Fleet running cost calculator: work out your true cost per mile
Enter seven numbers and see your fleet's cost per mile and monthly running cost instantly — everything computes in your browser, nothing is sent anywhere.
Calculate your fleet running costs
Estimates only — computed in your browser from the figures you enter. Excludes driver wages, finance interest, tolls, fines and admin overhead.
How does this calculator work out cost per mile?
The maths is deliberately transparent. Fuel cost per mile is derived from your mpg figure using UK gallons (4.54609 litres): litres per mile = 4.54609 ÷ mpg, multiplied by your pence-per-litre price. That per-mile fuel cost is scaled up by annual mileage, then insurance, maintenance and depreciation are added as flat annual amounts per vehicle. Dividing the per-vehicle annual total by annual miles gives cost per mile; multiplying by vehicle count and dividing by twelve gives the monthly fleet figure. Every keystroke recalculates instantly — no data leaves the page.
What does the model deliberately leave out?
Driver wages, finance interest, tolls, parking, fines and office overhead are all excluded, and that's a design decision rather than an omission. Those costs vary with how you operate rather than with what you drive, so folding them in produces a per-mile figure that shifts every time your staffing changes and stops being comparable between vehicles or over time. Keep this output as your vehicle-only baseline, then layer labour and overhead on top when you build a quote. The model also assumes mileage is spread evenly across the year; if your work is strongly seasonal, run the calculator twice — peak and off-peak — to see how far your cost per mile swings between them.
What is a normal running cost for a UK van?
Published UK estimates commonly put van running costs somewhere between roughly 30p and 90p per mile, with the spread driven mainly by vehicle size, age, annual mileage and how depreciation is counted. A high-mileage small van spreads its fixed costs across many miles and lands near the bottom of that band; a low-mileage 3.5-tonne Luton with newer-vehicle depreciation can sit near the top. Treat any single benchmark with caution — your own figures, entered above, beat an industry average every time.
Where do I find accurate inputs for each field?
- Annual miles per vehicle — average the last twelve months of odometer readings or service invoices rather than guessing.
- Mpg — real-world figures from fuel receipts and odometer deltas are usually 10–20% worse than the brochure number; use what you actually achieve.
- Fuel price — your average pence per litre from recent receipts, not today's forecourt board.
- Insurance — annual fleet premium divided by vehicle count.
- Maintenance — a year of servicing, tyres, MOTs and repairs per vehicle; garage invoices are the source of truth.
- Depreciation — (purchase price − expected resale value) ÷ years you'll keep the vehicle; for leased vans, use the annual lease cost instead and set depreciation to that.
What can I do with my cost-per-mile number?
Three things. First, price work properly: a job quoted below your cost per mile plus driver time loses money before it starts. Second, compare vehicles: running the calculator per vehicle exposes the one van whose maintenance and thirst quietly drag the fleet down. Third, track direction: recalculate quarterly and the trend tells you whether fuel discipline and preventive maintenance are paying off — our guide on reducing fleet fuel costs covers the levers that move the number most.
The weak point in any calculation is input quality. Smart Strix captures the raw data as a by-product of normal operations: fuel logs record litres, price and odometer photos at every fill-up, and maintenance history keeps every repair against the vehicle — so next quarter's inputs come from records, not memory. If you're weighing up software costs alongside vehicle costs, see our UK fleet software cost guide.