Fuel Consumption Calculator

Calculate your vehicle’s metric fuel consumption in litres per 100 kilometres (L/100 km) and cross-convert between km/L, US MPG, and UK imperial MPG.

Automotive

Distance Traveled

distance

Distance driven during the measurement interval.

Fuel Volume Consumed

volume

Total volume of fuel consumed.

Measurement System

Select input units for distance and fuel volume.

Formula & Methodology

L/100 km = (Litres Consumed ÷ Kilometres Driven) × 100 | km/L = Kilometres ÷ Litres

Metric fuel consumption calculates the exact volume of fuel needed to drive 100 kilometres. Kilometres per litre (km/L) expresses distance achieved per unit volume. Conversions to US MPG use the exact factor: US MPG = 235.215 ÷ (L/100 km). Conversions to UK imperial MPG use UK MPG = 282.481 ÷ (L/100 km).

Fuel Consumption

7.5 L/100 km

Overview

Calculate your vehicle’s metric fuel consumption in litres per 100 kilometres (L/100 km) and cross-convert between km/L, US MPG, and UK imperial MPG. In metric consumption, a lower L/100 km value signifies greater fuel efficiency, which is the inverse of miles per gallon. Note that 1 US gallon equals 3.7854 litres, while 1 UK imperial gallon equals 4.5461 litres.

Worked Examples

500 Kilometres on 37.5 Litres of Fuel

Distance 500 km, 37.5 litres consumed (Metric mode).

Calculate L/100 km: (37.5 L ÷ 500 km) × 100 = 7.5 L/100 km.
Calculate km/L: 500 km ÷ 37.5 L = 13.33 km/L.
Convert to US MPG: 235.215 ÷ 7.5 = 31.4 MPG (US).
Convert to UK MPG: 282.481 ÷ 7.5 = 37.7 MPG (UK).

Final Answer: 7.5 L/100 km | 13.33 km/L | 31.4 MPG (US) | 37.7 MPG (UK)

300 Miles on 10.0 US Gallons (US Mode)

Distance 300 miles, 10.0 US gallons used.

Convert to metric: 300 × 1.609344 = 482.80 km; 10.0 × 3.785412 = 37.85 L.
Calculate L/100 km: (37.85 ÷ 482.80) × 100 = 7.84 L/100 km (rounded to 7.8 L/100 km).
Calculate US MPG: 300 ÷ 10.0 = 30.0 MPG (US).
Calculate UK MPG: 30.0 × 1.20095 = 36.0 MPG (UK).

Final Answer: 7.8 L/100 km | 12.75 km/L | 30.0 MPG (US) | 36.0 MPG (UK)

800 Kilometres on 40.0 Litres of Fuel (Efficient Hybrid)

Distance 800 km, 40.0 litres consumed.

Calculate L/100 km: (40.0 L ÷ 800 km) × 100 = 5.0 L/100 km.
Calculate km/L: 800 km ÷ 40.0 L = 20.00 km/L.
Convert to US MPG: 235.215 ÷ 5.0 = 47.0 MPG (US).
Convert to UK MPG: 282.481 ÷ 5.0 = 56.5 MPG (UK).

Final Answer: 5.0 L/100 km | 20.00 km/L | 47.0 MPG (US) | 56.5 MPG (UK)

How to Use This Calculator

Enter your trip distance (in kilometres or miles).

Input the total volume of fuel consumed (in litres or gallons).

Select your measurement system (Metric, US Customary, or UK Imperial).

Review the primary L/100 km consumption figure.

Compare across the 4-way cross-conversion table for km/L, US MPG, and UK MPG.

Reference Table

L/100 km	km/L	US MPG	UK Imperial MPG	Relative Efficiency
4.0 L/100 km	25.00 km/L	58.8 MPG (US)	70.6 MPG (UK)	Plug-In Hybrid / Ultra-Efficient
5.0 L/100 km	20.00 km/L	47.0 MPG (US)	56.5 MPG (UK)	Standard Hybrid (Prius)
6.0 L/100 km	16.67 km/L	39.2 MPG (US)	47.1 MPG (UK)	Efficient Compact Diesel / Petrol
7.0 L/100 km	14.29 km/L	33.6 MPG (US)	40.4 MPG (UK)	Midsize European Sedan
8.5 L/100 km	11.76 km/L	27.7 MPG (US)	33.2 MPG (UK)	Compact SUV / Crossover
10.0 L/100 km	10.00 km/L	23.5 MPG (US)	28.2 MPG (UK)	Standard US Family Sedan
12.0 L/100 km	8.33 km/L	19.6 MPG (US)	23.5 MPG (UK)	Midsize Truck / V6 SUV
15.0 L/100 km	6.67 km/L	15.7 MPG (US)	18.8 MPG (UK)	Heavy Duty Truck / V8

Frequently Asked Questions

Why does a lower L/100 km number mean better fuel economy?

L/100 km measures fuel consumption (the amount of fuel burned over a fixed distance). Less fuel burned to cover 100 kilometres means higher efficiency. Conversely, MPG measures distance per unit of fuel, where higher numbers are better.

How do I convert L/100 km into US MPG?

Divide 235.215 by your L/100 km value. For example: 235.215 ÷ 7.5 L/100 km = 31.36 US MPG.

How do I convert L/100 km into UK imperial MPG?

Divide 282.481 by your L/100 km value. For example: 282.481 ÷ 7.5 L/100 km = 37.66 UK MPG. This factor is 20.1% higher than the US factor because an imperial gallon is larger than a US gallon.

What is a good fuel consumption rating in L/100 km for modern cars?

For gasoline passenger cars, under 6.0 L/100 km is considered excellent (common in hybrids), 6.5 to 8.5 L/100 km is average for sedans and crossovers, and over 11.0 L/100 km represents high consumption typical of large trucks or older V8s.

Why do most European and Asian countries use L/100 km instead of MPG?

L/100 km presents a linear relationship with fuel consumed and carbon emissions. Replacing an 18 L/100 km vehicle with a 13 L/100 km vehicle saves exactly 5 litres per 100 km, whereas MPG gains are non-linear and can mislead consumers about actual fuel savings.