Customary Units of Measurement – Definition with Examples

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What Are Customary Units?

The customary system of measurement, also called the U.S. Customary System, uses customary units. It is based on the English system of measurement. 

Customary units are a system of measurement commonly used in the United States for everyday purposes, such as measuring length, weight, capacity, and temperature. Unlike the metric system, which is widely used around the world, the customary system is specific to the United States and a few other countries.

Definition of Customary Units

Customary units (US Customary Units) are the units that are used to measure length, weight, and volume in the Customary system of measurement which is most commonly in the USA.

U.S. Customary Units

The customary units are used in the United States. 

Some examples of the U.S. Customary Units are foot, ounce, pint, etc. 

Customary Units of Length

We can use the customary units like inch, foot, yard, and mile to measure length.

Inch: Inch is used to measure the length of small objects. Example: Length of a sharpener.

Foot: Foot is used to measure short height and distances. Example: Height of a chair.

Yard: Yard is used to measure length of longer distance. Example: Length of a basketball field. 


A paperclip is about 1 inch long.
A measuring ruler is 1 foot long.
A hockey stick is 1 yard long approx.

The following are some conversions based on the customary units of length.

  • 1 foot (ft) $= 12$ inches (in.)
  • 1 yard (yd) $= 3$ feet (ft)
  • 1 mile (mi) $= 5,280$ feet (ft)

Customary Units of Weight

We can use the customary units like ounce, pound, and ton to measure weight. 

Ounce: Ounce is used to measure the weight of small objects. Example: weight of a tomato.

Pound: Pound is used to measure weight of a body or furniture. Example: weight of a chair.

Ton: Ton is used to measure the weight of large, heavier things. Example: weight of a truck. 


A pencil weighs about 1 ounce.
A loaf of bread is about 1 pound.
An African elephant weighs about 1 ton.

Following are some conversions based on the customary units of weight. 

  • 1 pound (lb.) $= 16$ ounces (oz.)
  • 1 ton $= 2,000$ lbs.

Customary Units of Capacity

We can use the customary units like fluid ounce, cup, pint, quart, and gallon to measure capacity.

Fluid Ounce: Fluid ounce (fl oz or fl. oz.) is used to measure the capacity of a liquid in very less quantities. For example: Fluid ounces of milk.

Cup: Cup (c) is used to measure the capacity of a liquid in less quantities. For example: A cup of tea.

Pint: Pint (pt) is used to measure the capacity of a liquid in medium quantities. For example: A pint of cold drink.

Quart: Quart (qt) is used to measure a little large capacity of liquid. For example: A quart of liquid detergent.

Gallon: Gallon (gal) is used to measure large capacity of liquid. For example: A gallon of water. 


Two bottles of ink hold about 1 fluid ounce.
A teacup has a capacity of 1 cup.
A large glass has a capacity of 1 pint.
A packet of liquid cleanser contains about 1 quart.
A jug of water contains 1 gallon.
You can convert between these units. Use the table to see how.

  • 1 cup $= 8$ fluid ounces 
  • 1 pint $= 2$ c
  • 1 quart $= 2$ pt
  • 1 gallon $= 4$ qt

Customary Units of Area

The US customary units of Area include square inches, square feet, square yards, and acre.

$1\; ft^{2} = 144\; in^{2}$

$1\; yd^{2} = 9\; ft^{2}$

We use acres and $mi^{2}$ for measuring large areas.

1 acre $= 43,560\; ft^{2}$

$1\; mi^{2}\; d$.

$1\; ft^{3} = 1,728\; in^{3}$

$1\; yd^{3} = 27\; ft^{3}$

Customary Units of Temperature

In the US customary system, the Fahrenheit $(^{\circ}\text{F})$ scale is typically used for measuring temperature. Two reference points are:

$32\; ^{\circ}\text{F}$: The freezing point of water

$212\; ^{\circ}\text{F}$: The boiling point of water

Metric System vs. Customary System

The metric system is the measurement system based on the decimal system. It uses the base units meter, liter, and gram. The international system of units (SI system), also known as the modern form of the metric system, is used across most countries in the world other than in the United States. 

