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Golden Spiral Calculator — Fibonacci Spiral Overlay

Calculate golden spiral overlay dimensions and focal point for your image frame.

Width in pixels

Height in pixels

How We Calculate This

The golden spiral is constructed from successive golden rectangles:

Spiral Construction

A golden rectangle (aspect ratio φ:1) is divided into a square and a smaller golden rectangle. This process repeats, creating successively smaller squares. Quarter-circle arcs through each square form the golden spiral.

Focal Point

Focal X = width / φ ≈ 61.8% from left

Focal Y = height / φ ≈ 61.8% from top

Each quarter turn, the spiral radius decreases by a factor of 1/φ, converging on the focal point.

Frequently Asked Questions

Last updated: February 2026

All calculations are estimates based on standard optical and photographic formulas. Results may vary with specific equipment.