Convert Gallons (US) to Fluid Ounces (US)
gal to fl oz · volume conversion
What are gallons (us) and fluid ounces (us)?
A US gallon is 4 quarts (about 3.785 L), the standard unit for fuel and large liquids in the US. A US fluid ounce is about 29.57 mL, used for liquids and beverages. For scale: a standard water bottle holds about 500 mL (17 fl oz), and a US gallon is 3.785 L.
How to convert gallons (us) to fluid ounces (us)
1 gal = 128 fl oz. To convert, multiply the number of gallons (us) by 128. For example, 5 gal = 640.001 fl oz, and 20 gal = 2,560 fl oz. To go the other way, multiply fluid ounces (us) by 0.00781249 (since 1 fl oz = 0.00781249 gal).
Gallons (US) to Fluid Ounces (US) conversion table
| Gallons (US) (gal) | Fluid Ounces (US) (fl oz) |
|---|---|
| 1 | 128 |
| 2 | 256 |
| 5 | 640.001 |
| 10 | 1,280 |
| 20 | 2,560 |
| 50 | 6,400.01 |
| 100 | 12,800 |
FAQ
What is 1 gal in fl oz?
1 gal = 128 fl oz. To convert any amount, multiply the number of gallons (us) by 128.
How do I convert fluid ounces (us) back to gallons (us)?
Go the other way: 1 fl oz = 0.00781249 gal, so multiply fluid ounces (us) by 0.00781249 to get gallons (us).
Is a gallons (us) bigger than a fluid ounces (us)?
Yes — 1 gal is the larger unit, equal to 128 fl oz.
Are these volume conversions exact?
They use the standard internationally-defined conversion factors. Results are rounded to six significant figures for readability, which is accurate enough for everyday and most technical use.