About the Square Footage Calculator
Square footage of a room, floor or plot, including multiple rooms and a waste allowance.
Also known as: sq ft calculator, square feet of a room, floor square footage, how many square feet, square-meter.
How to use this calculator
- Enter measurements in, length, width, number of identical rooms and the other fields.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
area = length × width × rooms × (1 + waste)
Worked example
Using the values pre-filled in the calculator above:
- Measurements in: Feet
- Length = 12
- Width = 10
- Number of identical rooms = 1
- Additional area = 0
- Waste allowance = 0 %
- Price per unit area = 0
the calculator returns:
- Square feet: 120
- Square metres: 11.148
- Square yards: 13.333
- Without waste: 120 ft²