Hexagon Area Calculator
The area of a regular hexagon from its side — six equilateral triangles, so a√3 × 3a ÷ 2.
A regular hexagon is exactly six equilateral triangles meeting at the centre, which makes it unusually tidy: the area is 3√3 ÷ 2 × a², about 2.
How the hexagon area calculator works
A regular hexagon is exactly six equilateral triangles meeting at the centre, which makes it unusually tidy: the area is 3√3 ÷ 2 × a², about 2.598 a². The distance from the centre to any corner equals the side length, another property no other regular polygon has, and the reason hexagons tile a plane with the least perimeter for a given area — the shape honeycomb settles into.
Formula: square a²; rectangle ab; triangle ½bh; circle πr²; parallelogram bh; trapezoid ½(a+b)h; ellipse πab
Worked examples
| Inputs | Area | Note |
|---|---|---|
| Side 10 | 259.8076 | 259.81 |
| Side 1 | 2.5981 | 2.598 |
| A 25 mm bolt head across the flats | 540.9842 | about 541 mm² |
FAQFrequently asked questions
What is the area of a hexagon?
3√3 ÷ 2 times the side squared — about 2.598 a².
Why is a hexagon six triangles?
Because each central angle is 60°, so every triangle formed with a side is equilateral.
What is the distance across a hexagon?
Across the corners it is twice the side; across the flats it is a√3, about 1.732 times the side.
Why is honeycomb hexagonal?
Hexagons tile with the smallest total wall length for a given area, so bees use the least wax.
How do I get the side from a bolt size?
Bolt heads are measured across the flats, so divide that by √3 to get the side.
Where these figures come from
- NIST Digital Library of Mathematical Functions — reference definitions for elementary and special functions
- Wolfram MathWorld — definitions and formulas for every topic on this page
- NIST/SEMATECH e-Handbook of Statistical Methods — the statistical formulas (mean, variance, z, confidence intervals, sample size)
- National curriculum in England — Mathematics — the terms and methods taught in UK schools
Last checked: September 2026. Formulas are fixed by mathematics and do not change with tax years or regulations.