About Square Footage Calculator
Calculate square footage for any room, floor, or yard. Add multiple sections for irregular shapes and convert between sq ft, sq meters, and sq yards. Free, no signup.
How to use
- Select the shape that matches the area you are measuring: rectangle (most rooms), triangle, circle, or trapezoid. For L-shaped rooms, irregular spaces, or complex floor plans, break the area into multiple simpler shapes and calculate each separately.
- Enter the dimensions in your preferred unit: feet, inches, metres, or centimetres. For rectangles, enter length and width. For triangles, enter base and height. For circles, enter the radius or diameter. The calculator handles unit conversions automatically.
- Add multiple sections for irregular or multi-room spaces. Click Add Section for each shape, and the calculator sums all sections into a single total. This is ideal for calculating total flooring needs across an entire floor plan or the total area of a property with additions and bump-outs.
- View the total square footage with automatic conversions to square metres, square yards, and acres. Square footage is used for flooring, paint, and property listings. Square metres are standard in Canadian real estate listings and construction specifications. Square yards are used for carpeting.
- Use the result as the starting point for material estimates: flooring (add 10% waste for standard installations, 15% for diagonal patterns), paint (divide by 350 for gallons needed per coat), tile (divide by tile area and add 10-15% for cuts and waste), and landscaping materials.
- Save or print your calculations for contractor communication. Providing accurate measurements helps contractors quote more precisely and prevents material shortages or expensive overages on your project.
Frequently asked questions
How do I calculate square footage of a room?
For rectangular rooms: multiply length by width in feet. A 12 x 15 foot room is 180 square feet. Measure at floor level along the longest wall in each direction. For rooms with closets, alcoves, or bay windows, measure the main rectangle first, then add the square footage of each extension separately. For accuracy, measure in feet and inches (12 feet 6 inches = 12.5 feet) rather than rounding. If the room has angled walls, break it into a rectangle plus a triangle and calculate each section.
How do I convert square feet to square metres?
Divide square feet by 10.764 to get square metres. A 1,500 sq ft home is approximately 139 square metres. To convert square metres to square feet, multiply by 10.764. Quick approximations: 100 sq ft is about 9.3 sq m, 500 sq ft is about 46.5 sq m, 1,000 sq ft is about 93 sq m. Canadian real estate listings typically use square feet for houses and square metres for condos and commercial spaces. International real estate uses square metres exclusively. This calculator converts automatically between all common area units.
How do I calculate square footage of an irregular shape?
Break the irregular shape into a combination of rectangles, triangles, and circles. Calculate each shape separately, then add them together. For an L-shaped room, divide it into two rectangles. For a room with a bay window, calculate the main rectangle plus the triangular or trapezoidal bay area. For curved walls, approximate with a semicircle or quarter circle. For very irregular spaces, use the triangulation method: divide the floor plan into triangles, calculate each triangle's area (base x height / 2), and sum them all.
How many square feet is a 10x10 room?
A 10x10 room is exactly 100 square feet. Common room sizes and their square footage: 10x10 = 100 sq ft (small bedroom), 10x12 = 120 sq ft (standard bedroom), 12x14 = 168 sq ft (master bedroom), 10x16 = 160 sq ft (living room), 12x20 = 240 sq ft (large living room), 10x10 = 100 sq ft (home office). For reference, the average Canadian home is approximately 1,800-2,000 square feet. A single-car garage is typically 200-250 sq ft, and a two-car garage is 400-500 sq ft.
What is the difference between square feet and linear feet?
Square feet measures area (two-dimensional: length x width). Linear feet measures only length (one-dimensional: just length). A 10-foot-long 2x4 board is 10 linear feet regardless of its width. A 10 x 10 foot room is 100 square feet. The distinction matters when purchasing materials: flooring is sold by the square foot, trim and moulding by the linear foot, and fencing by the linear foot. Confusing the two leads to major ordering errors. For example, a room perimeter of 50 linear feet of baseboard requires 50 linear feet of moulding, but the floor area of the same room might be 150 square feet of flooring.
How do I measure square footage for real estate listings?
In Canada, the RECA (Real Estate Council of Alberta) standard requires measuring exterior wall dimensions and calculating the total area within the outer walls of each level, excluding garages, unfinished basements, and covered porches. Most provinces follow similar standards. Measure each floor separately and specify above-grade versus below-grade square footage. Finished basement space is typically listed separately because it has lower value per square foot than above-grade living space. Always measure to the outside of exterior walls (not interior room dimensions) for listing purposes. Once you know your home's total square footage, use the
Home Affordability Calculator to understand how size impacts value and what you can afford to buy or build.
How accurate do my measurements need to be?
For flooring and material estimates, accuracy within 6 inches is usually sufficient because you are adding waste factor anyway (10-15%). For real estate listings, measure to the nearest inch since small differences affect the total significantly in large spaces. For construction and building permits, measure to the nearest quarter inch. Use a tape measure at least 25 feet long for room measurements. For large areas, a laser distance measurer ($30-$100) provides accuracy within 1/8 inch over distances up to 100+ feet and is far easier than wrestling with a tape measure across large rooms.
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