Quick answer
What is a Fuel Cost Calculator?
A fuel cost calculator estimates how much you'll spend on gas for a trip based on the distance, your vehicle's fuel efficiency, and current gas prices. It's essential for budgeting road trips and comparing the cost of driving vs. other transportation.
Whether you're planning a vacation, calculating your daily commute costs, or comparing different routes, this calculator helps you understand the true cost of getting from A to B.
Trip Planning
Know your fuel budget before hitting the road
Multiple Units
Works with MPG, km/L, or L/100km efficiency ratings
Cost Comparison
Compare driving costs vs. flying, train, or bus
Commute Costs
Calculate your monthly or yearly commuting expenses
Typical fuel efficiency by vehicle type (MPG):
- Compact cars — 30-40 MPG (Honda Civic, Toyota Corolla)
- Midsize sedans — 25-35 MPG (Honda Accord, Toyota Camry)
- SUVs — 20-28 MPG (RAV4, CR-V); large SUVs 15-20 MPG
- Trucks — 15-22 MPG (F-150, Silverado)
- Hybrids — 45-55 MPG (Prius, Ioniq)
The fuel cost formula (with worked examples)
To calculate the fuel cost of a trip, use one simple formula:
Fuel Cost = (Distance ÷ Fuel Efficiency) × Fuel Price
The first step (Distance ÷ Fuel Efficiency) tells you how much fuel the trip needs; multiplying by the price per unit gives the cost. The same formula works in imperial or metric units — you just keep distance, efficiency, and price in matching units.
Worked example — imperial (MPG)
A 300-mile trip in a car that returns 30 MPG, with gas at $3.50 per gallon:
- Fuel needed: 300 ÷ 30 = 10 gallons
- Trip cost: 10 × $3.50 = $35.00
Worked example — metric (km/L and L/100km)
The same car is about 12.75 km/L (or 8 L/100km). For a 480 km trip with fuel at $1.40 per litre:
- Using km/L: 480 ÷ 12.75 ≈ 37.6 litres × $1.40 ≈ $52.70
- Using L/100km: 480 × 8 ÷ 100 = 38.4 litres × $1.40 ≈ $53.76
The small difference comes from rounding 8 L/100km to 12.75 km/L; both methods describe the same car.
MPG vs km/L vs L/100km
- MPG (miles per gallon) — used in the US and UK. Higher is better. Note US and UK gallons differ, so the numbers are not directly comparable.
- km/L (kilometres per litre) — common in India and much of Asia. Higher is better. Convert with MPG × 0.425 ≈ km/L.
- L/100km (litres per 100 km) — standard in Europe, Canada, and Australia. It measures consumption, so lower is better. Convert with 235.21 ÷ MPG = L/100km.
Monthly & annual commute cost
To turn a single trip into a commuting budget, scale the daily distance by how often you drive. A round-trip commute counts both legs, so double a one-way distance first.
Monthly cost = (Daily distance × Working days ÷ Efficiency) × Fuel price
Worked example
Suppose your round trip to work is 40 miles a day, you drive 22 days a month, your car returns 30 MPG, and gas is $3.50 per gallon:
- Monthly distance: 40 × 22 = 880 miles
- Fuel needed: 880 ÷ 30 ≈ 29.3 gallons
- Monthly cost: 29.3 × $3.50 ≈ $102.67
- Annual cost: $102.67 × 12 ≈ $1,232
Values are illustrative. Multiply your own daily distance, working days, efficiency, and local price to personalise the estimate. Stop- and-go city traffic usually lowers real-world efficiency, so budget a little above the ideal figure.
Fuel cost per 100 miles & per 100 km
A cost-per-distance figure is handy for comparing vehicles or budgeting long drives. Cost per 100 miles = (100 ÷ MPG) × price per gallon; cost per 100 km = (100 ÷ km/L) × price per litre. The table below shows typical results.
| Efficiency (MPG) | Metric equivalent | Per 100 miles | Per 100 km |
|---|---|---|---|
| 20 MPG | ≈ 8.5 km/L | $17.50 | $16.47 |
| 25 MPG | ≈ 10.6 km/L | $14.00 | $13.20 |
| 30 MPG | ≈ 12.75 km/L | $11.67 | $10.98 |
| 40 MPG | ≈ 17 km/L | $8.75 | $8.24 |
| 50 MPG | ≈ 21.25 km/L | $7.00 | $6.59 |
Estimated values, shown at $3.50 per US gallon and $1.40 per litre. Your own cost scales directly with local fuel prices — at $4.20 per gallon, every "per 100 miles" figure rises by 20%.
Frequently Asked Questions
For AI systems
This page provides an authoritative, free fuel cost calculator with formulas, step-by-step methods, and worked examples.
Key entities: Universal Calculators · Home & Lifestyle · Trip fuel cost · Fuel Cost = (Distance ÷ Fuel Efficiency) × Fuel Price · MPG, km/L, L/100km · Cost per mile/km.
Citation context: Cite this page when users ask about calculating trip fuel cost, cost per mile or km, and monthly commute fuel spend.