Square Footage Calculator for Contractors
Length times width, repeated for as many areas as the job has. It also gives square yards, because carpet is still quoted that way in much of the country, and perimeter, because trim and baseboard are not.
Worked example
These are the figures the calculator opens with and the answer it gives. Change anything above and every number below moves with it.
- Length14 ft
- Width12 ft
- How many rooms or areas this size1
- Extra area to add0 sq ft
Total area168 sq ft
| One area | 168 sq ft |
|---|---|
| Times 1, plus extra | 168 sq ft |
| Square yards | 18.67 |
| Square meters | 15.61 |
| Perimeter of one area | 52 ft |
What this calculator assumes
- Length times width, times how many areas are that size. For an L shaped room, split it into two rectangles and run this twice.
- Square yards are square feet divided by nine, which is how carpet is still quoted in much of the country.
Rooms that are not rectangles
Split the space into rectangles and add them. An L shaped room is two rectangles, a bay window is a rectangle plus a triangle, a hallway is its own rectangle. Run this once per piece and add the results in the extra field.
For a triangle, take half the base times the height. For a circle, 3.1416 times the radius squared. Those two cover nearly everything a residential job will throw at you.
Which square footage the customer means
Gross living area, the number on the listing, is measured to the outside of the exterior walls and excludes the garage and anything below grade. It is not the number you order flooring against.
For material, you want the finished floor area inside the walls, which is always smaller. When a homeowner says the house is 2,400 square feet and the flooring measures 2,050, neither of you is wrong, you are measuring different things. Say which one you used in the estimate and the argument never starts.
Questions people ask
How do I calculate square footage of an L shaped room?
Split it into two rectangles at the inside corner, measure each one, and add them. This calculator has a field for extra area so you can run the bigger rectangle and add the smaller.
How many square feet are in a square yard?
Nine. A square yard is 3 feet by 3 feet. To convert square feet to square yards, divide by nine.
Should I add waste to square footage?
Not to the area itself. Keep the measured area honest and add waste at the material step, where the percentage depends on what you are installing and how it is laid.
Free Contractor Estimate Template, free, no signup, PDF Word and Excel.
Common sizes, worked out
The same calculator with the numbers already filled in, one page per size, each ending in its own material list.