Unit Conversion
Unit conversion is a multistep process that involves multiplication or division by a numerical factor. There are different ways to measure weight, distance, and temperature. In several countries, distance is measured in kilometers, weight in kilograms, and temperature in celsius. Let's say you're on vacation in India, and you're told that the distance between the two cities is 100 kilometers. How much is that in miles? This is where unit conversion comes into the picture.
1.  What is Unit Conversion? 
2.  Length, Temperature, Area, Volume, and Weight Units 
3.  Unit Conversion Charts 
4.  Conversion Factors 
5.  FAQs on Unit Conversion 
What is Unit Conversion?
Unit conversion is a process with multiple steps that involves multiplication or division by a numerical factor or, particularly a conversion factor. The process may also require selection of the correct number of significant digits, and rounding. Different units of conversion are used to measure different parameters.
In mathematics, we convert the units of measurement to understand better. For example, the length of a table is measured in inches whereas the length of a garden is measured in yards to make it simple to understand. We cannot measure the length of a finger in miles. To measure different quantities, units of measurements are required.
The conversion of units is required to solve various mathematical problems. For example, if the length of a rectangle is given is inches whereas the breadth is given in feet, then to determine the perimeter of the rectangle, we need to convert the units to make them uniform. Hence, it necessary to learn the concept of unit conversion.
Length, Temperature, Area, Volume, and Weight Units
Different units are used to measure different quantities. Let us explore the units used to measure the following:
 Length
 Temperature
 Area
 Volume
 Weight
Quantity  Units 
Length  inch (in), feet (ft), yards (yd), miles 
Temperature  Kelvin (K), Fahrenheit (F), Celsius (C) 
Area  Square Inch, Square Feet, Acre, Square Yard, Square Mile 
Volume (Capacity)  Fluid Ounces (fl oz), pint (pt), quarts (qt), gallons (gal) 
Weight (Mass)  Ounces, Pounds (lb), Tons 
Nonstandard units of measurement are used in the early years of learning, to introduce children to the concept of measuring without them having to read any scales. Reading scales of any kind is a difficult skill in itself, so the idea of nonstandard measures is to focus the child on the concept of heavier, lighter, longer, shorter, etc. before they move onto the next step of measuring using standard units.
To measure the length of the objects the nonstandard measure used is that of hand spans. Using a handspan to measure objects is an informal way of figuring out the lengths. However, the measurements may vary owing to the subjectivity involved.
Given below is a unit conversion table depicting the relationship between different units.
Quantity  Relationship 

Length  1 mile = 1760 yards = 5280 feet = 63,360 inches 
Temperature  C/5=F32/9=K273/5 
Volume (Capacity)  1 gallon = 4 quarts = 8 pints = 128 fluid ounces 
Weight (Mass)  1 ton = 2000 pounds = 32,000 ounces 
Unit Conversion Charts
Unit Conversion Charts provide us with conversion factors for conversions of different units of length, area, volume, temperature, etc, and serves as a reference for easy and quick calculations. Let's have a look at the unit conversion chart tables below:
Length Unit Conversions
1 millimeter  0.001 meter 
1 centimeter  0.01 meter 
1 decimeter  0.1 meter 
1 decameter  10 meters 
1 hectometer  100 meters 
1 kilometer  1000 meters 
1 inch  2.54 x 10^{2} meters 
1 foot  0.3048 meters/ 12 inches 
1 yard  0.9144 meters/ 3feet 
1 mile  1.609344 kilometers/ 1760 yards/ 5280 feet/ 63,360 inches 
Area Unit Conversions
1 sq. inch  6.4516x10^{4} sq. meters 
1 sq. foot  9.2903x10^{2} sq. meters 
1 acre  4.0468x10^{3} sq. meters 
1 hectare  1x10^{4 }sq. meters 
1 sq. mile  2.5888x106 sq. meters 
1 barn  1x10^{28} square meters 
Temperature Unit Conversions
C/5 = F32/9 = K273/5 
Volume Unit Conversions
1 milliliter  0.001 liter 
1 centiliter  0.01 liter 
1 deciliter  0.1 liter 
1 decaliter  10 liters 
1 hectoliter  100 liters 
1 kiloliter  1000 liters 
1 cubic inch  1.639x10^{2} liters 
1 pint  473.16 milliliters/ 0.57 liters 
1 quart  946.353 milliliters/ 0.946353 liters/ 2 pints 
1 gallon  3.785 liters/ 4 quarts/ 8 pints/ 128 fluid ounces 
1 cubic foot  28.316 liters 
Mass Unit Conversions
1 milligram  0.001 grams 
1 centigram  0.01 grams 
1 decigram  0.1 grams 
1 decagram  10 grams 
1 ounce  28.3495 grams 
1 hectagram  100 grams 
1 kilogram  1000 grams 
1 stone  6350.29 grams 
1 pound  453.592 grams/ 0.453592kg/ 16 ounces 
1 ton  907.185kg/ 2000 pounds/ 32,000 ounces 
Conversion Factors
A conversion factor is a value or a number that is used to change one set of units to another, either by multiplication or division. An appropriate conversion factor makes calculation quick and easy. For example, the appropriate conversion value, to convert inches to feet, is 12 inches = 1 foot, and for temperature conversions, we use C/5=F32/9=K273/5.
Solved Examples on Unit Conversion

Example 1:
Robert has 200 ounces of sand in a box. He adds 100 ounces of more sand into it. How much sand does he have in total in pounds?
Solution:
First, determine the total amount of sand in ounces.
200 ounces +100 ounces = 300 ounces
Now, convert the amount of sand into pounds.
1 ounce = 0.0625 pounds. 300 ounces of sand in pounds is: 300 ounces x 0.0625 pounds/ounce = 18.75 pounds
Therefore, Robert has 18.75 pounds of sand.

Example 2:
Amy traveled 15 miles to visit her grandmother. How did she travel in yards?
Solution:
Since 1 mile = 1760 yards, multiply 15 miles by 1760 to determine the distance traveled in yards: 15 miles x 1760 yards/mile = 26,400 yards
Therefore, Amy traveled 26,400 yards to visit her grandmother.
Practice Questions on Unit Conversion
FAQs on Unit Conversion
How many Feet go into a Mile?
To determine how many feet go into a mile, we know that 1 mile = 5280 feet. Therefore, 5280 feet go into a mile.
What is the SI Unit of Mass?
The SI unit of mass is the kilogram (kg).
Is Kelvin a SI unit?
Yes, Kelvin is the SI unit of temperature.
How to do Unit Conversion?
The following steps are followed for the unit conversions:
 Step 1: Write the conversion as a fraction.
 Step 2: Multiply or divide, as required.
 Step 3: Cancel the units (same units from top and bottom)
 Step 4: Write the simplified answer with its correct unit.
Why is Unit Conversion Important?
Unit Conversions are important to solve many realtime problems, be it exchange of money, purchasing and selling, cooking, baking, etc.
How do you Set up a Conversion Equation?
To set up a conversion equation:
 Look for a conversion factor between the given units and the desired units.
 Make an equation, using them.
 Convert that equation to a fraction, putting the desired units on top and the given units on the bottom.
What are the Conversion Factors?
A conversion factor is a number that is used to change one set of units to another, either by multiplying or by dividing. An appropriate conversion factor makes calculation quick and easy. For example, the appropriate conversion value, to convert inches to feet, is 12 inches = 1 foot.
What is the Purpose of Unit Conversion?
Unit conversion is very important because all countries do not follow the standard metric system and they have different units for measuring length, weight, area, etc. So, converting units becomes the main concern and unit conversion thus, solves the purpose.