Gallons to Liters Conversion
Quick formula: liters = gallons × 3.785 — with common conversions
⚡Quick Answer
1 US gallon = 3.785 liters (roughly 3.8 L). Quick trick: multiply gallons by 4 and subtract 5-10% for accuracy.
Step-by-Step Guide
The Formula
liters = US gallons × 3.785 — For quick estimates, multiply by 4 (slightly high).
Common Conversions
1 gal = 3.79 L | 2 gal = 7.57 L | 5 gal = 18.93 L | 10 gal = 37.85 L | 20 gal = 75.7 L
US vs UK Gallons
US gallon = 3.785 L | UK (Imperial) gallon = 4.546 L. The UK gallon is about 20% larger!
Quick Mental Math
Multiply by 4, then subtract about 5-10%. Example: 5 gal × 4 = 20, then 20 - 1 = 19 L (actual: 18.93 L).
Frequently Asked Questions
How many liters in a gallon?
1 US gallon = 3.785 liters. 1 UK (Imperial) gallon = 4.546 liters. Most online references use US gallons.
How do I convert liters to gallons?
Divide liters by 3.785. For quick math: liters ÷ 4 gives a rough estimate (slightly low).
Why are US and UK gallons different?
The US gallon was based on the English wine gallon (231 cubic inches), while the UK Imperial gallon was standardized in 1824 based on the weight of water (10 lbs).