QI Macros Control Chart and Capability Formulas
QI Macros control chart formulas, capability analysis formulas and other calculations are taken from widely accepted SPC References including, Montgomery, Breyfogle, Juran and NIST. The exact formulas and other information for each chart can be found by clicking on the links below:
Control Chart Formulas
Attribute Control Charts
Variable Control Charts
Other Control Chart Calculation Information
Process Capability Analysis Formulas
 Cp, Cpk Formulas
 Pp, Ppk Formulas
 Cp Cpk vs Pp Ppk
 Histogram Metrics including % Defects, PPM, Sigma and Z scores
 Histograms  # of Bars
Download a free pdf of histogram formulas and sample calculations (PDF, 153 KB)
If you still need more help after reading the following information and our free pdf, consider our Histogram Whitepaper.
Other Resources
Six Sigma and SPC Reference Books
If you want a good Lean Six Sigma reference, consider my Lean Six Sigma DeMystified book:
If you don't have a good statistical reference book, I can recommend:

Douglas Montgomery, Introduction to Statistical Process Control (4th), John Wiley & Sons, NY, 2001. 
Douglas Montgomery, Design and Analysis of Experiments (5th), John Wiley & Sons, NY, 2001 


NIST  Engineering Statistics On Line Handbook 