Convert the RGB values to the range 0-1, this can be done by dividing the value by 255 for 8-bit color depth (r,g,b – are given values):

`R = r / 255 = 0.09 G = g / 255 = 0.38 B = b / 255 = 0.46`

Find the minimum and maximum values of R, G and B.

Depending on what RGB color channel is the max value. The three different formulas are:

- If Red is max, then
`Hue = (G-B)/(max-min)`

- If Green is max, then
`Hue = 2.0 + (B-R)/(max-min)`

- If Blue is max, then
`Hue = 4.0 + (R-G)/(max-min)`

- If Red is max, then

The Hue value you get needs to be multiplied by 60 to convert it to degrees on the color circle. If Hue becomes negative you need to add 360 to, because a circle has 360 degrees.

Here is the full article.