How do I calculate petrol cost for a round trip?

Enter the distance for one direction, select return trip, add your vehicle's real fuel efficiency and the petrol price. The calculator doubles the distance, calculates fuel required, and multiplies it by the entered price.

Should I enter one-way or total round-trip distance?

Enter one-way distance only when the outward and return routes are the same, then select return trip. If you already know the complete distance for both legs, enter that total and leave the trip type set to one way to avoid doubling it again.

What if the return route has a different distance?

Add the outward distance, return distance, and any material detours or local driving. Enter that complete distance and keep the calculator set to one way, because its return option is intended for two equal-distance legs.

Can I include several stops in a return journey?

Yes. Add the distance of each outward leg, each return leg, and any detours. Use the combined route distance as a one-way calculation when the route is not a simple same-road return.

Can I use miles and MPG?

Yes. Select miles and either US MPG or Imperial MPG. Choose the exact gallon type because a US gallon is 3.785411784 litres while an Imperial gallon is 4.54609 litres.

How is the passenger share calculated?

The calculator divides total petrol expense equally by the number of people sharing it. This is fuel only; add tolls, parking, ferries, and other agreed costs separately.

Why can the actual return-trip cost be different?

Traffic, idling, hills, weather, route changes, speed, tyre pressure, passengers, luggage, towing, and fuel-price changes can alter actual consumption and cost.

Outward and return

Round Trip Petrol Cost Calculator

Estimate petrol required and fuel expense for an outward and return journey. Calculate two equal route legs, cost per kilometre or mile, and an equal share for passengers.

Round-trip auto-double
Carpool split per rider
Bike, scooter, car, or truck
Privacy-first

Calculate Your Round Trip Petrol Cost

Enter one-way distance · return trip is selected automatically

Live

Vehicle

Region

Currency

Distance unit

Trip

Motorcycle / Bike default: 30 km/day at 50 km/L.

Distance (km)

Mileage unit

Vehicle mileage

km/L

Typical bike: 35–65 km/L.

Petrol price (LOCAL)

Enter the price shown on your local pump or fuel receipt.

Options

Carpool riders

people

Splits the total cost across riders.

Formula and example

How the Round Trip Petrol Calculator Works

Round-trip distance equals one-way distance multiplied by two. Fuel required equals total distance divided by mileage. Petrol cost equals fuel required multiplied by petrol price. When efficiency is L/100 km, litres required equals total kilometres multiplied by consumption, divided by 100.

Petrol cost formula

Cost = (Distance ÷ Mileage) × Price

For example, suppose the outward route is 75 km, the car returns by the same road, efficiency is 10 km/L, and three people share the cost. The total distance is 150 km and the car requires 15 litres. Multiply 15 by your local petrol price to get the trip cost.

Return distance

75 × 2

150 km

Fuel required

150 ÷ 10

15 L

Trip cost

15 × price

Your total

Illustrative reference

Round Trip Mileage Calculator Example

Fuel required and the petrol cost for a 150 km trip across common vehicle types. Replace these ranges with mileage measured for your own vehicle.

Currency

Detecting your currency — pick one manually if you prefer.

Petrol price per litre

per litre

Use the current pump price in your currency. It is not fetched automatically.

Vehicle

km/L

Vehicle	Fuel economy	Fuel / day	Cost / day	Cost / month
Light commuter bike	55–65	2.50 L	—	—
Standard commuter bike	45–50	3.16 L	—	—
Mid-size commuter bike	45–50	3.16 L	—	—
Sport commuter bike	40–45	3.53 L	—	—
Larger commuter bike	38–42	3.75 L	—	—
Light city scooter	50–55	2.86 L	—	—
Comfort scooter	42–48	3.33 L	—	—
Urban scooter	48–52	3.00 L	—	—
Compact hatchback	18–22	7.50 L	—	—
Small family car	14–17	9.68 L	—	—
Mid-size sedan	12–15	11.11 L	—	—
Compact sedan	13–16	10.34 L	—	—
Large sedan	11–13	12.50 L	—	—
Large SUV	8–10	16.67 L	—	—
Pickup truck	9–12	14.29 L	—	—
Compact SUV	12–14	11.54 L	—	—

Based on a 150 km trip using the midpoint of each economy range. Add a petrol price to see daily and monthly cost.

How to use it

Calculate Round Trip Petrol Expense

Select the vehicle used for the journey. Enter the distance for one direction and choose kilometres or miles. Enter real fuel efficiency in km/L, L/100 km, US MPG, or Imperial MPG. Enter petrol price with the matching litre or gallon unit and choose a currency. Select return trip so the tool counts two equal-distance legs.

If the way home is longer or follows a different route, add both legs and all meaningful stops yourself. Enter that complete distance with the trip type set to one way so it is not doubled.

01Use case

Same-road return

Enter one-way distance and select return when both legs match.

02Use case

Different route home

Add both legs yourself and enter the total as one way.

03Use case

Shared journey

Enter the rider count to divide the fuel bill equally.

Round-trip fuel guide

Round Trip Fuel Cost Guide

Choose the correct return-trip option, use the right mileage units, and account for the conditions that change return-journey fuel use.

Same-route returns, different routes, and stops

Returning by the same road

Use the return-trip switch when both legs cover the same distance. The calculator doubles the entered one-way distance before applying the fuel-consumption formula.

Taking a different way home

Do not use automatic doubling when the return route differs. Add the exact outward and return distances, then enter the combined figure as a one-way calculation. This also works for circular routes.

Adding stops and detours

Include each route leg, local driving at the destination, planned diversions, and travel to fuel stops when they materially change distance. A mapping app can help establish route length, but this calculator does not fetch or optimize routes.

Mileage, gallons, distance, and currency

Higher km/L or MPG means better efficiency; lower L/100 km means better efficiency. Convert with L/100 km = 100 / km/L. One mile equals 1.609344 kilometres.

One US gallon equals 3.785411784 litres and one Imperial gallon equals 4.54609 litres. US MPG and Imperial MPG are therefore not interchangeable. Currency labels your entered petrol price and results; the tool does not convert exchange rates or retrieve live fuel prices.

What changes return-journey fuel use?

Different conditions

Traffic or headwinds may differ between outward and return legs, so the same road distance does not guarantee the same fuel consumption.

Vehicle load

Passengers, luggage, roof boxes, trailers, and towing can reduce real fuel efficiency.

Road and driving

Hills, rough surfaces, high speed, hard acceleration, braking, idling, and air conditioning can increase petrol use.

Input quality

Observed mileage across several refills is generally more representative than an advertised or guessed figure.

Methodology, Accuracy and Assumptions

The estimate assumes the entered distance, mileage, petrol price, units, trip type, and passenger count are correct. It assumes one efficiency value and one fuel price across the journey. It cannot predict traffic, route closures, weather, gradients, odometer error, fuel leaks, price changes, or driving behaviour.

This page is deliberately focused on an outward journey plus travel back. Use the Trip Petrol Calculator for broader one-way, repeated, or general journey planning; use the Carpool Split Calculator when dividing a shared bill is the main task.

The tool applies the formulas displayed above, retains full precision during calculation, and rounds only visible results. It uses the exact distance and volume conversion constants stated on this page.

Read the petrol expense formula guide and shared calculation methodology. Last reviewed: 17 September 2026.

FAQ

Round Trip Calculator Questions

Answers about return distance, different routes, stops, mileage units, and passenger sharing.

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