Calculate the perimeter or circumference of any shape by entering its dimensions.
Select your shape from the dropdown — the input fields update automatically to match. Enter the required dimensions in any unit (cm, m, inches — the result uses the same unit). Click Calculate to see the perimeter. For a circle, the result is the circumference (2πr).
Results from this calculator are estimates based on standard geometric perimeter formulas and are provided for general informational purposes. Rounding, regional standards and manufacturer variations can cause small differences from official or brand-specific figures.
For decisions where precision is critical — engineering, construction or legal contexts — verify results with a qualified professional or an official reference source.
This calculator uses standard geometric perimeter formulas. The underlying logic was built and manually cross-checked against independent reference calculators and textbook worked examples across dozens of test cases before publication.
Every formula on elCalculador is reviewed by our editorial team for mathematical accuracy, and pages are re-audited whenever a calculator's logic or inputs are updated.