A US liquid gallon equals 4 US quarts, or exactly 3.785411784 liters.
Gallon to Fluid ounce
Convert Gallon to Fluid ounce instantly. Free online cooking unit converter with exact formula, conversion table and FAQ.
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A US fluid ounce is 1/128 of a US gallon, equal to about 29.57 milliliters.
fl oz = gal × 128
Results update instantly for Gallon to Fluid ounce conversions.
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Formula
fl oz = gal × 128
gal = fl oz × 0.0078125
Conversion table
| 1 gal | 128 fl oz |
| 5 gal | 640 fl oz |
| 10 gal | 1280 fl oz |
| 20 gal | 2560 fl oz |
| 50 gal | 6400 fl oz |
| 100 gal | 12800 fl oz |
| 500 gal | 64000 fl oz |
| 1000 gal | 128000 fl oz |
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Frequently asked questions
What is the source unit in this conversion?
The source unit is the gallon (gal). A US liquid gallon equals 4 US quarts, or exactly 3.785411784 liters.
What is the destination unit in this conversion?
The destination unit is the fluid ounce (fl oz). A US fluid ounce is 1/128 of a US gallon, equal to about 29.57 milliliters.
How do I convert gallon to fluid ounce?
Multiply the gallon value by 128. For example, 10 gal × 128 = 1280 fl oz.
Is the gallon to fluid ounce conversion exact?
Yes. This conversion uses a fixed factor defined for cooking measurement standards, so results are consistent every time.
Where is this conversion commonly used?
It's used when following recipes, adjusting ingredient quantities, or converting between US customary and metric cooking measurements.
Can I convert fluid ounce back to gallon?
Yes. Multiply the fluid ounce value by 0.0078125 to get gallon.
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About this conversion
This page converts gallon (gal) to fluid ounce (fl oz) within the cooking converter.
A US liquid gallon equals 4 US quarts, or exactly 3.785411784 liters. A US fluid ounce is 1/128 of a US gallon, equal to about 29.57 milliliters.
The formula is fl oz = gal × 128, based on each unit's fixed relationship to the cooking converter's reference units.
Results are consistent because the conversion relies on a fixed numerical ratio rather than an estimate.
Use the calculator above for instant results, or the table below for common gallon values already converted to fluid ounce.