How to Calculate the Area of a Space

An area calculation can be used to determine the square footage of a room.
••• ULTRA.F/Photodisc/Getty Images

Area is a size measurement of a specific region and is expressed in square units such as square meters or square kilometers. Calculating the area of a space is an important for everyday activities, including estimating the amount of carpet for a bedroom or landscaping a yard. The formula for calculating the area of a rectangle is slightly different from the formula used to calculate the area of a circle or triangle.

Area of a rectangle

    Measure the length of the rectangle.

    Measure the width of the rectangle.

    Multiply the length of the rectangle by the width of the rectangle to obtain the area. Ensure the units used for the length and the width are the same. The resulting value will be the units squared.

Area of a circle

    Determine the radius of the circle.

    Square the radius by multiplying it by itself. The resulting value will be the units squared.

    Multiply the value by pi, which is 3.1415927. You now have the area.

Area of a Triangle

    Measure the length of the base of the triangle.

    Measure the height of the triangle.

    Multiply the base by the height. Ensure the units used for the base and the height are the same.

    Divide the value by two to obtain the area of a triangle. The resulting value will be the units squared.

    Things You'll Need

    • Calculator
    • Tape measure


    • When determining the area of a section that is not a perfect square, it is useful to divide the area up into a series of smaller sections and then add them all together.

Related Articles

How to Calculate Area From Width & Length
How to Determine Square Feet Area
How to Convert an Area to Square Feet
How to Convert Square Meters to Linear Yards
What Are the Units for Diameter?
How to Calculate a Circular Area
How to Calculate Hectares
How to Calculate Volume of a Circular Cylinder
How to Find the Area of Squares
How to Convert Meters Squared to Meters Cubed
How to Convert Centimeters to Centimeters Squared
How to Calculate Perimeter and Area Ratio
How to Convert 55 X 40 X 20 CM to Inches
How to Calculate the Volume of Water in a Square Tank
How to Calculate a T-Statistic
How to Convert Kilopascals to Joules
How to Convert Kilojoules to Kilocalories
How to Calculate Volume Using Density
How to Convert Square Feet to Yards
How to Calculate Square