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It's divine

Calculate with Phi

Φ, Phi, the Fibonacci sequence, the golden ratio, the golden section, the golden mean, the divine proportion. It’s known as many things, but the mysterious ratio they all refer to is the same,

Found in art, architecture, design, and most intriguingly, in nature, this ratio has been used throughout history and to this day for its aesthetic beauty.

How do I use it?

Number Entry

Simply type a number into either of the entry boxes and Phiculator will calculate the corresponding number according to the golden ratio.

Enter a number into the larger box at the top, to calculate the smaller proportional value in the box below, or vice-versa enter a number into the smaller box at the bottom, to calculate the larger proportional value in the box above. Confused? Oh come on, read all that again. Got it? Ok good.


Indicates which way you are performing the calculation, up or down the ratio, small to large or large to small.


Switch to Φ INT (phi, integer) mode to get your calculations as integers i.e. rounded to the nearest whole number, no decimals.


Switch back to Φ and they'll be calculated to 12 decimal places.


Resets your Phiculator to the default values,


Information about Phiculator.

Further reading

Universal Principles of Design
100 Ways to Enhance Usability, Influence Perception, Increase Appeal, Make Better Design Decisions, and Teach Through Design

Geometry of Design
Studies in Proportion and Composition

The Golden Ratio
The Story of Phi, the Extraordinary Number of Nature, Art and Beauty

Divine Proportion
Phi in Art, Nature, and Science


This tool is offered free and with no guarantees. The author does not warrant or assume any legal liability or responsibility for the accuracy of results from its use or misuse.

Created using only HTML/CSS & Javascript, there should be no reason why Phiculator is not safe. However, any loss of data, or other destructive effect occurring while using this tool is not the responsibility of the author. The author will not be held responsible or liable for any damages resulting from its use or misuse. You use this product entirely at your own risk. If you do not agree with this disclaimer or these conditions of use, you should not use Phiculator. Upon using Phiculator, you have agreed to these terms.

Phiculator users

  • Graphic designers
  • Fine artists
  • Architects
  • Engineers
  • Mathematicians
  • Kitchen designers
  • Aquarium designers
  • Origamists
  • Glass blowers
  • Tell me how you use it