Proportion facades and layouts with classic ratios

Any unit — the ratio is dimensionless.

Golden ratio φ ≈ 1.6180339887, where (a + b) / a = a / b = φ.

Classic architectural ratios

Pick a ratio to get the matching partner for your base dimension.

1 : φ
If your value is the short side, the long side is
If your value is the long side, the short side is

Golden-ratio partners

Whole (a + b)
Larger part (a)
Smaller part (b)

About Golden Ratio Tool

The golden ratio tool divides any dimension according to φ (phi), the golden ratio of approximately 1.618. Enter a base value and tell the tool what it represents — the whole, the larger part, or the smaller part — and it returns the other two so that (a + b) / a = a / b = φ.

Designers and architects have used this proportion for centuries to set facade divisions, room proportions, layout columns, and typography scales, because golden-ratio pairs read as naturally balanced. A live diagram draws the golden rectangle and spiral for your value so you can see the proportion, not just the number.

Alongside φ, the tool includes a library of classic architectural ratios — pick any of them and it computes the matching partner dimension for your base value, both if your value is the short side and if it is the long side. The math is dimensionless, so it works with millimeters, feet, or pixels, free in your browser.

How to use Golden Ratio Tool

  1. Enter your base dimension — any unit works, since the ratio is dimensionless.
  2. Choose what the value represents: the whole (a + b), the larger part (a), or the smaller part (b).
  3. Read the two golden-ratio partner dimensions and check the golden-rectangle diagram.
  4. Optionally pick a classic architectural ratio to get its matching partner for the same base value.

Frequently asked questions

φ ≈ 1.6180339887, the unique proportion where the whole relates to the larger part exactly as the larger part relates to the smaller: (a + b) / a = a / b. It is the limit of the ratio between consecutive Fibonacci numbers.

Divide it by φ. A 1,000 mm whole splits into a larger part of 1000 ÷ 1.618 ≈ 618 mm and a smaller part of 382 mm. The tool does this from whichever of the three values you know.

Typical uses include facade and window proportions, canvas and card aspect ratios, logo construction grids, layout column splits (roughly 62/38), and typographic scales where each size is the previous one times φ.

A rectangle whose sides are in the ratio 1 : 1.618. Remove a square from it and the leftover strip is another golden rectangle — repeating that operation traces the familiar golden spiral shown in the diagram.

A set of classic architectural proportions alongside φ. For each one you get the partner value in both directions — treating your dimension as the short side or as the long side — so you can compare proportion systems on a real measurement.

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