Fuel cost calculator

Fuel cost is distance divided by economy, multiplied by the pump price. Three hundred miles at 45 imperial MPG is 6.67 gallons; at £1.45 per litre — £6.59 per gallon — that journey costs about £44.

Fuel is rarely the whole cost of driving, and treating it as such makes driving look cheaper than it is. Tyres, servicing, depreciation and the share of insurance and tax attributable to the mileage roughly double the real per-mile figure for most cars. Government mileage allowances exist precisely because of this — the UK rate of 45p a mile and the US IRS rate are both several times the pure fuel cost. If you are working out what to charge someone, the fuel figure here is the floor, not the answer.