Statistical tables

Student's t Table (Critical Values)

Table of critical values, density function f(t,ν) and cumulative distribution P(T ≤ t) for any degrees of freedom. Click a cell to read the value.

How to read the table: each column is a significance level α and each row a degrees of freedom ν. The same critical t value works for two cases depending on the test:
  • One-tailed test: leaves an area α in the right tail, P(T > t) = α. Use the "1 tail" row.
  • Two-tailed test: leaves an area α split between both tails, P(|T| > t) = α. Use the "2 tails" row.
Since the two tails split the area, always α (2 tails) = 2 × α (1 tail). Example: with ν = 10, for a two-tailed test at 5% (column "2 tails: 0.05" ↔ "1 tail: 0.025") the critical value is t = 2.228.
Click a cell to read the critical value.
ν (df)Significance level α (tail area)
1 tail: 0.25
2 tails: 0.5
1 tail: 0.2
2 tails: 0.4
1 tail: 0.15
2 tails: 0.3
1 tail: 0.1
2 tails: 0.2
1 tail: 0.05
2 tails: 0.1
1 tail: 0.025
2 tails: 0.05
1 tail: 0.01
2 tails: 0.02
1 tail: 0.005
2 tails: 0.01
1 tail: 0.001
2 tails: 0.002
11.0001.3761.9633.0786.31412.70631.82163.657318.309
20.8161.0611.3861.8862.9204.3036.9659.92522.327
30.7650.9781.2501.6382.3533.1824.5415.84110.215
40.7410.9411.1901.5332.1322.7763.7474.6047.173
50.7270.9201.1561.4762.0152.5713.3654.0325.893
60.7180.9061.1341.4401.9432.4473.1433.7075.208
70.7110.8961.1191.4151.8952.3652.9983.4994.785
80.7060.8891.1081.3971.8602.3062.8963.3554.501
90.7030.8831.1001.3831.8332.2622.8213.2504.297
100.7000.8791.0931.3721.8122.2282.7643.1694.144
110.6970.8761.0881.3631.7962.2012.7183.1064.025
120.6950.8731.0831.3561.7822.1792.6813.0553.930
130.6940.8701.0791.3501.7712.1602.6503.0123.852
140.6920.8681.0761.3451.7612.1452.6242.9773.787
150.6910.8661.0741.3411.7532.1312.6022.9473.733
160.6900.8651.0711.3371.7462.1202.5832.9213.686
170.6890.8631.0691.3331.7402.1102.5672.8983.646
180.6880.8621.0671.3301.7342.1012.5522.8783.610
190.6880.8611.0661.3281.7292.0932.5392.8613.579
200.6870.8601.0641.3251.7252.0862.5282.8453.552
210.6860.8591.0631.3231.7212.0802.5182.8313.527
220.6860.8581.0611.3211.7172.0742.5082.8193.505
230.6850.8581.0601.3191.7142.0692.5002.8073.485
240.6850.8571.0591.3181.7112.0642.4922.7973.467
250.6840.8561.0581.3161.7082.0602.4852.7873.450
260.6840.8561.0581.3151.7062.0562.4792.7793.435
270.6840.8551.0571.3141.7032.0522.4732.7713.421
280.6830.8551.0561.3131.7012.0482.4672.7633.408
290.6830.8541.0551.3111.6992.0452.4622.7563.396
300.6830.8541.0551.3101.6972.0422.4572.7503.385
350.6820.8521.0521.3061.6902.0302.4382.7243.340
400.6810.8511.0501.3031.6842.0212.4232.7043.307
450.6800.8501.0491.3011.6792.0142.4122.6903.281
500.6790.8491.0471.2991.6762.0092.4032.6783.261
600.6790.8481.0451.2961.6712.0002.3902.6603.232
700.6780.8471.0441.2941.6671.9942.3812.6483.211
800.6780.8461.0431.2921.6641.9902.3742.6393.195
900.6770.8461.0421.2911.6621.9872.3682.6323.183
1000.6770.8451.0421.2901.6601.9842.3642.6263.174
1200.6770.8451.0411.2891.6581.9802.3582.6173.160
1500.6760.8441.0401.2871.6551.9762.3512.6093.145
2000.6760.8431.0391.2861.6531.9722.3452.6013.131
5000.6750.8421.0381.2831.6481.9652.3342.5863.107
10000.6750.8421.0371.2821.6461.9622.3302.5813.098
How to read the table: each cell shows P(T ≤ t) for the selected degrees of freedom. For negative t: P(T ≤ −t) = 1 − P(T ≤ t), or switch the sign with the button.
Click a cell to read the value.

