices, or an avoidance credit quoted at removal prices, is a red flag worth investigating — either the classification is wrong or the credit is not what it claims. The mechanism-and-durability ordering in the table above is the quickest plausibility test.
Carry the uncertainty
Enter a genuine low–high spread, not a single point. The resulting budget range is more useful to a decision-maker than a false-precision figure, and it makes the sensitivity of the total to the project mix visible. A portfolio weighted to durable removals will show a much wider absolute range than one weighted to avoidance.
The one built-in reference band: direct air capture
Direct air capture is the single project type for which a published price is defensible enough to pre-fill. When you set the currency to USD, the tool offers an indicative DACCS band — roughly $500 low, $750 central, $1,000 high per tonne (vintage 2025), read from MasterBrain and carried with an MB reference · USD · 2025 badge on the row. It comes from the offsets.price.daccs reference band and is corroborated by published direct-air-capture operating costs; both source records surface in the provenance list at the foot of the page.
Treat it as a sanity-check, not a quote. The band is editable — overtype any of the three figures and the row reverts to your own input, dropping the reference badge. It is native-USD only: switch to GBP or EUR and the band is withdrawn rather than converted, because no exchange rate is applied. And it is indicative and vintaged, not an authoritative GreenCalculus price — verify it against a current quote before carrying it into a budget. Every other project type has no built-in band by design; direct air capture is the exception precisely because its price is the one the public market reports with any consistency.
GreenCalculus does not broker, price, endorse, or link to any credit or seller. The direct-air-capture reference band is an indicative starting point to verify, not a quote to rely on, and the prices in the worked example below are illustrative placeholders. Source your own prices for your own project, vintage, and volume. Any figure carried into a budget or disclosure should trace to a dated quote or a dated market assessment you can cite.
Worked example — one tonnage, a blended portfolio
This mirrors the calculator’s shipped default so the page matches what you see the moment the tool loads. It prices a 1,000 tCO2e residual across a three-project removals portfolio, in GBP, with zero overhead. The per-tonne prices are the tool’s illustrative placeholders — replace them with your own quotes.
| Project type | Allocation | Tonnes | Price £/t (low–central–high) | Subtotal (low–central–high) |
|---|---|---|---|---|
| Afforestation / reforestation (ARR) | 50% | 500 | 18 – 25 – 35 | £9,000 – £12,500 – £17,500 |
| Biochar | 30% | 300 | 110 – 140 – 180 | £33,000 – £42,000 – £54,000 |
| Direct air capture (DACCS) | 20% | 200 | 320 – 500 – 700 | £64,000 – £100,000 – £140,000 |
| Portfolio | 100% | 1,000 | — | £106,000 – £154,500 – £211,500 |
The portfolio’s central budget is £154,500, a range of £106,000 to £211,500, at a blended central price of £154.5 per tonne. The whole portfolio is removals, and 91.9% of the central spend goes to durable removals (biochar plus direct air capture) — even though those two types cover only half the tonnage. That inversion is the lesson: the 20% of tonnage allocated to direct air capture accounts for £100,000 of the £154,500 central budget, because its per-tonne price is twenty times the afforestation credits’. On this market, the allocation to durable removal drives the budget far more than the headline tonnage.
To see how sensitive the budget is to mix, re-run with the allocation shifted. Moving ten percentage points from direct air capture to afforestation drops the central budget sharply, because it swaps £500/t credits for £25/t ones. The tonnage neutralised is identical — only the quality and durability of the neutralisation changed. That trade-off between cost and durability is the central decision in offset-portfolio design, and it is exactly what the low–high range is there to expose.
Quality and integrity — what a credible credit requires
Price gets a portfolio budgeted; integrity gets it defended. Two complementary frameworks now govern voluntary-market credibility — one on the supply side, one on the claim side — and a credit that fails either is a reputational liability regardless of its price.
ICVCM — supply-side integrity
The Integrity Council for the Voluntary Carbon Market’s Core Carbon Principles set a threshold for what makes a credit high-integrity: additionality, robust quantification, permanence with reversal safeguards, no double-counting, and sound governance. A credit carrying the CCP label has cleared an independent assessment against those principles.
VCMI — claim-side integrity
The Voluntary Carbon Markets Integrity Initiative’s Claims Code of Practice governs what a company may say once it retires credits — the conditions, disclosures, and reduction prerequisites for a defensible claim. ICVCM addresses whether the credit is good; VCMI addresses whether your claim about it is honest.
Underneath both frameworks sit four attributes every credible credit must satisfy, and which price alone never confirms:
- Additionality — the reduction or removal would not have happened without the credit revenue. A project that would have proceeded anyway sells no real climate benefit.
- Permanence — the carbon stays stored, with reversal risk (fire, harvest, leakage) either low or buffered. This is the durability axis in accounting form.
