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Fuel cost calculator

  

The prices and mileages here are only starting points. Type today's pump price and the mileage your car really gives, which in city traffic is often 20 to 30% below the claimed figure.

km

Fuel

km/l

Monthly cost

₹6,667

66.7 litres, or ₹6.67 per km. A year is ₹80,000.

What a kilometre actually costs you

Most of us know the price of fuel and nothing about what a trip costs. The sum is simple. Distance divided by mileage gives the litres, and litres times price gives the cost. A 15 km/l petrol car at ₹100 a litre costs ₹6.67 a kilometre, so 1,000 km a month is ₹6,667.

That number is the quickest way to compare cars. Diesel at ₹90 and 18 km/l comes to ₹5 a km. CNG at ₹80 a kg and 22 km/kg is about ₹3.64. An electric car charged at home at ₹8 per unit and 6 km per unit is around ₹1.33. On 1,000 km a month the gap between petrol and electric is more than ₹5,000.

The cheaper fuel does not always win overall. A diesel or CNG model costs more to buy, and an EV costs much more still. Take the monthly saving and divide it into the price difference to see how long it takes to pay back. For low-use cars it can take well over five years.

Use your own prices for a proper answer, and use the real mileage you get, not the brochure's. Pick each fuel in the calculator and enter its price and mileage; the bars compare them for the same distance.

Sources

What this calculator does not account for

  • Fuel price changes during the month.
  • Real mileage, which depends on traffic, load and driving style.
  • Servicing, tyres and the purchase price of the vehicle.

How this is calculated

Formula: Fuel cost

cost =distance ÷ mileage × price per unit

What the symbols mean

  • mileageKilometres per litre (or per kg of CNG, or per kWh).
  • pricePrice per litre, per kg or per kWh.

Good to know

  • To find your real mileage: fill the tank, reset the trip meter, and divide kilometres by litres at the next fill.
  • For charging at home, find your rate with the electricity bill calculator.

Read the full methodologyFound an error? Contact us

Worked examples

Each example is worked out by the same code as the calculator above.

1,000 km in a month

Petrol 15 km/l at ₹100: ₹6,667. Diesel 18 km/l at ₹90: ₹5,000. CNG 22 km/kg at ₹80: ₹3,636. EV 6 km/kWh at ₹8: ₹1,333.

Embed this calculator

The frame shows the tool only.

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Questions

How do I find my real mileage?

Fill the tank to the brim, note the odometer, drive normally, then fill up again. Divide the kilometres by the litres you put in.

Is an EV really cheaper per km?

At ₹8 per kWh and 6 km per kWh, charging costs about ₹1.33 a km. A 15 km/l petrol car at ₹100 costs ₹6.67. Public fast chargers cost more, and the price of the car matters too.

Is CNG cheaper than petrol?

Per kilometre, usually by 40 to 50%, but CNG cars cost more upfront and boot space is smaller.

Why is my mileage lower than the brochure?

Brochure figures come from lab tests. Traffic, air conditioning, tyre pressure and speed can cut real mileage by 20 to 30%.