Apothem Calculator
Calculate the apothem of a regular polygon from the number of sides and side length, plus the polygon area.
- Polygon area
- 41.5692
Formula: a = s / (2 × tan(π/n))
About Apothem Calculator
Apothem Calculator is a free online calculator that gives you an instant, accurate result as you type. Calculate the apothem of a regular polygon from the number of sides and side length, plus the polygon area.
The calculation uses the standard formula a = s / (2 × tan(π/n)) and updates live with every change to the inputs. Everything runs client-side in your browser — fast, private, and free to use as often as you like.
The apothem is the perpendicular distance from the polygon center to the midpoint of a side — it equals the radius of the inscribed circle.
Frequently Asked Questions
Is Apothem Calculator free to use?
Yes. Apothem Calculator is completely free, with no sign-up, no downloads, and no usage limits. You can use it as many times as you like on any device with a web browser.
How accurate is this calculator?
The calculator applies the standard formula (a = s / (2 × tan(π/n))) with full floating-point precision and rounds only the displayed result. For most practical purposes the results are exact.
Related Tools
Rhombus Calculator
Calculate the area, side length, and perimeter of a rhombus from its two diagonals.
Kite Calculator
Calculate the area of a kite from its two diagonals, plus its perimeter from the two pairs of sides.
Octagon Calculator
Calculate the area and perimeter of a regular octagon from its side length.
Heptagon Calculator
Calculate the area and perimeter of a regular heptagon (7-sided polygon) from its side length.
Nonagon Calculator
Calculate the area and perimeter of a regular nonagon (9-sided polygon) from its side length.
Decagon Calculator
Calculate the area and perimeter of a regular decagon (10-sided polygon) from its side length.