Choose your shape
Area Calculator
Choose a shape and enter its dimensions. Get its area in square feet, square meters and other useful units.
Enter your measurements
Explore area calculators
Choose the shape that matches your surface
Area measures a flat, two-dimensional surface. It is expressed in square units, such as square feet (ft²) or square meters (m²). Choose a shape above, then enter every length in the same unit.
Rectangle or square
A = L × W
Multiply the side lengths. For a square, both sides are equal: A = s².
Circle
A = πr²
The radius is half the diameter. If you have the diameter, use A = πd² ÷ 4.
Triangle
A = b × h ÷ 2
Use the height perpendicular to the base, rather than the length of a sloping side.
Trapezoid
A = (a + b) × h ÷ 2
Average the two parallel side lengths, then multiply by the perpendicular height.
Example: a rectangular room
A room measuring 12 ft by 10 ft has an area of 120 ft², or approximately 11.15 m². This is its floor area, before any allowance for cuts or waste.
What if the shape is irregular?
Split the surface into rectangles, triangles or circles. Calculate each area, then add the sections that do not overlap. Subtract holes or cutouts. This calculator does not estimate area from a map or address.
Area and volume are different
Area uses two dimensions. Volume includes a third dimension, such as depth or height. For a box or container, open the volume calculator.
Results are rounded for display. Calculations use unrounded values and international foot-based conversions. Enter actual lengths, rather than squared units.