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Fuel Efficiency Calculator Guide: Calculate Mileage, Cost Per KM & Trip Fuel (2026)

Calculate vehicle mileage (km/l), fuel cost per kilometre, trip fuel requirements, and compare fuel costs between petrol, diesel, CNG, and electric vehicles in India.

9 min readUpdated April 9, 2026Auto, Fuel, India, Calculator

A fuel efficiency calculator helps you track your vehicle's actual mileage (km/l), calculate fuel cost per kilometre, estimate trip fuel requirements, and compare running costs between petrol, diesel, CNG, and electric vehicles. With Indian fuel prices at ₹95-110/litre (2026), knowing your exact fuel costs can save thousands per month.

Free Tool

Calculate Fuel Efficiency & Trip Cost

Enter distance, fuel, and price to see mileage and cost per km. Compare fuel types.

Open Fuel Calculator →

How to Calculate Vehicle Mileage (km/l)

Mileage (km/l) = Distance Travelled (km) / Fuel Consumed (litres)

Example

Full tank: 40 litres. Distance covered: 520 km.
Mileage = 520 / 40 = 13 km/l

Typical Mileage by Vehicle Type (India)

Vehicle TypeCity (km/l)Highway (km/l)
Hatchback (Petrol)14-1818-22
Sedan (Petrol)12-1616-20
SUV (Petrol)8-1212-16
Hatchback (Diesel)18-2422-28
SUV (Diesel)12-1616-22
CNG (Hatchback)22-28 km/kg28-32 km/kg
Electric (Hatchback)8-10 km/kWh6-8 km/kWh
Tank-to-Tank Method

Most accurate way: fill tank completely → note odometer → drive normally → fill tank completely again → note odometer and litres filled. Mileage = (Odometer2 - Odometer1) / Litres filled. Repeat 3-4 times for reliable average.

Fuel Cost Per Kilometre

Cost per km = Fuel Price (₹/litre) / Mileage (km/l)

Running Cost Comparison (2026 India Prices)

Fuel TypePriceAvg MileageCost/km
Petrol₹102/litre15 km/l₹6.80/km
Diesel₹90/litre20 km/l₹4.50/km
CNG₹76/kg25 km/kg₹3.04/km
Electric₹8/kWh (home)9 km/kWh₹0.89/km

Electric vehicles cost ~₹1/km — roughly 7× cheaper than petrol per km. Even with higher purchase price, EVs save ₹3-5 lakh over 5 years in fuel costs alone for daily commuters.

Diesel vs Petrol Break-Even

Diesel cars cost ₹1-2L more upfront but save ₹2.30/km. Break-even: at 1,500 km/month, diesel recovers the extra cost in ~2 years. Below 1,000 km/month, petrol is more economical considering lower maintenance costs.

Trip Fuel Calculator

Fuel needed = Trip distance (km) / Vehicle mileage (km/l)
Fuel cost = Fuel needed × Price per litre

Example: Mumbai to Goa (590 km)

VehicleMileageFuel NeededCost (one way)
Hatchback Petrol18 km/l (hwy)32.8 L₹3,345
SUV Diesel16 km/l (hwy)36.9 L₹3,319
CNG Hatchback30 km/kg (hwy)19.7 kg₹1,497
Electric (Nexon EV)7.5 km/kWh78.7 kWh₹630 (home charge)

Tips to Improve Fuel Efficiency

  • Maintain tyre pressure — Under-inflated tyres reduce mileage by 3-5%. Check weekly.
  • Drive at 60-80 km/h on highways — fuel efficiency drops sharply above 80 km/h (aerodynamic drag increases with speed squared)
  • Avoid idling — turn off engine if stopped for more than 30 seconds
  • Use cruise control on highways — maintains constant speed, avoids throttle fluctuation
  • Service regularly — dirty air filter alone can reduce mileage by 10%
  • Remove roof rack when not in use — reduces aerodynamic drag, saves 5-10% fuel at highway speeds
  • Use correct engine oil grade — manufacturer-recommended grade reduces friction
  • AC at 24°C, not max — AC at full blast can reduce mileage by 10-20%

Understanding Indian Fuel Prices

Indian fuel prices include multiple taxes:

ComponentPetrol (₹/l approx)Diesel (₹/l approx)
Base price₹38-42₹40-44
Central excise₹19.90₹15.80
State VAT₹15-30 (varies)₹10-20
Dealer commission₹3-4₹3-4
Retail price₹95-110₹85-100

Taxes constitute 55-60% of petrol price and 50-55% of diesel price. Prices vary by state due to different VAT rates — Rajasthan and Maharashtra have the highest; Goa and Puducherry the lowest.

How to Use the Tool (Step by Step)

  1. 1

    Open the Calculator

    Navigate to Fuel Efficiency Calculator on ToolsArena.

  2. 2

    Enter Distance and Fuel

    Enter distance travelled (km) and fuel consumed (litres) for mileage calculation.

  3. 3

    Set Fuel Price

    Enter current fuel price per litre for cost calculations.

  4. 4

    View Results

    See mileage (km/l), cost per km, and trip fuel estimates.

Frequently Asked Questions

How do I calculate my car mileage?+

Fill tank completely → note odometer → drive normally → fill again → note odometer and litres. Mileage = distance / litres. Example: 520 km driven, 40 litres filled = 13 km/l.

What is good mileage for a car in India?+

Petrol hatchback: 15+ km/l city, 20+ highway is good. Diesel: 20+ city, 25+ highway. CNG: 25+ km/kg. These are real-world numbers — ARAI certified figures are 10-30% higher than actual.

Is diesel still cheaper to run than petrol?+

Yes, per km. Diesel costs ₹4.50/km vs petrol ₹6.80/km. But diesel cars cost ₹1-2L more upfront. Break-even at ~1,500 km/month driving. Below that, petrol is more economical overall.

How much does an electric car cost per km?+

~₹0.89/km on home charging (₹8/kWh). About 7× cheaper than petrol. Even with public fast charging (₹15-20/kWh), it is still 3× cheaper than petrol.

Why does ARAI mileage differ from real-world?+

ARAI tests under ideal conditions (no AC, no traffic, constant speed, flat road). Real-world mileage is typically 15-30% lower due to traffic, AC usage, driving style, and road conditions.

How much fuel for a road trip?+

Divide trip distance by your vehicle's highway mileage. Mumbai-Goa (590 km) in a hatchback (18 km/l highway) = ~33 litres = ~₹3,350. Add 10% buffer for detours and city driving at destination.

Is this calculator free?+

Yes. Calculate in your browser. No vehicle data stored.

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Calculate Fuel Efficiency & Trip Cost

Enter distance, fuel, and price to see mileage and cost per km. Compare fuel types.

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