How to calculate fibonacci retracement value?

[Arman]

I am trying to get the price of  fibonacci level , but cant seems to get it right , whats the actual formula to calculate the fib level ? 

i tried this :

Range=High-low (100%)

eg. 23.6% retracement

Retracement = Range*23.6/100

if drawing from low to high, high - Retracement

if drawing from high to low, low + Retracement

its from an answer posted By Keith Watford on a post from 2016  
but this isnt working 

[Keith Watford]

Show your code and what result you are getting.

[Arman]

Keith Watford:
Show your code and what result you are getting.

This is the code :

//---

   double Range=High[4] - Low[4];

         

         double Retracement = Range*50;

         Retracement= Retracement/100;

         

         Print (Retracement);

and this is what i am getting : GBPUSD,H1: 0.001144999999999952