Square Footage Calculator
Split a space into rectangles and L-shapes, enter each one, and the square footage calculator gives the total in square feet and square meters. Use it to order flooring, or as a floor plan square footage calculator for a whole home, one area per room.
Square footage calculator
- Area 114.00 m²
Meters, e.g. 4.2, 420 cm or 4200 mm
Meters, e.g. 4.2, 420 cm or 4200 mm
- Area 226.00 m²
Meters, e.g. 4.2, 420 cm or 4200 mm
Meters, e.g. 4.2, 420 cm or 4200 mm
The notch taken out of one corner
The notch taken out of one corner
- Total in square feet
- 430.6 sq ft
- Total in square meters
- 40.00 m²
How to use it
Choose a shape for each area
Rectangle or L-shape. Add as many areas as you need and remove the ones you don’t.
Enter the sizes
Feet and inches or meters; a bare number is feet in imperial mode and meters in metric mode.
Read the total
Each area shows its own size, and the total is given in both square feet and square meters.
Open an area in the editor
Every area has a button that opens it as a room in the editor, L-shapes included.
Measuring an L-shaped area
Enter an L-shape as its overall width and length plus the size of the notch missing from one corner. The calculator subtracts the notch: a 20 ft by 16 ft area with a 6 ft by 6 ft notch is 320 − 36 = 284 sq ft.
Splitting the same L into two rectangles that do not overlap gives the same answer, so use whichever is easier to measure. The mistake to avoid is multiplying the two longest sides and stopping there: that counts the missing corner as floor.
If a shape is more complicated, break it into rectangles and add one area for each. Any area with a missing or unreadable size counts as zero until you fix it, and the total says so.
Units and rounding
All sums are worked out in millimeters and rounded only for display: square feet to one decimal place and square meters to two. That way, adding many small areas does not pile up rounding errors, and switching between metric and imperial never changes the total.
When it helps
Ordering flooring
Add up every area that gets the same floor, including an L-shaped kitchen or a hallway.
Odd-shaped rooms
A room with a chimney breast or a cut corner is one L-shape or two rectangles.
Reading a listing
Convert a figure in square meters to square feet, or the reverse, by entering the room sizes.
Before drawing
Check the overall area, then open the shape in the editor as the first room of a plan.
Only need to convert a total?
Frequently asked questions
How do I calculate the square footage of an L-shaped room?
Measure the full width and length as if the room were a rectangle, then measure the missing corner. Square footage is the full rectangle minus the corner. Choose “L-shape” in the calculator to do this automatically.
How do I convert square feet to square meters?
Multiply square feet by 0.09290304, or divide by about 10.764. The calculator always shows both totals.
Do walls count in square footage?
That depends on who is measuring and why. This calculator adds the areas you enter, so measure inside the walls if you want floor space and to the outside if you want a building’s footprint.
Should I add extra when buying flooring?
Suppliers usually ask for some extra to cover cuts and waste, and how much depends on the material and the shape of the room. This calculator gives the measured area only, so ask your supplier what to add.
Can I open the shape in the floor plan editor?
Yes. Each area has its own button that creates a project with that rectangle or L-shape drawn as a room, ready for doors, windows and furniture.
Ready to plan your space?
It is free, runs in your browser and needs no account. Projects are saved privately on this device.