# How Do You Calculate the Area of a Room?

By Staff WriterLast Updated Apr 3, 2020 7:13:10 PM ET Gary Burchell/Taxi/Getty Images

Calculate the area of a rectangular room by measuring the length of the room and the width of the room, and then multiply the numbers together to determine the room’s area. This method works for any units desired, such as inches, feet or meters.

If a room is oddly shaped, its area can be determined by breaking the room down into smaller, square units. For example, if a room is L-shaped, draw an imaginary line across the bottom of the “L” to create two small rectangles. Measure the length and width of each rectangle, and multiply the measurements together to obtain the area of each one. Add these two areas together to yield the room’s total area.

To determine the area of a room with a semicircular extension, such as a bay window, draw an imaginary line that separates the semi-circle from the rest of the room. Then measure the length and width of the rectangular portion of the room, and multiply the two measurements together to obtain the area. To find the area of the semi-circular portions, measure the diameter of the circle. Divide this measurement in half, and then square the result. Multiply this result by 3.14, and then divide the product in half. The resulting number is the area of the semicircle. Add this area to the area of the rectangle to determine the total area of the room.