The Golden ratio is a number found by dividing a line into two parts so that the longer part divided by the smaller part is also equal to the whole length divided by the longer part. It is symbolized using phi, after the Greek alphabet. In an equation form, it looks like this: a/b = (a+b)/a = 1.618033988749894842 As with pi, the digits go on and on, theoretically into infinity. Phi is usually rounded off to 1.618.
The Golden Ratio: a designer's guide. The Golden Ratio is a beautifully simple piece of mathematical theory that can help make your designs feel well proportioned and pleasing on the eye. We explain how to use it.