Calculate area and perimeter for rectangles, circles, and triangles.
To calculate area and perimeter:
The calculator returns both the area and perimeter (or circumference for circles).
Area and perimeter formulas:
Area = length × width, Perimeter = 2(length + width)Area = π × r², Circumference = 2πrArea = ½ × base × height, Perimeter = a + b + cRectangle: Length 10, Width 5.
10 × 5 = 502(10 + 5) = 30Circle: Radius 7.
π × 7² = 153.942π × 7 = 43.98The calculator works with any units — just be consistent. If you enter meters, the area is in square meters and perimeter in meters. If you enter feet, results are in square feet and feet.
You need all three side lengths for perimeter. If you only have base and height, you can find the area (½ × base × height), but you'll need at least one more side length or angle to determine the full perimeter.