l km to mpg calculator

How to use this calculator

This calculator is built for quick fuel economy conversion. Many countries list fuel use in liters, while others use miles per gallon. If you ever compare vehicles from different markets, this tool makes the numbers easy to understand.

• Step 1: Enter your fuel consumption value.
• Step 2: Choose whether your value is in L/km or L/100 km.
• Step 3: Click Calculate MPG to see the converted results.

Understanding L/km and MPG

What is L/km?

L/km means liters of fuel used per kilometer traveled. Lower numbers are better because the vehicle uses less fuel per unit distance.

What is L/100 km?

L/100 km is a more common format and means liters used to travel 100 kilometers. This is simply 100 times the L/km value.

What is MPG?

MPG stands for miles per gallon. In this system, higher numbers are better because the vehicle travels farther on one gallon of fuel.

US MPG vs UK MPG

Not all MPG values are the same. A UK (Imperial) gallon is larger than a US gallon, so UK MPG values appear higher for the same vehicle.

• US gallon: 3.785 liters
• UK gallon: 4.546 liters

This calculator shows both so you can compare correctly.

Conversion formulas

If your input is in L/km, convert to L/100 km first:

L/100 km = L/km × 100

Then calculate MPG:

• US MPG = 235.214583 ÷ (L/100 km)
• UK MPG = 282.480936 ÷ (L/100 km)

Example conversions

Example 1: 0.07 L/km

First convert to L/100 km: 0.07 × 100 = 7.0 L/100 km.

US MPG: 235.214583 ÷ 7.0 = 33.60 MPG

UK MPG: 282.480936 ÷ 7.0 = 40.35 MPG

Example 2: 8.5 L/100 km

US MPG: 235.214583 ÷ 8.5 = 27.67 MPG

UK MPG: 282.480936 ÷ 8.5 = 33.23 MPG

Common mistakes to avoid

• Mixing up L/km and L/100 km.
• Comparing US MPG with UK MPG without checking gallon type.
• Rounding too early in multi-step calculations.

Tips to improve fuel economy

• Maintain steady speeds and avoid hard acceleration.
• Keep tires inflated to recommended pressure.
• Remove unnecessary cargo weight.
• Use the correct engine oil and follow service intervals.
• Plan routes to reduce stop-and-go traffic.

FAQ

Is lower L/100 km always better?

Yes. Lower L/100 km means less fuel consumed for the same distance.

Is higher MPG always better?

Yes. Higher MPG means more distance traveled per gallon of fuel.

Can I convert MPG back to L/100 km?

Absolutely. Use the inverse formulas:

• L/100 km = 235.214583 ÷ US MPG
• L/100 km = 282.480936 ÷ UK MPG