Fluid Ounces to Gallons Converter
Enter the volume in fluid ounces below to convert it to gallons.
Convert Fluid Ounces (US) to Gallons (US)
Enter a value in fluid ounces (us) (fl oz) to convert to gallons (us) (gal (US)).
Fluid Ounce to Gallon Conversion Table
Table showing various fluid ounce measurements converted to gallons. Click any preset value or arrow to load it into the converter.
| Fluid Ounces (US) (fl oz) | Gallons (US) (gal (US)) |
|---|---|
| 1 fl oz | 0.0078125 gal (US) |
| 2 fl oz | 0.015625 gal (US) |
| 5 fl oz | 0.0390625 gal (US) |
| 10 fl oz | 0.078125 gal (US) |
| 15 fl oz | 0.1171875 gal (US) |
| 20 fl oz | 0.15625 gal (US) |
| 25 fl oz | 0.1953125 gal (US) |
| 30 fl oz | 0.234375 gal (US) |
| 32 fl oz | 0.25 gal (US) |
| 50 fl oz | 0.390625 gal (US) |
How to Convert Fluid Ounces to Gallons
To convert fluid ounces to gallons, multiply the volume by the following conversion ratio: 0.0078125 gallons/fluid ounce.
Since one fluid ounce is equal to 0.0078125 gallons, you can use this simple formula to convert:
The volume in gallons is equal to the volume in fluid ounces multiplied by 0.0078125.
For example, here's how to convert 64 fluid ounces to gallons using the formula above.
How Many Gallons Are in a Fluid Ounce?
There are 0.0078125 gallons in a fluid ounce, which is why we use this value in the formula above.
Our fluid ounce to gallon calculator automatically converts your volume measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Fluid Ounces and gallons are both units used to measure volume. Keep reading to learn more about each unit.
What Is a Fluid Ounce?
A fluid ounce is a unit of volume equal to 0.0295735 liters (L), the base unit for volume. 1/128 of a US gallon (29.5735 mL). [1]
The fluid ounce is classified as a US customary unit of volume. Fluid Ounces can be abbreviated as fl oz; for example, 1 fluid ounce can be written as 1 fl oz.
When working with fluid ounces (fl oz) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, fluid ounces (fl oz) are widely used across standard volume applications within US customary workflows, engineering documentation, and technical data sheets.
What Is a Gallon?
A gallon is a unit of volume equal to 3.7854118 liters (L), the base unit for volume. US liquid gallon defined as exactly 231 cubic inches (3.78541 L). [2]
The gallon is classified as a US customary unit of volume. Gallons can be abbreviated as gal (US); for example, 1 gallon can be written as 1 gal (US).
When working with gallons (gal (US)) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, gallons (gal (US)) are widely used across standard volume applications within US customary workflows, engineering documentation, and technical data sheets.
When converting volume between fluid ounces (fl oz) and gallons (gal (US)), keep full floating-point precision (1 fl oz = 0.0078125 gal (US); 1 gal (US) = 128 fl oz) during intermediate calculations and round only the final gallon figure to match your instrument tolerance.
More Fluid Ounce & Gallon Conversions
Need to calculate in the opposite direction? Use our gallons (us) to fluid ounces (us) converter (gal (US) to fl oz) to switch your starting unit immediately. You can also explore related tools such as converting liters to gallons (us), converting quarts (us) to gallons (us), or converting fluid ounces (us) to milliliters.
Convert from Fluid Ounces
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Frequently Asked Questions
References
- [1]NIST OWM StandardNIST OWM (SI Units — Volume)·Volume & Liquid Metrology Standard — Fluid Ounces (US) (fl oz) to Gallons (US) (gal (US))
- [2]NIST HB 44 SpecificationNIST HB 44 (Liquid & Dry Capacity Tables)·Unit Specifications: Fluid Ounce (US) (fl oz) & Gallon (US Liquid) (gal (US))
- [3]NIST SP 811 ReferenceNIST SP 811 (NIST SP 811 App. B.9)·Conversion Factors & Mathematical Basis (fl oz to gal (US))