Square Footage & Area Calculator
Calculate the area of rooms, plots and surfaces — rectangles, circles, triangles and trapezoids — in square feet, square metres, square yards and acres, with material cost.
How to use
- 1Pick the shape and the unit you measured in.
- 2Enter the dimensions; add a price per square foot or metre to estimate cost.
How it's calculated
Rectangle = length × width. Circle = π × r². Triangle = base × height ÷ 2. Trapezoid = (a + b) ÷ 2 × height. 1 m² = 10.7639 ft²; 1 acre = 43,560 ft².
Frequently asked questions
How do I measure an L-shaped room?
Split it into two rectangles, calculate each, and add them together.
How much extra flooring should I buy?
Add 5–10% for cuts and waste, or 15% for diagonal layouts and patterned tiles.
How many square feet are in a square metre?
10.7639. To convert m² to ft², multiply by 10.7639; to go the other way, divide.