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Fuel Cost Calculator

Work out what a drive will actually cost in fuel before you set off. Enter the distance, how efficient your vehicle is in MPG or litres per 100 km, and the current fuel price to see the fuel needed, the total cost, and the cost per mile or kilometre.

Who this calculator helps

  • Budgeting a road trip or a long weekend drive.
  • Comparing the cost of driving against a train or flight.
  • Working out the fuel cost of a commute over a month.
  • Sellers and makers costing delivery runs, craft-fair travel, or supply pickups.
  • Deciding whether a cheaper item across town is worth the drive.

One-way distance — tick round trip below to double it.

Trip fuel cost

28.75

250 miles total

Fuel needed (gallons)

8.33

One-way cost

28.75

Cost per mile

0.115

Estimates fuel only. Tolls, parking, wear, and traffic conditions are not included.

All calculations are estimates based on average platform fees. Real profits may vary depending on category, ads, and shipping.

Fuel estimates only. Actual consumption varies with driving conditions, load, and weather.

How to use this calculator

  1. Enter your numbers in each field above — the calculator updates instantly as you type, so there's nothing to submit.
  2. Use your real figures when you have them, or sensible estimates while you're planning. If a field doesn't apply, leave it at zero.
  3. Compare the results, then change one input at a time to see how each lever (price, cost, fees, volume) moves the outcome.

When to use this calculator

  • You want the fuel line of a trip budget before you commit.
  • Fuel prices have moved and you want to re-check a familiar journey.
  • You are choosing between two vehicles for the same trip.
  • You need a defensible per-mile figure for mileage reimbursement conversations.

Formula

MPG: Fuel used = Distance ÷ MPG · L/100km: Fuel used = Distance × L per 100 km ÷ 100 · Fuel cost = Fuel used × Fuel price

Worked example

A 250-mile drive in a car doing 30 MPG, with fuel at $3.45 per gallon.

  1. Fuel used: 250 ÷ 30 = 8.33 gallons
  2. Fuel cost: 8.33 × 3.45 = $28.75
  3. Cost per mile: 28.75 ÷ 250 = $0.115

Answer: About $28.75 one way, or $57.50 round trip

More worked examples

A 600 km drive in a car using 7.5 L/100km, with fuel at 1.65 per litre.

  1. Fuel used: 600 × 7.5 ÷ 100 = 45 litres
  2. Fuel cost: 45 × 1.65 = 74.25
  3. Cost per km: 74.25 ÷ 600 = 0.124

Answer: About 74.25 for the drive

A 22-mile round-trip commute, 5 days a week, at 28 MPG and $3.60 per gallon.

  1. Weekly distance: 22 × 5 = 110 miles
  2. Fuel used: 110 ÷ 28 = 3.93 gallons
  3. Cost: 3.93 × 3.60 = $14.14

Answer: Roughly $14 a week in fuel

How it works

Fuel cost is two steps: work out how much fuel the distance needs, then multiply by the price you pay. The only thing that changes between countries is the direction of the efficiency figure. MPG tells you how far you go per unit of fuel, so you divide distance by it. Litres per 100 km tells you how much fuel a fixed distance consumes, so you multiply.

Because both routes end at 'fuel used', keeping your units consistent is the whole game: miles with gallons and MPG, kilometres with litres and L/100km. Mixing them produces a number that looks plausible and is badly wrong.

The round-trip toggle simply doubles the distance before the maths runs, and the cost-per-distance figure is the total cost divided by the total distance — handy for comparing vehicles or justifying a mileage rate.

Efficiency is never a fixed number. Cold weather, roof boxes, towing, heavy traffic, and a full car all push real consumption above the manufacturer figure.

Expert tips

  • Use the MPG your trip computer reports over the last few hundred miles, not the brochure number.
  • Add 10–15% to consumption for winter driving, heavy loads, or hilly routes.
  • For a monthly commute cost, enter the total monthly distance rather than the daily figure.
  • Fuel is only part of a trip: tolls, parking, and wear are real costs the fuel figure hides.
  • Comparing two cars? Run the same distance and price through both efficiency figures to see the annual gap.

How to interpret your results

  • Dollar values are shown per sale, per order, or per item unless a result is explicitly labelled monthly, weekly, or daily.
  • Percentages (margin, ROI, conversion rate) are easier to compare across products and price points than raw dollars — use them when you benchmark.
  • A positive result means you're ahead after the costs and fees you entered. A negative result means the current numbers don't work — change a lever (raise price, cut a cost, lower ad spend) and recalculate.
  • Treat the output as a planning estimate, not a guarantee. Fees, taxes, and conversion rates shift over time — re-run the numbers whenever a key input changes.

Limitations

  • Tolls, parking, maintenance, tyres, and depreciation are not included.
  • It assumes a single steady efficiency figure for the whole journey.
  • Price changes mid-trip, or a partial tank at a different price, are not modelled.

Common mistakes

  • Mixing units — entering kilometres with an MPG figure, or miles with L/100km.
  • Using the manufacturer's advertised MPG rather than the efficiency you actually get.
  • Forgetting the return leg when the trip is there and back.
  • Entering a fuel efficiency of zero, which has no meaningful fuel figure.

Related Guides

Go deeper with plain-English guides on the same topic.

FAQ

How do I calculate the fuel cost of a trip?
Divide the distance by your MPG to get gallons needed, then multiply by the price per gallon. In metric, multiply distance by L/100km, divide by 100, then multiply by price per litre.
Does this work in kilometres and litres?
Yes. Switch the efficiency units to L/100km and enter your distance in kilometres and price per litre.
How do I include the return journey?
Tick the round-trip box. The calculator doubles the distance and shows both the one-way and round-trip cost.
What MPG should I use?
Your real-world average from the trip computer or from fill-up records. Advertised figures are usually optimistic.
Is cost per mile the same as a mileage rate?
No. Cost per mile here is fuel only. Official mileage rates also cover wear, insurance, and depreciation, so they are higher.
Why is my actual cost higher than the estimate?
Traffic, cold weather, air conditioning, roof racks, towing, and a heavy load all raise consumption above your usual efficiency figure.

Why trust this calculator?

This tool uses standard mathematical formulas and commonly accepted calculation methods, shown openly in the Formula section above so you can verify the math yourself. Results are estimates based on the information you enter and do not account for every individual circumstance. For important financial, tax, legal, medical, or business decisions, please double-check with a qualified professional before acting on the numbers.

Keep going

One calculator rarely tells the full story. Pair this one with a related tool below to pressure-test your numbers from a different angle, or browse Everyday Math Calculators for more in the same category.

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