Calculators
Dodecagon Calculator
Calculate regular dodecagon area, perimeter, apothem, and circumradius from a side length locally in your browser.
Enter a side length from 0 (exclusive) to 1000000000 to see the area (3 × (2 + √3) × s²), perimeter (12 × s), apothem (s ÷ (2 × tan(π/12))), and circumradius (s ÷ (2 × sin(π/12))). The calculation runs locally in your browser; your value is not uploaded or stored.
Find regular dodecagon measurements without uploading anything.
Enter a side length from 0 (exclusive) to 1000000000 to see the area, perimeter, apothem, and circumradius. Everything runs locally in your browser, so your value is not uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
What does the dodecagon calculator show?
Enter a side length from 0 (exclusive) to 1000000000. The calculator returns the area (3 times (2 plus the square root of 3) times side squared), the perimeter (12 times the side), the apothem (side divided by (2 times tan(pi divided by 12))), and the circumradius (side divided by (2 times sin(pi divided by 12))). For example, a side of 5 gives area about 279.903810568, perimeter 60, apothem about 9.33012701892, and circumradius about 9.65925826289.
Which formulas does the dodecagon calculator use?
It uses perimeter = 12 x s, apothem = s / (2 x tan(pi / 12)), area = (1 / 2) x perimeter x apothem (equivalent to 3 x (2 + square root of 3) x s^2), and circumradius = s / (2 x sin(pi / 12)), where s is the side length you enter. This tool covers regular dodecagons with twelve equal sides and equal interior angles of 150 degrees.
Which inputs are accepted?
Enter a side length greater than zero through 1000000000. Decimal values are accepted. Zero, negative numbers, non-numeric text, and values above the limit show a clear error instead of a result.
Do my numbers stay private?
Yes. The calculation and copy action run locally in your browser. CodeASystem does not upload or store the value you enter.