Convert volume units — liters, gallons, cups, milliliters, cubic meters, barrels and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 fl oz | 7.8125e-06 gal | |
| 0.01 fl oz | 7.8125e-05 gal | |
| 0.1 fl oz | 0.00078125 gal | |
| 1 fl oz | 0.0078125 gal | |
| 5 fl oz | 0.0390625 gal | |
| 10 fl oz | 0.078125 gal | |
| 50 fl oz | 0.390625 gal | |
| 100 fl oz | 0.78125 gal | |
| 1000 fl oz | 7.8125 gal |
Common fluid ounce values converted to us gallon — factor: 1 fl oz = 0.007812 gal
| Fluid Ounce (fl oz) | US Gallon (gal) | Context |
|---|---|---|
| 0.5 fl oz | 0.003906 gal | Half ounce |
| 1 fl oz | 0.007812 gal | Shot |
| 2 fl oz | 0.01562 gal | Double shot |
| 4 fl oz | 0.03125 gal | Half cup |
| 6 fl oz | 0.04687 gal | One cup |
| 8 fl oz | 0.0625 gal | One cup |
| 12 fl oz | 0.09375 gal | Soda can |
| 16 fl oz | 0.125 gal | One pint |
| 20 fl oz | 0.1562 gal | Large cup |
| 32 fl oz | 0.25 gal | One quart |
| 64 fl oz | 0.5 gal | Half gallon |
| 128 fl oz | 1 gal | One gallon |
| 256 fl oz | 2 gal | 2 gallons |
| 512 fl oz | 4 gal | 4 gallons |
| 1,024 fl oz | 8 gal | 8 gallons |
Converting fluid ounce to us gallon comes up frequently in cooking, chemistry, medicine, and engineering. A recipe written in metric units may need to be adapted for a kitchen using us gallon, or a laboratory protocol may specify volumes in fluid ounce that need to be measured with equipment calibrated in us gallon.
In everyday use, knowing that 5 fl oz = 0.03906 gal and 10 fl oz = 0.07812 gal covers most common situations. For bulk calculations, 100 fl oz = 0.7812 gal is a useful anchor. The reverse conversion — us gallon back to fluid ounce — uses the factor 128, so 1 gal = 128 fl oz.
All conversions use the internationally recognized factor of exactly 1 fl oz = 0.007812 gal. Calculations are performed in IEEE 754 double-precision floating point, giving accuracy to at least 8 significant figures — more than sufficient for any practical application.
Formula: US Gallon = Fluid Ounce × 0.0078124959
Multiply any fluid ounce value by 0.0078124959 to get us gallon. One fluid ounce equals 0.0078124959 gal.
Reverse: Fluid Ounce = US Gallon × 128.00007
Fluid ounces ÷ 128 = US gallons. Exact.
128 fl oz = 1 gal. 64 fl oz = ½ gal. 32 fl oz = 1 qt.
Gallons × 128 = fl oz.
Labels product nutrition facts and serving sizes in fluid ounces as required by FDA.
Measures spirit pours and mixers in fl oz using jiggers for cocktail consistency.
Tracks soda fountain syrup and cup sizes (12, 16, 20, 32 fl oz) for inventory.
Designs bottle fill levels in fluid ounces for US retail compliance.
Recommends daily fluid intake for children in fluid ounces by age group.
Compares unit prices per fluid ounce on beverage labels to find the best value.
The US fluid ounce is defined as 1/128 of a US gallon, exactly 29.5735 mL. The US and UK fl oz differ: the US is 29.57 mL while the Imperial fl oz is 28.41 mL.
Fluid ounces appear on every US beverage container: a soda can is 12 fl oz, a water bottle is 16.9 fl oz, and a US shot glass is 1.5 fl oz.
Interesting fact: Despite sharing the name 'ounce', the fluid ounce measures volume, not weight. One fl oz of water weighs about 1.04 oz, but one fl oz of honey weighs about 1.5 oz.
The US liquid gallon is defined as exactly 231 cubic inches, or 3.785411784 liters. It traces its origins to the Queen Anne wine gallon of 1707, which American colonies adopted.
The US gallon differs from the UK Imperial gallon by about 16.5%. This matters for fuel economy: a US MPG figure is lower than the equivalent UK MPG for the same car.
Interesting fact: The United States, Liberia, and Myanmar are the only countries using the US gallon as a primary everyday volume unit.