Convert Gallons (US) to Fluid Ounces (US)
One gallon (US) equals 128 fluid ounces (us). Type any value to convert gallons (us) to fluid ounces (us) instantly — with a full reference table below.
Convert Gallons (US) to Fluid Ounces (US)
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How to convert Gallons (US) to Fluid Ounces (US)
To convert gallons (us) to fluid ounces (us), multiply by 128. One gallon (US) equals 128 fl oz, and one fluid ounce (US) equals 0.0078125 gal.
- Take the value in gallons (us) — for example 7.5 gal.
- Multiply by 128 (the number of fluid ounces (us) in one gallon (US)).
- 7.5 × 128 = 960 fl oz.
Quick mental estimate: Multiply the number of gallons (us) by 128 — that is exact.
Gallons (US) to Fluid Ounces (US) conversion table
| Gallons (US) | Fluid Ounces (US) |
|---|---|
| 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 |
| 8 gal | 1,024 fl oz |
| 10 gal | 1,280 fl oz |
| 12 gal | 1,536 fl oz |
| 16 gal | 2,048 fl oz |
| 20 gal | 2,560 fl oz |
| 24 gal | 3,072 fl oz |
| 32 gal | 4,096 fl oz |
| 50 gal | 6,400 fl oz |
| 100 gal | 12,800 fl oz |
| Fluid Ounces (US) | Gallons (US) |
|---|---|
| 1 fl oz | 0.0078125 gal |
| 2 fl oz | 0.015625 gal |
| 3 fl oz | 0.0234375 gal |
| 4 fl oz | 0.03125 gal |
| 5 fl oz | 0.0390625 gal |
| 6 fl oz | 0.046875 gal |
| 8 fl oz | 0.0625 gal |
| 10 fl oz | 0.078125 gal |
| 12 fl oz | 0.09375 gal |
| 16 fl oz | 0.125 gal |
| 20 fl oz | 0.15625 gal |
| 24 fl oz | 0.1875 gal |
| 32 fl oz | 0.25 gal |
| 50 fl oz | 0.390625 gal |
| 100 fl oz | 0.78125 gal |
About converting Gallons (US) to Fluid Ounces (US)
Gallons (US) (gal) and Fluid Ounces (US) (fl oz) are both units of volume. The exact factor is 1 gal = 128 fl oz, so multiply by 128 to go from gallons (us) to fluid ounces (us) (or divide to go back).
The conversion runs entirely in your browser. Need the reverse? Use the Fluid Ounces (US) to Gallons (US) converter, or the full unit converter for every unit at once.
Real-world volume in gallons (us) and fluid ounces (us)
| Example | Gallons (US) | Fluid Ounces (US) |
|---|---|---|
| A US soda can (12 fl oz) | 0.09375 gal | 12 fl oz |
| A wine bottle | 0.198129 gal | 25.36052 fl oz |
| A US gallon of milk | 1 gal | 128 fl oz |
| A typical car fuel tank | ≈ 13.2086 gal | ≈ 1,690.701 fl oz |
| A typical bathtub | ≈ 39.62581 gal | ≈ 5,072.103 fl oz |
“≈” marks typical values; the rest are defined or measured figures.
The units
The US liquid gallon: 231 cubic inches, exactly 3.785411784 L. (The UK imperial gallon is larger: 4.54609 L.)
Used for: US fuel and milk.
The US fluid ounce: 1/128 US gallon, 29.5735295625 mL.
Used for: US drink and cosmetics labels.
US customary volumes are exact by definition: the US gallon is 231 cubic inches, which is exactly 3.785411784 litres.