Upper Control Limit Calculator
Find the control chart limits from the mean and standard deviation.
Control limits flag when a process drifts out of its normal range.
The math behind it
UCL = mean + kσ, LCL = mean − kσ, usually with k = 3 (the 3-sigma rule).
Worked example
Mean 50, σ 2, 3σ → UCL 56, LCL 44.
FAQ
What does crossing a limit mean?
A likely special cause — the process may be out of control.