>>   Attend the ASQ Inspection Division Conference, sponsored by PQ Systems.
Contact us
Free monthly quality tips!

FREE Newsletter on training tips, statistical help, book reviews and new product informationSubscribe to our free monthly newsletter, Quality eLine. It offers quality improvement information, quality training tips, statistical process control help, gage R&R information, and more.
Have questions? Click to chat with one of our service and support staff.
p-chart formulas

The p formula (for the proportion of nonconforming units from subgroups that can vary in size):

p formula

p bar formula

To calculate control limits for the p-chart:

p-chart upper & lower control formula