Area & Perimeter Calculator

Calculate area and perimeter for 7 common shapes. Select a shape, enter the measurements, and get instant results with formulas.

Select a Shape

Area = πr²  ·  Circumference = 2πr  ·  Diameter = 2r
Area = l × w  ·  Perimeter = 2(l + w)
Area = a²  ·  Perimeter = 4a  ·  Diagonal = a√2
Area = ½ × b × h  ·  Perimeter = a + b + c
Area = ½(a+b) × h  ·  Perimeter = a+b+c+d
Area = b × h  ·  Perimeter = 2(a + b)
Area = πab  ·  Perimeter ≈ π(3(a+b) − √((3a+b)(a+3b)))
Formula applied

Area vs Perimeter

Area is the space inside a 2D shape, measured in square units (cm², m², ft²). Perimeter is the total length around the outside of a shape, measured in linear units. For circles, the perimeter is called the circumference.