Free calculator
Square Footage Calculator
Calculate area in square feet and square metres for rectangles, circles, and triangles. Add quantity and a price per unit for a cost. Free, no sign-up.
For irregular spaces, split the area into rectangles, triangles, and circles, calculate each, and add them up. For whole plans, measure areas to scale straight off the drawing in the app.
Estimating a whole job? Calibrate the plan once and take off quantities straight off the drawing with ContractorCounter's drywall takeoff software so they flow into a live bill of quantities and a quote.
How to calculate square footage
For a rectangular space, square footage is length × width with both measurements in the same unit. A round area is π × (diameter ÷ 2)², and a triangle is (base × height) ÷ 2.
For an irregular room, break it into rectangles and triangles, calculate each, and add them up, the same way a takeoff handles a complex floor plate.
FAQ
How do you calculate square footage?
Multiply length by width for a rectangle (both in the same unit). For a circle use π × (diameter ÷ 2)²; for a triangle use (base × height) ÷ 2. This calculator handles all three and converts between square feet and square metres.
How do I find the area of an irregular room?
Split it into simple shapes (rectangles, triangles, and circles), calculate each area, and add them together. For a whole plan, it is faster to measure areas to scale directly on the drawing.
How many square feet are in a square metre?
One square metre is about 10.76 square feet, so one square foot is about 0.093 square metres. The calculator shows both units at once.