UK gov’s 2025 carbon emission conversion factors

10 June 2025

The UK gov has published the 2025 carbon emission conversion factors. You can use numbers like these (or from sources like Climatiq) to work out your organisation’s carbon emissions.

The major changes document is interesting. Electricity is among the numbers that have changed because the UK is cutting emissions. Others have changed because there’s simply an annual variation.

Freight vehicle numbers are worse because goods vehicles are emptier than they were in previous years (but why are they emptier?). Air flight numbers are the opposite: they’ve improved because there are more passengers post-Covid sharing the same capacity. Which might be another way of saying: lockdowns were good for absolute carbon emissions.

And “homeworking” - a useful way of quickly guestimating freelancer emissions - hasn’t changed.