Gas Trip Cost Calculator

How to estimate the fuel cost of a trip

Working out what a drive will cost in fuel comes down to three numbers: how far you're going, how efficiently your vehicle uses fuel, and the price of fuel. In US units, the fuel you'll burn is distance ÷ MPG gallons, and the cost is that figure times the price per gallon. The calculator also handles metric units (kilometres, litres per 100 km) and can double the distance for a round trip or split the cost between passengers.

US vs. metric units

• US: distance in miles, efficiency in miles per gallon (MPG), price per gallon. Fuel used = distance ÷ MPG.
• Metric: distance in kilometres, efficiency in litres per 100 km, price per litre. Fuel used = distance ÷ 100 × (L/100km).

Switch the units selector to match how your car and local fuel prices are measured.

Getting an accurate estimate

Use your car's real-world fuel economy rather than the sticker figure — actual mileage is often 10–20% lower, especially in city driving or with a loaded vehicle. Highway trips tend to be more efficient than stop-and-go city miles. For fuel price, check a current local average, since prices move week to week.

Ways to cut the cost

• Maintain steady highway speeds; hard acceleration and high speeds waste fuel.
• Keep tyres properly inflated and remove roof racks or heavy cargo you don't need.
• Split the drive with passengers — the per-person cost drops fast when shared.

FAQ

Does this include tolls or wear-and-tear?

No — it's fuel cost only. Add tolls, parking, and a rough per-mile maintenance figure separately if you want the full cost of driving.

What if I don't know my MPG?

Check your vehicle's rated economy as a starting point, or calculate it by dividing miles driven by gallons used on a recent fill-up. Knock off a little for real-world conditions.

How do I cost a round trip?

Tick the round-trip box and the calculator doubles the distance automatically, so you don't have to enter it twice.