Electric car (battery EV): carbon footprint per km
Live factor value
0.02951 kgCO2e per km
Source: UK DESNZ greenhouse-gas conversion factors, 2026 (revision 2). Factor set desnz-2026-r2.
A battery-electric car on today's UK grid emits around a fifth to a sixth of a comparable combustion car per kilometre — the official DESNZ 2026 average-BEV figure is shown live below. The factor covers the electricity used for charging at average UK grid intensity; there is no tailpipe term at all.
Two things follow. First, the EV factor falls automatically every year as the grid decarbonises — no change to the car required. Second, the figure is a driving-energy factor, not a lifecycle one: manufacturing emissions (especially the battery) sit outside it, which is why keeping any car longer and driving it less remain the biggest levers.
Worked example
Typical UK annual mileage (~10,000 km) in a BEV: 10,000 × 0.02951 = 295 kgCO2e.
Measure your own with the free commuting calculator.
Frequently asked questions
- How much lower is an EV than a petrol car per km?
- On the official 2026 UK averages, a battery-electric average car is roughly five to six times lower per km than the petrol equivalent — and the gap widens as the grid gets cleaner.
- Does this factor include making the battery?
- No — DESNZ driving factors cover the energy used to move the car. Manufacturing sits in separate embodied-carbon accounting, which is why total-lifecycle comparisons look less dramatic than per-km ones.