Room Area Calculator

Get square feet, square meters and perimeter from any rectangle - switch units with one click.

How the area estimate works

Area is simply length x width. We convert between feet and meters using 1 ft = 0.3048 m, so 1 sq ft = 0.0929 sq m. Perimeter is 2 x (length + width), and wall area multiplies perimeter by ceiling height - exactly what paint and wallpaper tools use downstream.

sq ft = length x width (in ft)
sq m = sq ft x 0.092903
perimeter = 2 x (length + width)

Why both units matter

In the US, flooring, drywall and paint are quoted in square feet. In most of the world, product datasheets list square meters. Keeping both on one screen prevents the classic mistake of ordering based on the wrong unit and coming up short by a factor of ten.

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Use cases

Flooring takeoff - area + 5% waste feeds directly into the tile calculator.
Paint planning - wall area here is the input the paint calculator expects.
Rental listings - international tenants expect square meters; locals expect square feet.
Trim and molding - perimeter x height + waste estimates baseboard length.

Conversion cheat sheet

1 ft = 0.3048 m. 1 sq ft = 0.0929 sq m (divide by 10.764). 1 sq m = 10.764 sq ft. A 200 sq ft room is about 18.6 sq m; a 5 m x 4 m room is 20 sq m or ~215 sq ft.

Frequently asked questions

How do I convert square feet to square meters?

Divide square feet by 10.764. One square meter is about 10.76 square feet, so a 200 sq ft room is roughly 18.6 sq m.

Why do I need the perimeter?

Perimeter drives baseboard, crown molding, flooring transitions and many trim quotes. Multiply it by the trim height and add waste to estimate material length.

Estimates only. Irregular rooms need dividing into rectangles. Confirm with your contractor.

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Measuring rooms accurately

How to use this calculator

Clear a path along the walls, then measure wall-to-wall at floor level — baseboards can add a fraction of an inch that matters for materials.
Multiply length × width for each rectangular section.
For L-shaped or irregular rooms, divide the floor into rectangles, calculate each, and add them together.
Convert units as needed: 1 square foot = 0.0929 square meters; 1 square meter = 10.76 square feet.
For flooring orders, add the material's recommended waste factor (typically 5–10% for plank products) on top of the measured area.

Quick reference

Conversion	Value	Value
1 sq ft	144 sq in	0.0929 sq m
10 sq ft	0.93 sq m	1.11 sq yd
100 sq ft	9.29 sq m	11.11 sq yd
1 sq m	10.76 sq ft	1.20 sq yd

Pro tips

Measure twice, cut once still applies: re-check any dimension that will drive a material order before you buy.
Closets count toward floor area for flooring and heating calculations but are often excluded from advertised room sizes in real-estate listings.
Round each measurement up to the nearest inch — accumulated rounding down is how flooring orders come up short.

Frequently asked questions

Do I include closets in room area?

For flooring and paint projects, yes — the materials go inside them. Real-estate style square footage usually measures the overall dwelling rather than individual rooms, so the two figures serve different purposes.

How do I measure a room with alcoves or bay windows?

Sketch the floor shape first, break it into rectangles that cover every alcove, measure each one, and add the results. A simple pencil sketch with all dimensions labeled prevents missed sections.

Is ceiling area the same as floor area?

For flat ceilings, yes. Vaulted, coffered, or tray ceilings have more surface than the floor below, so paint coverage for those needs separate measurements.