Skip the tape measure: scan the room with an iPhone Pro and get exact areas. See how it works.

Free Tool

Square Footage Calculator

Enter measurements in feet and inches. Add rectangles, triangles and circles for odd-shaped rooms, or switch to wall area. Get square feet, square meters and square yards.

Sections

One rectangle for a simple room. For an L-shape, add two rectangles (shown), or add the full rectangle and subtract the missing corner.

Section 1

Shape

Add or subtract

Length

Width

Section 2

Shape

Add or subtract

Length

Width

Results

Sections added

Sections subtracted

Total area

sq ft

Square meters

Square yards

Measure inside, wall to wall. Results are as accurate as the measurements you enter.

How to calculate square footage

Multiply length by width, both in feet. For inches, divide by 12 first. For odd shapes, break the room into rectangles, triangles and circles, find each area, and add them (or subtract a cut-out). Divide by 9 for square yards; multiply by 0.0929 for square meters.

Rectangle = Length × Width

Triangle = Base × Height ÷ 2

Circle = π × (Diameter ÷ 2)²

Wall area = 2 × (Length + Width) × Height − openings

sq yd = sq ft ÷ 9 · m² = sq ft × 0.0929

Worked example: an L-shaped room

The main part of the room is 20 ft by 12 ft. The leg of the L is 10 ft by 8 ft 6 in.

Main rectangle: 20 × 12 = 240 sq ft.
Convert 8 ft 6 in: 6 ÷ 12 = 0.5, so 8.5 ft. Leg: 10 × 8.5 = 85 sq ft.
Total: 240 + 85 = 325 sq ft.
Square yards: 325 ÷ 9 = 36.11 sq yd. Square meters: 325 × 0.0929 = 30.19 m².

Buying material for the area? Run it through the flooring calculator or the tile calculator to add waste and round up to full boxes. For measuring tips, read how to measure a room for flooring.

Skip the tape measure

Odd-shaped room? Scan it instead of splitting it into rectangles.

SiteScope uses the LiDAR sensor on iPhone Pro and iPad Pro to scan a space and build a measured 2D floor plan with walls, doors, windows and room areas. Angled walls, bump-outs and closets are captured as they are, so you don't have to break the room into shapes and add them up.

Room areas and wall areas on a measured floor plan
Multi-room and multi-floor projects
Share the plan by link, or export PDF, DXF and IFC

Start for free How 3D room scanning works

Scanning needs an iPhone Pro or iPad Pro with LiDAR.

By hand vs from a scan

By hand

Sketch the room, measure each leg, convert inches, multiply, add, check your math.

From a scan

Walk the room with an iPhone Pro. Read each room's area off the plan.

Square Footage FAQ

How do I calculate the square footage of a room?

Measure the length and the width in feet and multiply them. A 12 ft by 15 ft room is 12 × 15 = 180 sq ft. If a measurement has inches, divide the inches by 12 first, so 12 ft 6 in becomes 12.5 ft.

How do I find the square footage of an L-shaped room?

Split the L into two rectangles, find the area of each, and add them. Or measure the full bounding rectangle and subtract the missing corner. Both give the same answer. The calculator does either: add sections, or add one and subtract another.

How do I convert square feet to square meters or square yards?

Multiply square feet by 0.0929 to get square meters (1 sq ft = 0.09290304 m²). Divide square feet by 9 to get square yards, since a yard is 3 ft and 3 × 3 = 9. So 325 sq ft is about 30.19 m² or 36.11 sq yd.

How do I calculate the square footage of a wall?

Multiply the wall length by the wall height. For a whole room, multiply the perimeter, 2 × (length + width), by the ceiling height, then subtract doors and windows. Use the Wall area tab above.

How do I calculate the area of a circle or triangle?

Triangle: base × height ÷ 2. Circle: π × radius², where the radius is half the diameter. A 10 ft circle is 3.1416 × 5 × 5 = 78.5 sq ft. A half circle, like a round bay, is half of that.

Is room square footage the same as a home's listed square footage?

No. Adding up room areas measures inside, wall to wall. Listed square footage for a house is usually measured to the outside of the exterior walls under a standard such as ANSI Z765, so it includes wall thickness, halls and stairs and comes out larger.