wikiHow Calculating Area of a Rectangle Calculator To calculate the area of a rectangle, you need to multiply its length by its width. Here are the steps: 1. Measure the length of the rectangle in meters, centimeters, or any other unit of length. 2. Measure the width of the rectangle in the same unit of length. 3. Multiply the length by the width to find the area of the rectangle. The formula for calculating the area of a rectangle is: Area = Length x Width where: Area = the total surface area of the rectangle (in square meters, square centimeters, or other appropriate units) Length = the length of the rectangle (in meters, centimeters, or other appropriate units) Width = the width of the rectangle (in meters, centimeters, or other appropriate units) Example: Suppose you have a rectangle with a length of 4 meters and a width of 3 meters. What is the area of the rectangle? Area = Length x Width Area = 4 meters x 3 meters Area = 12 square meters Therefore, the area of the rectangle is 12 square meters. Page