What this calculator does
Golden rectangle works out finds the sides, diagonal and area of a rectangle whose side ratio equals the golden ratio. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formulaφ = (1+√5)/2 ≈ 1.618. Long side = short side × φ. Diagonal = √(short² + long²)
The inputs explained
| Field | What to enter |
|---|---|
| Short side (width) | A number. Starts at 10. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with short side (width)
Every other input is held at the calculator’s starting values while short side (width) varies. Select any row to load that scenario into the calculator.