Fuel Cost Calculator
Estimate trip fuel cost for any distance, vehicle, and price — US, UK, or metric. Updates live as you adjust.
Distance
Fuel Economy
Fuel Price & Trips
Currency
Total Trip Cost
$11.67
1 trip × 100 miles each
Per trip
$11.67
Per mile
$0.12
Fuel used
12.6 L
Fuel consumed
3.33 US gal
12.62 litres
Cost per trip
$11.67
Cost per mile
$0.12
Annual cost (daily use)
$4,258.33
If driven every day
Cost Projections
Recurring Cost Estimate
Estimate based on stated values. Real fuel use varies with driving style, traffic, AC use, load, and temperature.
Guide
How it works
This calculator estimates how much fuel a trip consumes and what it costs. Everything is converted to a common metric base internally, so you can freely mix miles with US gallons, kilometres with litres, or UK MPG with pence per litre — the math handles the unit conversions for you.
How it works: Fuel used equals distance divided by fuel economy. Trip cost equals fuel used multiplied by the unit price. The trips multiplier lets you scale a single trip into a round trip, a weekly commute, or a monthly total in one step.
US vs UK gallons: A UK gallon (4.546 L) is about 20% larger than a US gallon (3.785 L). That is why the same car scores higher MPG when quoted in UK terms — more distance per a larger gallon. Always match the MPG and price units to the same country or the estimate will be off by around 20%.
L/100 km explained: Unlike MPG, a lower number means better efficiency — 5 L/100 km is more economical than 10 L/100 km. The two scales move in opposite directions, which is why the calculator handles both without you needing to convert.
Improving accuracy: Manufacturer fuel economy figures are measured under controlled conditions. Real-world consumption is typically 10–25% higher due to city driving, cold starts, highway speeds above 60 mph, air conditioning, cargo weight, and tyre pressure. For budgeting, using a slightly worse figure than the official rating gives a more realistic result.
The projection table shows how daily or weekly driving habits compound over time. A commute that feels affordable at $8 per trip amounts to over $4,000 per year for a typical 5-day-a-week commuter — useful context when deciding between a more fuel-efficient vehicle or switching to an EV.
What is the difference between US MPG and UK MPG?expand_more
A UK gallon (4.546 litres) is larger than a US gallon (3.785 litres), so the same vehicle shows a higher MPG figure when quoted in UK terms. Always match the unit to the source of the figure. Mixing them produces an estimate off by roughly 20%.
How do I find my vehicle's fuel economy?expand_more
Check your owner's manual, the manufacturer's website, or the fueleconomy.gov database (US). For real-world estimates, fill the tank, drive normally until nearly empty, then divide distance driven by fuel added at the next fill-up.
How do I estimate my monthly fuel bill?expand_more
Enter your typical one-way trip distance. Set trips to your total monthly one-way legs — for example, a 5-day commute is roughly 44 one-way trips per month. The total cost line gives your monthly estimate, and the projection table shows additional scenarios.
Why is my real cost higher than the estimate?expand_more
Official fuel economy figures are measured under ideal lab conditions. City traffic, cold weather, heavy loads, air conditioning, and aggressive acceleration all increase real-world consumption by 10–25%. Use a slightly lower efficiency figure than the rating to get a more realistic budget estimate.
Can I use this for diesel or hybrid vehicles?expand_more
Yes — enter the fuel economy in whatever unit applies to your vehicle (diesel MPG works the same way). For hybrids, use your real-world combined economy. For EVs, fuel cost calculators don't apply directly — use a kWh per mile cost calculator instead.
Next steps