Fuel Cost Calculator

Our fuel cost calculator works out your annual fuel spend based on mileage, MPG, and current pump prices. It also calculates cost per mile — useful for HMRC mileage allowance claims (45p/mile for first 10,000 business miles).

Enter your vehicle’s fuel economy in miles per gallon (MPG). Use the real-world figure from your onboard trip computer over mixed driving rather than the WLTP official figure, which typically overstates economy by 10-20% for petrol and diesel vehicles. Hybrid vehicles show the greatest divergence — their official economy assumes optimal conditions. The fuel price field defaults to current average pump prices; adjust for your local forecourt. Annual mileage: total your commute miles, business miles, and leisure mileage. The result shows annual fuel cost and cost per mile, which is useful for comparing driving against public transport, for business mileage reimbursement planning, and for evaluating the running cost difference between vehicles at different economy ratings.