How this calculation works
Compute a sample variance ratio and its upper-tail probability under equal variances.
THE FORMULA
F=s₁²/s₂², degrees of freedom n₁−1 and n₂−1A worked example
Standard deviations 6 and 3 produce F=4.
Good to know
The probability assumes independent normal samples.
Reference: OpenStax Introductory Statistics (opens in a new tab) ↗
Read the result
Compute a sample variance ratio and its upper-tail probability under equal variances.
The primary result is labeled “F ratio”. Keep the input definitions in view when comparing this result with another method.
Try a related calculation
The probability assumes independent normal samples.
For a related exercise, try the statistics calculator.
A few questions, answered
How can I check the default inputs by hand?
Standard deviations 6 and 3 produce F=4.
Which rule does this calculator apply?
F=s₁²/s₂², degrees of freedom n₁−1 and n₂−1