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Fuel Consumption Converter

Convert fuel consumption values quickly and accurately. Instant conversions with detailed step-by-step solutions.

Last Updated: May 26, 2026
5 min read

About this converter

Convert between 37 different units of fuel consumption. Enter a value and select units to see the conversion result instantly with step-by-step solution.

This tool converts fuel economy values between common systems like miles per gallon (MPG), liters per 100 kilometers (L/100 km), and kilometers per liter (km/L). Fuel economy is shown differently around the world, so comparing vehicles, reading spec sheets, or planning trips can feel confusing. This calculator helps drivers, fleet managers, delivery teams, and anyone tracking fuel use. You enter a number, select the unit you have, then choose the unit you need. The calculator returns the same fuel efficiency expressed in the new unit, so you can compare vehicles and plan trips more easily.

How to Use This Calculator (step-by-step)

  1. Enter your fuel economy value (example: 8).
  2. Choose the From unit (example: L/100 km).
  3. Choose the To unit (example: MPG US).
  4. View the converted result.
  5. Optional: swap units to convert back and confirm.

What This Calculator Measures

Fuel consumption (also called fuel economy) shows how efficiently a vehicle uses fuel. Around the world, it is displayed in two main styles, which can look very different even when they mean the same thing.

Fuel used per distance

This format shows how much fuel you need to travel a set distance.

Examples: L/100 km, gal/100 mi.

In this style, lower numbers are better.

Distance per fuel used

This format shows how far you can travel using a set amount of fuel.

Examples: MPG, km/L.

In this style, higher numbers are better.

Formula or Logic (Easy Explanation)

This converter follows one simple idea: it rewrites the same efficiency using different distance units and fuel volume units.

  • If your unit is fuel per distance (like L/100 km), the calculator converts liters and kilometers into the target system.
  • If your unit is distance per fuel (like MPG or km/L), the calculator converts miles or kilometers and gallons or liters into the target system.
  • When converting between the two styles, the relationship is basically an inverse. "Fuel per distance" is the flipped view of "distance per fuel."

You do not need to calculate anything manually. Just pick the correct units.

Example Calculations

Example 1: L/100 km to MPG (US)

  • Input: 8 L/100 km
  • Output: 29.40 MPG (US)

Example 2: MPG (US) to L/100 km

  • Input: 30 MPG (US)
  • Output: 7.84 L/100 km

Example 3: km/L to MPG (US)

  • Input: 12 km/L
  • Output: 28.23 MPG (US)

Understanding Your Results

  • If your result is in L/100 km (or any fuel-per-distance unit), smaller numbers mean better efficiency, because less fuel is used for the same trip.
  • If your result is in MPG or km/L (distance-per-fuel units), larger numbers mean better efficiency, because the vehicle goes farther using the same fuel.
  • If the converted number looks surprising, the most common cause is choosing the wrong gallon type, because US gallons and UK/Imperial gallons are different sizes.

Common Mistakes to Avoid

  • Mixing up MPG (US) and MPG (UK/Imperial)
  • Confusing L/100 km with km/L
  • Entering a trip distance instead of a fuel economy value
  • Swapping From and To units by mistake
  • Missing a decimal point (80 instead of 8.0)
  • Comparing values without checking the unit style
  • Assuming all "gallons" are the same everywhere
  • Rounding too early and losing accuracy

Frequently Asked Questions

It converts fuel economy numbers from one unit to another, so you can compare vehicles, understand specifications, and track fuel efficiency in the unit you prefer.
They describe the same idea, but in different styles. Fuel consumption often means fuel per distance (like L/100 km). Fuel economy often means distance per fuel (like MPG).
Both can mean "better," depending on the unit. Higher MPG is better. Lower L/100 km is better.
MPG can be based on the US gallon or the UK/Imperial gallon. Since the gallon sizes differ, the MPG values differ too.
It means how many liters of fuel you use to drive 100 kilometers. Lower numbers mean you use less fuel.
It means how many kilometers you can drive using 1 liter of fuel. Higher numbers mean you go farther per liter.
Yes. Convert both values to the same unit first, then compare directly.
That is normal, especially when switching between the two styles (fuel-per-distance versus distance-per-fuel). The same efficiency can look very different in another unit.
Check how the value is written. If it looks like "liters per 100 km," pick L/100 km. If it looks like "miles per gallon," pick MPG. If it looks like "km per liter," pick km/L.
For daily driving and comparisons, rounding to 1–2 decimals is fine. For reporting or detailed tracking, keep more decimals and round at the end.
Yes. Acceleration, speed, tire pressure, load, road conditions, and maintenance can all change real-world fuel economy compared to official ratings.
Yes. Convert your vehicle's fuel economy to a unit you understand, then combine it with your trip distance and fuel price to estimate cost.

Fuel economy is measured in different ways worldwide, which makes comparisons tricky. This calculator converts common fuel consumption and fuel economy units so you can read specs clearly, compare vehicles fairly, and plan trips with less guesswork. Try the calculator above to see your results.