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Kilometers per Liter Calculator

AutomotiveVehicle Ownership Costs

Trip meter reading between two full tanks.

Litres pumped to refill the tank at the end of the distance.

Fuel economy (km/L) —
Litres per 100 km
—
US miles per gallon
—
UK (imperial) mpg
—

Kilometres per litre is the distance driven divided by the fuel used. Fill the tank, reset the trip meter, drive, refill and divide. For 500 km on 40 litres, economy is 12.5 km/L, equal to 8 litres per 100 km, 29.4 US mpg or 35.3 imperial mpg.

About this tool

Drivers in South Asia, Latin America and Japan usually quote economy in kilometres per litre, while European manuals print litres per 100 km and US window stickers show miles per gallon. This calculator takes the distance from your trip meter and the litres from the pump receipt, returns km/L, and restates it in the other three common units so a figure from a review or a brochure can be compared with your own car. The working shows each division and conversion factor. The result is only as good as the fill-up method: a tank topped off to a different level than at the start can shift a single reading by several percent, so averaging over three or more tanks gives a steadier figure.

How to use it

  1. Enter the distance

    Type the kilometres shown on the trip meter between two full fill-ups.

  2. Enter the fuel used

    Type the litres needed to refill the tank at the end of that distance.

  3. Read the four units

    km/L appears as the headline, with L/100 km, US mpg and UK mpg below and the working underneath.

Examples

500 km on 40 litres

Distance driven
500
Fuel used
40

Result Fuel economy (km/L): 12.5
Litres per 100 km: 8
US miles per gallon: 29.4
UK (imperial) mpg: 35.3

  1. km/L = 500 km ÷ 40 L = 12.5
  2. L/100 km = 100 ÷ 12.5 = 8
  3. US mpg = 12.5 × 3.785411784 ÷ 1.609344 = 29.4
  4. UK mpg = 12.5 × 4.54609 ÷ 1.609344 = 35.3

A typical tank of a compact petrol car: 12.5 km/L, which is 8 L/100 km or about 29.4 US mpg.

600 km on 45 litres

Distance driven
600
Fuel used
45

Result Fuel economy (km/L): 13.33
Litres per 100 km: 7.5
US miles per gallon: 31.4
UK (imperial) mpg: 37.7

  1. km/L = 600 km ÷ 45 L = 13.33
  2. L/100 km = 100 ÷ 13.3333 = 7.5
  3. US mpg = 13.3333 × 3.785411784 ÷ 1.609344 = 31.4
  4. UK mpg = 13.3333 × 4.54609 ÷ 1.609344 = 37.7

600 ÷ 45 gives 13.33 km/L; flip it to 7.5 litres for every 100 km.

How it is calculated

km/L = d ÷ V; L/100 km = 100 ÷ (km/L); mpg = (km/L) × G ÷ 1.609344

d
distance driven in kilometres
V
fuel used in litres
G
litres per gallon: 3.785411784 for US, 4.54609 for imperial

Economy is a plain ratio of distance to fuel. Litres per 100 km is its reciprocal scaled by 100, so a higher km/L means a lower L/100 km. Miles per gallon multiplies km/L by the litres in one gallon and divides by the kilometres in one mile; both are exact legal definitions, which is why a US and a UK mpg figure for the same car differ by about 20 percent.

When not to use it

  • For electric vehicles, which are rated in kWh per 100 km or km per kWh rather than litres.
  • For a single partial fill, where the tank level at start and end is not the same.

Common mistakes

  • Using the dashboard's estimated range or average instead of the pump litres, which often reads several percent optimistic.
  • Comparing a US mpg figure with a UK mpg figure as if the gallons were the same size.
  • Treating L/100 km like km/L, where a bigger number means better economy rather than worse.

Frequently asked questions

What is a good km/L figure for a petrol car?

Small petrol hatchbacks commonly return 15 to 20 km/L on mixed driving, mid-size sedans around 10 to 14 km/L, and large SUVs 6 to 9 km/L. Hybrids can exceed 20 km/L in town. Your own figure depends on traffic, speed, load and tyre pressure.

How do I convert km/L to litres per 100 km?

Divide 100 by the km/L figure. 12.5 km/L becomes 100 ÷ 12.5 = 8 L/100 km. The relationship is reciprocal, so going from 10 to 20 km/L halves consumption from 10 to 5 L/100 km.

Why are UK mpg figures higher than US mpg for the same car?

An imperial gallon holds 4.54609 litres and a US gallon 3.785411784 litres. The same car travels about 20 percent further on the larger gallon, so its UK mpg is about 1.2 times its US mpg.

How many tanks should I measure for a reliable average?

Pumps shut off at slightly different levels each time, so one tank can be off by a few percent. Adding up the distance and litres over three to five fill-ups and dividing the totals gives a steadier figure than averaging individual tank results.

Why does my measured km/L differ from the official rating?

Official figures come from laboratory cycles such as WLTP with fixed speeds and temperatures. Real driving with air conditioning, short trips, motorway speeds or roof racks commonly gives 10 to 25 percent lower economy than the rated number.

Can I enter diesel or LPG consumption?

Yes. The ratio works for any liquid fuel measured in litres. Keep in mind that diesel holds more energy per litre than petrol and LPG less, so km/L figures across fuels are not a direct comparison of efficiency.

Cite this tool

Using this tool in an assignment, article or report? Copy a citation, or a link for your website.

APA

Tools Directory Editorial Team. (2026, October 9). Kilometers per Liter Calculator. Tools Directory. Retrieved October 26, 2026, from https://tools.milunir.com/automotive/vehicle-ownership-costs/kilometers-per-liter-calculator/

MLA

Tools Directory Editorial Team. “Kilometers per Liter Calculator.” Tools Directory, 9 Oct. 2026, https://tools.milunir.com/automotive/vehicle-ownership-costs/kilometers-per-liter-calculator/. Accessed 26 Oct. 2026.

Chicago

Tools Directory Editorial Team. “Kilometers per Liter Calculator.” Tools Directory. Last modified October 9, 2026. Accessed October 26, 2026. https://tools.milunir.com/automotive/vehicle-ownership-costs/kilometers-per-liter-calculator/.

Link<a href="https://tools.milunir.com/automotive/vehicle-ownership-costs/kilometers-per-liter-calculator/">Kilometers per Liter Calculator – Tools Directory</a>