P(T ≤ t) for t from 0.00 to 6.09

t.00.01.02.03.04.05.06.07.08.09
0.00.50000.50390.50780.51170.51560.51940.52330.52720.53110.5350
0.10.53880.54270.54660.55040.55430.55810.56200.56580.56960.5734
0.20.57730.58110.58490.58860.59240.59620.59990.60370.60740.6111
0.30.61480.61850.62220.62590.62960.63320.63680.64050.64410.6476
0.40.65120.65480.65830.66180.66540.66880.67230.67580.67920.6826
0.50.68610.68940.69280.69620.69950.70280.70610.70940.71260.7159
0.60.71910.72230.72540.72860.73170.73480.73790.74100.74400.7471
0.70.75010.75300.75600.75890.76180.76470.76760.77040.77330.7761
0.80.77880.78160.78430.78700.78970.79240.79500.79770.80020.8028
0.90.80540.80790.81040.81290.81530.81770.82020.82250.82490.8272
1.00.82960.83180.83410.83640.83860.84080.84300.84510.84720.8494
1.10.85140.85350.85560.85760.85960.86150.86350.86540.86730.8692
1.20.87110.87290.87480.87660.87840.88010.88190.88360.88530.8870
1.30.88860.89030.89190.89350.89510.89660.89820.89970.90120.9027
1.40.90410.90560.90700.90840.90980.91120.91250.91380.91520.9165
1.50.91770.91900.92030.92150.92270.92390.92510.92630.92740.9285
1.60.92970.93080.93180.93290.93400.93500.93600.93710.93810.9390
1.70.94000.94100.94190.94280.94380.94470.94550.94640.94730.9481
1.80.94900.94980.95060.95140.95220.95300.95370.95450.95520.9560
1.90.95670.95740.95810.95880.95950.96010.96080.96140.96210.9627
2.00.96330.96390.96450.96510.96570.96620.96680.96740.96790.9684
2.10.96900.96950.97000.97050.97100.97150.97190.97240.97290.9733
2.20.97380.97420.97470.97510.97550.97590.97630.97670.97710.9775
2.30.97790.97820.97860.97900.97930.97970.98000.98040.98070.9810
2.40.98130.98170.98200.98230.98260.98290.98320.98340.98370.9840
2.50.98430.98450.98480.98510.98530.98560.98580.98610.98630.9865
2.60.98680.98700.98720.98740.98760.98780.98810.98830.98850.9887
2.70.98880.98900.98920.98940.98960.98980.98990.99010.99030.9904
2.80.99060.99080.99090.99110.99120.99140.99150.99170.99180.9919
2.90.99210.99220.99230.99250.99260.99270.99290.99300.99310.9932
3.00.99330.99340.99360.99370.99380.99390.99400.99410.99420.9943
3.10.99440.99450.99460.99470.99470.99480.99490.99500.99510.9952
3.20.99530.99530.99540.99550.99560.99560.99570.99580.99590.9959
3.30.99600.99610.99610.99620.99630.99630.99640.99640.99650.9966
3.40.99660.99670.99670.99680.99680.99690.99690.99700.99700.9971
3.50.99710.99720.99720.99730.99730.99740.99740.99750.99750.9975
3.60.99760.99760.99770.99770.99770.99780.99780.99780.99790.9979
3.70.99790.99800.99800.99800.99810.99810.99810.99820.99820.9982
3.80.99830.99830.99830.99830.99840.99840.99840.99840.99850.9985
3.90.99850.99850.99860.99860.99860.99860.99870.99870.99870.9987
4.00.99870.99880.99880.99880.99880.99880.99890.99890.99890.9989
4.10.99890.99890.99900.99900.99900.99900.99900.99900.99910.9991
4.20.99910.99910.99910.99910.99910.99920.99920.99920.99920.9992
4.30.99920.99920.99920.99930.99930.99930.99930.99930.99930.9993
4.40.99930.99930.99940.99940.99940.99940.99940.99940.99940.9994
4.50.99940.99940.99940.99950.99950.99950.99950.99950.99950.9995
4.60.99950.99950.99950.99950.99950.99950.99960.99960.99960.9996
4.70.99960.99960.99960.99960.99960.99960.99960.99960.99960.9996
4.80.99960.99960.99960.99970.99970.99970.99970.99970.99970.9997
4.90.99970.99970.99970.99970.99970.99970.99970.99970.99970.9997
5.00.99970.99970.99970.99970.99970.99980.99980.99980.99980.9998
5.10.99980.99980.99980.99980.99980.99980.99980.99980.99980.9998
5.20.99980.99980.99980.99980.99980.99980.99980.99980.99980.9998
5.30.99980.99980.99980.99980.99980.99980.99980.99980.99980.9998
5.40.99980.99990.99990.99990.99990.99990.99990.99990.99990.9999
5.50.99990.99990.99990.99990.99990.99990.99990.99990.99990.9999
5.60.99990.99990.99990.99990.99990.99990.99990.99990.99990.9999
5.70.99990.99990.99990.99990.99990.99990.99990.99990.99990.9999
5.80.99990.99990.99990.99990.99990.99990.99990.99990.99990.9999
5.90.99990.99990.99990.99990.99990.99990.99990.99990.99990.9999
6.00.99990.99990.99990.99990.99990.99990.99990.99990.99990.9999
How to read the table: each cell shows the density f(t, ν). The function is symmetric: f(−t, ν) = f(t, ν). As ν increases the curve approaches the standard Normal.
Click a cell to read the value.

