Fuel Cost Calculator

Find out what a trip will cost in fuel, and how much each passenger should chip in.

Result
Fuel cost—
Fuel needed—
Total distance—
Cost per mile—
Each person pays—

How to use the fuel cost calculator

  1. Choose US, UK or metric units.
  2. Enter the trip distance, your car's fuel economy and the current fuel price.
  3. Tick round trip if you're coming back the same way, and enter how many people are sharing the cost.

Fuel cost formulas

US: Cost = (Miles ÷ MPG) × Price per gallon UK: Cost = (Miles ÷ MPG) × 4.546 × Price per litre Metric: Cost = (Km × L/100km ÷ 100) × Price per litre

Example (US): a 300-mile trip in a car that gets 30 mpg uses 10 gallons. At $3.50 a gallon, that's $35, or about 11.7 cents a mile.

Example (UK): 300 miles at 45 mpg with petrol at £1.45 a litre uses about 30.3 litres, costing roughly £43.95.

Ways to cut your fuel costs

  • Ease off the speed: fuel economy drops noticeably above about 55–60 mph (90–100 km/h).
  • Keep tires properly inflated: under-inflated tires increase rolling resistance.
  • Lose the weight and drag: empty roof boxes and unneeded cargo cost fuel.
  • Drive smoothly: gentle acceleration and anticipating stops can improve economy by 10–30%.
  • Compare fuel prices with an app before filling up on a long trip.

Estimates only. Actual fuel use depends on traffic, speed, terrain, weather and load.

Frequently asked questions

How do I calculate the fuel cost of a trip?
Divide the distance by your car's fuel economy to get the fuel needed, then multiply by the price of fuel. For example, 300 miles ÷ 30 mpg = 10 gallons; at $3.50 a gallon the trip costs $35.
Where do I find my car's fuel economy?
Check your car's trip computer, the owner's manual or the manufacturer's website. In the US, fueleconomy.gov lists official MPG ratings. Real-world economy is often 10–15% worse than official figures, especially at highway speeds or with a loaded car.
Are UK and US miles per gallon the same?
No. A UK (imperial) gallon is about 20% bigger than a US gallon, so the same car shows a higher MPG figure in the UK. Choose the UK option if your MPG figure comes from a UK source.
How should we split gas money?
The simplest fair split is the total fuel cost divided by everyone in the car, including the driver. Some groups also add a share of tolls and parking, or a small amount for wear and tear on the driver's car.