US Gallon to US Fluid Ounce Conversion Chart
| US Gallon (gallon) | US Fluid Ounce (fl oz) | Reference Benchmark | Formula Step |
|---|---|---|---|
| 0.0625 gallon | 8 fl oz | Eight-Ounce Half-Pint School Milk Paper Carton | 0.0625 × 128 = 8 fl-oz-us |
| 0.125 gallon | 16 fl oz | One-Pint Sixteen-Ounce Craft Beer Draft Glass | 0.125 × 128 = 16 fl-oz-us |
| 0.25 gallon | 32 fl oz | One-Quart Thirty-Two-Ounce Motor Oil Bottle Container | 0.25 × 128 = 32 fl-oz-us |
| 0.5 gallon | 64 fl oz | Half-Gallon Sixty-Four-Ounce Glass Brewery Growler | 0.5 × 128 = 64 fl-oz-us |
| 0.75 gallon | 96 fl oz | Ninety-Six-Ounce Commercial Coffee Catering Caddy | 0.75 × 128 = 96 fl-oz-us |
| 1 gallon | 128 fl oz | Standard One-Gallon Whole Milk Polyethylene Jug | 1 × 128 = 128 fl-oz-us |
| 1.25 gallon | 160 fl oz | Five-Quart Automotive Oil Sump Service Capacity | 1.25 × 128 = 160 fl-oz-us |
| 1.5 gallon | 192 fl oz | Six-Quart Electric Multi-Cooker Pressure Vessel | 1.5 × 128 = 192 fl-oz-us |
| 2 gallon | 256 fl oz | Two-Gallon Garden Fertilizer Hand-Pump Jug | 2 × 128 = 256 fl-oz-us |
| 2.5 gallon | 320 fl oz | Two-and-a-Half-Gallon Emergency Drinking Water Jug | 2.5 × 128 = 320 fl-oz-us |
| 3 gallon | 384 fl oz | Three-Gallon Commercial Countertop Beverage Urn | 3 × 128 = 384 fl-oz-us |
| 4 gallon | 512 fl oz | Four-Gallon Agricultural Backpack Spraying System | 4 × 128 = 512 fl-oz-us |
| 5 gallon | 640 fl oz | Standard Five-Gallon Construction Joint Compound Pail | 5 × 128 = 640 fl-oz-us |
| 8 gallon | 1024 fl oz | Eight-Gallon Commercial Wet-Vacuum Recovery Tank | 8 × 128 = 1024 fl-oz-us |
| 10 gallon | 1280 fl oz | Ten-Gallon Residential Aquarium Water Volume Tank | 10 × 128 = 1280 fl-oz-us |
US Gallon to US Fluid Ounce Formula & Unit Definitions
One US liquid gallon equals exactly 128 US fluid ounces (1 gal = 128 fl oz). To convert US gallons to US fluid ounces, multiply by 128. Conversely, to convert US fluid ounces to US gallons, divide by 128 (or multiply by 0.0078125).
Quick Estimation: A gallon is 128 ounces. Half a gallon is 64 oz, a quart is 32 oz, and a pint is 16 oz. Multiply gallons by 128.
US Liquid Gallon Scale (gal)
US Statutory Liquid Unit- Creator & Origin: Derived from the Queen Anne wine gallon established in England in 1707.
- Standard Definition: Defined by NIST as exactly 231 cubic inches (3.785411784 liters).
- Everyday Focus: Gasoline dispensing, dairy milk jugs, paint buckets, and chemical drums.
US Fluid Ounce Scale (fl oz)
US Statutory Liquid Unit- Creator & Origin: Derived from the historical English wine gallon (1/128th of a gallon).
- Standard Definition: Standardized by NIST as exactly 29.5735295625 cubic centimeters.
- Everyday Focus: Beverage cans, cosmetic bottles, cough syrups, and cocktail measures.
Frequently Asked Questions
Q.How many US fluid ounces are in one US liquid gallon?
There are exactly 128 US fluid ounces in one US liquid gallon (1 gal = 128 fl oz).
Q.What is the formula to convert US gallons to US fluid ounces?
The formula is: US Fluid Ounces = US Gallons × 128. For example, 2.5 gal × 128 = 320 fl oz.
Q.How do I reverse this calculation from US fluid ounces to US gallons?
To convert US fluid ounces back to US gallons, divide by 128 (or multiply by 0.0078125). You can also use our US Fluid Ounce to US Gallon Converter.
Q.Is an Imperial gallon also 128 Imperial fluid ounces?
No. An Imperial gallon equals 160 Imperial fluid ounces (8 pints × 20 fl oz), whereas a US gallon equals 128 US fluid ounces.