How to calculate your car’s cost per kilometre
By Osvald Studio
Fuel is only part of what a car costs. To compare months or plan a driving budget, use the expenses and distance from the same period. Your result is an estimate based on the costs you include, not a prediction of your next trip.
The formula
Cost per km = total vehicle costs for the period ÷ kilometres driven in that period.
Choose what to include
For a running-cost view, add fuel, charging, maintenance, repairs, insurance, vehicle taxes and parking that belong to the period. For a broader ownership view, also include depreciation and finance costs if you have reliable figures. Keep loan principal separate from depreciation so you do not count buying the same car twice. Choose one scope and keep it consistent between comparisons.
A worked example
Illustrative figures in your chosen currency: fuel 120, maintenance 45, insurance allocation 30 and parking 15 total 210. If you drove 700 km in that period, 210 ÷ 700 = 0.30 per km. These are example inputs, not average car costs or Moneta prices.
Make the numbers comparable
- Choose a period, such as a calendar month, and record its starting and ending odometer readings. Subtract the start from the end. If the distance is zero, cost per km is undefined; keep the costs for your records without dividing.
- Collect expenses for that same period. Allocate an annual cost consistently: for example, an annual insurance bill divided by 12 for a monthly estimate. Record that allocation rule so you can repeat it.
- Add the included costs and divide by distance. Keep all costs in one currency and all distances in one unit. A result per mile must use miles throughout; do not mix miles and kilometres.
- Compare several periods rather than judging one month with a large repair bill. For a combined result, divide total costs by total distance; do not simply average monthly rates with different distances.
Keep the records together in Moneta
Moneta’s vehicle expense tracking helps you keep car costs alongside your other spending on Android. Use your recorded costs and distance with the formula above; this guide does not promise an automatic cost-per-km report. Keep receipts and check your inputs before using an estimate to set a budget.