Octagram Calculator

Calculator and formulas for the eight-pointed star

Octagram Calculator

The Octagram

An octagram is an eight-pointed star created by connecting every 3rd vertex of an octagon. Symbol of regeneration and new beginnings.

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Octagram parameters

a: Octagon side length | b: Star point length | d: Diagonal | l: Chord length
The star is created by connecting every 3rd vertex of the underlying octagon

Octagram calculation results
Octagon length a:
Point length b:
Diagonal d:
Chord length l:
Perimeter U:
Area A:

Octagram structure

Octagram

The octagram is created by connecting every 3rd vertex of an octagon.
8 points form the eight-pointed star of regeneration.

What is an octagram?

An octagram is a fascinating eight-pointed star with unique properties:

  • Eight-pointed star: 8 evenly distributed points
  • Octagon base: Constructed from a regular octagon
  • Every 3rd vertex: Connection skips 2 vertices
  • Symmetric structure: 8-fold rotational and mirror symmetry
  • Regeneration symbol: Renewal and rebirth
  • Mathematical elegance: √2-based relationships

Construction of the octagram

The construction of the octagram follows precise geometric steps:

Step 1: Octagon
  • Draw a regular octagon
  • All 8 sides have equal length a
  • Each interior angle is 135°
  • Central angle: 360°/8 = 45°
Step 2: Connections
  • Connect each vertex to the next-but-one
  • Skip 2 vertices each time
  • 8 star lines are created
  • Point length b is defined

Symbolism and meaning of the octagram

The octagram carries deep symbolic meanings in various cultures:

Regeneration & renewal
  • Symbol of rebirth and new beginnings
  • Eight phases of the life cycle
  • Transformation and change
  • Spiritual renewal
Direction & balance
  • Eight cardinal directions
  • Completeness and wholeness
  • Cosmic order
  • Harmony of opposites

Applications of the octagram

The octagram finds diverse applications in culture, art and science:

Religious symbolism
  • Christian symbol of rebirth
  • Islamic octagon art (Khatam)
  • Buddhist Eightfold Path
  • Spiritual meditation
Architecture & design
  • Church windows and rosettes
  • Islamic palace decoration
  • Modern architectural elements
  • Garden design and landscape architecture
Art & crafts
  • Decorative art and ornamentation
  • Textile design and patterns
  • Jewelry and spiritual amulets
  • Calligraphy and mandala art
Modern applications
  • Logo design and corporate identity
  • Computer graphics and gaming
  • Wellness and spa design
  • 3D printing and digital art

Formulas for the octagram

Octagon length a
\[a = (\sqrt{2} - 1) \cdot l \approx 0.4142 \cdot l\]

Side length of the underlying octagon

Point length b
\[b = \frac{2-\sqrt{2}}{2} \cdot l \approx 0.2929 \cdot l\]

Length of the star points

Diagonal d
\[d = \sqrt{4+2\sqrt{2}} \cdot a \approx 2.613 \cdot a\]

Diagonal of the octagon

Chord length l
\[l = a + 2b\]

Connection between star vertices

Perimeter U
\[U = 16 \cdot b\]

16 outer edges of the star

Area A
\[A = (6\sqrt{2} - 8) \cdot l^2 \approx 0.4853 \cdot l^2\]

Total area of the eight-pointed star

√2 relationships
\[\sqrt{2} \approx 1.414\] \[\sqrt{2} - 1 \approx 0.414\]

Fundamental constants of octagon geometry

Construction angles
\[45° = \frac{\pi}{4} \text{ rad}\]

Central angle between octagon vertices

Calculation example for an octagram

Given
Chord length l = 10

Find: All properties of the eight-pointed star

1. Calculate basic measures
\[a = 0.4142 \times 10 = 4.14\] \[b = 0.2929 \times 10 = 2.93\]

Octagon and point lengths

2. Diagonal and perimeter
\[d = 2.613 \times 4.14 = 10.82\] \[U = 16 \times 2.93 = 46.88\]

Octagon diagonal and star perimeter

3. Area calculation
A = 0.4853 × 100 = 48.53
Constant ≈ 0.4853

Total area of the eight-pointed star

4. Complete octagram
Octagon a = 4.14 Points b = 2.93 Diagonal d = 10.82
Chord l = 10.00 Perimeter U = 46.88 Area A = 48.53

The eight-pointed star - symbol of regeneration and new beginnings

The octagram: Star of regeneration

The octagram is far more than just a geometric construct - it is a symbol of transformation and eternal cycle. As an eight-pointed star created through the elegant connection of every third vertex of an octagon, it combines mathematical precision with spiritual symbolism and finds its place both in sacred art and modern design applications.

Geometric construction: Elegance of simplicity

The beauty of the octagram lies in its simple yet powerful construction method:

  • Regular octagon: 8 uniform vertices on a circle
  • "Every 3rd vertex" rule: Connection skips 2 intermediate points
  • √2 mathematics: All relationships based on √2 ≈ 1.414
  • 45° symmetry: 8-fold rotational symmetry (360°/8 = 45°)
  • Two star types: 8/3 star through different connection patterns
  • Self-similarity: Inner structure repeats outer patterns

The number eight: Symbol of infinity

Eight has special significance in all cultures:

Universal symbolism

The horizontal eight (∞) symbolizes infinity. The upright octagram connects heaven and earth, time and eternity, finite and infinite.

Religious traditions

In Christianity, eight symbolizes rebirth and baptism. In Buddhism, it represents the Eightfold Path to enlightenment.

Cosmic order

Eight cardinal directions, eight winds, eight moon phases - eight structures our perception of the cosmos.

Life cycle

From birth to death, from seed to harvest - the octagram symbolizes the eight phases of the eternal life cycle.

Cultural manifestations: From sacred to secular

The octagram permeates human culture in diverse ways:

  • Islamic art: Octagonal stars in mosques and palaces (Khatam patterns)
  • Christian architecture: Baptisteries and church windows in octagon form
  • Chinese philosophy: Bagua (eight trigrams) as organizing principle of I-Ching
  • Navigation: Wind rose with eight main directions
  • Heraldry: Eight-pointed stars in coats of arms and flags
  • Modern logos: Corporate design uses octagram symmetry

Practical applications and design

The octagram finds broad practical application:

Architecture and construction

Octagonal floor plans create unique spatial experiences. From historic baptisteries to modern auditoriums, architecture uses the special acoustics and aesthetics.

Handicrafts

Quilts, ceramics, wood inlays, and metalwork use octagram patterns for decorative and structural purposes.

Digital media

In computer graphics, octagram-based algorithms enable efficient rendering techniques and aesthetic interface designs.

Therapeutic applications

Mandala therapy and meditation use the octagram to promote balance and spiritual centering.

Summary

The octagram embodies the perfect synthesis of mathematical elegance and spiritual depth. Its simple construction - connecting every third vertex of an octagon - creates a form of timeless beauty and universal meaning. As a symbol of regeneration and eternal cycle, it speaks to the deepest human longings for renewal and transcendence. From the sacred spaces of medieval baptisteries to the digital interfaces of the 21st century, the octagram remains a powerful symbol for the connection between order and transformation, between mathematical precision and spiritual truth. In a world of constant change, the eight-pointed star reminds us that true regeneration does not mean chaos, but conscious reordering according to universal principles of harmony and symmetry.

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