Convert electricity or gas use in kWh to kg or tonnes of CO₂e with dated, sourced emission factors.
Emissions
23.7t CO₂e
Ireland grid electricity. Scope 2, location-based.
Check the values to see a result.
A grid average. A supplier-specific or market-based figure can differ, and so can the factor for another year.
CO2e (kg) = energy (kWh) × emission factor (kg CO2e/kWh)
100,000 kWh of Irish grid electricity at 0.237 kg CO₂e per kWh is 23.7 t CO₂e.
Tip: Use the factor for the year the energy was used, and keep the same source year to year so a change in the number is a change in the site.
To convert kWh to CO₂ emissions, multiply the energy by an emission factor in kg CO₂e per kWh, for the grid the site is on and the year the energy was used.
CO₂e, carbon dioxide equivalent, adds methane and nitrous oxide to the CO₂, weighted by how strongly each warms the climate. Published factors include all three.
kg CO2e = kWh × grid factor
Use the location-based factor for the grid the site is on and the year the energy was used. For Ireland and the EU the calculator uses the European Environment Agency’s 2024 intensity of electricity generation, by country; for the UK, DESNZ’s factor for electricity generated; for the US, the EPA eGRID rate for the country or, better, the site’s eGRID subregion.
kg CO2e = kWh × transmission and distribution factor
Some electricity is lost on the way to the site. DESNZ publishes a separate factor for those losses, 0.01853 kg CO₂e/kWh in 2025, reported under Scope 3.
kg CO2e = kWh (gross CV) × gas factor
Gas burnt on site is a direct emission. Use kWh on a gross calorific value basis, as on the bill, with a gross-basis factor: 0.18296 kg CO₂e/kWh in the DESNZ 2025 set.
Grid factors change every year as the generation mix changes: the EEA’s figure for Ireland fell from 449 g CO₂e/kWh in 2014 to 237 g in 2024, and the UK factor has roughly halved in ten years. Keep the factor year with the result, and restate earlier years with their own factors, so a trend shows the site rather than the grid.
250,000 kWh × 0.237 kg CO₂e/kWh = 59,250 kg, or 59.25 t CO₂e of Scope 2 emissions. The same consumption on the EU-27 average grid, 0.18344 kg CO₂e/kWh, is 45.86 t CO₂e; in France, where most generation is nuclear, it is 9 t CO₂e.
Emissions 59.25 t CO₂e Open in the calculator
250,000 kWh × 0.177 kg CO₂e/kWh = 44,250 kg, or 44.25 t CO₂e of Scope 2 emissions. Adding transmission and distribution losses at 0.01853 kg CO₂e/kWh adds 4,633 kg of Scope 3, for 48.88 t CO₂e in total.
Emissions 44.25 t CO₂e Open in the calculator
3,927 kWh of gas, the energy in 350 m³ from the gas m³ to kWh calculator, at 0.18296 kg CO₂e/kWh is 718.5 kg CO₂e.
Emissions 718.5 kg CO₂e Open in the calculator
Emissions in kg CO₂e for common annual consumptions, with the factors named in each column.
| Energy (kWh) | Ireland, EEA 2024 (kg CO₂e) | EU-27, EEA 2024 (kg CO₂e) | UK electricity, DESNZ 2025 (kg CO₂e) | Natural gas, DESNZ 2025 (kg CO₂e) |
|---|---|---|---|---|
| 1,000 | 237 | 183.4 | 177 | 183 |
| 10,000 | 2,370 | 1,834 | 1,770 | 1,830 |
| 50,000 | 11,850 | 9,172 | 8,850 | 9,148 |
| 100,000 | 23,700 | 18,344 | 17,700 | 18,296 |
| 250,000 | 59,250 | 45,860 | 44,250 | 45,740 |
| 500,000 | 118,500 | 91,720 | 88,500 | 91,480 |
| 1,000,000 | 237,000 | 183,440 | 177,000 | 182,960 |
It depends on the country and the year. The European Environment Agency puts 2024 generation at 0.237 kg CO₂e/kWh in Ireland, 0.291 in Germany, 0.245 in the Netherlands, 0.036 in France and 0.183 on average across the EU-27. The UK government’s 2025 factor is 0.177 kg CO₂e/kWh. The US national average in eGRID2023 is 770.884 lb CO₂e/MWh, or 0.3497 kg CO₂e/kWh. For other countries, or for a national agency’s own figure such as SEAI’s for Ireland, enter it as your own factor.
Location-based reporting uses the average factor of the grid. Market-based reporting uses the factor of the electricity the organisation has bought, such as a renewable tariff backed by certificates. The GHG Protocol asks for both; this calculator does the location-based figure.
No. A tonne of carbon is contained in 3.67 tonnes of CO₂, the ratio of their molecular masses, 44 to 12. Reports should say which they mean; almost all now use CO₂e.
Because the grid changed. Report each year against its own factor, and name the factor set, so the figures can be checked.
Emissions are only as good as the kWh behind them. A ZEM per main circuit gives interval energy that carbon reporting can split by building, process or tenant.
