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Golden Ratio Calculator

Split a length in golden ratio (φ ≈ 1.618).

Longer (a)
100.00
Shorter (b)
61.80
Total (a+b)
161.80

Visual

a (longer)
b (shorter)

φ = (1 + √5) / 2 ≈ 1.618. Two lengths are in golden ratio when (a + b) / a = a / b. Used in classical architecture, the Parthenon's facade, and a lot of design systems. Most modern type scales use 1.5 or 1.25 instead since 1.618 ratios feel a bit too dramatic on screen.

About

Enter a length and pick whether it's the longer or shorter side. Get the matching pair and total. Useful for sizing layouts, picture frames, or design grids. Includes a visual split.

How to use

  1. Enter a length.
  2. Pick whether it's the longer or shorter side.
  3. Read the matched pair.

FAQ

Where does φ come from?+

It's the positive solution to a/b = (a+b)/a, which is (1 + √5) / 2 ≈ 1.618. The Fibonacci sequence approximates it; consecutive ratios converge on φ.