Enter one value
Formulas used
r = (√3 / 2) · s
r = (√3 / 12) · P
r = √( A / (2√3) )
r = (√3 / 2) · R
Area A = 3 · s · r = (3√3 / 2) · s²
Across flats = 2r, Across corners = 2R
Results
Results will appear here after you calculate.
Tips
- Provide exactly one input and select the correct type from the dropdown.
- Use the precision control to format the outputs for reports or drawings.
- Units are labels only; the calculator does not convert between different units.
- Supports scientific notation like 1.23e4.
Frequently Asked Questions
1) What is the inradius of a regular hexagon?
The inradius, also called the apothem, is the distance from the center to the midpoint of any side. It is perpendicular to the side.
2) How do I compute the inradius from side length?
Use r = (√3/2) × s. For example, if s = 10, then r ≈ 8.6603.
3) Can I get the inradius from the perimeter?
Yes. With perimeter P, r = (√3/12) × P because P = 6s.
4) How is the area related to the inradius?
Area A = 3 × s × r = (3√3/2) × s². If you only know A, then r = √(A / (2√3)).
5) What is the difference between circumradius and inradius?
For a regular hexagon, the circumradius R equals the side length s. The inradius r equals (√3/2) × s, so r ≈ 0.866 × R.
6) Does the calculator convert units?
No. The unit field is a label. Enter all inputs in the same unit to keep results consistent.
7) Why do I get an error about multiple inputs?
The solver expects a single known value. If more than one field is filled, it cannot determine which formula to use, so it asks you to provide exactly one input.