Trip Petrol Calculator

A one-way trip ends at the destination, while a return trip includes the outward journey and travel back. Select return only when the entered distance covers one direction. The calculator doubles that value before estimating fuel and cost.

For a circular route, several stops, a detour, or a different road home, add every route leg and enter the complete distance as a one-way calculation. Include local driving at the destination and the distance to planned fuel stops when they materially change the route.

For repeated identical journeys, multiply one complete journey distance by the number of trips. Calculate routes separately when city traffic, towing, payload, or road conditions produce meaningfully different mileage.

Kilometres per litre vs litres per 100 km

Higher km/L means better fuel efficiency, while lower L/100 km means better efficiency. They express the same consumption in opposite ways: L/100 km = 100 ÷ km/L and km/L = 100 ÷ L/100 km. For example, 12.5 km/L equals 8 L/100 km.

US MPG vs Imperial MPG

A US gallon contains 3.785411784 litres; an Imperial gallon contains 4.54609 litres. Imperial MPG is therefore numerically higher for the same vehicle efficiency. Select the exact MPG type and petrol-price unit rather than treating “gallon” as an interchangeable measure.

Kilometres, miles, litres, and gallons

One mile equals 1.609344 kilometres. The calculator converts distance and fuel volume when the selected inputs use different systems. Currency is only a label for the entered price and calculated result; no exchange-rate conversion takes place.

Use mileage measured over several refills under similar operating conditions. If your journey includes both dense city traffic and steady highway driving, a blended observed mileage value is usually more useful than a single advertised figure.

Enter the number of people sharing the petrol expense to divide the total equally. The result is a planning figure for fuel only. Decide separately whether the driver is included and how tolls, parking, ferries, or other charges will be shared.

Extra passengers and luggage add load and may change actual fuel efficiency. For a heavily loaded trip, use mileage observed under a similar load instead of assuming the vehicle will return its usual unloaded figure.

The estimate assumes the entered route distance, trip type, mileage, petrol price, price unit, and currency are correct and remain constant. It also assumes fuel efficiency is representative across the whole journey and that no fuel is lost through a leak.

The result does not automatically adjust for traffic delays, long idling, hills, wind, weather, detours, road closures, passenger weight, cargo, towing, engine condition, tyre pressure, air-conditioning use, fuel quality, odometer error, or price changes between fuel stops. Results are estimates, not exact journey bills.

This page focuses on a specific journey. Use the daily commute calculator for recurring commute spending, the monthly petrol calculator for a monthly budget, or a vehicle-specific calculator when you need guidance tailored to a bike, scooter, or car.

The calculator applies the formulas shown above and converts units using 1 mile = 1.609344 kilometres, 1 US gallon = 3.785411784 litres, and 1 Imperial gallon = 4.54609 litres. It retains unrounded intermediate values before formatting fuel and cost results.

You control the distance, mileage, fuel price, and currency. Read the petrol expense formula guide and the shared calculation methodology for more detail. Last reviewed: 17 September 2026.