Square Footage Calculator
Area of a room or a whole floor.
| Area of one room | 180 sq ft |
| Total area | 180 sq ft(1 room(s) of the same size) |
| Square yards | 20 sq yd(useful for carpet and turf) |
| Square metres | 16.7 m² |
| Cost | —(area × price per sq ft) |
Results update instantly and are computed entirely in your browser. For general information and planning only — not engineering, structural or code advice.
About the square footage calculator
Square footage is the most quoted number in property and renovation, and the simplest to get wrong. The basic calculation is length times width, but real rooms are rarely perfect rectangles: alcoves, chimney breasts, bay windows, cupboards and under-stair areas all complicate the outline, and whether they count depends on what you are measuring for. For flooring or tiling, the answer you need is the usable area within the walls, and awkward shapes are best split into rectangles and added together. For estate-agent style measurement, conventions differ from country to country and sometimes ignore certain areas entirely, so a figure that is correct for ordering carpet may not match a listing. Knowing which number you are after prevents a costly misunderstanding. Units are the other source of confusion. A square metre is about ten and three-quarters square feet, so a room measured as twenty square metres is roughly two hundred and fifteen square feet, not sixty-five. When comparing quotes from suppliers who use different units, convert both to the same measure before comparing prices — a quote per square metre always looks cheaper than the same price per square foot. This calculator multiplies length by width, handles a number of identical rooms at once, and restates the result in square feet, square yards and square metres, with an optional cost. For an irregular room, measure it as several rectangles and run them separately, then add. Always measure at floor level rather than trusting a plan, since plans and reality often differ.
This calculator returns estimates for planning and general information only. It is not engineering, architectural, structural, electrical or code advice, and it cannot replace a qualified professional who has seen the site. Material quantities depend on the actual dimensions, the product you buy and local building codes, so confirm the figures before ordering materials or starting work, and always follow local regulations.
Common questions
How do I work out square footage?
Multiply the length of a space by its width, both measured in feet. A room fifteen feet by twelve is one hundred and eighty square feet. For an L-shaped space, split it into rectangles, calculate each one and add the results together.
Why is the area not the same as the number of boxes I need?
Because material is bought in fixed packs and cutting around the edges wastes some of it. Divide the area by the coverage printed on the pack and round up, then add a waste allowance — ten percent for a simple rectangular room, more where the space is irregular or the pattern has to line up.
How do I measure a room with alcoves and bays?
Break it into rectangles, including each alcove as its own shape, and add them. Measuring the widest point and the longest point and multiplying gives an inflated figure, because the corners you counted twice do not actually exist. Careful splitting is what keeps an order from being too large.