Perimeter Calculator – Find Perimeter of Circles, Triangles, Squares & More

Use this free Perimeter Calculator to find the perimeter of shapes like circles, triangles, squares, polygons, and trapezoids. Supports diameter, arc, and area-based inputs. Whether you're solving algebra problems or measuring land in acres, this tool gives fast, accurate results. Ideal for students, builders, and DIY planners—mobile-friendly and no downloads required.

Perimeter Calculator

Select Shape: Triangle Rectangle Circle Square Pentagon