Instantly convert US gallons to fluid ounces. Free, accurate, and works on any device.
Quick Answer: One US gallon equals 128 fluid ounces. To convert gallons to oz, multiply your gallon value by 128. For example, 2 gallons = 256 fl oz, and 0.5 gallons = 64 fl oz.
Formula: fl oz = gallons × 128
Fluid Ounces = Gallons × 128
One US liquid gallon contains exactly 128 US fluid ounces. Multiply any gallon value by 128 to get the equivalent in fluid ounces.
| Gallons (gal) | Fluid Ounces (fl oz) | Equivalent |
|---|---|---|
| 0.125 gal | 16 fl oz | 1 pint |
| 0.25 gal | 32 fl oz | 1 quart |
| 0.5 gal | 64 fl oz | half gallon |
| 0.75 gal | 96 fl oz | 3/4 gallon |
| 1 gal | 128 fl oz | 1 gallon |
| 2 gal | 256 fl oz | 2 gallons |
| 3 gal | 384 fl oz | 3 gallons |
| 4 gal | 512 fl oz | 4 gallons |
| 5 gal | 640 fl oz | 5-gal jug |
| 10 gal | 1,280 fl oz | 10 gallons |
Need the reverse? Convert fluid ounces back to gallons:
Oz to Gallon Converter →We offer free, accurate tools for all common liquid volume conversions.
All the liquid volume converters you need, in one place.
Convert fluid ounces to US gallons instantly. The most common liquid volume conversion.
Switch between US fluid ounces and metric liters for international recipes and labels.
Convert fluid ounces to quarts — ideal for cooking, canning, and storage containers.