Statistical process control

Process Capability Calculator

Paste or upload your process measurements, set the specification limits, and get Cp, Cpk, Pp, Ppk and Cpm calculated from scratch — with a histogram of your data against spec.

1 — Your data

Measurements (comma, space or newline separated)

Upload CSV / TXT No file selected

2 — Specification

Upper spec limit (USL)

Lower spec limit (LSL)

Target (optional, for Cpm)

Units (optional)

Subgroup size (short-term σ for Cp / Cpk). Use 1 for a plain list of readings.

Results

Enter your measurements and at least one specification limit, then press Calculate to see Cp, Cpk, Pp, Ppk and Cpm here.

Distribution vs. specification

Index reference

Index	Variation used	Considers centering	Main focus
Cp	Short-term (within-process)	No	Potential capability based on spread alone
Cpk	Short-term (within-process)	Yes	Capability accounting for how centered the process is
Pp	Overall (long-term)	No	Actual performance based on total spread
Ppk	Overall (long-term)	Yes	Actual performance including spread and centering
Cpm	Overall + deviation from target	Yes (relative to target)	Capability weighted by closeness to the target value