Fuel Cost Calculator — Annual & Trip Cost

Todd Mitchell (photo)
By Todd Mitchell
On: Saturday, June 13, 2026 7:00 PM
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Fuel Cost Calculator

Calculate annual fuel costs and the cost of any specific trip from miles, MPG, and gas price. Compare two vehicles to see lifetime fuel cost difference — over 5 years, a 5-MPG gap typically costs $3 000–5 000.

Fuel Cost Calculator

Annual, monthly and per-trip fuel cost in one place.

Monthly fuel
Annual fuel
Trip cost

How It Works

Fuel cost = (Miles ÷ MPG) × Gas price. The math is simple, but compounding effects over the life of the car make small MPG differences significant. The calculator also handles unit conversion (MPG to L/100km, US to UK gallons) for international users.

Formula: Annual fuel cost = (Annual miles ÷ MPG) × Price per gallon. Trip cost = (Trip miles ÷ MPG) × Price per gallon. Liters per 100 km = 235.21 ÷ MPG.

How to Use This Calculator

  1. Enter annual miles driven.
  2. Enter combined MPG (use EPA estimate or your actual real-world average).
  3. Enter local gas price per gallon.
  4. The calculator returns annual and 5-year fuel cost.
  5. Switch to "compare two cars" mode to see lifetime fuel cost gap.

Worked Example

Example: 15 000 mi/yr, 30 MPG combined, $3.60/gal. Annual fuel $1 800. 5 years $9 000. Switch to a 24-MPG car at the same miles and price: $2 250/yr, $11 250 over 5 years — $2 250 more. Equivalent to a $400/year insurance premium difference.

Reference Table

Cost per mile by typical vehicle type at $3.60/gallon. Multiply by your annual miles for yearly cost.

Vehicle type Typical combined MPG $1.50 / mile cost @ $3.60 gas
Hybrid sedan (Prius) 52 MPG $0.069 per mile
Compact petrol (Civic) 36 MPG $0.100 per mile
Midsize sedan (Camry) 32 MPG $0.113 per mile
Compact SUV (CR-V, RAV4) 30 MPG $0.120 per mile
Midsize SUV (Highlander) 25 MPG $0.144 per mile
Full-size pickup (F-150) 22 MPG $0.164 per mile
Heavy-duty truck (Ram 2500) 16 MPG $0.225 per mile
Performance V8 18 MPG $0.200 per mile
EV @ home charging $0.04/mi (equivalent ~110 MPG) $0.040 per mile

Frequently Asked Questions

What's the difference between EPA combined MPG and real-world MPG?

EPA combined is a weighted average of standardized city/highway tests. Real-world results are typically 10–20% lower for gas cars and 15–30% lower for hybrids and EVs (especially in cold weather).

How do I convert MPG to L/100km?

L/100km = 235.21 ÷ MPG. So 30 MPG = 7.8 L/100km. Or 9 L/100km = 26 MPG. Note: this is US gallons. UK gallons are 20% bigger; UK MPG = US MPG × 1.2.

Is premium fuel worth it for fuel economy?

Only if your car requires it. Engines tuned for premium gain 1–3% MPG and 5–10% power on premium. Engines designed for regular gain almost nothing — premium's 50¢/gallon premium ($600+/year) is wasted.

How can I improve my real-world MPG?

Tire pressure at placard spec: +1–2%. Smooth acceleration: +5–10%. Reduce highway speed from 80 to 65 mph: +15–20%. Remove roof boxes/racks when not in use: +5–10%. Clean engine air filter: +1–2%.

Does ethanol-free gas give better MPG?

Yes, about 3–5% better because ethanol has lower energy density than gasoline. But ethanol-free is usually 30–50¢ more per gallon — the MPG gain doesn't cover the price premium for most drivers.