Customary units  Definition with Examples
Customary system
The customary system of measurement is defined as a set of weights and measures used for measuring length, weight, capacity, and temperature. Based on the English system of measurement, it is also known as the U.S. Customary System.
The customary units to measure length and distances in the customary system are inches, feet, yards, and miles.
Customary Units for Measuring Length 

Inches 
Feet 
Yards 
Miles 
We can use the given chart for conversion of one customary unit of length to another.
Example: Convert 5 foot to inches.
1 foot = 12 inches
5 foot = 12 × 5 = 60 inches
The table given below shows the relation between customary units and standard metric units.
Customary Unit 
Customary Equivalent 
Standard Metric Equivalent 
1 inch 
 
2.54 centimeters 
1 foot 
12 inches 
0.3048 meters 
1 yard 
3 feet 
0.9144 meters 
1 mile 
1760 yards 
1.609 344 kilometers 
The U.S. customary units for measuring weight are ounces, pounds, and tons.
Customary Units for Measuring Weight 

Ounces 
Pound 
Ton 
We can convert the customary unit of weight by using the giving relations.
Example: How many ounces are there in 1 ton?
1 ton = 2000 pounds
1 pound = 16 ounces
So, 2000 pounds = 2000 × 16 = 32000 ounces
Customary Unit 
Customary Equivalent 
Standard Metric Equivalent 
1 ounce 
 
28.349523125 grams 
1 pound 
16 ounces 
453.59237 grams 
1 ton 
2000 pounds 
907.18474 kilograms 
The U.S. customary capacity or volume measurement units are ounces, cups, pints, quarts, and gallons.
Customary Units for Measuring Capacity (Volume) 

Fluid Ounce  Cup  Pint  Quart  Gallon 
Example: Convert 3 quarts to cups.
1 quart = 2 pints
3 quarts = 6 pints
1 pint = 2 cups
6 pints = 6 × 2 = 12 cups
Customary Unit 
Customary Equivalent 
Standard Metric Equivalent 
1 fluid ounce 
2 tablespoons 
29.5735295625 milliliters 
1 cup 
8 fluid ounces 
236.5882365 milliliters 
1 pint 
2 cups 
473.176473 milliliters 
1 quart 
2 pints 
0.946352946 liters 
1 gallon 
4 quarts 
3.785411784 liters 
The U.S. customary measurement unit for temperature is °Fahrenheit.
1 °C = 33.8 °F
Fun Facts

In the US customary system, inch, foot, yard, and mile are used for measuring length. 1 foot = 12 inches, 1 yard = 3 feet, and 1 mile = 1,760 yards.
There are three countries in the world that use customary units – the United States, Myanmar, and Liberia. The majority of countries use metric units and a few countries use a hybrid system.
In the metric system, units have the same root word & only the prefix changes (e.g., millimeter, centimeter, decimeter, etc.), so they are easier to learn. In the US customary system, units do not sound alike (e.g., inch, foot, yard).
Imperial and customary systems are not exactly the same. Units such as cubic inches, cubic feet, etc. are the same in both systems, however, units like bushels, gallons, etc. are different in the two systems. One set of units is used for fluids and another for dry goods in the US standard system (e.g., US liquid quart and US dry quart). There is only one set of units for both fluids and dry goods in the imperial system.