# Fuel Cost Calculator

> Free fuel cost calculator for road trips. Enter distance, fuel economy (US mpg, UK mpg or L/100 km) and fuel price to get the total gas cost, fuel needed and cost per person.

Find out what a drive will cost in fuel before you set off. Enter the distance, your car's fuel economy and the pump price, and split the total between passengers. Works with US gallons, UK mpg or litres per 100 km.

*Interactive tool: enter your values at https://toollantern.win/fuel-cost-calculator/ and results update instantly in your browser.*

## The fuel cost formulas

- **Metric**: fuel (L) = distance (km) × L/100 km ÷ 100. Cost = fuel × price per litre.

- **US**: fuel (gallons) = miles ÷ mpg. Cost = gallons × price per gallon.

- **UK**: fuel (litres) = miles ÷ UK mpg × 4.546. Cost = litres × price per litre (UK pumps price per litre even though economy is quoted in mpg).

## Worked example

A **300 km** drive in a car using **6.5 L/100 km** burns 300 × 6.5 ÷ 100 = **19.5 L**. At 1.80 per litre that is **35.10**. Shared between three people, each pays 11.70.

In the US, a **250-mile** trip at **30 mpg** uses 8.33 gallons. At $3.40 a gallon, that is **$28.33**.

## Converting between mpg and L/100 km

L/100 km = 235.21 ÷ US mpg, or 282.48 ÷ UK mpg. So 30 US mpg is about 7.8 L/100 km, and 50 UK mpg is about 5.6 L/100 km. Lower L/100 km means a more efficient car, while higher mpg means a more efficient car.

## Limitations

The calculator assumes constant consumption across the trip. City traffic, hills, speed and weather change real figures, and official ratings are usually optimistic. It covers fuel only: tolls, parking and wear are not included. For electric cars, use kWh per 100 km as the consumption and your price per kWh as the fuel price in the metric mode; the math is identical.

## Frequently asked questions
### How do I calculate fuel cost for a trip?

Work out the fuel you need (distance × L/100 km ÷ 100, or miles ÷ mpg), then multiply by the fuel price. A 300 km trip at 6.5 L/100 km uses 19.5 L; at 1.80 per litre that costs 35.10.

### How do I convert mpg to L/100 km?

Divide 235.21 by US mpg, or 282.48 by UK mpg. 30 US mpg is about 7.8 L/100 km.

### Why is UK mpg different from US mpg?

A UK (imperial) gallon is 4.546 litres while a US gallon is 3.785 litres. The same car shows about 20 percent higher mpg in UK figures.

### How should passengers split fuel costs?

The simplest fair method is to divide the total fuel cost equally. Set the number of people and the calculator shows each share. Some groups also add tolls and parking before splitting.

### Can I use this for an electric car?

Yes. In metric mode enter consumption in kWh per 100 km instead of litres, and the price per kWh instead of the price per litre. The result is your charging cost for the trip.

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Interactive version: https://toollantern.win/fuel-cost-calculator/