Square Footage Calculator

Calculate the square footage of a room, a yard or any area. Choose a rectangle, triangle or circle, enter the measurements in feet or meters, and get the area in square feet, square yards, square meters and acres.

Area120 sq ft

In square meters: 11.15 m²
In square yards: 13.33 sq yd
In acres: 0.0028 acres

How this calculator works

Rectangle: length × width. Triangle: base × height ÷ 2. Circle: π × radius², where the radius is half the diameter.

For irregular rooms, split the space into simple shapes, calculate each one and add them together using the "How many" field or by running the calculator several times.

One square yard is 9 square feet, one square meter is about 10.76 square feet, and one acre is 43,560 square feet.

Example: a 12 × 10 ft bedroom

Area: 12 × 10 = 120 sq ft.
In square yards: 120 ÷ 9 = 13.33 sq yd.
In square meters: 120 ÷ 10.764 = 11.15 m².
At $4 per sq ft for flooring: 120 × 4 = $480.

Quick reference

Common room sizes
Room size	Square feet	Square meters
10 × 10 ft	100	9.29
10 × 12 ft	120	11.15
12 × 12 ft	144	13.38
12 × 15 ft	180	16.72
15 × 20 ft	300	27.87

Common room sizes

Room size

Square feet

Square meters

10 × 10 ft

100

9.29

10 × 12 ft

120

11.15

12 × 12 ft

144

13.38

12 × 15 ft

180

16.72

15 × 20 ft

300

27.87

Tips before you buy

Measure wall to wall at floor level, and round up to the nearest inch.
For L-shaped rooms, measure two rectangles and add them, rather than multiplying the longest sides.
When buying materials, add the extra recommended for that product (usually 5–15%) on top of the square footage.

Frequently asked questions

How do I calculate square footage?

Multiply the length by the width, both in feet. A room that is 12 ft long and 10 ft wide is 120 square feet.

How do I calculate square footage of an irregular room?

Divide the room into rectangles, triangles or circles, calculate the area of each, then add them together.

How many square feet are in an acre?

One acre is 43,560 square feet, or about 4,047 square meters.

How do I convert square meters to square feet?

Multiply square meters by 10.764. For example, 20 m² is about 215 square feet.