Perimeter Calculator
Calculate the perimeter of common shapes such as squares, rectangles, and triangles.
Example
→ Perimeter = 2 × (8 + 5)
→ Perimeter = 2 × 13
→ Final answer: 26
What does this calculator do?
It calculates the total distance around the boundary of a shape. Depending on the selected figure, the calculator applies the correct perimeter formula automatically.
Why use this calculator?
It is useful for geometry homework, design measurements, construction planning, and any situation where boundary length matters. The tool gives fast and accurate results without doing the formula manually.
How is the result calculated?
The formula depends on the selected shape:
Square: 4 × side
Rectangle: 2 × (length + width)
Triangle: side A + side B + side C
Frequently Asked Questions
What is perimeter?
Perimeter is the total length around the outside of a two-dimensional shape.
Can I use decimals?
Yes. The calculator accepts whole numbers and decimal values.
Why do some shapes need more inputs?
Different shapes use different formulas. A square needs one side, a rectangle needs two, and a triangle needs three.