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Golden Spiral Calculator — Fibonacci Spiral Overlay

Calculate golden spiral overlay dimensions, focal point and phi grid lines for your image frame.

Width in pixels

Height in pixels

Corner where the spiral converges

Pre-fills image dimensions

How We Calculate This

The golden spiral is constructed from successive golden rectangles, each divided into a square and a smaller golden rectangle.

Focal Point

Default focal X = width / phi (61.8% from left)

Default focal Y = height / phi (61.8% from top)

Phi Grid

The phi grid places lines at 1/phi (38.2%) and 1 - 1/phi (61.8%) of each dimension, compared to 33.3% and 66.7% for the rule of thirds.

Frequently Asked Questions

Last updated: March 2026

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