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Weibull distribution calculator

The Weibull distribution calculator returns probabilities and quantiles for a lifetime with a given shape and scale.

What is Weibull distribution calculator?

The Weibull is the workhorse of reliability and survival modelling because its shape parameter sets the hazard: below 1 the hazard falls with time (early failures), at 1 it is constant (exponential), above 1 it rises (wear-out).

That single parameter is what lets one family cover infant mortality, random failure and ageing, which is why it underpins accelerated-failure-time survival models.

When should I use Weibull distribution calculator?

Reading a survival probability at a given time.
Finding the time by which a stated fraction will have failed.
Interpreting a fitted shape parameter as a hazard direction.

What data does it need?

Distribution parameters, plus a value x, a tail probability p, or both.

What does it report?

For x: the density or exact probability and each tail. For p: the lower, upper and two-tailed critical values.

What does it assume?

None — this evaluates a distribution rather than testing data against one.