Room Square Footage Calculator + Flooring Boxes
Add rooms and closets, subtract fixtures and calculate flooring boxes from your net floor area.
Plan your space
Add separate spaces; do not overlap them. Use a subtracting area for an island or fixture. Changing units reinterprets the numbers; re-enter dimensions in the selected unit.
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At a glance
Enter your measurements, then calculate.
Keep full precision while calculating. Round only when planning or ordering.
See formulas & sources ↗A simple way to measure
- Sketch the space and divide it into shapes that do not overlap.
- Enter each shape’s dimensions. For feet and inches, enter 10 and 6 for a 10 ft 6 in measurement.
- Add closets or separate spaces as new areas. Mark an island or other exclusion as a subtraction.
- Check the net area before adding a material allowance. Waste increases the order quantity; it does not increase your measured floor or land area.
Example: two spaces and a cutout
A 12 × 10 ft space is 120 sq ft. Add a 4 × 6 ft space and subtract a 2 × 3 ft fixture: the net is 138 sq ft. With 10% extra, plan for 151.8 sq ft.
Choose the right dimensions
For a circle, measure the radius from the center to the edge, not the full diameter. A triangle needs a perpendicular height. A trapezoid needs two parallel sides and the perpendicular distance between them. For an L-shape, enter the full outer rectangle and the missing corner.
Closets, fixtures and flooring boxes
List each closet separately so it is not forgotten or counted twice. Subtract a fixed cabinet or island only if your installation will actually stop at its edge. Follow the flooring manufacturer’s guidance for heavy fixtures.
Box count rounds up after adding extra material. At 20 sq ft per box, 151.8 sq ft requires 8 boxes. Compare product coverage labels and keep cutting allowance separate from your room’s measured area.
Formulas and exact conversion constants: methodology and sources.