How to Convert Gallons to Liters
Converting gallons to liters is essential when buying fuel abroad, comparing beverage sizes, or working with international volume measurements.
1.00 gal = 3.7854 L
To convert gallons to liters, multiply by 3.78541. One US gallon equals approximately 3.79 liters.
Step-by-Step
- Start with your value: 1.00 gal
- Multiply by 3.78541
- Result: 3.7854 L
Formula: L = gal × 3.78541
💡 Memory Tip: 1 gal = 3.79 L. A US gas tank of 15 gallons = about 57 liters. A barrel of oil = 42 gallons = 159 liters.
Gallons to Liters Quick Reference
| Gallons (US) | Liters | Common Reference |
|---|---|---|
| 1 | 3.79 | Large milk jug |
| 5 | 18.93 | Gas canister |
| 10 | 37.85 | Water heater tank |
| 42 | 158.99 | One oil barrel |
| 55 | 208.20 | Standard gas tank |
What does 1 gallons look like in real life?
Real-world objects and measurements that are approximately 1 gallon (3.79 liters) — useful for visualizing the size of 1 gallon without a ruler:
Real-world reference examples are not available for this value.
Understanding Gallons and Liters
What is a Gallon?
The gallon is a unit of volume. The US liquid gallon equals about 3.785 liters. The UK (imperial) gallon equals about 4.546 liters. The US gallon is used for fuel, milk, and other large liquid quantities.
Learn more about gallons on Wikipedia →
What is a Liter?
The liter is a metric unit of volume equal to one cubic decimeter (1,000 cubic centimeters). Although not an SI unit, it is accepted for use with the SI and is the standard volume unit in most countries worldwide.
Learn more about liters on Wikipedia →
Common Uses of Gallons
Fuel (US, UK), Milk (US), Water heaters, Aquariums.
Key Conversion Facts
- 1 US gallon = 3.78541 L
- 1 UK gallon = 4.54609 L
- 1 US gallon = 128 US fl oz
- 1 US gallon = 4 quarts = 8 pints
- US fuel economy: 1 gal ≈ 30 miles
- Standard for fuel (US, UK)
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Frequently Asked Questions
1 US gallons equals 3.7854 L. Multiply by 3.78541.
L = gal × 3.78541
For 1 gal: 1 × 3.78541 = 3.7854 L
1 gal = 3,785 mL.
This converter uses US gallons (3.785 L). UK gallons are larger (4.546 L). UK gallons would give 4.55 L.
1 L = 0.26 gal (reverse calculation).
