Calculator Suite

Professional statistical tools for experiment design

Free

Basic Calculators

Sample Size Calculator

Power analysis for continuous, binary, and time-to-event endpoints

Chi-Square Calculator

A/B test significance for conversion rates (2×2 contingency)

Pro

Frequentist

Survival analysis, group sequential design, and CUPED variance reduction.

Survival Sample Size

Log-rank power analysis with Schoenfeld/Freedman formulas

Docs

Group Sequential Design

Interim analyses with stopping boundaries (gsDesign-validated)

gsDesign 3.6 · validated

Docs

CUPED Calculator

Reduce sample size by 30-50% using pre-experiment data

Docs

Pro

Adaptive

Sample size re-estimation and adaptive randomization within a single trial.

Blinded SSR

Interim sample size re-estimation using blinded variance or rate data

Docs

Unblinded SSR

Promising zone sample size re-estimation with inverse-normal combination test

Docs

Adaptive RandomizationNEW

RAR (DBCD, Thompson) and Pocock-Simon minimization for multi-arm trials

Docs

Pro

Master Protocol

Basket, umbrella, and platform trial designs for multi-arm master protocols.

Comparison guide →

Basket TrialNEW

Multi-indication design with BHM and EXNEX information borrowing

Docs

Umbrella TrialNEW

Biomarker-stratified sub-studies with shared control arm

Docs

Platform TrialNEW

Multi-arm multi-stage (MAMS) design with shared control and staggered arm entry

Docs

Pro Add-on

Bayesian Toolkit

Requires Pro

FDA-aligned Bayesian trial design. Follow the numbered steps.

Prior Elicitation

Define interpretable Bayesian priors with ESS and credible bounds

Docs

Bayesian Borrowing

Incorporate historical data with power prior, commensurate, or MAP

Requires Prior

Docs

Single-Arm Size

Sample size for single-arm trials with operating characteristics

Requires Prior

Docs

Two-Arm Design

Randomized treatment vs. control with superiority or NI testing

Requires Prior

Docs

Sequential Monitoring

Bayesian posterior probability stopping rules for interim analyses

Requires Prior

Docs

Predictive Power

Estimate trial success probability given interim data

Requires Prior

Docs

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