statistical-power-calculator

Calculate statistical power and sample sizes for hypothesis tests using scipy and statsmodels.

86|18|Updated Dec 14, 2025
One-click install
npx skills add https://github.com/dkyazzentwatwa/chatgpt-skills --skill statistical-power-calculator
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: statistical-power-calculator
Source: https://github.com/dkyazzentwatwa/chatgpt-skills/tree/main/statistical-power-calculator
Command: npx skills add https://github.com/dkyazzentwatwa/chatgpt-skills --skill statistical-power-calculator

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires scipy, statsmodels, numpy, and includes scripts (resource) components.

What problem does it solve?

This Skill addresses the critical need for robust experimental design by enabling users to calculate statistical power and determine appropriate sample sizes, ensuring research is adequately powered to detect meaningful effects.

Core Features & Use Cases

  • Power Calculation: Determine the probability of detecting a true effect.
  • Sample Size Determination: Calculate the minimum sample size needed for a desired level of power.
  • Effect Size Estimation: Estimate the minimum detectable effect size given power and sample size.
  • Multiple Test Types: Supports t-tests, proportion tests, ANOVA, and chi-square tests.
  • Use Case: A researcher planning a clinical trial can use this Skill to determine the exact number of participants needed to achieve 80% power in detecting a specific treatment effect, given a significance level of 0.05.

Quick Start

Use the statistical power calculator to determine the required sample size per group for a t-test with an effect size of 0.5, 5% significance, and 80% power.

Frequently Asked Questions about statistical-power-calculator

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I calculate statistical power and sample size for a t-test?

To calculate statistical power and sample size for a t-test, input your desired effect size, significance level, and target power. The calculator uses scipy and statsmodels to return the exact minimum sample size needed per group to detect the specified effect.

What is statistical power analysis and when do I need it for experimental design?

Statistical power analysis determines the probability of detecting a true effect during hypothesis testing. You need it for experimental design to ensure your research is adequately powered, preventing false negatives and calculating the minimum sample size required for meaningful results.

Can I estimate effect size for ANOVA and chi-square tests using Python?

Yes, you can estimate effect size for ANOVA and chi-square tests using Python. The calculator supports multiple test types, allowing you to estimate the minimum detectable effect size given your constraints for sample size and statistical power.

Does this power calculator work for proportion tests and clinical trial planning?

This power calculator works for proportion tests and clinical trial planning by utilizing Python libraries like statsmodels. You can determine the exact number of participants needed to achieve specific power levels, such as 80%, given a 0.05 significance level for treatment effects.

What sample size do I need for 80% power in hypothesis testing?

The sample size you need for 80% power in hypothesis testing depends on your expected effect size and significance level. By providing these parameters, the calculator determines the minimum number of observations required per group to reliably detect true effects.