Fuel Efficiency Converter
Convert between MPG, L/100km, and km/L
What is the Fuel Efficiency Converter?
A fuel efficiency converter translates between the different systems used to measure how far a vehicle travels on a given amount of fuel, miles per gallon (MPG), liters per 100 kilometers (L/100km), and kilometers per liter (km/L). The US uses MPG, most of Europe and Asia use L/100km, and some regions use km/L. When you're comparing car specs across markets, estimating road trip costs, or just trying to understand a foreign car review, this converter gives you the number in whatever unit makes sense to you.
How Does It Work?
Fuel efficiency units don't convert with a simple multiplication, some require inversion because they measure the same thing from opposite directions (distance per fuel vs fuel per distance).
Key conversions:
MPG (US) to L/100km: 235.215 ÷ MPG
L/100km to MPG (US): 235.215 ÷ L/100km
MPG to km/L: MPG × 0.4251
km/L to L/100km: 100 ÷ km/L
Input: your vehicle's fuel efficiency figure
Conversion Factor: depends on the unit pair
How to Use CalciHub's Fuel Efficiency Converter
1. Enter your vehicle's fuel efficiency number.
2. Select the unit whose number is in MPG, L/100km, or km/L.
3. Choose the unit you want to convert to.
4. The result appears immediately.
Tip: A lower L/100km number is better (using less fuel per distance), while a higher MPG number is better. Don't confuse the direction, this is where most conversion mistakes happen.
A Quick Example
A traveler is renting a car in Europe. The car specs list fuel consumption as 6.5 L/100km. They want to understand this in MPG since that's what they're familiar with from home.
Input: 6.5 L/100km
Converting to: MPG (US)
235.215 ÷ 6.5 = 36.19 MPG
Output: approximately 36.2 MPG
That's a reasonably efficient car by most standards. Knowing the MPG equivalent helps the traveller estimate fuel costs for the trip using pumping rates they understand.
Frequently Asked Questions
L/100 km directly tells you the cost of driving a fixed distance — it's easier to use for budgeting. MPG tells you range per tank, which some drivers find more intuitive. Neither is objectively better; it's a regional convention.
No. A US gallon is 3.785 litres, while a UK gallon is 4.546 litres. A car rated at 40 MPG (UK) is only about 33 MPG (US). When comparing international fuel economy data, always check which gallon is being used.
For a typical passenger car, anything above 35 MPG (about 6.7 L/100km) is generally considered good. Hybrid vehicles often hit 50+ MPG (under 5 L/100km), and plug-in hybrids or EVs are measured differently using MPGe (miles per gallon equivalent).
Yes. The converter works for any vehicle – motorcycles, sedans, SUVs, trucks. Just input the fuel efficiency figure and select the right units.
Yes, entirely free with no account required and instant results.
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