How to convert us gallons to liters
L = x × 3.785411784
This page starts with US liquid gallons. Do not apply this factor to imperial gallons or historical US dry gallons.
Worked example
L = 5 × 3.785411784
5 gal = 18.927059 L.
Conversion table in both directions
Values are generated by the same engine as the interactive converter.
| Input | gal → L | L → gal |
|---|---|---|
| 1 | 3.785412 | 0.264172 |
| 5 | 18.927059 | 1.32086 |
| 10 | 37.854118 | 2.641721 |
| 25 | 94.635295 | 6.604301 |
| 50 | 189.270589 | 13.208603 |
| 100 | 378.541178 | 26.417205 |
Unit definitions and sources
US liquid and Imperial measures differ. US cups here are customary cups, not 240 mL nutrition-label or 250 mL metric cups. Dry measures are not interchangeable with liquid measures.
| Unit and system | Use | Definition | Relationship |
|---|---|---|---|
| Liter (L); si | Common units | Liter measures volume. l = (value in L) × 1. Common use: Liquid quantities and container capacity. | Exact definition; numerical display may be rounded |
| Gallon (US) (gal); us | Common units | Gallon (US) measures volume. l = (value in gal) × 3.785411784. Common use: Liquid quantities and container capacity. | Exact definition; numerical display may be rounded |
Sources: BIPM: International System of Units; NIST: SP 811 Appendix B.8: conversion factors; BIPM: SI prefixes; NIST: Metric cup and spoon conventions
Precision of volume conversions
These 2 volume units convert through Liter (L). 2 have an exact defined relationship to the base unit and 0 are conventional or measured values. Results and the tables on this page come from the same engine, so a table value can be checked against the converter directly.
Standard display shows up to six decimal places, switching to scientific notation for very large or small values. Calculation uses JavaScript binary floating point independently of display rounding, so extra digits are not a claim about measurement accuracy. Each unit lists its own source; a citation records where the definition comes from, not an independent review. See Conversion methodology for the review and correction process.