- Leakage — the emissions avoided in one place are not simply displaced elsewhere, which would erase the benefit.
- No double-counting — the credit is retired once, claimed by one party, and not also counted toward a host country’s national target without a corresponding adjustment.
A cheap credit that fails additionality is worse than no credit — it costs money and delivers a claim that will not survive scrutiny. Integrity screening comes before price optimisation, not after. Use this calculator to budget once the eligible set of credits has passed a quality bar, not to shop for the lowest number irrespective of what it buys.
Where offsets fit — the mitigation hierarchy
Offsetting is the last step, not the first. Every credible net-zero framework places value-chain emission reductions ahead of offsetting, and treats credits as the way to address the residual that reduction cannot yet reach.
Reduce first, offset the residual. A credit retired in place of a reduction you could have made is not net zero — it is a deferral with a receipt.
Reduce, then neutralise the residual
Under the SBTi Corporate Net-Zero Standard, a company cuts emissions along a science-aligned pathway and neutralises only the residual at the target year, with durable removals. Offsets bought today are framed as beyond-value-chain mitigation — a contribution alongside reductions, not a substitute for them.
Offsetting vs insetting
Offsetting funds reductions or removals outside your value chain; insetting funds them within it, where they also reduce your own Scope 3. The choice affects both the accounting and the price — see the insetting vs offsetting methodology for how each is treated.
Neutrality claims and compliance markets
Standards such as PAS 2060 and ISO 14068-1 define what a carbon-neutrality claim requires — reductions plus offsetting of the remainder, disclosed. Separately, compliance schemes like CORSIA mandate offsetting for a sector, which is a different market from the voluntary one this tool budgets for.
Deciding whether to offset a tonne or abate it internally is itself a pricing question: if your marginal internal abatement cost is below the credit price, reduction is cheaper than offsetting. The marginal abatement cost methodology sets out that comparison.
Standards and reporting context
Offset pricing sits inside a governance stack spanning credit certification, market integrity, removals accounting, and neutrality claims. The frameworks below cover the surface a buyer navigates.
| Framework | Role for offset pricing and use |
|---|---|
| ICVCM Core Carbon Principles | Supply-side integrity threshold — defines what makes a credit high-integrity. The CCP label increasingly carries a price premium. |
| VCMI Claims Code of Practice | Claim-side integrity — governs what a company may say once it retires credits, and the reduction prerequisites for the claim. |
| Verra VCS · Gold Standard | The two dominant voluntary registries that certify and issue credits. Registry and methodology affect price. |
| GHG Protocol Land Sector and Removals | Accounting rules for land-based removals — how afforestation, soil, and blue-carbon removals are quantified and reported. |
| SBTi Corporate Net-Zero Standard | Places offsetting after value-chain reduction; residual neutralisation with durable removals at the target year. |
| PAS 2060 · ISO 14068-1 | Define the requirements for a carbon-neutrality claim, including offsetting the remainder after reduction. |
| CORSIA | The aviation compliance offsetting scheme — a mandatory, sector-specific market distinct from the voluntary one priced here. |
Price provenance and update transparency
This calculator is user-priced by design, with one exception. Voluntary carbon credit prices are not a standardised published dataset — they are negotiated, quality-stratified, and fast-moving — so GreenCalculus maintains no authoritative price bands and the tool reads no price index. The two things it does read from MasterBrain are the project-type taxonomy (mechanism, durability, integrity flag) and a single indicative reference band for direct air capture (USD, vintage 2025), offered as an editable default when you work in USD. Every other price in a result is one you entered.
The prices in the worked example are the tool’s illustrative defaults, carried so the page matches the calculator on load. They are not GreenCalculus price assessments, not quotes, and not endorsements. The one figure with named provenance is the direct-air-capture reference band, which cites its MasterBrain source below; every other price you rely on is your own sourcing — a dated quote for your project, vintage, and volume, or a dated market assessment you cite. Record the source and date in your audit trail; a price without a date is not defensible in a disclosure.
The project taxonomy, durability scoring, and the direct-air-capture reference band are versioned in MasterBrain and surfaced with their source records below; the tonne of CO2e itself is defined on the CO2-equivalent basis. The full method — how the portfolio arithmetic, the blended price, and the removal and durability shares are computed — is on the carbon offset pricing methodology page.
Frequently asked questions
There is no single price — it depends entirely on the project type. Voluntary carbon credits range from under £10 per tonne for avoidance credits such as REDD+ or renewable energy, through roughly £25–150 per tonne for nature-based and durable removals, to £300–700 per tonne for durable engineered removal like direct air capture. The mechanism (avoidance versus removal) and durability drive the price far more than anything else, which is why this calculator prices each project type on its own band rather than quoting a market average.
