Assume a 5 bar stochastic, the current bar’s close is 23.5, the highest high of the last 5 bars is 24.0 and the lowest low of the past 5 bars is 20.0. The calculation for regular stochastic %K is:
100 * ((23.5 - 20.0) / (24.0 - 20.0)) = 87.5
Assume the current bar’s regular %K value is 87.5, the previous bar’s regular %K value is 76.0 and regular %K value for the bar two bars ago is 70.25. The calculation for the regular stochastic %D, which is the same thing as the slow %K:
(87.5 + 76.0 + 70.25) / 3 = 77.9167
Assume the current bar’s regular %D value is 37.25, the previous bar’s regular %D value is 46.0 and regular %D value for the bar two bars ago is 50.25. The calculation for the slow stochastic %D:
(37.25 + 46.0 + 50.25) / 3 = 44.5