The United States follows the Customary units of measurement, which uses units like feet, quarts, and ounces for measurement. 

Let’s understand some important formulas for converting metric units of length to customary units.

  • 1 meter $= 39.4$ inches $= 1.09$ yards $= 3.2$ feet
  • 1 centimeter $= 0.39$ inches
  • 1 inch $= 2.54$ cm

While the metric system is preferred for scientific and international purposes due to its decimal-based structure and ease of conversion, the customary units remain prevalent in certain sectors and contexts within the United States.

Facts about Customary Units

  • Common customary units for length include inches, feet, and miles.
  • Pounds and ounces are customary units used for measuring weight.
  • Cups, pints, quarts, and gallons are customary units for measuring capacity or volume.
  • The Fahrenheit scale is a customary unit for measuring temperature in the United States.
  • Customary units are not as widely used internationally as the metric system.


In this article, we learned about the US customary units for different measurements such as length, weight, area, capacity, volume, temperature, etc. Let’s solve a few examples and practice problems for better understanding.

Solved Examples on Customary Units

1. How many inches are in 1 yard?


1 yard $= 3$ feet 

1 feet $= 12$ inches

1 yard $= 3 \times 12$ inches $= 36$ inches

2. How many cubic inches are in 1 cubic yard?


1 yard $= 36$ inches

1 cubic yard $= 36 \times 36 \times 36 = 46,656$ cubic inches

3. How many fluid ounces are in 2 pints?


1 cup (c) $= 8$ fluid ounces (fl oz)

1 pint (pt) $= 2$ c

1 pint (pt) $= 2 \times 8 = 16$ fluid ounces (fl oz)

2 pints $= 2 \times 16 = 32$ fluid ounces (fl oz)

Practice Problems on Customary Units

Customary Units of Measurement – Definition with Examples

Attend this Quiz & Test your knowledge.


How many pints are equal to 1 gallon?

2 pt
8 pt
16 pt
10 pt
Correct answer is: 8 pt
1 gallon (gal.) $= 4$ qt.
1 quart (qt.) $= 2$ pt.
1 gallon $= 4 \times 2 = 8 pt

4 ounces = ____ pound

Correct answer is: 0.25
1 pound (lb.) $= 16$ ounces (oz.)
1 ounce $= \frac{1}{16}$ pound
4 ounces $= 4 \times \frac{1}{16}$ pound $= 0.25$ pound

8 yards equals how many feet?

3 feet
11 feet
15 feet
24 feet
Correct answer is: 24 feet
1 yard (yd) $= 3$ feet (ft)
8 yards $= 8 \times 3 = 24$ feet

How many ounces make 1 ton?

32,000 oz.
16,000 oz.
18,000 oz.
6000 oz.
Correct answer is: 32,000 oz.
1 pound (lb.) $= 16$ ounces (oz.)
1 ton $= 2000$ lb.
1 ton $= 16 \times 2,000 = 32,000$ oz.

Which of the following is the correct unit to measure the radius of a coin?

Correct answer is: Inches
Inch is used to measure the length of small objects.

Frequently Asked Questions on Customary Units

Three countries in the world use customary units: the United States, Myanmar, and Liberia.

In the metric system, there is the same root word in units and only the prefix changes (for example: millimeter, centimeter, decimeter, etc.). So, it becomes easier to learn. In the US customary system, units do not have the same root word. (for example: inch, foot, yard). The customary units are a bit complex because you must know the conversion rates.

There is a slight difference between the imperial and customary systems.. Units like cubic inches, cubic feet, etc., are the same in both systems, but units such as bushels, gallons, etc., are different in each.

No, scientists do not use the customary units. They use the metric system all over the world.

The International System Of Units (SI) is the metric system accepted universally as a standard for measurements. The International System of Units (SI), is commonly known as the metric system (or the modern metric system).

The customary system or the U.S. customary system is the american measurement system based on the English system of measurement (imperial system).