For almost every project type there is no standardised, published price to build in — voluntary credits are negotiated per project, vintage, and volume, span two orders of magnitude, and move continually, so fixed “authoritative” bands would give a false impression of precision and could mislead a budget. The tool therefore takes the prices you source — from a quote or a dated market assessment — and does the portfolio arithmetic around them, which keeps the provenance of every figure with you. The single exception is direct air capture, where published pricing is consistent enough that the tool offers an indicative USD reference band (around $500–1,000 per tonne, 2025) as an editable starting point — you can overtype it, and it is withdrawn in any non-USD currency.
No. A GHG inventory records the emissions your organisation produced; retiring a carbon credit is a separate transaction that does not change that figure. Under the GHG Protocol and the SBTi Corporate Net-Zero Standard, credits neutralise a residual after value-chain reductions, and they are reported separately, not netted against your gross emissions. This calculator prices that residual purchase and makes no claim about your inventory or your neutrality status.
An avoidance credit pays for an emission that does not occur — protecting a forest from clearing, or replacing a polluting cookstove. A removal credit pays to take CO2 out of the atmosphere and store it, through trees, soil, biochar, or engineered capture. Removals are scarcer and generally more expensive, and net-zero science increasingly treats durable removals as the only credits that can neutralise residual emissions at a target year. The calculator classifies every project type as one or the other, alongside a durability score.
Often, but not reliably. Price correlates with durability and verification rigour, so a durable, independently rated removal costs more than a bare avoidance credit for good reasons. But price can also reflect scarcity, hype, or a premium co-benefit story, and a low price does not automatically mean a weak credit. Price is a signal to verify, not a guarantee. Assess additionality, permanence, leakage, and double-counting separately — against the ICVCM Core Carbon Principles — before treating a price as justified.
Reduce first. Every credible net-zero framework places value-chain emission reductions ahead of offsetting and treats credits as the way to address the residual that reduction cannot yet reach. Offsets bought before reductions are framed as beyond-value-chain mitigation — a contribution, not a substitute. If your marginal cost to abate a tonne internally is below the credit price, reduction is also the cheaper option, a comparison set out in the marginal abatement cost methodology.
Whichever you select — GBP, USD, or EUR — but the currency is a display label only, with no conversion. Enter every price band in that one currency. If your quotes are in mixed currencies, convert them to a single currency before entering them, and record the FX rate and date you used in your own audit trail, since the tool does not perform or store that conversion.
No. GreenCalculus does not broker, price, endorse, or link to any credit or seller. This calculator is an indicative budgeting estimator, not purchasing or investment advice. The prices in the worked example are illustrative placeholders that ship with the tool so the page and the calculator agree on load; they are not quotes to rely on. Source your own prices for your own project, vintage, and volume.
Methodology notes and limitations
User-priced by design, with one reference band. Every price is user-entered as a low, central, and high band per project type — with a single exception. The calculator reads the MasterBrain offsets.* family for the project-type taxonomy (mechanism, durability score, integrity flag) and for one indicative reference price band, direct air capture (offsets.price.daccs: $500 / $750 / $1,000 per tonne, USD, vintage 2025), which pre-fills as an editable default when the selected currency is USD and is withdrawn otherwise (native currency, no FX); overtyping it reverts the row to user input. The prices in the worked example are the tool’s illustrative shipped defaults, carried here so the page matches the calculator on load; they are not GreenCalculus price assessments, quotes, or endorsements.
Formula. Total cost = Σ (tonnesi × pricei) × (1 + overhead%), where each row’s tonnes are the total tonnage × the row’s allocation share (× an annualisation factor when annualise mode is on). Overhead is a single optional adder for buffer-pool, retirement, or broker costs, defaulting to zero. There are no spreads, per-credit fees, or currency conversion.
Taxonomy. Ten project archetypes classified on two axes: mechanism (avoidance or removal) and a durability score from 0 (no storage) to 3 (durable for ~1000 years or more). “Engineered” removals — biochar, enhanced weathering, BECCS, and direct air capture — are not a separate mechanism; they are removals distinguished by a high durability score. The classification drives the reported removal and durability share of spend, not the price, which is always user-supplied.
Currency is display-only. The GBP/USD/EUR selector labels the output; it performs no FX conversion. All price bands must be entered in the selected currency.
Boundary and claims. The tool is an indicative budgeting estimator. Retiring credits does not reduce a reported GHG inventory, and the tool asserts no neutrality claim. Offsetting is the last step for a residual after value-chain reductions (per the SBTi Corporate Net-Zero Standard and GHG Protocol beyond-value-chain mitigation). Price is not a proxy for quality — additionality, permanence, and verification must be assessed separately. GreenCalculus does not broker, price, endorse, or link to any credit or seller; this is not purchasing or investment advice.
No assurance opinion. Results are budgeting estimates and should be reviewed by a qualified practitioner before use in procurement or disclosure. Any price relied upon should trace to a dated quote or dated market assessment held in the buyer’s own audit trail. The full method is on the carbon offset pricing methodology page.