Perimeter Calculator

• A free online perimeter calculator that computes the perimeter of 17 geometric shapes — square, rectangle, triangle, circle, ellipse, regular polygon, trapezoid, plus semicircle, sector, parallelogram, rhombus, star, and more
• Works with 8 length units across metric and imperial systems (meter, centimeter, inch, foot, yard, and more); the result is automatically converted and shown in every other unit
• Besides the final value, it shows the formula and step-by-step working, and lets you copy the result with one click; a button can also fill in example values to help you get started quickly

1. Open the tool page — no download or installation required
2. Pick a shape, enter its dimensions such as side lengths or radius, and choose the length unit
3. Click "Calculate" to get the result, then "Copy Result" to copy it; clear the inputs to calculate again

• Completely free to use, with no registration or login needed
• All calculations run locally in your browser — your data is never uploaded

Free online perimeter calculation tool, supports perimeter calculation of 7 common geometric shapes: square, rectangle, triangle, circle, ellipse, regular polygon, and trapezoid. Enter shape parameters to automatically calculate the perimeter, supports multiple length unit conversions.

Open the tool page — no download or installation required Pick a shape, enter its dimensions such as side lengths or radius, and choose the length unit Click "Calculate" to get the result, then "Copy Result" to copy it; clear the inputs to calculate again

Completely free to use, with no registration or login needed All calculations run locally in your browser — your data is never uploaded

Yes, Perimeter Calculator is completely free. No download or installation required — it runs right in your browser.