Fleet Fuel Cost Calculator
Estimate monthly and yearly fuel cost for a fleet from vehicles, distance, fuel economy, idle hours and fuel price, with cost per mile or km.
Fuel is one of the biggest running costs of any fleet. This calculator turns the distance each vehicle covers, its real fuel economy, idle time and the fuel price into a monthly and yearly fuel bill for the whole fleet, along with cost per mile (or kilometre) and how much a price rise would add over a year.
How to use this tool
- Pick US or metric units and enter the number of vehicles.
- Enter the average distance each vehicle covers per month and its average fuel economy.
- Enter the current fuel price.
- Add idle hours and idle fuel burn from your telematics, or set them to 0.
Formula
Fuel per vehicle = distance ÷ mpg + idle hours × idle burn (or distance × L/100 km ÷ 100 + idle hours × idle burn); fleet cost = fuel per vehicle × vehicles × price
Monthly figures are multiplied by 12 for the year. Cost per mile divides each vehicle’s fuel cost, including idling, by the distance it covered.
Example
12 trucks each run 9,000 miles a month at 6.5 mpg and idle 40 hours at 0.8 gallons an hour. Each truck burns 9,000 ÷ 6.5 = 1,384.6 gallons driving plus 32 gallons idling, 1,416.6 gallons in all. The fleet uses about 16,999 gallons; at $3.75 a gallon that is $63,747.69 a month, $764,972.31 a year and about $0.59 per mile. Every 10-cent rise in the price adds about $20,399 a year.
Frequently asked questions
How do I find my fleet’s real fuel economy?
Use driving distance divided by driving fuel when adding idle fuel separately. MPG based on all purchased fuel already includes idling: set idle hours to zero in that case.
Why include idling?
An idling engine burns fuel while covering no distance, which pushes up cost per mile. Telematics systems report idle hours and often the fuel used while idling, so you can see what cutting idle time would save.
How much does a fuel price change matter?
The calculator shows the yearly cost of each 0.10 rise per gallon or litre. Multiply it for bigger moves, or rerun with the new price to see the full picture.
Last updated: 2026-10-30