How Many Fluid Ounces Are in a US Gallon?
The short answer, a converter for any number, and a chart of common amounts.
Quick answer: There are 128 US fluid ounces in 1 US gallon. So 1 US fluid ounce is 0.00781 US gallons.
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The answer
There are 128 US fluid ounces in 1 US gallon. So 1 US fluid ounce is 0.00781 US gallons.
To convert US gallons to US fluid ounces, multiply by 128. To go from US fluid ounces to US gallons, multiply by 0.00781.
A fluid ounce measures volume, not weight. An ounce on a kitchen scale (weight) is a different unit: 16 ounces make a pound.
Us gallons to US fluid ounces chart
| Us gallons | Us fluid ounces |
|---|---|
| 1 US gallon | 128 US fluid ounces |
| 2 US gallons | 256 US fluid ounces |
| 3 US gallons | 384 US fluid ounces |
| 4 US gallons | 512 US fluid ounces |
| 5 US gallons | 640 US fluid ounces |
| 10 US gallons | 1,280 US fluid ounces |
| 20 US gallons | 2,560 US fluid ounces |
| 50 US gallons | 6,400 US fluid ounces |
| 100 US gallons | 12,800 US fluid ounces |
Us fluid ounces to US gallons chart
| Us fluid ounces | Us gallons |
|---|---|
| 10 US fluid ounces | 0.07812 US gallons |
| 50 US fluid ounces | 0.39062 US gallons |
| 100 US fluid ounces | 0.78125 US gallons |
| 500 US fluid ounces | 3.9062 US gallons |
| 1,000 US fluid ounces | 7.8125 US gallons |
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Questions
How many US fluid ounces are in a US gallon?
There are 128 US fluid ounces in 1 US gallon. So 1 US fluid ounce is 0.00781 US gallons.
How many US gallons are in a US fluid ounce?
There are 0.00781 US gallons in 1 US fluid ounce.
Is the number exact?
Yes, it uses the exact definitions of the units and is rounded only for display.
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Is anything saved or sent?
No. Everything runs in your browser. Only your own best score, where a page shows one, is kept on your device.
Last updated 2026-10-24. Free to use, no sign-up. Made by ficklestudio26.