Gallons to Fluid Ounces
Convert gallons (gal) to fluid ounces (fl oz). Type in either box; the other updates as you go.
How to convert gallons to fluid ounces
To convert gallons to fluid ounces, multiply the number of gallons by 128.
Example
Convert 5 gallons to fluid ounces:
Gallon to fluid ounce conversion chart
| Gallons (gal) | Fluid Ounces (fl oz) |
|---|---|
| 1 gal | 128 fl oz |
| 2 gal | 256 fl oz |
| 3 gal | 384 fl oz |
| 4 gal | 512 fl oz |
| 5 gal | 640 fl oz |
| 6 gal | 768 fl oz |
| 7 gal | 896 fl oz |
| 8 gal | 1,024 fl oz |
| 9 gal | 1,152 fl oz |
| 10 gal | 1,280 fl oz |
| 12 gal | 1,536 fl oz |
| 15 gal | 1,920 fl oz |
| 20 gal | 2,560 fl oz |
| 25 gal | 3,200 fl oz |
| 30 gal | 3,840 fl oz |
| 40 gal | 5,120 fl oz |
| 50 gal | 6,400 fl oz |
| 60 gal | 7,680 fl oz |
| 70 gal | 8,960 fl oz |
| 75 gal | 9,600 fl oz |
| 80 gal | 10,240 fl oz |
| 90 gal | 11,520 fl oz |
| 100 gal | 12,800 fl oz |
| 150 gal | 19,200 fl oz |
| 200 gal | 25,600 fl oz |
| 250 gal | 32,000 fl oz |
| 500 gal | 64,000 fl oz |
| 1,000 gal | 128,000 fl oz |
Going the other way? See the fluid ounces to gallons chart.
About the units
Gallon (gal)
A US gallon is 231 cubic inches, about 3.785 liters. It is the unit for fuel and milk in the US. The imperial gallon is about 20% larger.
Fluid Ounce (fl oz)
A US fluid ounce is 1/128 of a US gallon, about 29.57 milliliters. It measures liquid volume, not weight.
Frequently asked questions
How many fluid ounces are in a gallon?
There are 128 fluid ounces in a gallon.
How many gallons are in a fluid ounce?
There are 0.0078125 gallons in a fluid ounce.
How do you convert gallons to fluid ounces?
To convert gallons to fluid ounces, multiply the number of gallons by 128.
What is 5 gallons in fluid ounces?
5 gallons equals 640 fluid ounces.
Convert between liters, gallons, cups, fluid ounces, tablespoons and cubic units. Open the volume converter to see a value in every unit at once.