Gas Cost Calculator
Road trip fuel cost — MPG (US/UK) or L/100km — split by passengers
Quick answer: A 300-mile trip in a 30 MPG (US) car at $3.50/gal costs $35. The same trip in Europe: 483 km in a 7L/100km car at €1.70/L costs €57.50.
Unit note
US gallon = 3.785 L. UK imperial gallon = 4.546 L (20% larger). Same car rated 40 mpg (UK) uses more fuel than one rated 40 mpg (US).
Fuel Price & Economy Standards by Country
| Country | Economy unit | Typical price (2024) | Notes |
|---|---|---|---|
| 🇺🇸 USA | MPG (US) | ~$3.40/gal | US gallon = 3.785 L |
| 🇬🇧 UK | MPG (UK) | ~£1.55/L (~£7.00/gal) | Imperial gallon = 4.546 L |
| 🇪🇺 Germany/EU | L/100km | ~€1.75/L | EU-standard metric |
| 🇦🇺 Australia | L/100km | ~A$2.10/L | Metric since 1970s |
| 🇨🇦 Canada | L/100km | ~C$1.60/L | Metric; 11.2 cents US equiv. |
| 🇯🇵 Japan | km/L | ~¥175/L | JC08 test cycle used |
| 🇮🇳 India | km/L | ~₹103/L petrol | ARAI testing standard |
Frequently Asked Questions
How many litres per 100km is good fuel economy?
A typical efficient petrol car achieves 5-7 L/100km. Hybrids can reach 3-4 L/100km. SUVs typically use 8-12 L/100km. Electric vehicles are measured in kWh/100km or miles per kWh instead.
What is the US gas tax and how does it compare internationally?
The US federal gas tax is 18.4 cents/gallon, among the lowest in the developed world. Germany adds around 65 euro cents/litre in fuel tax. UK adds 52.95p/litre plus 20% VAT. Higher European fuel taxes are a major reason fuel prices are 2-3x higher than the US despite similar crude oil prices.
How do I convert MPG (US) to L/100km?
Divide 235.214 by the MPG (US) figure. For example: 30 MPG (US) = 235.214 / 30 = 7.84 L/100km. To convert MPG (UK) to L/100km: divide 282.48 by the MPG (UK) figure.