Area of a Rectangle Calculator
Welcome to our Area of a Rectangle Calculator page.
We explain how to find the area of a rectangle and provide a quick calculator to work it out for you, step-by-step.
There are also some worked examples and some worksheets for you to practice this skill.
Area of a Rectangle Calculator
This calculator finds the area of a rectangle when the side lengths are known.
How the Calculator Works
- Choose the length and width of the rectangle: you can choose a whole number, decimal or fraction.
- You can type a fraction by typing the numerator then '/' then the denominator.
- You can type a mixed number by typing the whole-number part, then a space then the fraction part.
- Examples: 2 1/2 (two and one-half); 3 4/5 (three and four-fifths); 7 1/3 (seven and one-third).
- Choose your units of measurement (default is none)
- Choose your desired accuracy (default is 2 decimal places)
- Click the Find Area button
- You will be shown the area as a decimal (and also a fraction if you typed the length as a fraction).
Area of a Rectangle Formula
The formula for the area of a rectangle is: \[ A = l \cdot w \; \]
where l is the length and w is the width of the rectangle
Area of a Rectangle Examples
Area of a Rectangle Example 1
Find the area of the rectangle below.
The length of rectangle is 12 cm and the width is 7 cm.
The area of a rectangle
\[ A = l \cdot w \; \] where l is the length and w is the width of the rectangle.
So if we substitute the values of the length and width into this equation, we get: \[ A = 12 \times 7 = 84 \]
The area of the rectangle is 84 cm2.
Area of a Rectangle Example 2
Find the area of the rectangle below.
The length of rectangle is 2.4 m and the width is 0.7 m.
The area of a rectangle
\[ A = l \cdot w \; \] where l is the length and w is the width of the rectangle.
So if we substitute the values of the length and width into this equation, we get: \[ A = 2.4 \times 0.7 = 1.68 \]
The area of the rectangle is 1.68 m2.
Area of a Rectangle Example 3
Find the area of the rectangle below giving your answer as a mixed fraction.
Although this shape is tilted, it is still a rectangle.
The length of rectangle is 3 ½ inches and the width is 8 ½ inches.
The area of a rectangle
\[ A = l \cdot w \; \] where l is the length and w is the width of the rectangle.
So if we substitute the values of the length and width into this equation, we get: \[ A = 3 {1 \over 2} \times 8 {1 \over 2} = {119 \over 4} = 29 {3 \over 4} \]
The area of the rectangle is 29 ¾ square inches.
Area of a Rectangle Example 4
Find the area of the rectangle below. Give your answer in cm2.
The length of rectangle is 2.1 m and the width is 45 cm.
First we need to convert 2.1 m into cm so that both measurements have the same units of measure.
1 m = 100 cm so 2.1 m = 2.1 x 100 = 210 cm
The area of a rectangle
\[ A = l \cdot w \; \] where l is the length and w is the width of the rectangle.
So if we substitute the values of the length and width into this equation, we get: \[ A = 210 \times 45 = 9450 \]
The area of the rectangle is 9450 cm2.
More Area Support and Resources
We have a range of other area worksheets and support pages for a range of different 2d shapes.
More Area & Volume Calculators
We have a range of area and volume calculators to help you find the area and volumes of a range of different 2d and 3d shapes.
Each calculator page comes with worked examples, formulas and practice worksheets.
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