About the Area Calculator
Whether you are buying flooring, paint, turf or a plot of land, you need area, and you need it in the unit the supplier sells by. Choose a shape, enter its dimensions in any common unit, and get the area in square feet, square metres, square yards and acres at once. Add a price per square foot to estimate the cost.
How to use the Area Calculator
- Choose the shape and the unit you measured in.
- Enter the dimensions the form asks for — length and width, base and height, or radius.
- Read the area in square feet, square metres, square yards and acres.
- Optionally add a price per square foot for a quick cost estimate; add 5–10% for waste when buying materials.
The formula behind it
Rectangle = length × width. Triangle = ½ × base × height. Circle = π × r². Trapezoid = ½ × (a + b) × height. Ellipse = π × a × b. Parallelogram = base × height.
Frequently asked questions
How do I calculate square footage of a room?
Multiply length by width in feet. A 12 ft by 10 ft room is 120 square feet. For L-shaped rooms, split it into rectangles and add them.
How many square feet are in a square metre?
One square metre is 10.7639 square feet, because a metre is 3.28084 feet and area scales with the square.
How much extra material should I buy?
Add 5–10% for cuts and waste on simple rooms, and 15% or more for diagonal layouts or patterned materials.
Why is a circle’s area π × r² and not π × d?
Area grows with the square of the radius. Doubling the radius makes the area four times larger. π × d is the circumference.
How many square feet are in an acre?
One acre is 43,560 square feet, or about 4,047 square metres.