## What is Capacity in Math?

Have you observed that when you fill water in a pan or a bottle, there is only a certain amount of water you can fill in them? All the sodas and chocolate syrups have a maximum amount mentioned on their containers. This certain amount that the pan, bottle, or any other container can hold is called **capacity**. In mathematics, capacity is defined as the maximum quantity a container can hold when full.

There are two types of **capacity** measurement: metric measurement and customary measurement.

## Metric Measurement

The standard units to measure capacity are liters and milliliters.

**Milliliter (ml): **Milliliter is denoted by the letters ml. A milliliter is a unit to measure very small quantities of liquids like cough syrup.

**Liter (l): **Liter is denoted by the letter l. A liter measures liquids like juice, milk, water, and so on.

**The units’ milliliter (ml) and liter (l) are related: **

**One liter is equal to a thousand milliliters.**

**1l = 1000 ml or 1000 ml = 1l **

## Customary Measurement

Customary measurement refers to gallons, quarts, pints, cups, and fluid ounces. This is US Standard Unit (English Unit or Customary Unit).

**Fluid Ounce: **A fluid ounce is a unit used to measure the volume of liquids. It is commonly abbreviated as fl. oz.

**Cup:** A cup is a unit of volume measurement equal to 16 tablespoons. A US cup is about 237 ml. It is usually used for drinking beverages like coffee or tea.

**Pint: **A pint is equal to 2 cups. A US pint is about 473 ml. We express the **capacity** of juice jars in pints.

**Quart: **A quart (qt) is the same as 2 pints. The **capacity **of milk cartons is expressed in quarts.

**Gallon: **A gallon (gal) is the largest liquid measurement. It is the same as 4 quarts. The **capacity** of fuel tanks is expressed in gallons.

## Solved Examples

**Example 1. Susie bought 4 liters of orange juice. She wants to convert this quantity into milliliters. Can you help her?**

**Solution:**

We know that 1l = 1000 ml

So, 4l = 4 ✕ 1000 ml = 4000 ml

Therefore, the quantity of orange juice bought by Susie in milliliters is 4000 ml.

**Example 2. Ray bought 6 gallons of paint to decorate his house. Help him convert the quantity of paint to quarts.**

**Solution:**

We know that 1 gallon = 4 quarts

So, 6 gallons = 6 ✕ 4 quarts = 24 quarts

Therefore, the quantity of paint bought by Ray is 24 quarts.

**Example 3. Danny drank 2 cups of an energy drink on Monday. How much quantity is that in fluid ounces?**

**Solution:**

We know that 1 cup = 8 fluid ounces

So, 2 cups = 2 ✕ 8 fluid ounces = 16 fluid ounces

Therefore, the quantity of energy drink Danny drank was 16 fluid ounces.

## Practice Problems

## Capacity in Math – Definition with Examples

### Jack made 4 pints of lemonade. If he divided it into an equal number of paper cups, how many paper cups would he need?

A pint is equal to 2 cups.

So, 4 pints = 4 ✕ 2 cups = 8 cups.

### Convert 4.5 liters into milliliters.

We know that 1 l = 1000 ml

So, 4.5 l = 4.5 ✕ 1000 ml = 4500 ml

### Convert 12 cups to pints.

We know that 1 pint is equal to 2 cups.

So, 1 cup is half of a pint.

So, 6 cups in pints = 12 ÷ 2 = 6 pints.

### Aisha’s mom poured 3 quarts of chocolate milk into an equal number of cups for children at a sleepover. How many cups did she use?

A quart is equal to 4 cups. So, 3 quarts = 3 ✕ 4 cups = 12 cups.

## Frequently Asked Questions

**What does capacity measure?**

Capacity measures the maximum amount of a liquid that a container can hold when full.

**What are the U.S. customary capacity measurement units?**

The U.S. customary capacity or volume measurement units are ounces, cups, pints, quarts, and gallons.

**What is the standard unit of capacity?**

A liter is the standard unit of capacity, and the smaller unit of capacity is a milliliter. In short, a liter is written as ‘l’ and milliliter as ‘ml.’ Liter (l) and milliliter (ml) are related to each other as 1 liter = 1000 milliliter (1 l = 1000 ml).