Trip Fuel Consumption Calculator
Estimate how much fuel your vehicle will use for a trip, plus optional fuel cost and CO₂ output.
Tip: For best accuracy, use your real-world fuel economy from recent fill-ups.
What this fuel consumed calculator does
This calculator estimates the amount of fuel used over a trip using two essential inputs: distance and fuel economy. It supports common fuel-efficiency formats used around the world, including L/100km, km/L, and mpg (US or UK).
In addition to fuel consumed, you can also estimate your total trip fuel cost when you enter a fuel price. This makes the tool useful for road-trip planning, delivery routes, fleet operations, and personal budgeting.
Fuel consumption formulas used
1) If your economy is in L/100km
Fuel consumed (liters) = Distance (km) × (L/100km) ÷ 100
2) If your economy is in km/L
Fuel consumed (liters) = Distance (km) ÷ (km/L)
3) If your economy is in mpg
Fuel consumed (gallons) = Distance (miles) ÷ mpg. Then gallons are converted to liters for a consistent final result.
- 1 US gallon = 3.785411784 liters
- 1 UK gallon = 4.54609 liters
How to use the calculator
- Enter your trip distance.
- Select whether distance is in kilometers or miles.
- Enter your vehicle fuel economy value.
- Select the fuel economy unit.
- Optionally add fuel price and price unit to estimate cost.
- Click Calculate Fuel Consumed.
Worked examples
Example A: Compact car (metric)
Distance = 420 km, Economy = 6.5 L/100km Fuel consumed = 420 × 6.5 ÷ 100 = 27.3 liters.
Example B: Highway trip (US mpg)
Distance = 300 miles, Economy = 30 mpg (US) Fuel used = 300 ÷ 30 = 10 US gallons = 37.85 liters (approx).
Why tracking fuel consumed matters
- Budget control: Predict fuel expenses before long drives.
- Route comparison: See if alternate routes reduce consumption.
- Vehicle health: A sudden increase in fuel use can indicate maintenance issues.
- Environmental awareness: Lower fuel use generally means lower emissions.
Tips to reduce fuel consumption
- Keep tire pressure at recommended levels.
- Avoid harsh acceleration and heavy braking.
- Reduce unnecessary idling.
- Remove excess cargo weight.
- Use cruise control on steady highway speeds.
- Service air filters, spark plugs, and engine oil on schedule.
Common mistakes to avoid
- Mixing miles with km-based efficiency without converting.
- Using advertised fuel economy instead of your real-world average.
- Forgetting that city driving usually consumes more fuel than highway driving.
- Ignoring seasonal effects (winter fuel blends, temperature, traffic).
Quick FAQ
Is this calculator for petrol and diesel?
Yes. It works for any fuel type as long as your fuel economy and price are entered correctly.
Can I use it for motorcycles or vans?
Absolutely. The formulas are universal for vehicles that report distance and fuel economy.
How accurate is the estimate?
Accuracy depends mostly on your fuel economy input. If you use your real measured average from recent trips, results will be much closer to actual consumption.