Lesson 13 — Activity 3:

Capacity

The last unit of imperial measurement you are going to learn about is capacity. As you may remember from the metric lesson on capacity, it is the amount a container can hold. This lesson will focus on the most common imperial units of capacity, including the fluid ounce, cup, pint, quart, and gallon (US gallon and Canadian gallon).

You can buy paint in a gallon.

Fluid Ounce

Fluid ounces are small. Remember the term ounce when you were measuring mass? Don't get these two units confused. An ounce measures weight, whereas a fluid ounce measures volume.

One fluid ounce fits in a small medicine cup. Fluid ounce can be abbreviated as fl oz.

Cup

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.

The abbreviation for cup is c.

Pint

A pint is equal to 2 cups (e.g., a large glass of milk). The abbreviation for pint is pt. You can usually order beer in a pint glass.

1 pint = 2 cups = 16 fluid ounces

Milk comes in a quart in the US.

Quart

When measuring many cups of liquid all put together, we might want to use quarts. A quart is the same thing as 4 cups or 2 pints. The abbreviation for quart is qt.

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

Gallon

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

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

1 gallon = 16 cups = 8 pints = 4 quarts

Note that a quart is a quarter of a gallon!

              

There are two different types of gallons in North America.

US Gallon

A US gallon is 3.785 litres. If you think of a 4 L container of milk, a US gallon would be slightly smaller than the milk container.

Canadian Gallon

A Canadian gallon is 4.54 litres. It is bigger than a US gallon. It would be slightly bigger than a 4 L container of milk.

Digging Deeper!