Fisher Exato 2×2 (aprox.)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
Odds Ratio
About this calculator
The 2x2 Fisher Exact Test Calculator is a useful tool for calculating the probability of obtaining observed results in a 2x2 study, considering the chi² approximation. This approximation is commonly used in statistical tests to evaluate the relationship between variables.
The formula used is based on the Odds Ratio (OR), which is a measure of the relationship between the probability of an event occurring in one group compared to another. The Odds Ratio can be calculated as the ratio between the ratio of the probabilities of events in two groups.
This calculator is especially useful in cases where you want to evaluate the strength of association between two binary numeric variables. It is essential to note that the chi² approximation is a simplification and may lose information about the data distribution.
To get accurate results, it is crucial to ensure that the data is consistent and that the calculator's usage conditions are met.
Frequently asked questions
What is the Odds Ratio?
The Odds Ratio (OR) is a measure of the relationship between the probability of an event occurring in one group compared to another. It is calculated as the ratio between the ratio of the probabilities of events in two groups.
When to use this calculator?
This calculator is useful in cases where you want to evaluate the strength of association between two binary numeric variables. It is especially useful in 2x2 studies.
How does the chi² approximation work?
The chi² approximation is a simplification that considers the data distribution as normal. This may lose information about the real data distribution.
What to keep in mind when using this calculator?
It is essential to ensure that the data is consistent and that the calculator's usage conditions are met.
What is the Fisher Exact Test?
The Fisher Exact Test is a statistical test used to evaluate the relationship between binary numeric variables in a 2x2 study.