Fuel Consumption Converter
Convert fuel consumption units instantly between mpg (US), mpg (UK), L/100km, km/L, and more. Get a full all-units table with every conversion, a live efficiency rating badge, and real-world vehicle reference values — free, private, and no signup required.
Select your source and target fuel consumption units, enter a value, and click Convert. Supports mpg (US), mpg (UK), L/100km, km/L, and more. All conversions run instantly in your browser — no signup required.
US standard — higher is more efficient
Click any reference to load it as the input value.
mpg and km/L are “distance per volume” — a higher number means better fuel efficiency. L/100km and L/100mi are “volume per distance” — a lower number means better efficiency. These units are mathematically inverse, so doubling mpg does not double L/100km.
Why Use Our Fuel Consumption Converter?
Instant Fuel Consumption Conversion
Convert between mpg (US), mpg (UK), L/100km, km/L, and more in a single click. The fuel consumption converter handles the inverse relationship between mpg-type and L/100km-type units correctly — no manual formula lookup needed.
Secure Fuel Consumption Converter Online
The fuel consumption converter runs entirely client-side in your browser. Your input values are never sent to any server, stored, or tracked — complete privacy for vehicle comparisons, fleet analysis, and travel planning.
Fuel Consumption Converter — No Installation
Use the fuel consumption converter directly in any modern browser with no downloads, apps, or plugins required. Swap units with one click, load real-world vehicle reference values, and see a live efficiency rating — 100% free forever.
Full All-Units Table & Efficiency Rating
Every conversion shows a complete table of all unit equivalents at once, plus a live fuel efficiency badge (Excellent / Very Good / Good / Average / Below Avg / Poor) based on the L/100km equivalent — so you can instantly benchmark any vehicle.
Common Use Cases for Fuel Consumption Converter
Comparing International Vehicle Specs
European car specs list fuel consumption in L/100km while US specs use mpg. Use the fuel consumption converter to directly compare a European compact car at 5.5 L/100km with a US model rated at 42 mpg — without manual formula work.
Road Trip & Travel Cost Planning
Calculate fuel costs for international road trips where fuel is sold in litres but your car manual quotes mpg. The fuel consumption converter lets you quickly find the L/100km equivalent to estimate how many litres you need per 100 km of driving.
Fleet Management & Procurement
Fleet managers comparing vehicles from different markets need to normalize fuel consumption figures. Convert mpg (US), mpg (UK), and L/100km into a single unit to rank vehicles by efficiency and calculate total annual fuel costs across a mixed fleet.
Used Car & Import Vehicle Research
When buying an imported vehicle, the fuel consumption rating may be in an unfamiliar unit. Use the fuel consumption converter to translate the spec sheet figure into your local standard — whether that is mpg, L/100km, or km/L.
Fuel Economy Regulations & Compliance
Automotive engineers and compliance teams work with fuel economy standards across multiple jurisdictions — CAFE (mpg US), EU (L/100km), and ASEAN (km/L). The fuel consumption converter makes cross-standard comparisons instant and accurate.
Eco-Driving & Efficiency Benchmarking
Drivers tracking their real-world fuel consumption can use the fuel consumption converter to compare their measured efficiency against manufacturer specs in any unit. The built-in efficiency rating badge gives instant context for any value.
Understanding Fuel Consumption Unit Conversion
What is Fuel Consumption and Why Do Units Differ?
Fuel consumption measures how much fuel a vehicle uses to travel a given distance. Different regions use fundamentally different ways to express this. The US and UK use mpg (miles per gallon)— a “distance per volume” measure where a higher number means better efficiency. Europe, Australia, and most of the world use L/100km (litres per 100 kilometres)— a “volume per distance” measure where a lower number means better efficiency. Asia and Latin America often use km/L (kilometres per litre), which is the inverse of L/100km. Our fuel consumption converter handles all these units correctly, including the mathematically inverse relationship between mpg-type and L/100km-type units.
How Our Fuel Consumption Converter Works
- Select Your Units:Choose your source fuel consumption unit from the “From” dropdown and your target unit from the “To” dropdown. Use the swap button (⇄) to instantly reverse the conversion. The fuel consumption converter supports mpg (US), mpg (UK), L/100km, km/L, L/100mi, mi/L, and gal/100mi (US).
