How do I convert square feet to square metres?

Multiply square feet by 0.09290304 to get square metres. Divide square metres by 0.09290304, or multiply by about 10.764, to get square feet. The calculator shows both values for every result.

How do I enter feet and inches?

With US units selected, type them as you read them from the tape: 11' 9", 11ft 9in or just 11 9 (feet, then inches). Fractions work too, such as 11' 9 1/2". The calculator converts them to feet, so 11' 9" becomes 11.75 ft. A decimal such as 11.75 is still accepted.

How do I measure a room with angled walls or curves?

Split the floor into rectangles that cover it as closely as possible and add their areas. For a triangle-shaped corner, measure the two sides that meet at the right angle, multiply them and divide by two, then add that area yourself. For material that is cut to fit, it is safer to measure the smallest rectangle that contains the whole shape.

Does the area include the space under cabinets and fixtures?

The calculator uses the measurements you enter. Whether flooring runs under kitchen cabinets, a bathtub or built-in furniture depends on the product and on how it is installed, so check the installation instructions and leave those areas out if they stay uncovered.

Why is the perimeter of an L-shaped room the same as that of a rectangle?

Cutting a rectangular corner out of a rectangle removes two pieces of wall and adds two new pieces of exactly the same lengths. The area gets smaller, but the distance around the room does not change.

Room area calculator: square metres and square feet

Find the floor area of a room from its measurements. The result is shown in square metres and square feet at the same time, so you can use it with any product label.

Result

This is the result for the example values. Enter your own values and select Calculate.

Area in square metres: 12 m²
Area in square feet: 129.2 sq ft
Perimeter: 14 m

Results are estimates. Measure on site and check the product label before you buy.

What this calculator does

It calculates the area of a floor, ceiling or wall from lengths that you measure with a tape. Three shapes are covered: a rectangle, an L-shape, and a room that you split into up to four rectangles.

For rectangles and L-shapes it also shows the perimeter, which is the length of baseboard, skirting board or trim around the room before you subtract door openings.

How to use it

Choose the units you measured in: metres or feet. In feet you can type 12' 6", 12 6 or 12.5 for 12 feet 6 inches.
Choose the shape of the room.
Rectangle: enter the length and the width.
L-shape: enter the full length and full width as if the room were a complete rectangle, then the length and width of the corner that is missing.
Several rectangles: split the floor into rectangles that do not overlap and enter each one. Sections 3 and 4 are optional.
Select Calculate.

How the result is calculated

Rectangle: area = length × width. Perimeter = 2 × (length + width).
L-shape: area = full length × full width − corner length × corner width. The perimeter is the same as that of the full rectangle, because the two walls of the corner are as long as the pieces of wall they replace.
Several rectangles: area = the sum of length × width of every section. No perimeter is shown, because it depends on how the sections touch.

One foot is exactly 0.3048 metres, so one square foot is 0.09290304 square metres and one square metre is about 10.764 square feet. Areas are rounded to the nearest 0.01 square metre and 0.1 square foot.

Worked example

A rectangular room is 4 m long and 3 m wide. Area: 4 × 3 = 12 m². In square feet: 12 ÷ 0.09290304 = 129.2 sq ft. Perimeter: 2 × (4 + 3) = 14 m.

The same room with a corner of 2 m by 1.5 m missing is an L-shape. Area: 12 − 2 × 1.5 = 9 m², which is 96.9 sq ft. The perimeter is still 14 m.

In US units: a room of 12 ft by 10 ft has 12 × 10 = 120 sq ft, which is 11.15 m². Its perimeter is 2 × (12 + 10) = 44 ft.

Common mistakes

Writing feet and inches as a decimal by mistake: 12 feet 6 inches is 12.5 feet, not 12.6. Type 12' 6" or 12 6 instead, and the calculator converts it.
Measuring along the baseboard or skirting board instead of wall to wall. Measure at floor level from one wall surface to the other.
Assuming the room is square. Measure the length at both sides of the room, and use the larger value when you buy material.
Letting sections overlap or leaving a gap between them when you split a room into rectangles. A quick sketch with the measurements prevents both.
Forgetting closets, alcoves and bay windows that get the same flooring.

What to do with the result

Use the area in the calculators for flooring and tile, which add the allowance for cuts and round up to whole boxes.

Frequently asked questions

How do I convert square feet to square metres?: Multiply square feet by 0.09290304 to get square metres. Divide square metres by 0.09290304, or multiply by about 10.764, to get square feet. The calculator shows both values for every result.
How do I enter feet and inches?: With US units selected, type them as you read them from the tape: 11' 9", 11ft 9in or just 11 9 (feet, then inches). Fractions work too, such as 11' 9 1/2". The calculator converts them to feet, so 11' 9" becomes 11.75 ft. A decimal such as 11.75 is still accepted.
How do I measure a room with angled walls or curves?: Split the floor into rectangles that cover it as closely as possible and add their areas. For a triangle-shaped corner, measure the two sides that meet at the right angle, multiply them and divide by two, then add that area yourself. For material that is cut to fit, it is safer to measure the smallest rectangle that contains the whole shape.
Does the area include the space under cabinets and fixtures?: The calculator uses the measurements you enter. Whether flooring runs under kitchen cabinets, a bathtub or built-in furniture depends on the product and on how it is installed, so check the installation instructions and leave those areas out if they stay uncovered.
Why is the perimeter of an L-shaped room the same as that of a rectangle?: Cutting a rectangular corner out of a rectangle removes two pieces of wall and adds two new pieces of exactly the same lengths. The area gets smaller, but the distance around the room does not change.

Last updated: September 29, 2026