Distribution Tables

F-Distribution Table

Complete F-distribution critical values table for ANOVA, regression analysis, and comparing variances at various significance levels.

Interactive F-Distribution Calculator

F-Distribution Calculator

Between-groups df
Within-groups df
Critical F value (F0.05,3,20)
3.0984
Reject H₀ if F > 3.0984
P-Value for F = 3.10
0.0499
✗ Significant at α = 0.05
For ANOVA:
  • df₁ (numerator) = k - 1, where k = number of groups
  • df₂ (denominator) = N - k, where N = total sample size

F-Distribution Table

The F-distribution table provides critical values for comparing variances and conducting ANOVA tests.

How to Use This Table

  1. Determine df₁ (numerator degrees of freedom) - columns
  2. Determine df₂ (denominator degrees of freedom) - rows
  3. Find the critical value at the intersection

Critical Values at α = 0.05

df₂ \ df₁1234567891012152024304060120
1161.4199.5215.7224.6230.2234.0236.8238.9240.5241.9243.9245.9248.0249.1250.1251.1252.2253.3254.3
218.5119.0019.1619.2519.3019.3319.3519.3719.3819.4019.4119.4319.4519.4519.4619.4719.4819.4919.50
310.139.559.289.129.018.948.898.858.818.798.748.708.668.648.628.598.578.558.53
47.716.946.596.396.266.166.096.046.005.965.915.865.805.775.755.725.695.665.63
56.615.795.415.195.054.954.884.824.774.744.684.624.564.534.504.464.434.404.36
65.995.144.764.534.394.284.214.154.104.064.003.943.873.843.813.773.743.703.67
75.594.744.354.123.973.873.793.733.683.643.573.513.443.413.383.343.303.273.23
85.324.464.073.843.693.583.503.443.393.353.283.223.153.123.083.043.012.972.93
95.124.263.863.633.483.373.293.233.183.143.073.012.942.902.862.832.792.752.71
104.964.103.713.483.333.223.143.073.022.982.912.852.772.742.702.662.622.582.54
114.843.983.593.363.203.093.012.952.902.852.792.722.652.612.572.532.492.452.40
124.753.893.493.263.113.002.912.852.802.752.692.622.542.512.472.432.382.342.30
134.673.813.413.183.032.922.832.772.712.672.602.532.462.422.382.342.302.252.21
144.603.743.343.112.962.852.762.702.652.602.532.462.392.352.312.272.222.182.13
154.543.683.293.062.902.792.712.642.592.542.482.402.332.292.252.202.162.112.07
164.493.633.243.012.852.742.662.592.542.492.422.352.282.242.192.152.112.062.01
174.453.593.202.962.812.702.612.552.492.452.382.312.232.192.152.102.062.011.96
184.413.553.162.932.772.662.582.512.462.412.342.272.192.152.112.062.021.971.92
194.383.523.132.902.742.632.542.482.422.382.312.232.162.112.072.031.981.931.88
204.353.493.102.872.712.602.512.452.392.352.282.202.122.082.041.991.951.901.84
254.243.392.992.762.602.492.402.342.282.242.162.092.011.961.921.871.821.771.71
304.173.322.922.692.532.422.332.272.212.162.092.011.931.891.841.791.741.681.62
404.083.232.842.612.452.342.252.182.122.082.001.921.841.791.741.691.641.581.51
604.003.152.762.532.372.252.172.102.041.991.921.841.751.701.651.591.531.471.39
1203.923.072.682.452.292.172.092.021.961.911.831.751.661.611.551.501.431.351.25
3.843.002.602.372.212.102.011.941.881.831.751.671.571.521.461.391.321.221.00

Critical Values at α = 0.01

df₂ \ df₁12345681012152024304060120
140524999540356255764585959826056610661576209623562616287631363396366
298.5099.0099.1799.2599.3099.3399.3799.4099.4299.4399.4599.4699.4799.4799.4899.4999.50
334.1230.8229.4628.7128.2427.9127.4927.2327.0526.8726.6926.6026.5026.4126.3226.2226.13
421.2018.0016.6915.9815.5215.2114.8014.5514.3714.2014.0213.9313.8413.7513.6513.5613.46
516.2613.2712.0611.3910.9710.6710.2910.059.899.729.559.479.389.299.209.119.02
613.7510.929.789.158.758.478.107.877.727.567.407.317.237.147.066.976.88
712.259.558.457.857.467.196.846.626.476.316.166.075.995.915.825.745.65
811.268.657.597.016.636.376.035.815.675.525.365.285.205.125.034.954.86
910.568.026.996.426.065.805.475.265.114.964.814.734.654.574.484.404.31
1010.047.566.555.995.645.395.064.854.714.564.414.334.254.174.084.003.91
129.336.935.955.415.064.824.504.304.164.013.863.783.703.623.543.453.36
158.686.365.424.894.564.324.003.803.673.523.373.293.213.133.052.962.87
208.105.854.944.434.103.873.563.373.233.092.942.862.782.692.612.522.42
247.825.614.724.223.903.673.363.173.032.892.742.662.582.492.402.312.21
307.565.394.514.023.703.473.172.982.842.702.552.472.392.302.212.112.01
407.315.184.313.833.513.292.992.802.662.522.372.292.202.112.021.921.80
607.084.984.133.653.343.122.822.632.502.352.202.122.031.941.841.731.60
1206.854.793.953.483.172.962.662.472.342.192.031.951.861.761.661.531.38
6.634.613.783.323.022.802.512.322.182.041.881.791.701.591.471.321.00

Degrees of Freedom

One-Way ANOVA

  • df₁ = k - 1 (between groups)
  • df₂ = N - k (within groups)
  • k = number of groups, N = total observations

Two-Way ANOVA

Sourcedf
Factor Aa - 1
Factor Bb - 1
A × B Interaction(a-1)(b-1)
Errorab(n-1)

Regression

  • df₁ = p (number of predictors)
  • df₂ = n - p - 1 (residual df)

Quick Reference for Common ANOVA

One-Way ANOVA at α = 0.05

Groupsdf₁Sample sizes (n each)df₂Critical F
3210273.35
3220573.16
4310362.87
4320762.73
5410452.58

Decision Rule

  • If F ≥ F(critical) → Reject H₀ (significant difference)
  • If F < F(critical) → Fail to reject H₀

F-Test Formula (ANOVA)

F = MS(between) / MS(within) = [SS(between)/df₁] / [SS(within)/df₂]


Example: One-Way ANOVA

Problem: Comparing 4 treatment groups with 15 subjects each at α = 0.05.

Solution:

  1. df₁ = 4 - 1 = 3 (between groups)
  2. df₂ = 60 - 4 = 56 (within groups, use df₂=60)
  3. Critical F(3, 60) at α = 0.05 ≈ 2.76
  4. If calculated F > 2.76, reject H₀

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