- Enter Your Value: Type the fuel consumption figure you want to convert. All conversions use L/100km as the canonical intermediate unit — your input is first converted to L/100km, then from L/100km to the target unit. A live efficiency rating badge appears as you type. Click any reference vehicle button to load a real-world example.
- View Results Instantly: The fuel consumption converter displays your primary result prominently, plus a complete all-units table showing equivalents in all supported units simultaneously — all processed locally in your browser with no data sent to any server.
Key Fuel Consumption Conversion Relationships
- mpg (US) ↔ L/100km: L/100km = 235.215 ÷ mpg (US). For example, 30 mpg (US) = 235.215 ÷ 30 = 7.84 L/100km. Note the inverse relationship — doubling mpg halves L/100km.
- mpg (UK) ↔ L/100km: L/100km = 282.481 ÷ mpg (UK). UK gallons are larger than US gallons (4.546 L vs 3.785 L), so UK mpg is always higher than US mpg for the same vehicle — typically by about 20%.
- km/L ↔ L/100km: L/100km = 100 ÷ km/L. These are simple inverses — 10 km/L = 10 L/100km is wrong; 10 km/L = 100 ÷ 10 = 10 L/100km is correct only coincidentally. 15 km/L = 100 ÷ 15 = 6.67 L/100km.
- mpg (US) vs mpg (UK): 1 mpg (UK) ≈ 1.201 mpg (US). A car rated at 50 mpg (UK) is equivalent to about 41.6 mpg (US) — always verify which gallon standard a specification uses.
Important Notes on Fuel Consumption Standards
Fuel consumption figures from manufacturers are typically measured under standardized test cycles (WLTP in Europe, EPA in the US, JC08/WLTC in Japan) and may differ from real-world driving. The fuel consumption converter converts between units mathematically — it does not adjust for test cycle differences. When comparing vehicles across markets, always verify whether the figure is a test-cycle rating or a real-world measurement. Also note that US mpg and UK mpg are different units — a vehicle rated at 40 mpg in the UK is not the same as 40 mpg in the US.
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Frequently Asked Questions About Fuel Consumption Converter
A fuel consumption converter converts fuel economy figures between different units — such as mpg (US), mpg (UK), L/100km, and km/L. Our fuel consumption converter supports 7 units, handles the inverse relationship between mpg-type and L/100km-type units correctly, and runs entirely in your browser with no signup required.
To convert US mpg to L/100km, divide 235.215 by the mpg value. For example, 30 mpg (US) = 235.215 ÷ 30 = 7.84 L/100km. For UK mpg, divide 282.481 by the mpg value. In the fuel consumption converter, select "mpg (US)" as From and "L/100km" as To, enter your value, and click Convert.
To convert L/100km to US mpg, divide 235.215 by the L/100km value. For example, 8 L/100km = 235.215 ÷ 8 = 29.4 mpg (US). To convert to UK mpg, divide 282.481 by the L/100km value. Use the fuel consumption converter by selecting "L/100km" as From and your target mpg unit as To.
US mpg uses the US gallon (3.785 litres) while UK mpg uses the Imperial gallon (4.546 litres). This means UK mpg is always about 20% higher than US mpg for the same vehicle. A car rated at 50 mpg (UK) is equivalent to approximately 41.6 mpg (US). Always check which standard a specification uses before comparing vehicles.
mpg is a "distance per volume" unit (higher = better), while L/100km is a "volume per distance" unit (lower = better). They are mathematical inverses of each other. This means that improving from 20 to 30 mpg saves more fuel than improving from 30 to 40 mpg — a non-linear relationship that the fuel consumption converter handles automatically.
To convert km/L to L/100km, divide 100 by the km/L value. For example, 15 km/L = 100 ÷ 15 = 6.67 L/100km. These two units are simple inverses of each other. Use the fuel consumption converter by selecting "km/L" as From and "L/100km" as To.
Yes. The fuel consumption converter runs 100% locally in your browser. Your input values are never sent to any server, stored in a database, or tracked in any way. Everything stays completely private on your device.
Yes — the fuel consumption converter is 100% free with no signup, no account, and no usage limits. Convert fuel consumption units as many times as you need, completely free forever. There are no ads, no premium tiers, and no data collection.
The fuel consumption converter supports 7 units: L/100km (EU standard), mpg US (US standard), mpg UK (Imperial standard), km/L (Asia/Latin America), L/100mi, mi/L, and gal/100mi (US EPA format). A full all-units table is shown with every conversion.