Cups & Temps

How many ounces in a gallon?

There are 128 fluid ounces in a gallon. Going the other way, 1 fluid ounce is 0.007812 gallon. These are fluid ounces, which measure volume.

Convert any amount

Change the amount or units. Fractions like 3/4 or 1 1/2 work.

128fluid ounces

1 gallon = 128 fluid ounces

    Gallons to fluid ounces

    gallons to fluid ounces
    GallonsFluid ounces
    1/4 gallon32 fl oz
    1/2 gallon64 fl oz
    3/4 gallon96 fl oz
    1 gallon128 fl oz
    1 1/2 gallons192 fl oz
    2 gallons256 fl oz
    3 gallons384 fl oz
    5 gallons640 fl oz

    Fluid ounces to gallons

    fluid ounces to gallons
    Fluid ouncesGallons
    1 fluid ounce0.007812 gal
    2 fluid ounces0.01562 gal
    4 fluid ounces0.03125 gal
    6 fluid ounces0.04688 gal
    8 fluid ounces0.0625 gal
    10 fluid ounces0.07812 gal
    12 fluid ounces0.09375 gal
    16 fluid ounces0.125 gal ≈ 1/8 gallon
    20 fluid ounces0.1562 gal
    24 fluid ounces0.1875 gal
    32 fluid ounces0.25 gal ≈ 1/4 gallon
    48 fluid ounces0.375 gal ≈ 3/8 gallon
    64 fluid ounces0.5 gal ≈ 1/2 gallon

    Good to know

    This is the US gallon (128 US fluid ounces). The UK imperial gallon is about 4.55 liters.

    In metric, 1 gallon is 3,785 mL and 1 fluid ounce is 29.57 mL.

    How to work it out

    Multiply gallons by 128 to get fluid ounces; divide fluid ounces by 128 to get gallons.

    Questions people ask

    How many oz in half gallon?

    1/2 gallon is 64 fluid ounces.

    Sources