Weibull Analysis Calculator (2-Parameter)
Free 2-parameter Weibull distribution analysis tool. Estimate shape (β) and scale (η) parameters with median rank regression.
Core Formula
R(t) = e^(-(t/η)^β) where β = shape, η = scale
Governing Standards
- IEEE 493 — Recommended Practice for Design of Reliable Systems
- IEC 61649 — Weibull Analysis
Frequently Asked Questions
What does the Weibull shape parameter (Beta) tell you?
β < 1 indicates infant mortality (early-life failures), β = 1 indicates random failures (exponential), β > 1 indicates wear-out failures. Most industrial equipment has β between 1.5 and 3.5.
How many data points do I need for Weibull analysis?
A minimum of 6–10 failure data points is recommended for reliable Weibull parameter estimation. More data points give more accurate β and η values.