Gallons to Liters Converter
Convert gallons to liters using the formula gal × 3.785412 = L. The calculator below shows higher precision results. The reference table is rounded for readability.
This converter uses US customary gallons. UK (imperial) gallons are a different size.
Formula and Step-by-Step
Step-by-step: 1 gal to L
- Start with 1 gal
- Multiply by 3.785412: 1 × 3.785412 = 3.79
- Result: 1 gal = 3.79 L
Conversion Table
Common gallons to liters values. The table and calculator both use the same conversion formula shown above.
Common Volumes in Liters
- 1 gal = 3.79 L, a large jug of milk
- 5 gal = 18.9 L, a water cooler bottle
- 10 gal = 37.9 L, a small aquarium
- 20 gal = 75.7 L, a large aquarium
Quick Mental Conversion
For a rough estimate, multiply gallons by 4. For example, 5 gal × 4 = 20 L. The exact answer is 18.93 L.
What Are Gallons and Liters?
What is a Gallon?
A US gallon is a unit of volume equal to approximately 3.785 liters. Note: a UK (imperial) gallon is larger at 4.546 liters. This converter uses US gallons.
What is a Liter?
A liter is a metric unit of volume equal to 1,000 milliliters. It is the standard volume unit used worldwide for liquids, fuel, and beverages.
Why convert gallons to liters?
People typically convert gallons to liters when understanding US fuel and liquid measurements in metric.