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Fuel Economy Calculator | km/L, L/100km, fuel cost, and cost per km

Enter distance, fuel used, and optional price per liter to calculate km/L fuel economy, L/100km, total fuel cost, and cost per km.

Auto/Cost
-Fuel economy (km/L)
-Fuel use per 100km
-Total fuel cost
-Fuel cost per km

Enter distance and fuel used to calculate fuel economy instantly.

Use positive numbers only. Distance and fuel are capped at 1,000,000, and fuel price is capped at 10,000,000 per liter.

Use this fuel economy calculator after a drive or refill

After a trip or a refill, you may want to know your real fuel economy and how much that drive actually cost.

This tool lets you enter:

  • Distance traveled (km)
  • Fuel used (L)
  • Fuel price per liter (optional)

Then it instantly shows fuel economy in km/L, fuel used per 100km (L/100km), total fuel cost, and fuel cost per km on one screen. Use it to keep a real-world mileage log after refueling, or to estimate fuel cost before a longer drive.

Why this tool was selected today

Recent quality work focused on tools such as image-resizer, lucky-draw-picker, pomodoro-timer, readability-checker, time-difference-calculator, korean-name-romanizer, png-compressor, json-merge, link-list-cleaner, and average-speed-calculator, so this pass avoids repeating the same tools. fuel-economy-calculator had little major work since its March 2026 launch, and auto cost calculators are especially sensitive to empty fields, zero or negative inputs, extreme values, and optional price handling.

How it works

  1. Distance ÷ Fuel used = km/L
  2. 100 ÷ km/L = L/100km
  3. Fuel used × Price per liter = Total fuel cost
  4. Total fuel cost ÷ Distance = Cost per km

All calculations run in your browser. If fuel price is blank, the calculator still shows km/L and L/100km first.

Examples

Example 1) Check trip fuel economy

  • Distance: 420km
  • Fuel used: 28L
  • Price per liter: 1,720 KRW

→ Fuel economy: 15.00 km/L
→ Fuel use per 100km: 6.67 L
→ Total fuel cost: 48,160 KRW
→ Fuel cost per km: about 115 KRW

Example 2) Compare vehicle running cost

For the same 100km drive:

  • Vehicle A: 12km/L
  • Vehicle B: 16km/L

Vehicle B uses less fuel for the same distance, so the fuel-cost gap becomes more noticeable if you often take long trips.

Especially useful for

  • Checking how your real-world fuel economy compares with official mileage
  • Estimating fuel cost before a long drive
  • Logging cost per trip in a car expense tracker
  • Comparing running costs between two vehicles
  • Rechecking whether fuel receipt liters and price per liter match the total paid

Good companion tools

FAQ

Is a higher km/L better?

Yes. A higher km/L means your car travels farther with the same amount of fuel.

Is a lower L/100km better?

Yes. A lower L/100km means less fuel is needed to travel the same distance.

Why should I enter fuel price?

Adding fuel price helps you translate efficiency into real driving cost, including total fill cost and cost per km.

What should I check when the result looks odd?

If fuel economy looks too low or too high, check whether distance and fuel were swapped, and confirm that the distance is in km rather than meters or miles. The calculator also warns when the result is unusual for a typical passenger car.

Summary

This fuel economy calculator quickly turns distance and fuel volume into a realistic driving-cost view. Enter the numbers from your latest refill to check both mileage and fuel cost in one place.

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