Golden Ratio Calculator
The golden ratio (φ) is one of mathematics' most famous constants, approximately 1.618. When a line segment is divided so that the ratio of the whole to the longer part equals the ratio of the longer part to the shorter part, the segments are in the golden ratio. This calculator divides any measurement into two segments in the golden ratio. Enter either the total length or one segment length, and the calculator shows both segments and their ratio. A golden rectangle has sides in the golden ratio, creating a visually harmonious shape used in architecture and design. The calculator also shows the connection to Fibonacci numbers: as the Fibonacci sequence progresses, consecutive ratios approach φ. Use this tool in design, architecture, photography composition, and mathematics.
Golden ratio formula
φ = (1 + sqrt(5)) / 2 ≈ 1.61803398875
longer segment = total / (φ + 1) * φ
shorter segment = total / (φ + 1)
ratio = longer / shorter = φ
Fibonacci sequence and golden ratio
The ratio of consecutive Fibonacci numbers approaches the golden ratio:
| F(n) / F(n-1) | Value | Difference from φ |
|---|---|---|
| 2 / 1 | 2.00000 | 0.382 |
| 3 / 2 | 1.50000 | 0.118 |
| 5 / 3 | 1.66667 | 0.048 |
| 8 / 5 | 1.60000 | 0.018 |
| 13 / 8 | 1.62500 | 0.007 |
| 21 / 13 | 1.61538 | 0.003 |
| 34 / 21 | 1.61905 | 0.001 |
Golden ratio calculator: frequently asked questions
What is the golden ratio?
The golden ratio, denoted by the Greek letter phi (φ), is approximately 1.61803398875. It is defined mathematically as (1 + sqrt(5)) / 2. When a line is divided into two segments such that the ratio of the whole to the longer segment equals the ratio of the longer segment to the shorter segment, those segments are in the golden ratio.
How does the golden ratio relate to Fibonacci numbers?
The Fibonacci sequence (1, 1, 2, 3, 5, 8, 13, 21, 34, ...) is formed by adding the previous two numbers. As you move further along the sequence, the ratio of consecutive Fibonacci numbers approaches the golden ratio. For example, 21/13 ≈ 1.615, 34/21 ≈ 1.619, 55/34 ≈ 1.618.
What is a golden rectangle?
A golden rectangle is a rectangle whose sides are in the golden ratio. If the longer side is φ times the shorter side, the rectangle is golden. A unique property: if you remove a square from a golden rectangle, the remaining rectangle is also golden. This creates a spiral called the Fibonacci spiral.
Where does the golden ratio appear in nature?
The golden ratio appears in many natural structures: the spiral of a nautilus shell, the arrangement of leaves on plants, the proportions of the human face and body, spiral galaxies, and the branching of trees. It also appears frequently in art, architecture, and design because the human eye finds these proportions aesthetically pleasing.
How is the golden ratio used in design?
Designers and architects use the golden ratio to create visually balanced compositions. It helps determine proportions of buildings, layouts of web pages, dimensions of photographs, and spacing in graphic design. The ratio naturally guides the human eye and creates a sense of harmony and balance.
Official sources
- Golden ratio mathematics: National Institute of Standards and Technology.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.