> Machine-readable version of https://bharometer.com/guides/fuel-cost-per-km.html — a Bharometer guide (Bharometer: fuel & mileage tracker for India, https://bharometer.com/).

# Fuel cost per km: what your car or bike really costs to run

**The short answer: ₹/km = fuel price ÷ your real mileage.** A car doing 15 km/l on ₹100/l petrol costs **₹6.7 per km**; a scooter doing 45 km/l costs about **₹2.2 per km**. Multiply by your monthly kilometres and you have your fuel budget — 1,000 km a month in that car is roughly ₹6,700.

## Two ways to compute it (they should agree)

- **From mileage:** ₹/km = price per litre ÷ km/l. Use your *measured* mileage — the [full-tank method](https://bharometer.com/guides/how-to-calculate-mileage.html), not the brochure figure or the dashboard's optimism — or the result inherits the same error.
- **From spend:** ₹/km = total fuel money over a period ÷ kilometres driven in it. Needs no mileage figure at all, just receipts and odometer readings, and works even if you never fill to full. If the two methods disagree noticeably, your mileage figure is probably flattering you.

## A real monthly picture

A hatchback averaging 14 km/l on ₹100/l petrol, driven 900 km a month:

- Fuel per km: 100 ÷ 14 = **₹7.1/km**
- Monthly fuel: 900 × 7.1 ≈ **₹6,430**
- Yearly fuel: ≈ **₹77,000**

Numbers like these are why a 1 km/l improvement matters: the same car at 15 km/l saves about ₹5,000 a year. Tyre pressure and timely servicing are usually the cheapest fuel discounts available — your [mileage trend](https://bharometer.com/guides/kitna-deti-hai-real-average.html) tells you when you've drifted.

## Fuel-only ₹/km understates the truth

Fuel is the visible cost; the rest hides in annual lumps. Add service, insurance, PUC, parking, tolls and repairs, and divide by the same kilometres:

- Fuel: ₹77,000/yr
- Service + consumables: ₹12,000/yr
- Insurance: ₹15,000/yr
- Tolls + parking: ₹8,000/yr

Total ≈ ₹1,12,000 over 10,800 km — a **true cost of ₹10.4/km**, not ₹7.1. That's the honest number when weighing a second car, a [CNG conversion](https://bharometer.com/guides/cng-mileage-km-per-kg.html), an EV, or just taking cabs.

## Getting the inputs right

- **Log every fill-up with its odometer reading** — spend ÷ distance only works if both sides are complete.
- **Use your prices, not city averages.** The rate printed on your receipt is the one you actually paid.
- **Keep non-fuel costs in the same log** so the true ₹/km updates itself instead of living in a year-end spreadsheet.

## Your ₹/km, computed live

Bharometer (fuel & mileage tracker for India, iPhone) shows cost per km on every fill-up, projects your monthly spend, and (with the Cost Log) folds service, insurance, PUC and tolls into a true running cost — automatically, from the numbers you already log at the pump. https://bharometer.com/ · Free on the App Store: https://apps.apple.com/in/app/bharometer-fuel-kmpl-costs/id6784579909

## Related guides

- [How to calculate your real mileage (km/l)](https://bharometer.com/guides/how-to-calculate-mileage.html)
- [Kitna deti hai? Finding your true average](https://bharometer.com/guides/kitna-deti-hai-real-average.html)
- [CNG mileage: km per kg explained](https://bharometer.com/guides/cng-mileage-km-per-kg.html)