1 gallon (us) = 3.785 liters
Convert gallons to liters with an exact, internationally defined factor — 1 gal = 3.785411784 l (exact).
gallons to liters
Computed with the exact factor · NIST SP 811
| Gallon (US) | Liter |
|---|---|
| 0.5 gal | 1.893 l |
| 1 gal | 3.785 l |
| 2 gal | 7.571 l |
| 3 gal | 11.36 l |
| 5 gal | 18.93 l |
| 10 gal | 37.85 l |
| 25 gal | 94.64 l |
| 50 gal | 189.27 l |
| 100 gal | 378.54 l |
Exact factor details
- Exact factor
- 1 gal = 3.785 l (exact definition)
- Significant digits
- up to 4 significant digits shown
- Data source
- NIST SP 811 — verified against official tables
Why gal to l trips people up
Volume conversions for cooking and everyday measuring — milliliters, liters, US cups, tablespoons, teaspoons, fluid ounces, and gallons. The US liquid gallon is defined as exactly 3.785411784 liters. The US liquid gallon is exactly 3.785411784 liters; the imperial gallon is 4.546 liters. The liter is the metric workhorse for volume; 1,000 liters make a cubic meter.
US customary volumes descend from English wine measures: 1 gallon is 4 quarts, 1 quart is 2 pints, 1 pint is 2 cups, and 1 cup is 16 tablespoons (or 48 teaspoons). The US cup of 236.5882365 ml differs from the metric cup (250 ml) used in Australia and much of Europe — check which one a recipe means before scaling. For water-like liquids, milliliters and grams are nearly interchangeable.
Use the quick-reference table for the amounts people actually look up, and the converter above for everything in between. Both are computed from the same factor at full precision, so the table and the converter can never disagree — there is no second, rounded copy of the data anywhere on this page.
Frequently asked questions
Is the gal to l conversion exact?
Yes. 1 gal = 3.785411784 l (exact) and SI derived unit are exact definitions, so the conversion is exact — results are rounded only for readability.
How do I convert gal to l in my head?
For rough work, treat 1 cup as 240 ml, 1 tablespoon as 15 ml, and 1 gallon as 3.8 liters.
Why do other sites show slightly different gal to l results?
They round at different steps. This page computes with the full-precision factor and rounds only the final displayed number, so small trailing digits can differ from sites that round earlier.