Golden Ratio Calculator

How to use the golden ratio calculator

1. Fill in the fields — they start with a worked example.
2. Read the answer, and the arithmetic shown beneath it.
3. Copy the results, or adjust the inputs to compare scenarios.

About this tool

The golden ratio is the number where the whole relates to the larger part exactly as the larger part relates to the smaller: about 1.618, usually written as phi. Divide a thousand-pixel width by it and you get 618 and 382 — a split that appears constantly in layout as a content column beside a sidebar.

It is useful for the same reason any fixed ratio is useful: it makes a set of decisions consistent, and consistency reads as intention. A layout where the sidebar, the margins and the spacing all derive from one proportion holds together in a way that individually chosen numbers do not.

The mystical claims attached to it are another matter, and worth being plain about. The recurring assertions that it governs the Parthenon, the Mona Lisa or the proportions of the human body do not survive measurement — most of them come from later authors imposing the ratio on things built without it. Sunflower seed spirals and pinecones genuinely do involve phi, because it is the number that packs a spiral most evenly; a painting from 1503 generally does not.

So use it as a good default ratio rather than as a law of beauty. The nearby ratios — 1.5, 1.6, the 1.414 of A-series paper — are equally defensible, and none of them will be noticed as such by anyone looking at the result.

Common uses

• Splitting a layout width into a content column and a sidebar.
• Generating a spacing scale that stays proportional.
• Sizing a cropped image or a card to a fixed proportion.

Frequently asked questions

What is the golden ratio?

About 1.618, the number where the whole is to the larger part as the larger part is to the smaller. Exactly, it is (1 + √5) ÷ 2.

How do I split a layout by the golden ratio?

Divide the total width by 1.618 for the larger part; the remainder is the smaller. A 1000-pixel width gives 618 and 382.

Is the golden ratio really found in art and nature?

In some plant growth, genuinely — it packs a spiral most evenly. In the Parthenon and the Mona Lisa, the claims do not survive measurement and mostly come from later authors.