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Gallons to Ounces Converter

Convert from US gallons or UK gallons to fluid ounces using this conversion tool and chart.

Disclaimer: Whilst every effort has been made in building this calculator, we are not to be held liable for any damages or monetary losses arising out of or in connection with the use of it. This tool is here purely as a service to you, please use it at your own risk. Full disclaimer. Do not use calculations for anything where loss of life, money, property, etc could result from inaccurate calculations.

How many ounces are in a gallon?

There are 128 US fluid ounces in a US gallon. If you're in the UK, you'll find a gallon measures 160 UK fluid ounces. This is due to the fact that the US liquid gallon is smaller than the UK imperial gallon (3.785 liters compared to 4.546 litres).

When converting gallons to ounces (fluid ounces), you should also bear in mind that the US fluid ounce is larger than the UK imperial fluid ounce. The US fluid ounce measures 29.5735mL. By comparison, the UK (imperial) fluid ounce measures 28.4131mL. So, the US has a smaller gallon than the UK, but a slightly larger fluid ounce. It's enough to cause your head to explode. When it comes to conversions between the two, here's the info you need:

  • 1 Gallon (US) = 128 Ounces (US, Fluid)
  • 1 Gallon (UK) = 160 Ounces (UK, Fluid)

You should probably bear the size differences in mind if you're considering changing your daily water intake, because there's a big difference between the two. You could be drinking 3/4 of a litre more water if you use the UK imperial gallon conversion. If you're interested in the weight of a gallon of water, by the way, you can find out how much a gallon of water weighs here.

How many ounces are in a gallon of water?

In the US, a gallon of water measures 128 fluid ounces. In the UK, a gallon of water measures 160 fluid ounces. This is because the US and UK use different measurements for gallons and fluid ounces.

As a side-note, if you're looking to convert gallons of water into pounds or ounces of weight, give our water weight calculator a try.

How many gallons does 64 ounces equal?

A gallon of liquid in the United States equates to 128 US fluid ounces. This means that 64 US fluid ounces measures the same as 1/2 a US gallon.

Is 1 gallon the same as 64 oz?

No. A gallon of liquid contains 128 US fluid ounces. This means that half a gallon measures 64 US fluid ounces.

How many 32 oz make a gallon?

If you're referencing the US gallon and US fluid ounce, 32 ounces equal one quart and equate to 1/4 of a gallon. You would therefore need 4 to make a US gallon.

Gallons to ounces conversions (US)

Gallons to fl oz (US) Gallons to fl oz (US)
1/4 gallon = 32 fl oz 10 gallons = 1280 fl oz
1/2 gallon = 64 fl oz 11 gallons = 1408 fl oz
3/4 gallon = 96 fl oz 12 gallons = 1536 fl oz
1 gallon = 128 fl oz13 gallons = 1664 fl oz
2 gallons = 256 fl oz14 gallons = 1792 fl oz
3 gallons = 384 fl oz15 gallons = 1920 fl oz
4 gallons = 512 fl oz16 gallons = 2048 fl oz
5 gallons = 640 fl oz17 gallons = 2176 fl oz
6 gallons = 768 fl oz18 gallons = 2304 fl oz
7 gallons = 896 fl oz19 gallons = 2432 fl oz
8 gallons = 1024 fl oz20 gallons = 2560 fl oz
9 gallons = 1152 fl oz21 gallons = 2688 fl oz
Conversions are rounded to max 3 decimal places

Gallons to imperial fluid ounces (UK)

Due to the fact that the UK uses the smaller imperial fluid ounce, conversions for UK gallons are as follows.

Gallons to fl oz (UK) Gallons to fl oz (UK)
1 gallon = 160 fl oz11 gallon = 1760 fl oz
2 gallons = 320 fl oz12 gallon = 1920 fl oz
3 gallons = 480 fl oz13 gallon = 2080 fl oz
4 gallons = 640 fl oz14 gallon = 2240 fl oz
5 gallons = 800 fl oz15 gallon = 2400 fl oz
6 gallons = 960 fl oz16 gallon = 2560 fl oz
7 gallons = 1120 fl oz17 gallon = 2720 fl oz
8 gallons = 1280 fl oz18 gallon = 2880 fl oz
9 gallons = 1440 fl oz19 gallon = 3040 fl oz
10 gallons = 1600 fl oz20 gallon = 3200 fl oz
Conversions are rounded to max 3 decimal places

If you wish to convert gallons to pounds, you can do so with our gallons to pounds converter.


If you have any problems using this gallons to ounces converter, please contact me.