Calculate fuel cost for any trip — enter distance, fuel efficiency and fuel price to get total cost, fuel used and cost per kilometre.
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Enter the trip distance, your vehicle's fuel efficiency and the current fuel price per litre or gallon.
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Fuel Cost = (Distance ÷ Fuel Efficiency) × Fuel Price. Example: 500 km trip, car does 12 L/100km, fuel costs £1.50/L: Fuel used = 500 ÷ 100 × 12 = 60 litres. Cost = 60 × £1.50 = £90. This calculator handles all unit conversions automatically — just enter your values and units.
A US gallon = 3.785 litres; a UK gallon = 4.546 litres (about 20% larger). So 30 MPG (UK) ≈ 25 MPG (US) for the same car. This is a common source of confusion when comparing fuel economy across countries. The EU, Australia and most of Asia use L/100km (lower = more efficient).
Proven methods to improve MPG: maintain correct tyre pressure (underinflation increases fuel use by 0.2% per 1 PSI drop), remove excess weight, reduce aerodynamic drag (remove roof boxes when not needed), avoid harsh acceleration and braking, use cruise control on motorways, service the car regularly (clean air filter, fresh spark plugs) and drive at optimal speeds (typically 50–80 km/h for maximum efficiency).
Most cars achieve peak fuel efficiency between 50–80 km/h (30–50 mph). Above 80 km/h, aerodynamic drag increases rapidly (proportional to speed²), consuming more fuel. At 110 km/h vs 90 km/h, aerodynamic drag is 50% higher. Motorway driving at high speed significantly reduces fuel economy compared to steady 80 km/h driving.
Running A/C typically increases fuel consumption by 5–25% depending on conditions. At low speeds in hot weather with the A/C working hard, the impact can be significant. At motorway speeds, it is generally more efficient to use A/C than to open windows (which increases aerodynamic drag). A/C compressors draw 1–5 horsepower from the engine.
EV efficiency is measured in kWh/100km or miles/kWh. A Tesla Model 3 uses approximately 15–18 kWh/100km. At £0.28/kWh (UK home charging), that's £4.20–5.04 per 100km. A petrol car at 7L/100km and £1.50/L costs £10.50 per 100km. EVs are typically 3–5× cheaper per kilometre to fuel, though purchase prices are higher.
Hypermiling means maximising fuel economy through advanced driving techniques: anticipating traffic to avoid braking, coasting to decelerate, maintaining optimal tyre pressures (slightly above recommended), reducing weight, planning routes to avoid hills and congestion, and shutting the engine at long stops. Extreme hypermilers have achieved 100+ MPG in standard petrol vehicles.
Stop-and-go city driving typically achieves 30–50% lower MPG than highway driving because frequent acceleration from rest is energy-intensive. Hills increase energy consumption on the climb (though modern hybrids recover some on descent). City EPA ratings are calculated from a standardised test cycle; real-world results vary by terrain, traffic and driving style.
