Regular Polygon Calculator
Calculate a regular polygon’s area, apothem and perimeter.
Your inputs
Calculation results
Formula & assumptions
Area = ns²/[4 tan(π/n)].
Values use the specified units. Calculations use floating-point arithmetic. Check input measurements and formula assumptions before applying the result.
Compare your scenarios
Save up to five results to compare changes side by side. Scenarios stay in this tab until you clear or reload it.
Using Regular Polygon Calculator
Calculate a regular polygon’s area, apothem and perimeter.
- Enter number of sides, side length using the units printed under each field.
- Choose Calculate, or enable live updates. Review the result labels and formula assumptions.
- Save scenarios to compare up to five variations, then copy the report or download JSON or CSV.
Example
Number of sides: 6 sides Side length: 5 cm Area · cm²: 64.951905 Perimeter · cm: 30 Apothem · cm: 4.330127 Interior angle · degrees: 120
Questions & answers
What does Regular Polygon Calculator calculate?
Calculate a regular polygon’s area, apothem and perimeter.
Which units should I enter?
Number of sides uses sides. Side length uses cm. Convert values to these units before calculating.
Which formula does it use?
Area = ns²/[4 tan(π/n)].
What does the included example show?
Number of sides: 6 sides; Side length: 5 cm. Result: Area · cm² = 64.951905; Perimeter · cm = 30; Apothem · cm = 4.330127; Interior angle · degrees = 120.
Can I compare different settings?
Yes. Save a scenario, change the inputs and save another result. Up to five scenarios are compared in this tab; they disappear when you reload or leave.
Can I export the calculation?
Copy the JSON report or download JSON and CSV with inputs, result labels and numeric values. Processing uses local JavaScript; no calculation request is sent to our server. Displayed values use up to 10 significant digits; exports retain JavaScript numeric precision.
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