Units of Area
Basics on the topic Units of Area
Units of Area
Units of measurement are something that let us describe and compare length, weight, area, volume, density and other values. Units can be imperial or metric and can describe something large or something small. Here is an overview of different imperial and metric units with their applications:
Application  Imperial unit  Metric unit 

length  inch, foot, yard, mile  millimetre, centimetre, metre, kilometre 
weight  ounce, pound, stone  milligram, gram, kilogram 
area  square inches, square foot  square centimetres, square metres, 
volume  pint, gallon, cubic foot  millilitre, centilitre, litre, centimetre cube, 
density  pound per cubic foot  grams per centimetre cube 
In this text, we will look at different units of measurements for the area of objects/spaces. We will be giving examples for small, medium or large spaces and use specific units.
Area – Definition
Area is a measure of total space on a flat surface (2D) surface or shape and is measured in square units. The area of a figure/shape is the number of unit squares that cover the surface of a closed figure. We can also measure area by counting the number of squares that fit inside the shape. The squares can be any size. We usually use squares with sides 1 cm long and call them centimetre squares (cm^{2}).
The units of area could be small or large units depending on the object that we measure.
Area – Units of Measurement
The units of area measurement are measured in imperial or in metric units. Let’s look at the table below for a better view/understanding:
Area Size  Imperial Units  Metric Units 

S  small spaces/objects  square inches (in²)  square millimetres (mm²) square centimetres (cm²) 
M/L  medium and large spaces/objects 
square feet (ft²) square yards (yd²) 
square metres (m²) 
XL  extra large spaces/objects  square miles (mi²)  square kilometres (km²) 
Area of a shape is a twodimensional quantity that is measured in square units. When we calculate an area of any 2D object/shape we always use square units as we multiply one length by another; area of a square, area of a rectangle, area of a triangle, etc. For example: The area of a square with a side of 1 cm is equal to 1cm x 1cm = 1 square centimetre.
Units of Area – Examples
When we calculate the area of a 2D shape, we multiply one dimension (length) by another dimension (width). That is why we must have the special number "2" square (cm x cm is cm², in x in = in², etc). We can also calculate the area by counting the number of squares that fit inside the shape; exactly like on the picture below:
AREA = 5 square units
Now we can look at some examples of how to measure area in "square units":
In this example if we want to make a blanket for a hamster, we will probably use measurement in square inches or square centimetres for the fabric needed as the blanket is small.
In the second example, if we want to make a blanket for a big blue whale, we will probably use measurements in square yards or square metres for the fabric needed as the blanket is big.
Units of Area – Summary
Let’s look at the most important aspects of Units of Area:
 Area always measured in square units
 The units of area are measured in imperial or in metric units
 For small spaces we use: square millimetres (mm²), square centimetres (cm²), square inches (in²)
 For big spaces we use: square metres (m²), square feet (ft²), square yards (yd²) and for really large spaces we use square kilometres (km²) or square miles (mi²)
 For a very large spaces we use: square kilometres (km²), square miles (mi²)
Frequently Asked Questions on Units of Area
Transcript Units of Area
Freddie and Zuri are starting an online business making blankets for all animals; no matter what size they are! To help understand the order requests that come in, they need to learn about units of area. As you might already know, area is the amount of space that is taken up by a flat, twodimensional object. Area is always measured in square units. When we want to calculate area, we can sometimes count the unit squares inside of a flat, twodimensional shape. The total number of squares is the area, which we state with 'square units'. If we can just count the squares inside of a flat, twodimensional shape, why do we need units of area? Well, a unit of area tells you how small or large something actually is! There are different types of units of area. There are small units of area, which we use for small spaces and there are larger units of area, which we use for medium and large spaces. But, there are also units of area that we use for very large spaces. The units of area we use for small spaces are square millimetres, square centimetres and square inches. Units of area we use for medium and large spaces are square feet, square yards and square metres. And if you have really large spaces, the units of area you can use are square kilometres and square miles. You might have noticed that we have the short form of each measurement here. But what is this special number two that we see here? The two tells us that the measurement is squared; the number of squares that cover the whole area! Now you might be wondering; but why do I need to know all these different units of area? Knowing the different units of area can help you understand the size of an area or help you to choose the best unit of area for specific measurements. For example, if Zuri and Freddie made a blanket for a hamster, we would probably use square inches, or square centimetres, to measure the fabric needed. If Freddie and Zuri made a blanket for a blue whale, which units of area might be used? You might use square yards or square metres since a blue whale would need a large blanket! While Freddie and Zuri begin making the blankets for their customers, let's review. Remember, area is always measured in square units. You can use units of area for small spaces, medium, large spaces, and also really large spaces! "Look! We have some reviews!" "And we covered all sizes of animals too!"
Units of Area exercise

