Fuel cost calculator
Estimate how much a drive will cost in fuel. Enter trip distance, vehicle consumption in liters per 100 km or miles per gallon (MPG), and local fuel price per liter or gallon.
How to estimate trip fuel cost
1. Enter total trip distance (km or miles).
2. Set fuel economy: l/100km (metric) or MPG (US/UK — check which MPG definition your car uses).
3. Enter current fuel price per liter or gallon.
4. Read total fuel volume, trip cost, and cost per distance — adjust for round trips by doubling distance.
Fuel cost examples
450 km highway, 6.5 l/100km, €1.85/L
Fuel needed ≈ 29.25 L; cost ≈ €54.11; ≈ €0.12/km. A thirstier 9 l/100km SUV → €74.80 for the same trip.
300 miles at 35 MPG, $3.60/gallon
Gallons ≈ 8.57; cost ≈ $30.86; ≈ $0.10/mile. At 28 MPG → $38.57 — 25% higher consumption = 25% higher cost.
Round-trip vacation
One-way 520 km → enter 1,040 km total. Add 10% buffer for city detours and A/C load in summer.
When to use this tool
• When you compare driving vs flying for family trips on a budget.
• When you evaluate a fuel-efficient car against your current MPG on your commute.
• When you split fuel costs among carpool passengers with a fair per-km figure.
Planning road trips with real numbers
Map distance from your routing app, then apply your car’s long-term average consumption — not just the brochure figure. Add 5–15% for mountains, towing, or winter idling. Multiply fuel cost by 2 for round trips; add parking and tolls for total travel budget. Comparing two vehicles: at 15,000 km/year and €1.80/L, 5 l/100km vs 7 l/100km saves about €540 annually in fuel alone.
Frequently asked questions
How do I convert MPG to l/100km?
l/100km ≈ 235.215 ÷ MPG (US). Example: 30 MPG ≈ 7.84 l/100km. UK imperial MPG uses a different gallon size.
US vs UK MPG?
US gallon = 3.785 L; UK imperial gallon = 4.546 L. A car rated 40 US MPG ≠ 40 UK MPG. Check which your dashboard uses.
Why does my real consumption differ?
Cold starts, speed, load, tires, and A/C affect burn rate. Official WLTP/NEDC figures are lab benchmarks.
Diesel vs petrol pricing?
Enter the price for the fuel you actually buy — diesel often differs per liter from petrol.
Electric vehicles?
This tool is for liquid fuel. EV trips use kWh/100km and electricity rates — different calculators apply.