Tools / Free to use
What is your carbon footprint, and which part of it actually matters?
Six short steps across home energy, travel, flights, food and the things you buy. It ends by ranking your own categories, because knowing your total is only useful if you know where to push.
Do you know your annual energy bills?
Bills give a far better answer than a property-type average. Dig one out if you can.
Your unit rates
Spend only tells us emissions once we know the price per unit. These default to recent UK averages — correcting them from your bill is the single biggest accuracy gain available here.
Renewable electricity tariff?
Method & limits
Where the numbers come from
UK Government (DEFRA) conversion factors for energy, transport and flights. Consumption categories use spend-based intensities derived from UK environmentally-extended input-output data. Flights include the additional warming effect of emissions released at altitude.
Why spend is a rough proxy
Food and shopping are estimated from what you spend, so buying expensive low-carbon goods looks worse than buying cheap high-carbon ones. It is the standard approach for consumer tools and it is directionally right, but treat those two sections as indicative rather than measured.
Household splitting
Home energy is divided by the number of adults, so a shared house gives each person a lower figure. That is correct for a personal footprint, and it is why two people in the same home should each run it separately rather than halving one result.
Nothing is stored
Every calculation runs in your browser. No answers are sent anywhere, nothing is saved, and there is no sign-up. Refreshing the page clears it.