What is the area of the rectangle?
HintsArea is the amount of space taken up by a flat 2D object.
Area is measured in square units. How many square units are there inside this rectangle?
SolutionTo calculate the area of a 2D object, we count the unit squares inside the shape.
There are 6 unit squares in each row of this rectangle. There are three rows of squares in the rectangle. The total number of unit squares is 6 + 6 + 6 = 18 unit squares.

Which unit of area should you use?
HintsThere are different units of area we use for small spaces, medium/large spaces and really large spaces. Is the farmland a small, medium, large, or really large space?
Farmland is a really large space. Think about the different units of area listed above. Which unit of area is used to measure very large spaces?
SolutionFarmland is a really large space.
Square kilometres (km$^{2}$) and square miles (mi$^{2}$) are the units of area we use for really large spaces.
The best unit of area to measure the very large farm from the options above is square kilometres (km$^{2}$)

Which unit of area should Freddie and Zuri use?
HintsThink about the size of each animal: a frog, a hedgehog, a horse, and a giraffe.
Is it a small, medium, or large animal? What size blanket would it need?
in$^{2}$ stands for square inches.
ft$^{2}$ stands for square feet.
Square inches are a smaller unit of area than square feet.
Here are the animals ordered from smallest to largest.
SolutionThe units of area used for small spaces are square millimetres, square centimetres and square inches.
The units of area used for medium/large spaces are square feet, square yards and square metres.
The frog and hedgehog would need small blankets, so you could use in$^{2}$ to measure the fabric for their blankets.
The horse and giraffe would need mediumsized blankets, so you could use ft$^{2}$ to measure the fabric for their blankets.

Which units of area do we use for each size of space?
HintsUnits of area tell you how small or large something actually is. There are small, medium, large and very large units of area.
There are three units of area we can use for medium and large spaces.
 a book would be measured using square inches
 a room would be measured using square metres
 the size of a city would be measured using square miles
Solution The three units of area used for small spaces are square millimetres, square centimetres and square inches.
 The three units of area used for medium and large spaces are square feet, square yards and square metres.
 The two units of area used for extra large spaces are square kilometres and square miles.

Which animal would this blanket work best for?
HintsThink about the size of each animal.
Is it a small, medium, or large animal? What size blanket would it need?
Square metres is a unit of area used for medium and large spaces.
SolutionThe correct answer is an elephant.
Since the squirrel, mouse and rabbit are small animals you would use a small unit of area to measure the fabric for their blankets.
Since the elephant is a large animal, you would use a large unit of area to measure the fabric for its blanket.
A blanket that is four square metres in area is a large blanket, so it is the right size for the elephant.

Sort the units of area from smallest to largest.
Hints There are 12 inches in a foot.
 There are 1,000 millimetres in a metre.
 There are 5,280 feet in a mile.
 square millimetres is the smallest unit of area
 square miles is the largest unit of area
Square metres (m$^{2}$) is a larger unit of area than square feet (ft$^{2}$).
SolutionThese units of area from smallest to largest are:
square millimetres (mm$^{2}$), square inches (in$^{2}$), square feet (ft$^{2}$), square metres (m$^{2}$), square miles (mi$^{2}$)