Natural gas: carbon footprint per kWh (gross CV)
Live factor value
0.18442 kgCO2e per kWh (gross CV)
Source: UK DESNZ greenhouse-gas conversion factors, 2026 (revision 2). Factor set desnz-2026-r2.
Burning mains natural gas releases a fixed amount of CO2e per kWh of energy — the official UK factor is published in the DESNZ 2026 conversion factors and shown below per kWh on a gross calorific value basis, the same basis your gas bill uses. That makes a gas bill the most accurate input for measuring home heating emissions.
Unlike electricity, the gas factor barely moves year to year: it is chemistry, not grid mix. For most UK homes with gas central heating, gas is the single largest source of household emissions — typically two to three times the electricity footprint.
Worked example
A typical UK household's annual gas use (~11,500 kWh): 11,500 × 0.18442 = 2,121 kgCO2e.
Measure your own with the free home energy calculator.
Frequently asked questions
- Is the gas factor per kWh the same as on my bill?
- Yes — the factor is published per kWh gross calorific value, the billing basis UK suppliers use, so you can multiply the kWh on your bill directly.
- Why doesn't the gas factor fall like the electricity factor?
- Because it measures the combustion of the fuel itself, which is fixed chemistry. Electricity's factor falls as the generation mix decarbonises; gas emissions per kWh stay essentially constant.