Fluid Ounce (US) to Gallon (US) (US fl oz to US gal)
Result
0.0078125 Gallon (US)
Formula
US gal = US fl oz × 0.0078125
1 US fl oz = 0.0078125 US gal, and 1 US gal = 128 US fl oz.
The litre is exactly 1 dm³ (0.001 m³). The US gallon is defined as 231 cubic inches, which makes it exactly 3.785411784 L; quarts, pints, cups and fluid ounces are fixed fractions of it.
Worked examples
- 1 US fl oz × 0.0078125 = 0.0078125 US gal
- 10 US fl oz × 0.0078125 = 0.078125 US gal
- 100 US fl oz × 0.0078125 = 0.78125 US gal
Common mistakes
- US and UK (imperial) measures share names but not sizes: the imperial gallon is 4.54609 L (20% larger), the imperial pint 568 mL and the imperial fluid ounce 28.41 mL.
- This converter uses US customary volumes. A US cup is 236.59 mL, a metric cup 250 mL, and US nutrition labels round a cup to 240 mL.
- US dry measures (dry pint, bushel) are a separate system and are not the same as liquid pints.
Fluid Ounce (US) to Gallon (US) table
| Fluid Ounce (US) (US fl oz) | Gallon (US) (US gal) |
|---|---|
| 1 | 0.0078125 |
| 2 | 0.015625 |
| 5 | 0.0390625 |
| 10 | 0.078125 |
| 20 | 0.15625 |
| 50 | 0.390625 |
| 100 | 0.78125 |
| 1,000 | 7.8125 |
The units
- Fluid Ounce (US) (US fl oz)
- One 128th of a US gallon: 29.5735295625 mL.
- Gallon (US) (US gal)
- The US liquid gallon: 231 cubic inches, exactly 3.785411784 L.
Sources for these factors
- Handbook 44 (2024), Appendix C: General Tables of Units of Measurement — NIST
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
- 21 CFR 101.9 (nutrition labeling: household measure equivalents) — U.S. FDA / eCFR
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy