Suppose a living room is 14 by 12 feet, a bedroom is 12 by 10 and a den is 10 by 9. Together they cover 378 square feet, or 35.12 square metres. Add 10% for waste and the flooring order becomes 415.8 square feet, which costs $1,871.10 at $4.50 a foot.
Measuring a room
Measure the floor from wall to wall, length first and then width, and multiply the two. Enter each room and the calculator adds the areas. Quick work. For an L-shaped room, split the floor into two rectangles and enter each as its own room. Alcoves work the same way, and a bay window is one more rectangle on top of the main one.
Feet and metres
One square metre equals 10.7639 square feet. Choose your unit at the top and the calculator converts for you. Listings in Ontario tend to quote square feet, whereas builders and some plans use square metres.
To check by hand, divide the 378 square feet above by 10.7639, which gives 35.12 square metres. Going the other way, multiply metres by 10.7639, so a 20 square metre room is 215.28 square feet. Convert the total, never each side, to keep rounding errors small.
What each foot costs
Type in the price of a home and you get the cost of each square foot, a number buyers lean on when they compare one home with another across town. Toronto condos often sell by the square foot, so a small unit can cost more per foot than a big house.
Material and waste
Flooring, tile and paint all need more than the exact area, because cuts and mistakes leave offcuts. A common allowance is 10%, and diagonal patterns need more. The calculator shows how much to order and what it will cost. Try a bedroom of 12 by 11 feet, a hall of 15 by 4 and a closet of 6 by 3. The areas are 132, 60 and 18, or 210 square feet. With 10% waste you would order 231 square feet, and at $4.50 a foot the material costs about $1,040.
Gross and usable area
Watch the label. Some listings show gross area, which includes walls, halls and sometimes balconies. Others give interior area. The two can differ by 10% or more. Before comparing prices, especially for condos, ask which one the seller means.
Measuring an entire home
For a whole house, measure each floor on the inside and add them up. Basements often get counted separately in listings. If you compare with other homes, leave unfinished space out of the living area.
Ceilings, walls and paint
Paint depends on wall area, not floor area. Multiply the room’s perimeter by the ceiling height, then subtract doors and windows. One litre covers about 10 square metres, though the can has the final word. Allow for a second coat and a little extra for touch-ups.
Common mistakes
People often measure to the outside of the walls, skip closets, or forget that a wall between rooms takes up space. Measure the floor you can walk on, and use one method for every room. When a listing’s size differs from yours by more than a few per cent, ask why. Round up to whole boxes or rolls.
Where to go next
Feed the size into the home value calculator. Then plan the purchase with the down payment calculator and the monthly budget calculator.
Frequently asked questions
How do I calculate square footage?
Multiply the length by the width of each room and add the areas.
What is a square metre in square feet?
10.7639.
How do I measure an L-shaped room?
Split it into two rectangles and add them.
Should I buy extra material?
About 10% for waste.
What is price per square foot?
The price divided by the area.
Do listings use gross or interior area?
It varies. Ask the seller which one they show.
Sources and updates
Last reviewed: . Full disclaimer. How we build calculators. Editorial policy.
Estimate only. This calculator gives general information for planning. It is not tax, legal or financial advice, and it is not affiliated with the City of Toronto, MPAC or the Canada Revenue Agency. Results depend on the numbers you enter and may differ from official amounts. Check official sources or a qualified professional before you decide.