Fuel Cost Calculator
Calculate how much a trip will cost in fuel. Works with mpg (US/UK) and L/100km (Europe, Canada, Australia) — select your country for preset defaults.
Formula: US mpg: cost = (miles ÷ mpg) × price/US-gallon. UK mpg: cost = (miles ÷ mpg) × 4.546L × price/litre (UK sells fuel by litre). Europe/Australia/Canada: cost = (km ÷ 100) × L/100km × price/litre. US and UK mpg figures are not equivalent — a UK imperial gallon is 4.546L vs US gallon at 3.785L, so a UK 40 mpg car ≈ US 33 mpg.
US gallon = 3.785 L. UK fuel uses imperial gallon (4.546 L) — select 🇬🇧 UK for that.
Fuel Prices & Efficiency Units by Country
| Country | Unit | Avg Fuel Price (2025) | Avg Car Efficiency |
|---|---|---|---|
| 🇺🇸 USA | US mpg | ~$0.95/L (~$3.60/gal) | ~28–32 mpg |
| 🇬🇧 UK | UK mpg | ~£1.50/L | ~40–50 mpg (UK) |
| 🇩🇪 Germany | L/100km | ~€1.75/L | ~7–9 L/100km |
| 🇫🇷 France | L/100km | ~€1.90/L | ~6–8 L/100km |
| 🇦🇺 Australia | L/100km | ~A$2.10/L | ~8–11 L/100km |
| 🇨🇦 Canada | L/100km | ~C$1.65/L | ~9–12 L/100km |
| 🇯🇵 Japan | km/L (or L/100km) | ~¥175/L | ~15–20 km/L (efficient kei cars) |
| 🇮🇳 India | km/L | ~₹102/L (petrol) | ~15–20 km/L |
US Gallon vs UK Imperial Gallon
This is the most common source of confusion for international car buyers and travellers. The US gallon is 3.785 litres; the UK imperial gallon is 4.546 litres — about 20% larger. This means a British car advertised at 50 mpg is roughly equivalent to a US car at 41.6 mpg. Always verify which standard a vehicle's fuel economy spec uses.
Electric Vehicle Equivalent
For EVs, the equivalent metric is kWh per 100km (Europe/Australia) or MPGe (miles per gallon equivalent, USA). A typical EV uses 15–20 kWh/100km. At €0.30/kWh, a 100km trip costs €4.50–6.00 — compared to €12–16 in a petrol car at 8 L/100km and €1.75/L.