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Area Calculator
Calculate the area of rectangles, triangles, and circles using different units of measurement.
What Is Area?
Area measures the amount of surface covered by a two-dimensional shape. It is commonly expressed in square units such as square feet, square meters, square inches, or square centimeters.
Area calculations are useful for home improvement projects, construction, flooring, landscaping, painting, and many other applications.
How to Calculate Area
The formula used to calculate area depends on the shape. This calculator supports rectangles, triangles, and circles.
Rectangle Area
The area of a rectangle is calculated by multiplying its length by its width.
Area = length × width
For example, a room that is 20 feet long and 10 feet wide has an area of:
20 × 10 = 200 ft²
Triangle Area
The area of a triangle is calculated by multiplying its base by its height and dividing the result by two.
Area = (base × height) ÷ 2
A triangle with a base of 20 feet and a height of 10 feet therefore has an area of 100 square feet.
Circle Area
The area of a circle is calculated using its radius and the constant pi (π).
Area = π × radius²
If a circle has a radius of 5 feet, its area is approximately 78.54 square feet.
Square Feet and Square Meters
Square feet (ft²) are commonly used in the United States for measuring rooms, homes, floors, yards, and other areas.
Square meters (m²) are commonly used in most countries around the world.
One square meter is approximately 10.764 square feet.
Area Calculator Example
Suppose you want to calculate the area of a rectangular room that is 20 feet long and 12 feet wide.
Using the rectangle formula:
Area = 20 × 12 = 240 ft²
The room therefore has an area of 240 square feet.
Where Is Area Used?
Area calculations are useful in many everyday and professional situations, including:
- Calculating flooring requirements
- Estimating paint coverage
- Measuring rooms and floors
- Planning landscaping projects
- Estimating construction materials
- Calculating land and property areas
For construction projects, you may also find our Square Footage Calculator and Concrete Calculator useful.
Frequently Asked Questions
How do you calculate the area of a rectangle?
Multiply the rectangle's length by its width. For example, a rectangle that is 10 feet by 20 feet has an area of 200 square feet.
How do you calculate the area of a triangle?
Multiply the triangle's base by its height and divide the result by two.
How do you calculate the area of a circle?
Multiply π by the radius squared. The formula is Area = π × r².
What is the difference between area and perimeter?
Area measures the surface inside a shape, while perimeter measures the total distance around the outside of a shape.
How many square feet are in one square meter?
One square meter is approximately 10.764 square feet.
Can I calculate area in meters?
Yes. Select meters as the unit and the calculator will return the area in square meters, along with the equivalent square-foot value.