Gallons to Liters (gal to L): US & Imperial Conversion
Official NIST legal conversion rate, common reference values table, and practical application guide.
Exact Conversion Factor (NIST SP 811)
1 US Liquid Gallon = 3.785411784 Liters (exact legal NIST standard)
Practical Context & Real-World Use
The international liquid trading standard. Standard 55-gallon industrial steel oil and chemical drums equal exactly 208.2 liters.
Quick Reference Table (gal to L)
| gal | L | Conversion Math |
|---|---|---|
| 1 gal | 3.79 L | 1 × 3.7854 = 3.79 |
| 2 gal | 7.57 L | 2 × 3.7854 = 7.57 |
| 5 gal | 18.93 L | 5 × 3.7854 = 18.93 |
| 10 gal | 37.85 L | 10 × 3.7854 = 37.85 |
| 20 gal | 75.71 L | 20 × 3.7854 = 75.71 |
| 55 gal | 208.2 L | 55 × 3.7854 = 208.2 |
| 100 gal | 378.54 L | 100 × 3.7854 = 378.54 |
| 250 gal | 946.35 L | 250 × 3.7854 = 946.35 |
Frequently Asked Questions
How many liters are in a US gallon?▼
There are exactly 3.785411784 liters in one US liquid gallon.
How many liters are in a UK Imperial gallon?▼
One UK Imperial gallon equals 4.54609 liters (approximately 20% larger than a US gallon).
Authoritative Sources & Reference Standards
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811 — National Institute of Standards and Technology (NIST). Verified 2026-10-01.
Official SI unit definitions, conversion factors (Appendix B), and precision standards for cubic meters, liters, and US customary units.
- The International System of Units (SI Brochure, 9th edition) — Bureau International des Poids et Mesures (BIPM). Verified 2026-10-01.
International metric definitions for derived units of volume (cubic meter and non-SI unit accepted for use: liter).