Square Footage Calculator
Calculate the square footage of any rectangular room, floor, wall, or outdoor space in seconds. Get the area in square feet, square meters, and square yards — plus an instant total cost estimate for flooring, paint, or any material priced per square foot.
How Square Footage Is Calculated
Square footage is the area of a flat surface measured in square feet. For any rectangular room or space, the calculation is straightforward: multiply length by width. The result tells you how much surface area you are working with — essential for buying flooring, calculating paint, estimating tiling, or planning a renovation project.
Square Footage Formulas
Area (sq ft) = Length (ft) × Width (ft)
Square Meters = Area (sq ft) × 0.0929
Square Yards = Area (sq ft) ÷ 9
Total Material Cost = Area (sq ft) × Price per sq ft
- Length × Width — basic area formula for rectangular spaces
- × 0.0929 — converts sq ft to sq meters (SI units)
- ÷ 9 — converts sq ft to sq yards (carpet is often sold this way)
- Price per sq ft — optional: gives total material cost estimate
Square Footage for Common Home Projects
Knowing your square footage is the first step in almost every home improvement project. For flooring, always order 10% more than your measured area to allow for waste and cuts — 15% for diagonal installations or rooms with many alcoves. For paint, one gallon typically covers 350–400 sq ft per coat; for two coats divide total wall area by 175–200. For tile, the same 10% waste rule applies, plus tile spacers affect the final count.
Average room sizes in US homes: a standard bedroom is 132 sq ft (11×12), a living room is 330 sq ft (15×22), a kitchen is 161 sq ft (13×12.4), and a bathroom averages 40 sq ft. Use these as quick sanity checks when measuring — if your result is wildly different, re-measure to confirm.
Tips for Accurate Measurements
Always measure at the longest and widest points of the room, including any closets or alcoves you want to include. For non-rectangular rooms, break the space into multiple rectangles, calculate each separately, and add them together. Use a laser measure for large spaces — tape measures can sag and give inaccurate readings over distances greater than 20 feet. Round up to the nearest inch before converting to feet (12 inches = 1 foot, 6 inches = 0.5 feet). Last updated: April 2026.