Customary Units
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, is also known as the U.S. Customary System.
Customary Units for Length
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 the conversion of one customary unit of length to another.
Example: Convert 5 feet 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 
Customary Units for Weight
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 
Customary Units for Capacity (Volume)
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 
Customary Units for Temperature
The U.S. customary measurement unit for temperature is °Fahrenheit.
1 °C = 33.8 °F
Fun Facts

Practice Problems
Customary Units11 gallon equals how many pints?6 pints 16 pints 4 pints 8 pints CorrectIncorrect Correct answer is: 8 pints 1 gallon = 4 quarts 1 quart = 2 pints Therefore, 1 gallon = 4 x 2 pints = 8 pints. 2How many ounces make 4 pounds?80 20 64 500 CorrectIncorrect Correct answer is: 64 Using the Customary Unit System of weights, 1 pound = 16 ounces Therefore, 4 pounds = 4 × 16 = 64 ounces. 3Convert 10ºC into Fahrenheits.338ºF 3.38ºF 3380ºF 0.338ºF CorrectIncorrect Correct answer is: 338ºF 1ºC = 33.8ºF Therefore 10ºC = 33.8 × 10 = 338ºF 47 yards equals how many feet?36 21 84 24 CorrectIncorrect Correct answer is: 21 Using the Customary Unit System of length, 1 yard = 3 feet Therefore, 7 yards = 7 × 3 = 21 feet. 
Frequently Asked Questions
What are customary units of length?
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.
How many countries use customary units?
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.
What are some advantages of using metric units instead of customary units?
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).
Are imperial and customary systems the same?
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.