How to calculate fleet fuel cost per mile

Divide fuel cost by miles travelled for the same vehicles and period—then check whether the comparison is fair.

The calculation

Fuel cost per mile = fuel cost ÷ miles travelled. A fictional example: £1,200 divided by 6,000 miles equals £0.20 per mile, or 20p.

Match the records

Use identical start and end dates for mileage and fuel.
Identify each vehicle consistently across files.
Check missing readings, refunds and duplicate transactions.
Keep a consistent VAT basis when comparing vehicles.

Fuel cost is not total running cost

Leasing, maintenance, insurance and driver time are excluded unless you deliberately add them. If you do, call the result a broader running-cost measure and list what it contains.

Compare like with like

A loaded delivery van on city routes is not directly comparable with a car on motorways. Group similar vehicles and duties. A rise may reflect fuel prices, routes or incomplete mileage—not necessarily driver behaviour.

Turn findings into checks

Write “vehicle B’s cost per mile increased; check mileage completeness and duty changes” rather than declaring it inefficient. Record what evidence would confirm the explanation.

The £245 Fleet & fuel report covers up to 10 vehicles and three months of structured records, with human checks and practical priorities. No VAT charged; it is not an engineering assessment and does not guarantee savings.