Price Per Liter to Price Per Gallon Calculator
Convert a fuel price per liter to price per US gallon and per imperial gallon (and back), compare two fuel prices quoted in different units to find the cheaper one, and estimate fuel cost per 100 km or per 100 miles from your vehicle's consumption. Type any currency symbol; the math is identical for dollars, euros, pounds, rupiah and more.
Convert price per liter to price per gallon
Type a price in any one field; the other two update instantly. 1 US gallon = 3.785411784 liters exactly, 1 imperial gallon = 4.54609 liters exactly.
Compare two fuel prices
Enter two prices in any units. Both are normalized to per-liter so the comparison is apples to apples.
Fuel cost per distance
From your fuel price and consumption, get cost per 100 km, per 100 miles, and for any trip distance.
Quick reference table
Price per liter converted to per US gallon and per imperial gallon (4 decimals).
| Per liter | Per US gallon | Per imperial gallon |
|---|---|---|
| 0.50 | 1.8927 | 2.2730 |
| 0.75 | 2.8391 | 3.4096 |
| 1.00 | 3.7854 | 4.5461 |
| 1.25 | 4.7318 | 5.6826 |
| 1.50 | 5.6781 | 6.8191 |
| 1.75 | 6.6245 | 7.9557 |
| 2.00 | 7.5708 | 9.0922 |
| 2.50 | 9.4635 | 11.3652 |
| 3.00 | 11.3562 | 13.6383 |
Worked examples
$1.50 x 4.54609 = $6.8191 per imperial gallon.
Methodology
- Exact constants. The US gallon is legally defined as exactly 231 cubic inches; with 1 inch = 2.54 cm exactly, that is 231 x 2.543 / 1000 = 3.785411784 liters. The imperial gallon is defined as exactly 4.54609 liters. No approximation is involved; displayed values are rounded to 4 decimals.
- Comparison. Both prices are converted to per-liter, then cheaper-by % = (higher - lower) / higher x 100.
- Fuel cost. Cost per 100 km = consumption (L/100 km) x price per liter. Cost per 100 mi multiplies by 1.609344 km per mile. MPG inputs convert via 100 x liters-per-gallon / (mpg x 1.609344).
- Scope. Any currency symbol may be typed; never mix two currencies in one comparison because this tool has no exchange rates. Price conversion is unit arithmetic and is identical for petrol, diesel, kerosene and LPG.
- Boundary. This tool converts fuel price per unit. Converting fuel economy (MPG to L/100 km, car-vs-car thirst comparison) is the job of our fuel economy converter; pure volume conversion (gallons to liters, quarts, pints) lives in the gallon converter.
Frequently asked questions
How do I convert price per liter to price per gallon?
Multiply the per-liter price by the number of liters in a gallon. For a US gallon multiply by 3.785411784; for an imperial gallon multiply by 4.54609. Example: $1.50 per liter is 1.50 x 3.785411784 = $5.6781 per US gallon, and 1.50 x 4.54609 = $6.8191 per imperial gallon.
What is the difference between a US gallon and an imperial gallon?
A US gallon is exactly 3.785411784 liters (defined as 231 cubic inches), while an imperial gallon is exactly 4.54609 liters. The imperial gallon is about 20.1% larger, so the same fuel always costs more per imperial gallon than per US gallon. US gallons are used in the United States; imperial gallons are the historical UK unit, though UK fuel is now sold per liter.
How do I convert price per gallon back to price per liter?
Divide instead of multiply. Price per liter = price per gallon / liters per gallon. Example: $3.899 per US gallon is 3.899 / 3.785411784 = $1.0300 per liter. Use 4.54609 as the divisor for imperial gallons.
Why does fuel look cheaper per liter than per gallon?
It is the same fuel in a smaller unit. One US gallon holds 3.785411784 liters, so the per-gallon number is always about 3.79x the per-liter number (about 4.55x for imperial gallons). Neither is a better deal by itself; convert both prices to the same unit before comparing, which the comparator above does automatically.
