Convert mpg to L/100 km
To convert mpg to L/100 km, divide 235.215 by the mpg figure. It lets you compare US car fuel-economy ratings with European, Canadian and Australian figures. This mpg to liters per 100km converter works both ways: type mpg or L/100 km into either box above and the other box, the worked formula and the chart below update as you type.
Miles per gallon (mpg) is the distance a vehicle travels on one gallon of fuel, so a higher number is better. US mpg uses the 3.785-liter US gallon; UK mpg uses the larger 4.546-liter imperial gallon. Window stickers on new US cars show mpg for city, highway and combined driving. Because mpg is distance per fuel and L/100 km is fuel per distance, the conversion is a reciprocal: 30 mpg is 7.84 L/100 km.
Liters per 100 kilometers (L/100 km) is the amount of fuel a vehicle uses to travel 100 km, so a lower number is better. A car using 8 L/100 km achieves 29.4 mpg in US units. It is the official fuel-consumption measure in Europe, Canada and Australia.
How to convert mpg to liters per 100km with this tool
- Type a number into the US miles per gallon (mpg) box — it starts at 30 mpg as an example.
- Read the answer in the Liters per 100 km (L/100 km) box and in the result panel, which also shows the formula with your number.
- To go the other way, type into the L/100 km box, or press the swap button to open the L/100 km to MPG converter with your value carried over.
- Choose how many decimal places you want, or tap a quick value such as 15 mpg, 20 mpg, 25 mpg.
- Press Copy result to paste the conversion into a message, spreadsheet or note.
MPG to L/100 km converter features
Converts both ways
Type in the mpg box to get L/100 km, or in the L/100 km box to get mpg. The other box follows instantly.
Exact factor
Calculations use the full constant 235.2145833… (100 × 3.785411784 ÷ 1.609344), and rounding is applied only to the answer you see — choose Auto or 0–10 decimal places.
Formula with your number
The working is shown under the result, for example 235.215 ÷ 30 = 7.84 L/100 km, so you can check it or copy the method.
Quick values and chart
Tap common values like 15 mpg, 20 mpg, 25 mpg, or read the mpg-to-L/100 km table further down this page.
UK mpg covered
British mpg figures use the imperial gallon; the UK line under the result converts those correctly.
MPG to L/100 km formula
The formula is L/100 km = 235.215 ÷ mpg. It is exact because a US gallon is exactly 3.785411784 L and a mile exactly 1.609344 km, so the constant is 100 × 3.785411784 ÷ 1.609344 = 235.2145833… (the calculator uses the full value).
The reverse formula is mpg = 235.215 ÷ L/100 km — or use the L/100 km to MPG converter. Three worked examples:
- A 30 mpg sedan: 235.215 ÷ 30 = 7.84 L/100 km
- A 50 mpg hybrid: 235.215 ÷ 50 = 4.7 L/100 km
- A 20 mpg SUV: 235.215 ÷ 20 = 11.76 L/100 km
Why mpg and L/100 km move in opposite directions
Miles per gallon is distance per unit of fuel, so bigger is better. Liters per 100 km is fuel per unit of distance, so smaller is better. Because one is the reciprocal of the other, the conversion is a division rather than a multiplication, using the constant 235.214583 = 100 × 3.785411784 ÷ 1.609344 for US gallons.
With UK (imperial) gallons the constant is 282.480936, so UK and US mpg figures are not interchangeable: 30 mpg = 7.84 L/100 km with US gallons, but 30 UK mpg = 9.42 L/100 km with UK gallons.
MPG to L/100 km quick reference
The values people look up most often, worked out with the exact factor:
- 1 mpg = 235.215 L/100 km
- 1 L/100 km = 235.215 mpg
- 15 mpg = 15.68 L/100 km
- 20 mpg = 11.76 L/100 km
- 25 mpg = 9.41 L/100 km
- 30 mpg = 7.84 L/100 km
Quick tip: Divide 235.2 by the mpg figure for US gallons, or 282.5 for UK mpg. 25 mpg (US) is 9.41 L/100 km.
Related conversions: the full fuel economy converter.
MPG to L/100 km conversion table
Values in L/100 km are rounded to 2 decimal places (more for very small numbers). For any value not listed, type it into the converter above.
| mpg | L/100 km | mpg | L/100 km |
|---|---|---|---|
| 10 | 23.52 | 32 | 7.35 |
| 12 | 19.6 | 34 | 6.92 |
| 14 | 16.8 | 35 | 6.72 |
| 15 | 15.68 | 36 | 6.53 |
| 16 | 14.7 | 38 | 6.19 |
| 18 | 13.07 | 40 | 5.88 |
| 20 | 11.76 | 45 | 5.23 |
| 22 | 10.69 | 50 | 4.7 |
| 24 | 9.8 | 55 | 4.28 |
| 25 | 9.41 | 60 | 3.92 |
| 26 | 9.05 | 70 | 3.36 |
| 28 | 8.4 | 80 | 2.94 |
| 30 | 7.84 | 100 | 2.35 |
MPG to L/100 km FAQ
What is 25 mpg in L/100 km?
25 miles per gallon is 9.41 liters per 100 km: 235.215 ÷ 25 = 9.41 L/100 km.
How do I convert mpg to liters per 100km?
Divide 235.215 by the mpg figure. For example, 235.215 ÷ 40 = 5.88 L/100 km. To convert back, divide 235.215 by the L/100 km figure — the same formula, because the conversion is a reciprocal — or use the L/100 km to MPG converter.
What is 5 L/100 km in mpg?
5 liters per 100 km is 47.04 miles per gallon, because 235.215 ÷ 5 = 47.04 mpg.
What does 40 mpg equal in L/100 km?
Why does doubling mpg not halve fuel use evenly?
Because L/100 km is the reciprocal of mpg. Going from 10 to 20 mpg saves 11.76 L per 100 km, but going from 40 to 50 mpg saves only 5.88 − 4.7 ≈ 1.18 L/100 km. That is why L/100 km is better for comparing real fuel savings.