Enter a year of use from your bills. The calculator uses exactly the same factors and calculation engine as our reporting software, and shows 2025 and 2026 side by side so you can see how much of any change comes from the factors rather than from your business.
| What you used in a year | Amount | 2025 factors | 2026 factors |
|---|---|---|---|
| Scope 2. From your electricity bills | kWh | 3.54 t× 0.17700 | 2.62 t× 0.13096 |
| Scope 1. Gas bills usually show kWh | kWh (Gross CV) | 5.49 t× 0.18296 | 5.47 t× 0.18231 |
| Scope 1. Fuel cards or receipts | litres | 0.0 kg× 2.57082 | 0.0 kg× 2.58354 |
| Scope 1. Fuel cards or receipts | litres | 0.0 kg× 2.06916 | 0.0 kg× 2.07500 |
| Scope 1. Oil deliveries | litres | 0.0 kg× 2.54016 | 0.0 kg× 2.54016 |
| Scope 1. Generators and plant | litres | 0.0 kg× 2.75541 | 0.0 kg× 2.75541 |
| Scope 1. Bottled or bulk LPG | litres | 0.0 kg× 1.55713 | 0.0 kg× 1.55713 |
| TotalScope 1: 5.47 t · Scope 2: 2.62 t (2026) | 9.03 t | 8.09 t | |
Same use, 10.4% lower with the 2026 factors.
How the calculation works
Each line is your amount multiplied by the official conversion factor for that fuel and year, published by the Department for Energy Security and Net Zero (DESNZ). For example, 20,000 kWh of electricity in 2026 is 20,000 × 0.13096 = 2,619 kg, or 2.62 tonnes of CO2e.
Electricity counts as Scope 2, because the emissions happen at the power station. Gas, heating oil and fuel burned in your own boilers and vehicles count as Scope 1. Tick the Scope 3 box to add the emissions from producing and delivering the fuel (well-to-tank) and the electricity lost in the grid (transmission and distribution). PPN 006 and SECR don't require these, but many carbon reports include them.
The factors used
| Fuel | Unit | 2025 kg CO2e | 2026 kg CO2e | DESNZ factor ID |
|---|---|---|---|---|
| Electricity | kWh | 0.17700 | 0.13096 | 7_400_4000_5_1 |
| Mains gas | kWh (Gross CV) | 0.18296 | 0.18231 | 1_100_1004_6_1 |
| Diesel | litres | 2.57082 | 2.58354 | 1_101_1011_8_1 |
| Petrol | litres | 2.06916 | 2.07500 | 1_101_1017_8_1 |
| Heating oil (kerosene) | litres | 2.54016 | 2.54016 | 1_101_1010_8_1 |
| Red diesel (gas oil) | litres | 2.75541 | 2.75541 | 1_101_1014_8_1 |
| LPG | litres | 1.55713 | 1.55713 | 1_100_1003_8_1 |
Diesel and petrol are the forecourt fuels with the average biofuel blend. Every factor is the total for the seven greenhouse gases, in kg CO2e per unit.
Why did my footprint drop in 2026?
The UK grid electricity factor fell by about 26% between the 2025 and 2026 sets, because more of the country's power now comes from wind, solar and other low-carbon sources. Fuel factors such as gas and diesel barely move from year to year. So if your electricity use stayed flat, your Scope 2 emissions will fall by about a quarter on paper. That is real, but it isn't something your business did, and a good report says so. Read more in our guide to the 2026 conversion factors.
What this calculator leaves out
- Business travel, commuting, waste, freight and purchased goods, which make up most Scope 3 emissions.
- Market-based Scope 2, where a renewable tariff backed by certificates can count as zero.
- Refrigerant leaks from air conditioning, which are Scope 1.
Our software covers all of these and turns them into a Carbon Reduction Plan and an SECR report.