Equivalent in Gallons:
Table of Contents
The formula
Multiply liters by the reciprocal of the US gallon:
gal = L × 0.264172
- gal — US gallons (liquid, not dry; not imperial).
- L — liters (1 L = 1 dm³ = 1000 mL).
- 0.264172 — exact reciprocal of 3.78541 (1 ÷ 3.785411784).
For imperial gallons: multiply by 0.219969. To reverse (gallons to liters): L = gal × 3.78541. Or use the gallons to liters converter.
Worked example
Default input: 1 liter.
- Apply the formula: 1 × 0.264172 = 0.2642 US gallons.
- Mental shortcut: divide liters by 3.8 for a quick estimate.
So a 2-liter bottle of soda is about 0.528 US gallons — just over half a gallon.
Liters to gallons conversion table
| Liters | US Gallons |
|---|---|
| 1 L | 0.264 gal |
| 2 L | 0.528 gal |
| 3.785 L | 1.000 gal |
| 5 L | 1.321 gal |
| 10 L | 2.642 gal |
| 15 L | 3.963 gal |
| 20 L | 5.283 gal |
| 25 L | 6.604 gal |
| 40 L | 10.567 gal |
| 50 L | 13.209 gal |
| 75 L | 19.813 gal |
| 100 L | 26.417 gal |
History & standards — the US vs UK gallon gotcha
The litre was defined by France in 1795 as the volume of exactly 1 dm³ of water at 4°C. The BIPM today defines it as exactly 0.001 m³, so 1 mL = 1 cm³. It is the preferred unit for liquids in all metric countries.
The gallon has two living definitions that differ by about 20%:
- US liquid gallon: 3.78541 L = 231 in³ = 128 US fl oz = 4 US quarts. Standard in the United States.
- UK / Imperial gallon: 4.54609 L = 277.4 in³ = 160 imperial fl oz = 4 imperial quarts. Used in UK, some Commonwealth nations, and Canadian fuel until metrication.
Always check which gallon a document refers to, especially for fuel economy, beer recipes, and older UK appliance specs.
Common applications
- Fuel & driving abroad. European gas stations sell fuel in liters. A US driver buying 50 liters gets 13.2 US gallons. Knowing the rate is essential for budgeting fuel costs.
- Aquariums. US tank sizes are in gallons; European filtration equipment is rated in liters per hour. A 20-gallon tank needs a filter rated for ≥75 L/h for adequate turnover.
- Cooking & homebrewing. Beer recipes from metric countries list volumes in liters. A 19-liter batch is a standard 5-gallon homebrew.
- Water heaters & storage. International specs quote tank capacity in liters; US specs use gallons. A 40-gallon water heater holds 151 liters.
Limitations & gotchas
- 20% US vs UK error. Confusing US and imperial gallons produces a 20% error — significant for fuel, brewing, or chemical mixing.
- Dry vs liquid gallon. The US dry gallon (4.405 L) is used for grain and fruit; it is not this converter’s scope. This calculator uses the US liquid gallon (3.785 L) only.
- Rounding. 0.264172 rounds to 0.264. Using 0.26 instead introduces a 1.6% error — acceptable for rough estimates but not for chemical or pharmaceutical volumes.
Sources & references
- NIST, “SI Units — Volume.” nist.gov.
- BIPM, “SI Units.” bipm.org.
FAQs
One liter equals 0.264172 US gallons. Equivalently, 1 US gallon = 3.78541 liters. To convert liters to US gallons, multiply by 0.264172.
A US gallon = 3.78541 L; a UK (imperial) gallon = 4.54609 L — about 20% larger. To convert liters to imperial gallons, multiply by 0.219969 instead of 0.264172. Always check which gallon a source is using, especially for fuel economy figures.
10 L × 0.264172 = 2.642 US gallons. Or as a quick mental estimate: divide liters by 3.8.
No. A liter is smaller than a US gallon. One US gallon = 3.785 liters, so a gallon is about 3.8 times larger. A UK (imperial) gallon is even larger at 4.546 liters.
The United States uses liquid gallons for fuel and many household goods. Liberia and Myanmar also still use US customary measures. The UK officially uses liters for fuel (since 1995) but the imperial gallon persists informally. Most other nations use liters exclusively.
Because US mpg uses the smaller US gallon (3.785 L) while UK mpg uses the larger imperial gallon (4.546 L). The same car will show about 20% higher mpg in UK figures than in US figures. A car achieving 50 UK mpg achieves roughly 42 US mpg.