How do you calculate CCI?

You calculate CCI using the formula CCI = (Typical Price - 20-period SMA of TP) / (.015 x Mean Deviation), Typical Price (TP) = (High + Low + Close)/3.

First, find the typical price for each period, then average those values over your lookback (20 by default).

Next, calculate the mean deviation by averaging the absolute differences between each typical price and the SMA.

Lambert set the constant at .015 to ensure that approximately 70 to 80 percent of CCI values would fall between -100 and +100. Most charting platforms compute this automatically once you select the period.