Free tool
Car Mileage Calculator
Work out exactly what your car returns using the tank-to-tank method — the only measurement that reflects fuel you actually paid for. Works in km/l, mpg or L/100km, and saves each fill-up to build a running average.
Entries are stored in this browser only — nothing is uploaded and no account is needed.
Your mileage
—km/l
- Distance
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- Cost per km
- —
- This fill-up
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- Monthly fuel
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How to measure mileage the right way
- Fill the tank until the pump cuts off automatically. Do not top up past the click — it corrupts the baseline.
- Note the odometer reading, or reset a trip meter.
- Drive as you normally would. Do not change your driving style to chase a number.
- Refill at the same pump, again to the automatic cut-off, and note the litres dispensed.
- Divide the distance by the litres. That is your true km/l.
Repeat over three tanks and average the results. A single tank can be skewed by a long highway run, a week of monsoon traffic, or a pump that cuts off early.
What the number tells you
Compare your figure against the real-world average for your model on its car mileage page. If you are more than 15% below it, work through the service checklist — tyre pressure and a clogged air filter account for most unexplained drops.
To turn km/l into rupees, use the fuel cost calculator, which applies current city-wise prices for petrol, diesel, CNG and electricity.
Frequently asked questions
How do I calculate my car’s mileage correctly?
Use the tank-to-tank method. Fill the tank to the brim, note the odometer reading, drive normally, then fill to the brim again at the same pump. Divide the distance covered by the litres it took to refill. One tank is a rough guide; three consecutive tanks give you a reliable average.
Why is my calculated mileage different from the car’s display?
Trip computers estimate fuel flow from injector duty cycle and are typically optimistic by 5-8% on Indian cars. The tank-to-tank method measures fuel you actually paid for, so it is the number that matters for your wallet.
What is a good mileage for a petrol car?
For a 1.2-litre petrol hatchback, 15-19 km/l (35-45 mpg US, 5.3-6.7 L/100km) in mixed driving is normal. Compact SUVs typically return 12-15 km/l, midsize SUVs 11-14 km/l, and strong hybrids 21-24 km/l. Anything more than 30% below these bands is worth investigating.
Does this calculator work for CNG and electric cars?
Yes. Select CNG to work in km/kg and enter the kilograms filled, or Electric to work in km/kWh and enter the units consumed. Gas and electricity keep their native units everywhere, since neither is sold by the gallon; only the distance half switches to miles for countries that use them.
Is my logbook data stored on your servers?
No. Every entry is saved in your browser’s local storage on this device only. Nothing is uploaded, no account is required, and clearing your browser data removes it permanently.