Square Footage Calculator

1. Add your rooms and enter their width and length in feet.
2. For flooring, enter the tile size, square feet per box (shown on the package), and extra for waste.
3. For paint, enter the ceiling height, doors, windows, number of coats, and the can's coverage.
4. See the total area, number of flooring boxes, and suggested combination of paint cans.

To find the area of a rectangular room, multiply width × length: a 13 × 16 ft room is about 208 sq ft. For an L-shaped room, split it into two rectangles and add their areas. When buying flooring, add a waste allowance for cuts and breakage—about 10% for straight layouts and 15% for diagonal layouts or large tiles—and always round up to whole boxes.

To estimate paint, multiply the room’s perimeter × ceiling height to get the wall area, then subtract doors (about 20 sq ft each, 3 × 7 ft) and windows (about 13 sq ft each). Multiply by the number of coats (usually 2 or 3), then divide by the coverage listed on the can—typically 350 to 500 sq ft per gallon per coat for acrylic paint. The can-size recommendation favors larger containers, which often cost less per gallon.

These are estimates. Actual coverage depends on the paint, existing color, primer and surface. Always check the manufacturer’s label, and consult a professional for larger projects.