Fuel Cost Calculator

Calculate the fuel cost of a trip from distance, fuel economy (MPG or L/100km), and price, with round-trip and split options.

100% Browser-Based • Local Processing
Trip
ppl

Fuel only — tolls, parking and wear are not included. Real economy is worse than the official figure in traffic, in cold weather, and with a loaded car.

Fuel for the trip

56.00

Fuel needed 35.0 L
Cost per km 0.112
Each person pays 56.00
Economy 7.0 L/100km
Formula and working

The formula

fuel = distance × (L per 100 km) ÷ 100 · cost = fuel × price

Your numbers

500 km × 7 ÷ 100 = 35.0 L, at 1.60 a litre = 56.00.

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Privacy Focused

🔒 Local Processing. Your numbers never leave your device.

Instant Results

🌐 Fully Client-Side. Runs instantly in your browser.

No Signup

⚡ No accounts. No API keys. Just open and use.

Browser Based

🚀 No installs, no sign-ups, no server round-trip.

Overview

What is a Fuel Cost Calculator?

A Fuel Cost Calculator estimates how much fuel a trip will cost. From the distance, your vehicle's fuel economy (MPG or litres per 100 km), and the fuel price, it works out the fuel needed and the total cost — with round-trip and per-person split options. Cost = (distance ÷ fuel economy) × price. It runs in your browser.

Planning a road trip or splitting petrol with friends? Knowing the fuel cost up front helps you budget and divide it fairly. The math depends on distance, your car's economy, and the price per unit.

This calculator handles the different unit systems (miles or kilometres, MPG or L/100km, gallons or litres), and can do round trips and splits. It runs entirely in your browser and works offline.

Guide

How to calculate fuel cost

Step 1: Enter the trip distance and choose your units

Enter the trip distance and choose your units.

Step 2: Enter your vehicle's fuel economy and the fuel price

Enter your vehicle's fuel economy and the fuel price.

Step 3: Read the fuel needed and total cost; toggle round-trip or split among passengers

Read the fuel needed and total cost; toggle round-trip or split among passengers.

Screens

Fuel Cost Calculator in action

Fuel Cost Calculator estimating trip fuel cost in the browser.
Fuel + cost
Trip fuel cost with round-trip and per-person split.
Units / split
Calculating fuel cost on a phone, no app installed.
Mobile (stacked)
Details

Fuel cost across the different unit systems

The core calculation is simple: the fuel you'll use is the distance divided by your fuel economy, and the cost is that fuel times the price per unit — so cost = (distance ÷ economy) × price. The wrinkle is units, which differ by country and is where errors creep in. Fuel economy is expressed as miles per gallon (MPG) in the US and UK (but the US and UK gallon are different sizes), kilometres per litre (km/L) in some places, and — confusingly — litres per 100 km (L/100km) across much of the world, where a lower number means a more efficient car (the opposite of MPG). The calculator lets you pick the system so the math is right: with MPG, fuel = distance ÷ MPG; with L/100km, fuel = distance × (L/100km ÷ 100). It also handles round trips (doubling the distance) and splitting the cost among passengers, which is handy for shared journeys. It's an estimate, though: real fuel use varies a lot with how you drive, speed, traffic, load, terrain, air conditioning, and weather, so treat the figure as a planning guide and pad it a little for real conditions. Everything computes locally and works offline once loaded.

Support

Frequently Asked Questions

How do I calculate the fuel cost of a trip?

Divide the distance by your fuel economy to get the fuel used, then multiply by the price per unit: cost = (distance ÷ economy) × price. For 300 miles at 30 MPG and $4/gallon, that's (300 ÷ 30) × 4 = $40. The calculator does this and handles your unit system.

Can it use MPG or litres per 100 km?

Yes. It supports both — miles per gallon (US or UK), kilometres per litre, and litres per 100 km. These work differently: with MPG higher is more efficient, while with L/100km lower is more efficient. Pick your system and enter the figure; the calculator applies the correct formula.

Does it handle round trips?

Yes. Toggle the round-trip option and the calculator doubles the distance before computing the fuel and cost, so you get the total for there and back. You can also enter the one-way distance and leave it off if you only want a single leg.

Can it split the cost between passengers?

Yes. Enter the number of people sharing the trip and the calculator divides the total fuel cost evenly, showing the per-person amount. It's handy for carpools and road trips where everyone chips in for petrol fairly based on the actual fuel used.

Why is the real cost sometimes different?

Because real fuel consumption varies with driving style, speed, traffic, vehicle load, terrain (hills use more), air conditioning, tyre pressure, and weather. The calculator uses your stated economy figure, which is an average; actual use can be higher in stop-start traffic or on a loaded uphill trip. Treat the result as an estimate and add a margin.

What fuel economy figure should I use?

Use your vehicle's real-world average rather than the optimistic manufacturer rating if you can — many trip computers show a long-term average. If you only have the official figure, expect real consumption to be somewhat higher, especially in city driving. A realistic economy figure gives a more accurate cost estimate.

Is it free, and do I need to sign up?

Yes, it's completely free with no account, no trial, and no limit on how many times you use it. It runs entirely in your browser, so there's no sign-in wall — just open the page and calculate.

Is my data private?

Yes. Everything is calculated in your browser — the numbers you enter are never sent to a server, and nothing is stored once you close the tab. That keeps any personal figures (salary, loan, health) on your own device.

Does it work on mobile?

Yes. It runs in your phone's browser with nothing to install, so you can calculate on Android or iOS. The layout adapts to small screens, so entering numbers and reading the result is easy on the go.

Does it work offline?

Once the page has loaded, the calculation runs entirely on your device, so it keeps working without a connection. You only need to be online to open the page the first time — which is also why nothing you enter is uploaded.

Can I copy or share the result?

Yes. You can copy the result to your clipboard with one click, and many results can be shared. Because everything is calculated locally, copying is instant with no upload step.

How accurate is it, and is this professional advice?

The math is accurate for the inputs you give, and the formula is shown so you can verify it. But results are estimates for general use, not professional advice — finance calculators use simplified assumptions and ignore fees and rate changes, and health calculators are general estimates, not medical advice. For important decisions, consult a qualified professional.

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