Finding the square footage of an area has a variety of applications. It is important for determining market value as well the needed sizes of air conditioning units and heaters. If you are planning to install tile or carpet floors, you need to know the space that you have to cover. Once you have identified the shape that you want to calculate the square footage of, you need to measure the appropriate dimensions.

## Rectangular Areas

## Step 1

Measure the length in feet.

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## Step 2

Measure the width in feet.

## Step 3

Multiply the length times the width to calculate the square footage. For example, if the length is 20 feet and the width is 14 feet, the area would be 280 square feet.

## Triangular Areas

## Step 1

Measure the length in feet.

## Step 2

Measure the width in feet.

## Step 3

Multiply the length times the width times 0.5 to calculate the square footage. For example, if the length is 15 feet and the width is 10 feet, the square footage would be 75 square feet.

## Circular Areas

## Step 1

Measure the diameter in feet. The diameter is the distance from one side of the room through the center.

## Step 2

Divide the diameter by two to find the radius. For example, if the diameter is 14 feet, the radius would be 7 feet.

## Step 3

Square the radius and multiply by pi, about 3.14, to determine the square footage. For example, if the radius is 7 feet, the area would be 153.86 square feet.

## Oval Areas

## Step 1

Measure the short diameter in feet. This is the shortest distance from one side of the room to the other that goes through the center.

## Step 2

Divide the short diameter by two to find the short radius. For example, if the short diameter is 12 feet, the short radius would be 6 feet.

## Step 3

Measure the long diameter in feet. This is the longest distance from one side of the room to the other that goes through the center.

## Step 4

Divide the long diameter by two to find the long radius. For example, if the long diameter is 20 feet, the long radius would be 10 feet.

## Step 5

Multiply the long radius times the short radius times pi to find the area. For example, if the short radius is 6 feet and the long radius is 10 feet the area would be about 188.4 square feet.