Gallon to Fluid Ounce Converter
Convert gallon to fluid ounce instantly.
Standard volume units
liter 378.541
milliliter 378541.178
cup 1600
fluid ounce 12800
pint 800
Fun comparisons
espresso shots ☕~ 12618.04
standard water bottles 🍶~ 757.08
bathtubs 🛁~ 2
Olympic swimming pools 🏊~ Less than 0.01
How to convert gallon to fluid ounce
Enter your value in gallon and see the equivalent in fluid ounce instantly. The converter includes real-world comparisons - like water bottles and bathtubs - to help you picture the volume.
The US gallon is used for large liquid volumes; fluid ounces are used for smaller beverage and cooking measurements. There are exactly 128 fluid ounces in one US gallon.
Need the opposite direction? Convert fluid ounce to gallon just as easily, or explore all our volume conversions.
Common gallon to fluid ounce conversions
| Gallon (gal) | Fluid Ounce (fl oz) |
|---|---|
| 1 | 128 |
| 5 | 640 |
| 10 | 1280 |
| 25 | 3200 |
| 50 | 6400 |
| 100 | 12800 |
| 500 | 64000 |
| 1000 | 128 |
Frequently asked questions
1 gallon equals 128 fluid ounce.
Multiply by 128. For example, 5 gal = 640 fl oz.
A half gallon equals exactly 64 fluid ounces.
1 fluid ounce equals 0.0078125 gallon.
100 gallon equals 12800 fluid ounce.