F Critical Value Calculator

This calculator computes the right-sided F-critical value for an F-test. You only need to enter the significance level (α), the numerator degrees of freedom (df1), and the denominator degrees of freedom (df2) to get instant results with a clear explanation of whether or not to reject the null hypothesis.

Therefore, instead of looking up the value from the F table, this online tool provides a quick way to get similar results.

Enter the significance level (α), numerator degrees of freedom (df1), and denominator degrees of freedom (df2) and click the "Calculate" button.

Significance Level (α):

Numerator Degrees of Freedom (df1):

Denominator Degrees of Freedom (df2):

For other hypothesis tests that use different distributions, explore our Critical Value Calculator, which includes Z, T, Chi-square, and R critical values in one place.

How to Use the F-Critical Value Calculator

To find the F-critical value using this online calculator, follow these steps:

Step 1: Enter the significance level (α)
Step 2: Enter the numerator degrees of freedom (df1)
Step 3: Enter the denominator degrees of freedom (df2)
Step 4: Click the “Calculate” button

The calculator will instantly give you the correct F-critical value and explanation, telling you whether to reject or fail to reject the null hypothesis.

What is an F Critical Value?

An F critical value is a cutoff point on the F-distribution that is used to determine whether to reject or fail to reject the null hypothesis in an F-test. Specifically, after calculating an F-statistic value for ANOVA, equality of variances, or regression, you must compare this value with the critical value to decide whether the results are significant or not.

Here’s how you make decisions about a hypothesis using the F-critical value:

Reject the null hypothesis (H₀) if the F-statistic value is greater than the F-critical value
Fail to reject the null hypothesis (H₀) if the F-statistic is less than the F-critical value

How to Find F-Critical Value Using the Calculator

Are you in a hurry and need to find the F-critical value quickly? Our online F-critical value calculator provides instant results with a click of a button.

The following examples show how you can quickly find the F-critical value using the tool.

Example 1: Suppose a teacher wants to know if the average scores of three different classes are significantly different. The significance level is 0.05, the numerator degrees of freedom are 2, and the denominator degrees of freedom are 27.

To find the critical f-value, follow these steps:

Step1: Enter 0.05 as the significance level.
Step 2: Enter 2 as the numerator degrees of freedom (df₁)
Step 3: Enter 27 as the denominator degrees of freedom (df₂).
Step 4: Click the “Calculate” button.

The calculator tells you the critical value for F0.05, 2, 27 is 3.3541 (see Figure 1).

F critical value calculator result — *Figure 1.* F critical value solution 1

Example 2: Suppose a factory manager wants to check if three machines produce parts with different variances. The significance level is 0.01, df₁ is 2, and df₂ is 47.

To find the F-critical value using the tool, follow these steps:

Step 1: Enter 0.01 as the significance level.
Step 2: Enter 2 as the numerator degrees of freedom (df₁)
Step 3: Enter 47 as the denominator degrees of freedom (df₂)
Step 4: Click the “Calculate” button.

The calculator shows that the critical value that corresponds to F0.01, 2, 47 is 5.0874 (see Figure 2).

F critical value calculator result with alpha 0.01, df1 2 and df2 47 — *Figure 2.* F-critical value solution 2