f(t, ν) for t from 0.00 to 6.09 (symmetric: f(−t,ν) = f(t,ν))

t.00.01.02.03.04.05.06.07.08.09
0.00.38910.38910.38900.38890.38880.38860.38830.38810.38770.3874
0.10.38700.38650.38600.38550.38490.38430.38370.38300.38220.3815
0.20.38070.37980.37890.37800.37700.37600.37500.37390.37270.3716
0.30.37040.36920.36790.36660.36530.36390.36250.36110.35960.3581
0.40.35660.35500.35340.35180.35020.34850.34680.34500.34330.3415
0.50.33970.33790.33600.33410.33220.33030.32830.32640.32440.3224
0.60.32030.31830.31620.31410.31200.30990.30780.30560.30350.3013
0.70.29910.29690.29470.29250.29020.28800.28570.28350.28120.2789
0.80.27660.27430.27200.26970.26740.26510.26280.26050.25820.2559
0.90.25350.25120.24890.24660.24420.24190.23960.23730.23500.2327
1.00.23040.22810.22580.22350.22120.21890.21660.21440.21210.2099
1.10.20760.20540.20310.20090.19870.19650.19430.19210.19000.1878
1.20.18570.18350.18140.17930.17720.17510.17300.17100.16890.1669
1.30.16490.16280.16080.15890.15690.15490.15300.15110.14920.1473
1.40.14540.14350.14170.13980.13800.13620.13440.13270.13090.1292
1.50.12740.12570.12400.12240.12070.11910.11740.11580.11420.1126
1.60.11110.10950.10800.10650.10500.10350.10200.10060.09910.0977
1.70.09630.09490.09350.09220.09080.08950.08820.08690.08560.0844
1.80.08310.08190.08070.07950.07830.07710.07590.07480.07360.0725
1.90.07140.07030.06930.06820.06710.06610.06510.06410.06310.0621
2.00.06110.06020.05920.05830.05740.05650.05560.05470.05390.0530
2.10.05220.05130.05050.04970.04890.04810.04740.04660.04580.0451
2.20.04440.04370.04300.04230.04160.04090.04020.03960.03890.0383
2.30.03770.03700.03640.03580.03520.03470.03410.03350.03300.0324
2.40.03190.03130.03080.03030.02980.02930.02880.02830.02790.0274
2.50.02690.02650.02600.02560.02520.02470.02430.02390.02350.0231
2.60.02270.02230.02200.02160.02120.02090.02050.02020.01980.0195
2.70.01920.01880.01850.01820.01790.01760.01730.01700.01670.0164
2.80.01610.01580.01560.01530.01500.01480.01450.01430.01400.0138
2.90.01360.01330.01310.01290.01270.01240.01220.01200.01180.0116
3.00.01140.01120.01100.01080.01060.01050.01030.01010.00990.0097
3.10.00960.00940.00930.00910.00890.00880.00860.00850.00830.0082
3.20.00810.00790.00780.00760.00750.00740.00730.00710.00700.0069
3.30.00680.00670.00650.00640.00630.00620.00610.00600.00590.0058
3.40.00570.00560.00550.00540.00530.00520.00510.00500.00500.0049
3.50.00480.00470.00460.00450.00450.00440.00430.00420.00420.0041
3.60.00400.00400.00390.00380.00380.00370.00360.00360.00350.0034
