MPG to L/100km Converter
Convert miles per gallon into litres per 100 km.
Results update as you type.
How it works
Comparing a car rated in American miles per gallon with one rated in European litres per 100 kilometres is confusing because the two measures run in opposite directions, and this MPG to L/100km converter removes the guesswork. Enter a fuel economy figure in miles per gallon and it returns the exact metric equivalent, letting you line up specifications from different markets on a single scale. The conversion matters whenever you shop across borders, read an imported review, or try to understand a manufacturer's global brochure. A car advertised at 6 L/100km and one advertised at 39 MPG sound unrelated, yet they describe almost identical efficiency. Without a reliable conversion it is easy to misjudge which vehicle actually sips less fuel, and small differences in economy add up to real money over years of driving. The key idea is that MPG and L/100km are reciprocal quantities linked by a fixed constant. Miles per gallon rewards higher numbers, since more distance per gallon is better, while litres per 100 kilometres rewards lower numbers, since less fuel for the same distance is better. Because the relationship is not linear, a jump from 20 to 25 MPG saves far more fuel than a jump from 45 to 50 MPG, and viewing the same efficiency in metric terms makes that non-linearity visible and easier to reason about when weighing your options.
L/100km = 235.214583 ÷ MPG
Miles per gallon and litres per 100 kilometres describe the same thing from opposite ends: one counts distance per unit of fuel, the other counts fuel per fixed distance. Because they are reciprocals rather than a straight scaling, converting requires the fixed factor 235.214583, which bundles the gallon-to-litre and mile-to-kilometre conversions into a single constant. Dividing that constant by your MPG returns the metric figure, and a higher MPG always produces a lower L/100km.
Source:Standard fuel economy unit conversion
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter fuel economy.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
In L/100km updates instantly as you type — no button to press.
Frequently asked questions
Why is the conversion factor 235.214583?
The constant folds two unit conversions into one number. It accounts for the 3.785 litres in a US gallon and the 1.609 kilometres in a mile, arranged so that dividing it by miles per gallon yields litres per 100 kilometres directly. Because MPG and L/100km are reciprocal measures rather than proportional ones, a single multiply will not work, but this fixed divisor handles both steps at once accurately.
Does this use US or Imperial gallons?
This converter uses the US gallon, which is the standard for fuel economy ratings in the United States. The Imperial gallon used in the United Kingdom is about 20 percent larger, so an Imperial MPG figure would convert with a different constant near 282.5. If your MPG figure comes from a UK source, be aware it may be Imperial, which would overstate efficiency compared with the US measure.
Why is a small MPG gain worth more at low MPG?
Because fuel use is the reciprocal of MPG, the relationship is non-linear. Going from 15 to 20 MPG cuts fuel consumption far more than going from 40 to 45 MPG, even though both are five-MPG gains. Viewing the numbers in L/100km makes this obvious, since the litres-per-distance figure falls steeply at low MPG and only gently at high MPG, which is why efficient cars show diminishing returns.
What is a typical L/100km value for an efficient car?
A frugal modern hybrid often sits around 4 to 5 L/100km, a typical petrol sedan around 7 to 9 L/100km, and a large SUV or truck can exceed 12 L/100km. Lower numbers are better in this metric. Because conditions like city traffic, cold weather, and aggressive driving raise consumption, real-world figures usually run somewhat higher than the official rating you convert here.
Can I convert L/100km back to MPG?
Yes, the relationship is symmetric because both measures are reciprocals joined by the same constant. To go the other way, divide 235.214583 by the L/100km value and you recover the miles-per-gallon figure. This means the conversion never loses information: any economy expressed in one unit maps to exactly one value in the other, so you can move between American and metric ratings freely and consistently.