hexagon size calculator

What this hexagon size calculator does

A regular hexagon is one of the most useful shapes in geometry, engineering, design, and manufacturing. This calculator helps you convert between the most common hexagon measurements: side length, perimeter, area, apothem, circumradius, flat-to-flat distance, and point-to-point distance.

Instead of manually rearranging formulas every time, you can enter one known value and get all the related dimensions immediately. This is especially useful when you are working with CAD drawings, 3D printing models, tiling layouts, mechanical parts, or architectural patterns.

Hexagon dimensions explained

Core terms you will see

• Side length (s): Length of each equal side of a regular hexagon.
• Perimeter (P): Total distance around the shape. For a regular hexagon, it is six times the side length.
• Apothem (a): Distance from the center to the midpoint of a side (also called inradius).
• Circumradius (R): Distance from the center to a corner (vertex). In a regular hexagon, this is equal to side length.
• Flat-to-flat (F): Distance between opposite parallel sides.
• Point-to-point (D): Distance between opposite vertices; also the diameter of the circumscribed circle.
• Area (A): Total enclosed surface inside the hexagon.

Key formulas for a regular hexagon

If you like to verify values manually, these are the formulas used by the calculator:

• P = 6s
• a = (√3 / 2)s
• R = s
• F = √3 · s (equivalent to F = 2a)
• D = 2s (equivalent to D = 2R)
• A = (3√3 / 2)s²
• A = (P · a) / 2 (same area, alternate form)

These relationships are exact for regular hexagons only. If your hexagon is irregular, side lengths and angles differ, and a different approach is required.

Worked examples

Example 1: side length is known

Suppose side length is 12 mm. Then:

• Perimeter = 6 × 12 = 72 mm
• Apothem = (√3/2) × 12 ≈ 10.3923 mm
• Flat-to-flat = √3 × 12 ≈ 20.7846 mm
• Point-to-point = 2 × 12 = 24 mm
• Area = (3√3/2) × 12² ≈ 374.123 mm²

Example 2: area is known

Suppose area is 200 cm². Solve for side length first:

s = √(2A / (3√3)) → s ≈ 8.7738 cm

Once side length is known, all remaining dimensions follow directly from the formula set above.

Where these calculations are used in real projects

• Mechanical design: Nut profiles, socket geometry, cutouts, and fixtures.
• Architecture: Hexagon floor tile layout, decorative wall panels, and ceiling patterns.
• 3D printing: Honeycomb infill structures, lightweight lattice parts, and custom enclosures.
• Graphic design: Grids, icon systems, game maps, and data visualization layouts.
• Woodworking and fabrication: Template sizing, jig setup, and material estimates.

Common mistakes to avoid

• Mixing up flat-to-flat and point-to-point: They are not the same. Point-to-point is always larger.
• Using area as a linear unit: Area is square units (mm², cm², in²), not linear units.
• Applying regular formulas to irregular hexagons: These equations depend on equal sides and equal angles.
• Rounding too early: Keep extra precision during intermediate steps, then round final values.

Quick FAQ

Can I use this for an irregular hexagon?

No. This calculator is specifically for regular hexagons. Irregular hexagons need coordinate geometry, triangulation, or side-by-side decomposition methods.

What is the easiest value to start with?

Side length is typically easiest. But in manufacturing drawings, flat-to-flat or point-to-point dimensions are often given first, and this tool supports those directly.

Why is circumradius equal to side length in a regular hexagon?

A regular hexagon can be divided into six equilateral triangles from the center. Each triangle edge equals the side length, which makes center-to-vertex distance equal to side length.

Use the calculator above any time you need fast, accurate hexagon dimensions for design, planning, or checking your own hand calculations.