Area & Perimeter

Calculate area and perimeter for rectangles, triangles, circles, and more with labeled diagrams

A = 8 × 5 = 40
Area
40
Perimeter
26
W = 8H = 5

About this calculator

The Area & Perimeter Calculator instantly computes the area and perimeter of common 2D shapes including rectangles, squares, triangles, circles, trapezoids, and parallelograms. Enter the dimensions for your chosen shape and see the result with a labeled diagram. Useful for geometry homework, home improvement projects, and understanding how size and boundary measurements relate.

Common examples

  • Rectangle 8 cm × 5 cm → Area = 40 cm², Perimeter = 26 cm
  • Square with 6 m side → Area = 36 m², Perimeter = 24 m
  • Circle with radius 7 cm → Area ≈ 153.94 cm², Circumference ≈ 43.98 cm
  • Triangle with base 10 ft and height 6 ft → Area = 30 ft²
  • Parallelogram with base 12 m and height 5 m → Area = 60 m²