Transport & cars · 055

Fuel economy converter

How do MPG, L/100 km, and km/L compare?

Your numbers

L/100 km

Quick answer

What does the Fuel economy converter calculate?

How do MPG, L/100 km, and km/L compare? This calculator uses litres per 100 km to estimate fuel economy conversion immediately in your browser.

With the values currently entered, the result is 31.8 MPGUS fuel economy. It also shows us mpg, imperial mpg, and kilometres per litre.

How to use the Fuel economy converter

  1. Replace the example values with your own numbers.
  2. Review the result and supporting figures as they update automatically.
  3. Check the formula and assumptions before using the estimate for a decision.

Inputs used

  • Litres per 100 km — entered in L/100 km

Fuel economy converter formula

US MPG = 235.215 ÷ L/100 km; km/L = 100 ÷ L/100 km

Assumptions

  • MPG uses US gallons.
  • This is a unit conversion, not a driving-condition estimate.

Practical guide

Fuel economy converter example and edge cases

How do MPG, L/100 km, and km/L compare? Let's use a concrete example, then look at the assumptions that can move the answer.

Example: A practical fuel economy converter scenario

For this example, use litres per 100 km of 7.4 L/100 km. These are starting values, so replace them with numbers that match your situation.

Litres per 100 km
7.4 L/100 km

Calculated result31.8 MPGUS fuel economy

Start with US fuel economy. Then check us mpg, imperial mpg, and kilometres per litre to understand what sits behind the main result.

Example results use the default display profile. The calculator above follows your selected country and units.

How to read the result

  • Read the main result first. The supporting figures for us mpg, imperial mpg, and kilometres per litre explain how the estimate is built.
  • The method is US MPG = 235.215 ÷ L/100 km; km/L = 100 ÷ L/100 km. Keep the units consistent and use values from the same time period.

Edge cases worth checking

When litres per 100 km is unusual

MPG uses US gallons. Double-check this input before relying on the result.

When litres per 100 km is uncertain

This is a unit conversion, not a driving-condition estimate. Run a lower and higher value to see a useful range.

What changes the result most

Litres per 100 km

Measure litres per 100 km with the same unit shown beside the input. Convert first if your source uses another unit.

Try a different scenario

Small changes show whether the answer is stable or sensitive.

Litres per 100 km: 10% lower

6.66 L/100 km

35.3 MPGUS fuel economy

Litres per 100 km: 10% higher

8.14 L/100 km

28.9 MPGUS fuel economy

Common mistakes

Check litres per 100 km

MPG uses US gallons. Make sure this matches the number you enter.

Keep litres per 100 km consistent

This is a unit conversion, not a driving-condition estimate. Use the same units and time period throughout the calculation.

Do not rely on one fuel economy converter scenario

Run a cautious case and an optimistic case. The range is often more useful than one exact-looking number.

Use this result well

Use it for

How do MPG, L/100 km, and km/L compare?

Do not use it as

A vehicle quote, finance agreement, route, and driving conditions can change the real cost.