Convert Tonnes to US Short Tons CO₂(e)
Most of the world reports emissions in metric tonnes, but US figures often come in short tons — and the two are not the same. A US short ton is 2,000 pounds (about 907 kg), lighter than the 1,000 kg metric tonne, so a tonne is a little more than one short ton. The conversion is exact: 1 metric tonne = 1.10231 short tons. Multiply tonnes by 1.10231 to get short tons; it works the same for CO₂ and CO₂e.
To convert metric tonnes to US short tons of CO₂(e), multiply by 1.10231. So 100 t CO₂e = 110.2 short tons. To reverse it, multiply short tons by 0.90718 (or divide by 1.10231).
short tons = tonnes × 1.10231. Reverse: tonnes = short tons × 0.90718. The factor is exact — a short ton is 2,000 lb = 907.18474 kg, and 1,000 ÷ 907.18474 = 1.10231. The same factor applies whether the mass is CO₂ or CO₂e.
| Metric tonnes | × 1.10231 | US short tons |
|---|---|---|
| 1 t | × 1.10231 | 1.102 short tons |
| 10 t | × 1.10231 | 11.02 short tons |
| 100 t | × 1.10231 | 110.2 short tons |
| 1,000 t | × 1.10231 | 1,102 short tons |
The three “tons” — don’t mix them up
“Ton” is one of the most ambiguous units in measurement. Three are in common use, and they differ by up to about 12%. Getting the wrong one wrong throws a carbon figure off by roughly a tenth:
| Unit | Definition | Kilograms | Pounds |
|---|---|---|---|
| US short ton | 2,000 lb | 907.18474 | 2,000 |
| Metric tonne (t) | 1,000 kg | 1,000 | 2,204.62 |
| UK long ton | 2,240 lb | 1,016.05 | 2,240 |
When a US document says “tons of CO₂” without qualification, it almost always means short tons. Treating those as metric tonnes overstates the mass by about 10%. Always confirm the unit before comparing a US figure with an international one — and note that many modern US datasets (including the EPA’s own greenhouse-gas equivalencies) have switched to metric tonnes, so you cannot assume from the country alone.
Tonnes to short tons conversion table
The table reads both ways — metric tonnes to short tons on the left (× 1.10231), short tons back to tonnes on the right (× 0.90718).
| t CO₂e | → short tons (× 1.10231) | short tons CO₂e | → t (× 0.90718) |
|---|---|---|---|
| 1 | 1.102 | 1 | 0.907 |
| 10 | 11.02 | 10 | 9.072 |
| 100 | 110.2 | 100 | 90.72 |
| 1,000 | 1,102 | 1,000 | 907.2 |
| 10,000 | 11,023 | 10,000 | 9,072 |
Where short tons are used
- US regulatory and legacy reporting. US emissions data has traditionally been in short tons, and much state-level, industrial and older federal reporting still is — so converting to metric tonnes is often the first step in comparing a US figure internationally.
- International comparison. The GHG Protocol, IPCC and almost every non-US inventory use the metric tonne, so a US short-ton figure must be converted before it lines up with global data.
- Watch the modern switch. Many current US datasets — the EPA’s greenhouse-gas equivalencies and parts of eGRID — now report in metric tonnes, so check the unit rather than assuming from the source’s country.
- Molecule-agnostic. Because this is a mass conversion, it serves CO₂, CO₂e and any single gas identically — CO₂e simply bundles all gases into a CO₂-equivalent mass using their global warming potentials first.
A US plant reports 50,000 short tons of CO₂. To compare it with an international target set in metric tonnes, multiply by 0.90718: about 45,359 t CO₂. The ~10% gap between the two units is exactly why the conversion matters — reported as 50,000 metric tonnes, the same plant would look nearly 5,000 tonnes bigger than it is.
Frequently Asked Questions
Multiply the tonnes by 1.10231. For example, 100 t CO₂e × 1.10231 ≈ 110.2 short tons. To reverse it, multiply short tons by 0.90718. The factor is exact and applies to CO₂ and CO₂e alike.
About 1.10231. A metric tonne is 1,000 kg and a US short ton is 907.18474 kg (2,000 lb), so a tonne is a little over one short ton — 10% more, because the short ton is the lighter unit.
A US short ton is 2,000 lb (907 kg), a metric tonne is 1,000 kg (2,205 lb), and a UK long ton is 2,240 lb (1,016 kg). They span about 12% from lightest to heaviest, so it matters which “ton” a figure uses.
Usually, yes — an unqualified “ton” in a US source is typically a short ton. But many modern US datasets, including the EPA’s greenhouse-gas equivalencies, now use metric tonnes, so confirm the unit rather than assuming. Getting it wrong shifts the figure by about 10%.
Because the GHG Protocol, the IPCC and almost every non-US inventory report in metric tonnes. To compare a US figure with an international target or dataset, convert it to tonnes first so the units line up.
No. Converting a mass between units doesn’t depend on which gas it is, so the tonne-to-short-ton factor is identical for CO₂, CO₂e or any single greenhouse gas. CO₂e just means the gases have already been combined into a CO₂-equivalent mass using their global warming potentials.