Home & Room Calculator
Calculate room area, estimate paint coverage, flooring quantity and wallpaper rolls for home improvement projects.
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Home improvement projects always start with measuring. Whether you are calculating room square footage for a real estate listing, figuring out how many gallons of paint to buy for a bedroom, estimating flooring for a renovation or counting wallpaper rolls for a feature wall - getting the quantities right saves money and extra trips to the hardware store. All calculators work in both feet and meters.
Frequently asked questions
Multiply the room length by its width. A 12 × 10 foot room is 120 square feet (about 11.15 square meters). For L-shaped rooms, split into rectangles and add the areas.
A 12×12 foot room with 8-foot ceilings has about 384 sq ft of wall area. After subtracting doors and windows, you need roughly 1 gallon per coat. Two coats requires about 2 gallons (7.6 liters).
Calculate the room area and add 10% for waste (cuts, mistakes and future repairs). A 200 sq ft room needs about 220 sq ft of flooring. Use 15% waste for diagonal installations.
A standard US wallpaper roll (21 inches wide, 33 feet long) covers about 57 sq ft. With pattern matching waste, plan for about 48 usable sq ft per roll. Divide your wall area by 48 and round up.
Multiply feet by 0.3048 to get meters. A 12×10 foot room is 3.66×3.05 meters. For square footage to square meters, multiply by 0.0929.
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