Regular Hexagon Calculator — Area, Perimeter, Diagonals

Calculate all properties of a regular hexagon from side length, area, perimeter, apothem, or circumradius. Includes area, perimeter, apothem, diagonals, circumradius, inradius, and angles.

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Planning notes, formulas, and examples

About the Regular Hexagon Calculator — Area, Perimeter, Diagonals

The regular hexagon — a six-sided polygon with all sides and angles equal — is one of nature's favorite shapes. Honeybees build hexagonal cells because hexagons tile a plane with zero wasted space while minimizing wall material. The same efficiency makes hexagons popular in engineering, architecture, board games, and even traffic signs (the octagonal stop sign's close cousin).

A regular hexagon can be divided into exactly six equilateral triangles, all sharing a vertex at the center. This elegant decomposition gives rise to its key formulas: Area = (3√3/2)s², Perimeter = 6s, and a remarkable property — the circumradius (center-to-vertex distance) equals the side length itself. The apothem (center-to-side-midpoint distance, also the inradius) is s√3/2.

Hexagons have 9 diagonals: 3 "long" diagonals of length 2s pass through the center, and 6 "short" diagonals of length s√3 connect vertices separated by one vertex. Each interior angle is 120°, and each central angle is 60°.

This calculator works in reverse too — enter the area, perimeter, apothem, or circumradius, and it derives the side length and all other properties. Presets for real-world hexagons (honeycomb cells, hex bolts, stop signs, board game tiles) let you compare familiar examples quickly. Whether you're designing a hexagonal patio, analyzing crystal structures, or just curious, the page covers the full set of regular-hexagon properties.

When This Page Helps

The Regular Hexagon Calculator — Area, Perimeter, Diagonals is useful when you need fast and consistent geometry results without reworking the same algebra repeatedly. It helps you move from raw measurements to Side Length, Area, Perimeter in one pass, with conversions and derived values shown together.

How to Use the Inputs

  1. Select what you know: side length, area, perimeter, apothem, or circumradius.
  2. Choose a measurement unit (mm, cm, in, m, or ft).
  3. Enter the known value, or click a preset for a real-world hexagonal object.
  4. View all computed properties: area, perimeter, apothem, circumradius, diagonals, and angles.
  5. Compare key dimensions visually in the bar chart.
  6. Check the properties summary table for all values with their formulas.
  7. Scroll to the reference table for hexagons found in nature and engineering.
Formula used
Area: A = (3√3/2)s² Perimeter: P = 6s Apothem (inradius): a = (s√3)/2 Circumradius: R = s Short diagonal: d₁ = s√3 Long diagonal: d₂ = 2s Interior angle: 120° Central angle: 60° Number of diagonals: 9

Example Calculation

Result: Area ≈ 64.95 cm², Perimeter = 30 cm, Apothem ≈ 4.33 cm

For a regular hexagon with side 5 cm: Area = (3√3/2) × 25 ≈ 64.95 cm². Perimeter = 6 × 5 = 30 cm. Apothem = 5 × √3/2 ≈ 4.33 cm. Circumradius = 5 cm (equals side length). Short diagonal = 5√3 ≈ 8.66 cm. Long diagonal = 10 cm.

Tips & Best Practices

  • A regular hexagon's circumradius equals its side length — a unique property among regular polygons.
  • Hexagons tile a plane perfectly (no gaps), which is why they're used in honeycomb, floor tiles, and game boards.
  • The area of a hexagon is about 2.598 times the square of its side — close to 83% of its circumscribed circle.
  • Saturn has a persistent hexagonal cloud pattern at its north pole, roughly 32,000 km across.
  • Hex nuts use hexagonal geometry because 6 evenly-spaced points provide good grip with a standard wrench.

How This Regular Hexagon Calculator — Area, Perimeter, Diagonals Works

Where It Helps In Practice

Regular Hexagon Calculator — Area, Perimeter, Diagonals calculations show up in coursework, drafting, construction layout, packaging, tank sizing, machining, and quality control. Instead of solving each transformation manually, you can test scenarios quickly and verify whether your dimensions remain within tolerance.

Accuracy And Setup Tips

Sources & Methodology

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Frequently Asked Questions

  • A = (3√3/2)s², where s is the side length. For side 10: A = (3√3/2) × 100 ≈ 259.81 square units.