Natural gas emission factor 2026 (UK, kg CO2e per kWh)

The 2026 UK government emission factor for natural gas is 0.18231 kg CO2e per kWh, reported as Scope 1. That is 0.4% lower than the 2025 factor of 0.18296. Including well-to-tank, the full figure is 0.21252 kg CO2e per kWh.

Updated 3 October 2026 by the Carbon Recycling team. Figures use the official UK government conversion factors and are checked against the current gov.uk guidance.

Natural gas emission factor by year

Year	Scope 1 (kg CO2e per kWh)	Well-to-tank	Full figure	Change
2026	0.18231	0.030210	0.21252	-0.4%
2025	0.18296	0.030210	0.21317	+0.0%
2024	0.18290	0.030210	0.21311	-0.0%
2023	0.18293	0.030210	0.21314	+0.2%
2022	0.18254	0.031100	0.21364	-0.3%
2021	0.18316	0.031350	0.21451	-0.4%
2020	0.18387	0.023910	0.20778	+0.0%
2019	0.18385	0.023910	0.20776	–

Total kg CO2e for the seven greenhouse gases, from the official DESNZ files for each year. 2026 factor ID: 1_100_1004_6_1. Where a factor jumps sharply between two years, it is usually because DESNZ changed its method or data source, not because the activity itself changed.

Worked example

Take an office or small workshop using 80,000 kWh of gas a year. 80,000 kWh × 0.18231 kg CO2e = 14.58 tonnes CO2e, reported as Scope 1. Adding well-to-tank brings the full figure to 17.00 tonnes CO2e; the extra 2.42 tonnes are Scope 3 category 3.

How to report it

Gas burned in your own boilers, ovens or process equipment is Scope 1. Use the gross calorific value (Gross CV) factor, because UK gas bills are calculated on a gross basis.

If your bill only shows cubic metres or hundreds of cubic feet, convert to kWh with the calorific value printed on the bill, or record the cubic metres directly against the volume factor.

Where the data comes from

You'll usually find it in your gas bills, which show kWh worked out from the meter reading and the calorific value. Keep the source documents: anyone checking your Carbon Reduction Plan or SECR report may ask how each figure was worked out.

To convert your own figures straight away, use our free kWh to CO2e calculator, which shows 2026 and 2025 side by side.

Read more about how the factors change each year in our guide to the 2026 conversion factors, or see how we apply them in our methodology.

Related emission factors

UK grid electricity: 0.13096 kg CO2e per kWh
LPG: 1.5571 kg CO2e per litre
Heating oil (kerosene): 2.5402 kg CO2e per litre
All UK emission factors

Frequently asked questions

Should I use the gross or net CV factor for gas?

Gross. UK gas suppliers bill in kWh on a gross calorific value basis, so the Gross CV factor matches the kWh on your bill.

Which year's factor should I use?

The set for the year your reporting period falls in. If your financial year spans two calendar years, use the set for the calendar year most of it falls in, and keep the same rule every year. Don't restate past years with new factors unless you are correcting an error.

Is this the DEFRA factor?

Yes. The UK government conversion factors used to be published by DEFRA, then BEIS, and since 2023 by the Department for Energy Security and Net Zero (DESNZ). Many people still call them the DEFRA factors.

Do I need to include well-to-tank emissions?

They are Scope 3 category 3 (fuel- and energy-related activities). SECR doesn't require them, and PPN 006 doesn't list category 3 among its required Scope 3 categories, but including them gives a more complete footprint and some customers ask for them.

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