To convert gallons to liters, multiply US gallons by 3.785411784 or UK (imperial) gallons by 4.54609; both are exact definitions. Formula: L = US gal × 3.785411784; L = Imperial gal × 4.54609. For example, 5 US gal ≈ 18.93 L, and 5 UK gal ≈ 22.73 L.
On this page
How to use the gallons to liters converter
- Enter the volume in gallons, for example 12.
- Pick US or UK gallons.
- Read the gallons to liters converter result: 12 US gal ≈ 45.42 L, or 12 UK gal ≈ 54.55 L.
What is the gallons to liters formula?
liters = US gallons × 3.78541
The reverse is US gallons = liters × 0.26417205 (approximately).
The US liquid gallon is exactly 231 cubic inches (3.785411784 L) and the US customary cup is 1/16 of a gallon (236.5882365 mL), so these factors are exact. The multiplier 3.78541 is rounded to six significant digits; the calculator uses the full-precision value.
What are US gallons and liters?
Volume is the amount of three-dimensional space something occupies. The SI unit is the cubic meter; the liter is 1/1,000 of a cubic meter. A US liquid gallon is exactly 231 cubic inches (about 3.785 L), while an imperial gallon is exactly 4.54609 L.
- US gallon (gal US): 1 gal US = 0.003785411784 m³ (US Liquid unit).
- Liter (L): 1 L = 0.001 m³ (Metric unit).
Gallons to liters worked examples
- A gallon of milk: 1 × 3.78541 = 3.78541 L
- A 15-gallon fuel tank: 15 × 3.78541 = 56.7812 L
- A 55-gallon drum: 55 × 3.78541 = 208.198 L
Conversion chart
| gal US | L | gal US | L |
|---|---|---|---|
| 0.25 | 0.9464 | 15 | 56.7812 |
| 0.5 | 1.8927 | 20 | 75.7082 |
| 1 | 3.7854 | 25 | 94.6353 |
| 2 | 7.5708 | 30 | 113.56 |
| 3 | 11.3562 | 50 | 189.27 |
| 5 | 18.9271 | 55 | 208.2 |
| 10 | 37.8541 | 100 | 378.54 |
| 12 | 45.4249 | 500 | 1,892.71 |
Values are rounded to four decimal places, or two for results of 100 or more.
Quick mental conversion
Multiply by 4 and subtract 5%: 10 gal ≈ 40 − 2 = 38 L (exact 37.85 L).
US liquid gallon, US dry gallon and imperial gallon
| Gallon | Liters (exact definition) |
|---|---|
| US liquid gallon | 3.785411784 |
| US dry gallon | 4.40488377086 |
| Imperial (UK) gallon | 4.54609 |
This page converts US liquid gallons. Fuel and milk in the US are sold in US liquid gallons.
US gallons from liters: reverse chart
Going the other way, US gallons = liters × 0.26417205. Common values:
| liters | US gallons |
|---|---|
| 1 | 0.264172 |
| 2 | 0.5283441 |
| 5 | 1.32086 |
| 10 | 2.64172 |
| 20 | 5.283441 |
| 50 | 13.2086 |
| 100 | 26.4172 |
| 500 | 132.086 |
| 1,000 | 264.1721 |
Fuel prices per gallon and per liter
To compare fuel prices, divide the price per US gallon by 3.785411784 for the price per liter, or multiply a price per liter by the same number:
| Price per US gallon | Price per liter | Price per UK gallon |
|---|---|---|
| 3.00 | 0.793 | 3.60 |
| 3.50 | 0.925 | 4.20 |
| 4.00 | 1.057 | 4.80 |
| 4.50 | 1.189 | 5.40 |
| 5.00 | 1.321 | 6.00 |
The currency does not change the arithmetic; convert currency separately at the day’s rate.
Tank and container sizes in liters
A 5 gallon water jug holds 18.93 L, a 15 gallon car tank 56.78 L and a 55 gallon drum 208.2 L. Pool and aquarium volumes in gallons convert the same way: a 20 gallon aquarium holds about 75.7 L. Use the liters to gallons converter for the reverse and the fuel efficiency converter for mpg and km/L.
Showers and pools
US shower heads are rated in gallons per minute. A WaterSense-labeled head uses no more than 2.0 gpm, which is about 7.6 L/min. A 10 minute shower then uses about 76 liters. Comparing that with a European head rated in L/min is a simple gallons to liters step.
Pool chemicals are dosed by volume. A 20,000 gallon pool holds about 75,700 liters. Instructions printed per 10,000 liters can be scaled once you know the liters, which avoids mixing units in the middle of the calculation.
Car fuel economy figures also use this conversion, since US mpg and European L/100 km both depend on the gallon size. Check whether a gallon figure is US or imperial before converting; the imperial gallon is about 20% larger.
Paint and stains come in gallons in the US and liters elsewhere. A one gallon can is 3.79 liters, while a European 4 liter tin is a little more than a gallon. A gallons to liters step helps when coverage rates are quoted per liter.
Related converters and calculators
Related conversions:
- Liters to gallons: L to gal
- Fuel efficiency converter: mpg and km/L
- Cups to mL: kitchen volume
- Volume converter: L, gal, m³
- Flow rate converter: gpm, L/min, m³/h
Sources
NIST Special Publication 811, Appendix B; NIST: SI units – volume.
Questions about this calculator
How many liters are in a US gallon?
3.785411784 L exactly.
How do I convert gallons to liters?
Multiply US gallons by 3.78541. For example, 10 gal ≈ 37.85 L.
How many liters are in a UK gallon?
4.54609 L exactly.
How do I convert gas prices per gallon to per liter?
Divide by 3.78541. A $4.00 per gallon price is about $1.057 per liter.
How many liters is a 55 gallon drum?
About 208.2 L.
Check the assumptions and units before relying on a result. Financial, tax and health estimates do not replace advice for your individual circumstances.
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