US Standard Volume

These are the most common measurements:


fluid ounce

Fluid Ounces (fl oz) are small. 

About how much fits in a small medicine cup.


Fluid Ounce!

"Fluid Ounce" is used for volume, "Ounce" for mass, and they are different.

If you mean an ounce of fluid say "fluid ounce" ("fl oz")


cup 2/3


A small glass holds about 8 fluid ounces, which is also called 1 cup.

1 cup = 8 fluid ounces

Here we have 2/3 cup (two-thirds of a cup) of milk, or about 5 fluid ounces


By the way ... we can measure volume using special Measuring Cups ... !



A pint is equal to 2 cups (example: a large glass of milk!)

1 pint = 2 cups = 16 fluid ounces


When measuring many cups of liquid all put together we might want to use quarts.

A quart (qt) is the same thing as 4 cups or 2 pints. 

1 quart = 2 pints = 4 cups = 32 fluid ounces


If we still need more liquid we can switch to using gallons.

A gallon (gal) is the same as 16 cups or 8 pints or 4 quarts.  It is the largest liquid measurement.

(Note that a quart is a quarter of a gallon!)

gallon juh


In Summary:

1 gallon = 4 quarts = 8 pints = 16 cups = 128 fluid ounces

us gallon quart pint cup

Other Volume Measurements

Cubic Inch

cubeVolume is length by length by length,

so the Cubic Inch is a cube that is 1 inch on each side.

The Unit is written many ways, such as:

Barrel of Oil

1 oil barrel (bbl) is equal to 42 gallons (or about 160 Liters)


More Examples

A fluid ounce is:

A pint is:

A quart is:

A gallon is:


Activity: Discover Capacity