1 gallon (US) = 128 fluid ounces (US)
All conversions
| Unit | Symbol | Value |
|---|
Quick answer
To convert Gallons to OZ, multiply the number of gallons (US) by 128. For example, 0.5 Gallons = 64 OZ.
How to Convert Gallons to OZ
The formula is fluid ounces (US) = gallons (US) × 128. 1 gallon (US) = 128 fluid ounces (US). Type any value in the converter above for an instant answer, or use the chart below for the most common values.
This page is preset for gallon (US) to fluid ounce (US) conversions, but you can switch either list to any of the 76 units in the Volume Converter.
Gallons to OZ conversion chart
| Gallons | OZ |
|---|---|
| 0.1 gal (US) | 12.8 fl oz (US) |
| 0.25 gal (US) | 32 fl oz (US) |
| 0.5 gal (US) | 64 fl oz (US) |
| 1 gal (US) | 128 fl oz (US) |
| 2 gal (US) | 256 fl oz (US) |
| 3 gal (US) | 384 fl oz (US) |
| 4 gal (US) | 512 fl oz (US) |
| 5 gal (US) | 640 fl oz (US) |
| 6 gal (US) | 768 fl oz (US) |
| 7 gal (US) | 896 fl oz (US) |
| 8 gal (US) | 1,024 fl oz (US) |
| 9 gal (US) | 1,152 fl oz (US) |
| 10 gal (US) | 1,280 fl oz (US) |
| 11 gal (US) | 1,408 fl oz (US) |
| 12 gal (US) | 1,536 fl oz (US) |
| 13 gal (US) | 1,664 fl oz (US) |
| 14 gal (US) | 1,792 fl oz (US) |
| 15 gal (US) | 1,920 fl oz (US) |
| 16 gal (US) | 2,048 fl oz (US) |
| 17 gal (US) | 2,176 fl oz (US) |
| 18 gal (US) | 2,304 fl oz (US) |
| 19 gal (US) | 2,432 fl oz (US) |
| 20 gal (US) | 2,560 fl oz (US) |
| 25 gal (US) | 3,200 fl oz (US) |
| 30 gal (US) | 3,840 fl oz (US) |
| 40 gal (US) | 5,120 fl oz (US) |
| 50 gal (US) | 6,400 fl oz (US) |
| 60 gal (US) | 7,680 fl oz (US) |
| 70 gal (US) | 8,960 fl oz (US) |
| 75 gal (US) | 9,600 fl oz (US) |
| 80 gal (US) | 10,240 fl oz (US) |
| 90 gal (US) | 11,520 fl oz (US) |
| 100 gal (US) | 12,800 fl oz (US) |
| 150 gal (US) | 19,200 fl oz (US) |
| 200 gal (US) | 25,600 fl oz (US) |
| 250 gal (US) | 32,000 fl oz (US) |
| 500 gal (US) | 64,000 fl oz (US) |
| 1,000 gal (US) | 128,000 fl oz (US) |
Common Gallons to OZ conversions
- 1 gallon (US) = 128 fluid ounces (US)
- 0.5 gal (US) = 64 fl oz (US)
- 1 gal (US) = 128 fl oz (US)
- 2 gal (US) = 256 fl oz (US)
- 5 gal (US) = 640 fl oz (US)
- 10 gal (US) = 1,280 fl oz (US)
Popular volume converters
How to Use the Gallons to OZ Converter
- Type a value in the From box and choose its unit.
- Pick the unit you want in the To list — the result updates as you type.
- Use the swap button to reverse the conversion, or type in the To box to convert backwards.
- Check the All conversions table to see your value in every unit; click a row to make it the target.
Frequently Asked Questions
How many fluid ounces (US) are in a gallon (US)?
There are 128 fluid ounces (US) in 1 gallon (US). Going the other way, 1 fluid ounce (US) = 0.0078125 gallons (US).
How do I convert Gallons to OZ?
Use the formula fluid ounces (US) = gallons (US) × 128. For example, 1 gallon (US) = 128 fluid ounces (US). Or type the value in the converter above and the answer appears as you type.
What is the Gallons to OZ formula?
fluid ounces (US) = gallons (US) × 128 — the conversion factor is exact, using the international definitions of both units.
What is 0.5 Gallons in OZ?
0.5 Gallons = 64 OZ.
What is 1 Gallons in OZ?
1 Gallons = 128 OZ.
What is 2 Gallons in OZ?
2 Gallons = 256 OZ.
What is 5 Gallons in OZ?
5 Gallons = 640 OZ.
What is 10 Gallons in OZ?
10 Gallons = 1,280 OZ.
Is this Gallons to OZ converter accurate?
Yes. It uses exact unit definitions and double-precision maths, and you can show up to 15 significant digits. The table below is calculated with the same formula.
Can I convert Gallons to other volume units?
Yes — pick any unit in the From and To lists above, or open the full Volume Converter, which handles 76 volume units.
Is the Gallons to OZ converter free?
Yes, it is free with no sign-up, and every conversion runs in your browser so nothing is sent to a server.