What is the exact formula?
Price per US gallon = price per liter x 3.785411784. Price per imperial gallon = price per liter x 4.54609. Reverse: price per liter = price per US gallon / 3.785411784 = price per imperial gallon / 4.54609. Both constants are exact by definition, so the conversion itself introduces no rounding error; only the displayed decimals are rounded.
How do I compare two fuel prices quoted in different units?
Convert both to the same unit, then compare. Example: station A charges $1.52 per liter and station B charges $5.60 per US gallon. B in per-liter terms is 5.60 / 3.785411784 = $1.4794 per liter, so station B is cheaper by 2.67%. The comparator tool above normalizes mixed units to per-liter automatically.
How is the "cheaper by" percentage calculated?
Percentage cheaper = (expensive price - cheap price) / expensive price x 100, after converting both to the same unit. In the example above: (1.52 - 1.4794) / 1.52 x 100 = 2.67%. It answers "how much less than the expensive option," which matches how drivers read a saving.
How do I calculate fuel cost per 100 km?
Multiply consumption by price: cost per 100 km = (liters per 100 km) x (price per liter). Example: a car using 7.5 L/100 km at $1.50 per liter costs 7.5 x 1.50 = $11.25 per 100 km. If your price is quoted per gallon, convert it to per-liter first with the converter above.
How do I get cost per 100 miles instead of per 100 km?
100 miles is 1.609344 km, so multiply the per-100-km cost by 1.609344. Example: $11.25 per 100 km x 1.609344 = $18.11 per 100 miles at 7.5 L/100 km and $1.50 per liter. The fuel-cost calculator above shows both figures side by side.
Can I enter consumption in MPG instead of L/100 km?
Yes. The fuel-cost calculator accepts L/100 km, km/L, US MPG and UK MPG. For reference, 30 US MPG equals about 7.84 L/100 km. If you need to convert fuel-economy units themselves (MPG to L/100 km tables and car-vs-car economy comparison), see our dedicated fuel economy converter.
How many decimals should fuel prices use?
US pump prices are typically shown to 3 decimals (for example $3.199 per gallon). This calculator shows converted prices to 4 decimals so the conversion step does not lose precision, then you can round to your local convention. The underlying constants (3.785411784 and 4.54609) are exact, so any rounding you see comes only from display.
Does the currency matter for the conversion?
No. The conversion is a pure unit ratio, so dollars, euros, pounds, rupiah or any currency convert identically; only the symbol you type changes. Just never mix two different currencies in one comparison. This tool does not convert between currencies because exchange rates change constantly.
Are the conversion factors exact or approximate?
Exact. The US gallon is legally defined as exactly 231 cubic inches, and 1 inch is exactly 2.54 cm, giving 231 x 2.54^3 / 1000 = 3.785411784 liters with no approximation. The imperial gallon is defined as exactly 4.54609 liters. Using fewer decimals (like 3.785) is what introduces error, not the units themselves.
Does the same math work for diesel, petrol, kerosene or LPG?
Yes. Converting a price per liter to a price per gallon is unit arithmetic; it is identical for every liquid fuel. Only the price you type in changes between fuels. Density and energy content matter when converting between volume and weight or energy, which is a different calculation.
Can I compare a price in dollars per gallon with a price in euros per liter?
Not directly in one step: first convert the currencies with a current exchange rate, then convert the units here. This tool deliberately has no built-in exchange rates because they move every minute and any stored rate would silently go stale. Convert currency first, then compare units.
What is the difference between this tool and a fuel economy converter?
This tool converts fuel PRICE per unit ($/L to $/gallon) and compares prices and trip costs. A fuel economy converter converts CONSUMPTION per distance (MPG to L/100 km) and compares how thirsty two cars are. They answer different questions; for economy-unit conversion see our fuel economy converter.
Free tool by NRTechStudio