F-Table

F-distribution critical values by numerator/denominator degrees of freedom, with reverse lookup.

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Full printable reference table
F critical values (right-tail, α = 0.05)
df2 \ df11234568101220
1161.448199.500215.707224.583230.162233.986238.883241.882243.906248.013
218.51319.00019.16419.24719.29619.33019.37119.39619.41319.446
310.1289.5529.2779.1179.0138.9418.8458.7868.7458.660
47.7096.9446.5916.3886.2566.1636.0415.9645.9125.803
56.6085.7865.4095.1925.0504.9504.8184.7354.6784.558
65.9875.1434.7574.5344.3874.2844.1474.0604.0003.874
75.5914.7374.3474.1203.9723.8663.7263.6373.5753.445
85.3184.4594.0663.8383.6873.5813.4383.3473.2843.150
95.1174.2563.8633.6333.4823.3743.2303.1373.0732.936
104.9654.1033.7083.4783.3263.2173.0722.9782.9132.774
124.7473.8853.4903.2593.1062.9962.8492.7532.6872.544
154.5433.6823.2873.0562.9012.7902.6412.5442.4752.328
204.3513.4933.0982.8662.7112.5992.4472.3482.2782.124
244.2603.4033.0092.7762.6212.5082.3552.2552.1832.027
304.1713.3162.9222.6902.5342.4212.2662.1652.0921.932
404.0853.2322.8392.6062.4492.3362.1802.0772.0031.839
604.0013.1502.7582.5252.3682.2542.0971.9931.9171.748
1203.9203.0722.6802.4472.2902.1752.0161.9101.8341.659

About this tool

Enter numerator and denominator degrees of freedom with alpha for an F cut-off, or enter an F statistic for its p-value.

How to use

1
Step 1
Choose critical or p-value.
2
Step 2
Enter df1 (numerator), df2 (denominator) and alpha or F.
3
Step 3
Press Calculate.

How it works

The F distribution is the ratio of two scaled chi-square variables and is used for ANOVA and variance tests. It is right-skewed and has two df. In ANOVA df1 is groups − 1 and df2 is total observations − groups.

Reject H₀ when F > F(α, df1, df2)

Worked example

df1 = 3, df2 = 20

Input
Critical value, α = 0.05, right tail
Output
3.0984
Walkthrough
An F statistic of 3.1 just exceeds the cut-off and gives p = 0.0499.

Limitations

  • df1 and df2 are not interchangeable.
  • Left-tail values are rarely needed.

Questions

What is the F critical value for df 3 and 20?
3.0984 at 0.05.
Which df goes first?
Numerator (between-group) df first, then denominator (within-group) df.
What is the F critical value for df 2 and 30?
3.3158 at 0.05.

Features

  • Any df pair
  • Critical and p-value
  • Runs in your browser

Related resources

Guides and videos from around the web—opens on YouTube or the publisher’s site.

  • Mean, Variance and Standard Deviation

    StatQuest with Josh Starmer

    Descriptive stats behind table and test tools.

    Watch on YouTube
  • Chi-square distribution introduction

    Khan Academy

    Background for χ² tables and GoF/independence tools.

    Watch on YouTube