3.70.00340.00330.00330.00320.00320.00310.00310.00300.00300.0029
3.80.00290.00280.00280.00270.00270.00260.00260.00250.00250.0024
3.90.00240.00240.00230.00230.00220.00220.00220.00210.00210.0021
4.00.00200.00200.00200.00190.00190.00190.00180.00180.00180.0017
4.10.00170.00170.00170.00160.00160.00160.00160.00150.00150.0015
4.20.00150.00140.00140.00140.00140.00130.00130.00130.00130.0012
4.30.00120.00120.00120.00120.00110.00110.00110.00110.00110.0011
4.40.00100.00100.00100.00100.00100.00100.00090.00090.00090.0009
4.50.00090.00090.00090.00080.00080.00080.00080.00080.00080.0008
4.60.00080.00070.00070.00070.00070.00070.00070.00070.00070.0006
4.70.00060.00060.00060.00060.00060.00060.00060.00060.00060.0006
4.80.00050.00050.00050.00050.00050.00050.00050.00050.00050.0005
4.90.00050.00050.00040.00040.00040.00040.00040.00040.00040.0004
5.00.00040.00040.00040.00040.00040.00040.00040.00040.00030.0003
5.10.00030.00030.00030.00030.00030.00030.00030.00030.00030.0003
5.20.00030.00030.00030.00030.00030.00030.00030.00030.00030.0003
5.30.00020.00020.00020.00020.00020.00020.00020.00020.00020.0002
5.40.00020.00020.00020.00020.00020.00020.00020.00020.00020.0002
5.50.00020.00020.00020.00020.00020.00020.00020.00020.00020.0002
5.60.00020.00020.00020.00020.00010.00010.00010.00010.00010.0001
5.70.00010.00010.00010.00010.00010.00010.00010.00010.00010.0001
5.80.00010.00010.00010.00010.00010.00010.00010.00010.00010.0001
5.90.00010.00010.00010.00010.00010.00010.00010.00010.00010.0001
6.00.00010.00010.00010.00010.00010.00010.00010.00010.00010.0001

How to use these tables

Student's t Distribution

Student's t distribution with ν degrees of freedom has density function:

\( f(t,\nu) = \dfrac{\Gamma\!\left(\tfrac{\nu+1}{2}\right)}{\sqrt{\nu\pi}\;\Gamma\!\left(\tfrac{\nu}{2}\right)} \left(1+\dfrac{t^2}{\nu}\right)^{-\frac{\nu+1}{2}} \)

As ν → ∞ the distribution converges to the standard Normal N(0,1).

Critical values table

Shows the quantiles tα,ν such that P(T > tα,ν) = α (one-tailed test). For a two-tailed test at level α₂, use column α₁ = α₂/2.

  • Example: two-tailed test α = 0.05, ν = 20 → column α₁ = 0.025 → t = 2.086.
  • When ν = ∞ the values match the quantiles of the standard Normal.

Cumulative distribution table

Each cell shows P(T ≤ t) for the selected number of degrees of freedom. To compute two-tailed p-values: p = 2 · P(T > |tobs|) = 2 · (1 − P(T ≤ |tobs|)).

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