Free Lean Six Sigma calculators

Every calculator below runs entirely in your browser on the same statistics engine that powers the LeanProjax platform — its results are checked in CI against scipy/numpy reference values. No signup, no ads, and your numbers never leave your device.

Capability & Sigma

DPMO calculator

Free DPMO calculator: convert defects, units, and opportunities into DPMO, sigma level, yield, and DPU — with the standard Six Sigma conversion table.

Cpk calculator

Free process capability calculator: Cp, Cpk, CPU, CPL, sigma level, and expected PPM from your mean, standard deviation, and spec limits — with interpretation.

Sigma level converter

Free sigma level converter: translate between DPMO, process yield, Cpk, and short/long-term sigma using the standard 1.5σ shift convention.

Study design

Sample size calculator

Free statistical sample size calculator for continuous data, proportions, and capability studies — with power, confidence level, and finite population correction.

Lean & operations

OEE calculator

Free OEE calculator: availability × performance × quality with TEEP and the Six Big Losses breakdown, benchmarked against world-class OEE.

Working on a real improvement project? These calculators live inside LeanProjax as saved, shareable toolkit runs — alongside charters, SPC charts, FMEA, and one-click PDF reports. Start a free pilot.