Convert US gallons to Fluid Ounce (US)
Americas · Cooking Measures · active · modern
Conventional value The unit is customary but its modern value is settled and widely cited; the arithmetic itself is exact.
1 US gallon = 128 Fluid Ounce (US)
Fluid Ounce (US) = US gallons × 128.00013
Convert any amount
US gallons to Fluid Ounce (US) table
| US gallons | Fluid Ounce (US) |
|---|---|
| 0.25 US gallons | 32 Fluid Ounce (US) |
| 0.5 US gallons | 64.0001 Fluid Ounce (US) |
| 1 US gallon | 128 Fluid Ounce (US) |
| 2 US gallons | 256 Fluid Ounce (US) |
| 3 US gallons | 384 Fluid Ounce (US) |
| 4 US gallons | 512.001 Fluid Ounce (US) |
| 5 US gallons | 640.001 Fluid Ounce (US) |
| 10 US gallons | 1,280 Fluid Ounce (US) |
| 20 US gallons | 2,560 Fluid Ounce (US) |
| 25 US gallons | 3,200 Fluid Ounce (US) |
| 50 US gallons | 6,400.01 Fluid Ounce (US) |
| 100 US gallons | 12,800 Fluid Ounce (US) |
About the Fluid Ounce (US)
US fl oz = 29.57ml.
- Symbol
- fl oz
- Value in SI
- 1 Fluid Ounce (US) = 0.0295735 litre
- Typical use
- cooking
- Source
- UnitConvertLab measurement atlas
Every atlas conversion routes through the SI litre. See our methodology and data provenance pages for how these values are sourced and verified.
Related units and variant risk
Other cooking measures units in the Americas family, least settled first. If your figure came from a land record, invoice or historical document rather than a calculator, check these before assuming a single standard.
Related conversions
Frequently asked
How many Fluid Ounce (US) are in a US gallon?
1 US gallon = 128 Fluid Ounce (US). Multiply the number of US gallons by 128.00013 to get Fluid Ounce (US).
What is Fluid Ounce (US) used for?
US fl oz = 29.57ml. It is classified as active and dates from the modern period.
Is the Fluid Ounce (US) value exact?
Yes for practical purposes. UnitConvertLab converts every atlas unit through the SI litre, so the arithmetic itself introduces no rounding beyond the digits shown.
How reliable is this Fluid Ounce (US) conversion?
Conventional value — The unit is customary but its modern value is settled and widely cited; the arithmetic itself is exact. Source: UnitConvertLab measurement atlas.
Cite this page
UnitConvertLab. (2026). Convert US gallons to Fluid Ounce (US). UnitConvertLab. Retrieved from https://unitconvertlab.com/regional/us-gallon-to-fl-oz-us
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