The golden ratio: the 'divine' grid

The golden ratio is also known as the golden number, golden proportion or the divine proportion, and is a ratio between two numbers that equals approximately 1.618. Usually written as the Greek letter phi, it is strongly associated with the Fibonacci sequence: a series of numbers wherein each number is added to the last. It is used in art and architectural designs to bring out perfect proportions in constructions and paintings. It is also a mathematical ratio one can find almost anywhere, like nature, architecture, painting, and music. 

In relation to design, it creates an organic, balanced, and aesthetically pleasing composition which uses the golden rectangle: a geometric term that applies to a rectangle whose side lengths are in the golden ratio. The rectangle is such that the ratio of the length of its longer side to the length of its shorter side is equal to the golden ratio. This is said to be the most attractive rectangle to the human eye.

In practise, a simple made to measure method of construction is possible using only a ruler, a set square and a calculator. The process begins by limiting the value of Phi to 3 decimal places (φ = 1.618), and can produce a roughly accurate result.

The use of the golden rectangle could arguably be considered the first basic grid system in design. Some 20th-century artists and architects, including Le Corbusier and Salvador Dahli, have proportioned their works to approximate the golden ratio, believing it to be pleasing to the eye. Further examples of its application follow.