Moving Range chart control limits are calculated as follows:
Control Limits calculated
from 
Control Limits calculated
from 


NOTE: Moving Range chart analysis is usually performed on individual data (the default subgroup size is 1). However, if you enter a bigger subgroup size, subgroup averages are treated as individual data.
Moving Range
Lower Control Limit (LCL) (optional)
Upper Control Limit (UCL) (optional)
Warning lines (optional)
Lower Control Limit (LCL)
Upper Control Limit (UCL)
Center Line (CL)