Fuel Cost Calculator for Road Trips
Work out how much fuel a road trip will need and what it will cost, in kilometres or miles.
India: today's petrol and diesel prices by city on fuel rates.
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https://fastbuysale.com/tools/fuel-cost-calculator/Share result on WhatsAppEnter the distance, your vehicle's fuel economy and the fuel price, and the calculator shows the fuel needed, the total cost, the cost per person and the cost per kilometre or mile, with an option for a return trip.
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- Choose metric (km, litres) or US (miles, gallons) units; it is preset for your country.
- Enter the trip distance and tick return trip if needed.
- Enter your fuel economy and the fuel price per litre or gallon.
- Enter the number of travellers to see the cost per person.
Guide
The formula
In metric units, fuel needed = distance × (litres per 100 km) ÷ 100, and cost = fuel × price per litre. In US units, fuel needed = miles ÷ miles per gallon, and cost = gallons × price per gallon. The calculator also converts between km/L, L/100 km and mpg so you can enter the figure printed in your car's manual.
Worked example
A 450 km trip in a car using 7 litres per 100 km needs 31.5 litres. At 1.80 per litre that costs 56.70; a return trip costs 113.40, or 28.35 each for four people. In the US, 300 miles at 30 mpg needs 10 gallons; at 3.50 a gallon the trip costs 35.00.
Real-world fuel economy
Official consumption figures are measured in controlled tests and real driving is often 10–25% worse. Highway speeds above about 100 km/h (60 mph), heavy loads, roof boxes, air-conditioning, cold weather and city traffic all increase consumption. For a cautious budget, add 10–15% to the manufacturer's figure or use the average shown on your dashboard.
Ways to save fuel
Keep tyres at the correct pressure, remove unnecessary weight, drive smoothly, use cruise control on highways and avoid long idling. Comparing prices along your route can also make a difference, as fuel prices can vary considerably between stations and regions. If you are in India, see today's petrol and diesel prices by city on our rates page.
Sharing costs
When friends share a car, splitting the fuel cost per person is a fair starting point; some groups also add tolls and parking. The cost per kilometre or mile is useful for comparing driving with train, bus or flight fares. Everything runs locally in your browser.
Key terms
- L/100 km
- Litres of fuel used to drive 100 kilometres; lower is more efficient.
- km/L
- Kilometres driven per litre, common in India and parts of Asia; higher is better.
- MPG
- Miles per US gallon, used in the United States; UK mpg uses a larger imperial gallon.
- Return trip
- Doubles the distance to cover both directions.
- Cost per km or mile
- Total fuel cost divided by distance, handy for comparing with public transport.
- Fuel price
- The current pump price per litre or gallon in your area; update it before every long trip.
- Route efficiency
- The effect of terrain, traffic and speed on real-world consumption.
Frequently asked questions
How do I convert mpg to litres per 100 km?
Divide 235.21 by the US mpg figure. For example 30 mpg is about 7.84 L/100 km.
Does it include tolls?
No, only fuel. Add tolls and parking separately.
Which units are used by default?
US visitors see miles and gallons; everyone else sees kilometres and litres. You can switch at any time.
Can I use it for diesel or electric vehicles?
Diesel works the same way. For electric cars enter kWh per 100 km as consumption and the price per kWh.
Why is my real cost higher?
Real-world consumption is often worse than official figures because of speed, traffic, load and weather.