Perimeter Calculator
Calculate perimeter for rectangles, circles, triangles, and polygons
Shape Dimensions
Select a shape and enter its dimensions
Calculation Result
Perimeter and additional properties
Select a shape and enter dimensions to calculate perimeter
Common Shape Examples
Click to load common shape examples
A4 Paper (21×29.7 cm)
rectangle
Chess Board (8×8)
square
Pizza (15cm radius)
circle
3-4-5 Right Triangle
triangle
Hexagonal Tile (5cm)
hexagon
Perimeter Formulas
Basic Shapes
Rectangle: P = 2(l + w)
Square: P = 4s
Circle: P = 2πr
Triangle: P = a + b + c
Regular Polygons
Pentagon: P = 5s
Hexagon: P = 6s
Octagon: P = 8s
n-gon: P = n × s
Note: Perimeter is the distance around the outside of a shape. For circles, this is called the circumference. Regular polygons have all sides equal.