Rectangle Area Calculator






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Introduction to Rectangle Area Calculator

The rectangle area calculator is an online calculator to find the area, perimeter, and diagonals. It calculates the space occupied within the rectangle boundary by using the formula for area.

In geometry, the area of any shape is an important concept. But it has different formulas for different shapes. So remembering different formulas for a single variable is sometimes difficult for students. That’s why we introduce online software that can easily calculate the area of the rectangle and its perimeter and diagonals.

In this short article, we will discuss the working and benefits of this tool along with the concept which it is based.

How to calculate the area of a rectangle?

You can find the value of the area, perimeter, and diagonal of a rectangle by following these steps of rectangular area calculator:

  1. In the first step, enter the value for length and width in the “Length” and “Width” boxes.
  2. Click on the calculate button.
  3. As you click on the calculate button, the tool will give you the values for the rectangle's area, perimeter, and diagonal.
  4. If you want to calculate again, you can use the calculate button again.

Formula used by Rectangle Area and Perimeter Calculator:

The area of a rectangle is the space occupied by the rectangle within its shape. It can be denoted by ‘A’ and the formula is given as:

A = w × l


w = the width of the rectangle.

l = the length of the side of the rectangle.

Since all of the angles of the rectangle are equal, it can be also known as equiangular quadrilateral. In other words, it has parallel sides so it can be also called parallelogram. And the unit of the area is m2.

P = 2 × l + w

The perimeter of the rectangle will be the sum of all sides. The unit of perimeter of a rectangle is m.

  1. A rectangle is a four-sided shape that has four corners and four right angles each measuring is of 90o. It is a 2D shape having two sides parallel to each other.
  2. The total distance covered by the all four sides of the rectangle is called its perimeter. It is denoted as ‘P’ and the formula can be written as:
  3. The diagonal of a rectangle is a line joining the two non-adjacent vertices of the rectangle. The formula used to find the diagonal of a rectangle is given by:
  4. $$ d \;=\; \sqrt{l^2 \;+\; w^2} $$

The unit of diagonal is m. These three formulas are used by the rectangle calculator. An example is given below to understand how to calculate the area of a rectangle calculator.

Example: find the area of a rectangle including perimeter and diagonals whose length is 5 and width is 3.


Since l=5 and w=3

Put these values in the formula of area.

A = 5×3 = 8m2

Now to find perimeter,

P = 2 × 5 + 3

P = 2 × 8 = 16m

To find diagonal,

$$ d \;=\; \sqrt{5^2 \;+\; 3^2} $$ $$ d \;=\; \sqrt{25+9} \;=\; \sqrt{34} $$ $$ d \;=\; 5.83m $$

Benefits of using online Length and Width of a rectangle Calculator

Rectangle area calculator is an efficient tool online that helps students and mathematicians solve geometrical problems. There are a lot of advantages to using this tool. Some of these are as follows:

  1. Area of a rectangle calculator accurately provides you with the solution to any problem within a few moments.
  2. If you don’t know how to use it, there is an option to load examples. You can use it to check the working of the area calculator.
  3. It calculates the area of a rectangle and the perimeter and diagonal.
  4. The rectangle area and perimeter does not demand any subscription fee to use it.
  5. Rectangular area calculator has a simple and easy interface that makes it more unique and reliable.
Alan Walker

Alan Walker

Last Updated June 02, 2022

Studies mathematics sciences, and Technology. Tech geek and a content writer. Wikipedia addict who wants to know everything. Loves traveling, nature, reading. Math and Technology have done their part, and now it's the time for us to get benefits.