Discrete Distributions

Binomial Distribution Table: P(X = x)

The probability of exactly x successes in n independent trials, for n from 1 to 20.

  • n = 1 to 20
  • 15 values of p
  • Calculator included

Binomial Table

Jump to a value of n below. Rows: number of successes x · Columns: probability of success p · Cells: P(X = x)

n = 1

n = 1
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.99000.95000.90000.80000.75000.70000.60000.50000.40000.30000.25000.20000.10000.05000.0100
10.01000.05000.10000.20000.25000.30000.40000.50000.60000.70000.75000.80000.90000.95000.9900

n = 2

n = 2
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.98010.90250.81000.64000.56250.49000.36000.25000.16000.09000.06250.04000.01000.00250.0001
10.01980.09500.18000.32000.37500.42000.48000.50000.48000.42000.37500.32000.18000.09500.0198
20.00010.00250.01000.04000.06250.09000.16000.25000.36000.49000.56250.64000.81000.90250.9801

n = 3

n = 3
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.97030.85740.72900.51200.42190.34300.21600.12500.06400.02700.01560.00800.00100.00010+
10.02940.13540.24300.38400.42190.44100.43200.37500.28800.18900.14060.09600.02700.00710.0003
20.00030.00710.02700.09600.14060.18900.28800.37500.43200.44100.42190.38400.24300.13540.0294
30+0.00010.00100.00800.01560.02700.06400.12500.21600.34300.42190.51200.72900.85740.9703

n = 4

n = 4
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.96060.81450.65610.40960.31640.24010.12960.06250.02560.00810.00390.00160.00010+0+
10.03880.17150.29160.40960.42190.41160.34560.25000.15360.07560.04690.02560.00360.00050+
20.00060.01350.04860.15360.21090.26460.34560.37500.34560.26460.21090.15360.04860.01350.0006
30+0.00050.00360.02560.04690.07560.15360.25000.34560.41160.42190.40960.29160.17150.0388
40+0+0.00010.00160.00390.00810.02560.06250.12960.24010.31640.40960.65610.81450.9606

n = 5

n = 5
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.95100.77380.59050.32770.23730.16810.07780.03120.01020.00240.00100.00030+0+0+
10.04800.20360.32800.40960.39550.36010.25920.15620.07680.02830.01460.00640.00040+0+
20.00100.02140.07290.20480.26370.30870.34560.31250.23040.13230.08790.05120.00810.00110+
30+0.00110.00810.05120.08790.13230.23040.31250.34560.30870.26370.20480.07290.02140.0010
40+0+0.00040.00640.01460.02830.07680.15620.25920.36010.39550.40960.32810.20360.0480
50+0+0+0.00030.00100.00240.01020.03120.07780.16810.23730.32770.59050.77380.9510

n = 6

n = 6
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.94150.73510.53140.26210.17800.11760.04670.01560.00410.00070.00020.00010+0+0+
10.05710.23210.35430.39320.35600.30250.18660.09380.03690.01020.00440.00150.00010+0+
20.00140.03050.09840.24580.29660.32410.31100.23440.13820.05950.03300.01540.00120.00010+
30+0.00210.01460.08190.13180.18520.27650.31250.27650.18520.13180.08190.01460.00210+
40+0.00010.00120.01540.03300.05950.13820.23440.31100.32410.29660.24580.09840.03050.0014
50+0+0.00010.00150.00440.01020.03690.09380.18660.30250.35600.39320.35430.23210.0571
60+0+0+0.00010.00020.00070.00410.01560.04670.11760.17800.26210.53140.73510.9415

n = 7

n = 7
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.93210.69830.47830.20970.13350.08240.02800.00780.00160.00020.00010+0+0+0+
10.06590.25730.37200.36700.31150.24710.13060.05470.01720.00360.00130.00040+0+0+
20.00200.04060.12400.27530.31150.31770.26130.16410.07740.02500.01150.00430.00020+0+
30+0.00360.02300.11470.17300.22690.29030.27340.19350.09720.05770.02870.00260.00020+
40+0.00020.00260.02870.05770.09720.19350.27340.29030.22690.17300.11470.02300.00360+
50+0+0.00020.00430.01150.02500.07740.16410.26130.31770.31150.27530.12400.04060.0020
60+0+0+0.00040.00130.00360.01720.05470.13060.24710.31150.36700.37200.25730.0659
70+0+0+0+0.00010.00020.00160.00780.02800.08240.13350.20970.47830.69830.9321

n = 8

n = 8
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.92270.66340.43050.16780.10010.05760.01680.00390.00070.00010+0+0+0+0+
10.07460.27930.38260.33550.26700.19770.08960.03120.00790.00120.00040.00010+0+0+
20.00260.05150.14880.29360.31150.29650.20900.10940.04130.01000.00380.00110+0+0+
30.00010.00540.03310.14680.20760.25410.27870.21870.12390.04670.02310.00920.00040+0+
40+0.00040.00460.04590.08650.13610.23220.27340.23220.13610.08650.04590.00460.00040+
50+0+0.00040.00920.02310.04670.12390.21870.27870.25410.20760.14680.03310.00540.0001
60+0+0+0.00110.00380.01000.04130.10940.20900.29650.31150.29360.14880.05150.0026
70+0+0+0.00010.00040.00120.00790.03120.08960.19770.26700.33550.38260.27930.0746
80+0+0+0+0+0.00010.00070.00390.01680.05760.10010.16780.43050.66340.9227

n = 9

n = 9
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.91350.63020.38740.13420.07510.04040.01010.00200.00030+0+0+0+0+0+
10.08300.29850.38740.30200.22530.15560.06050.01760.00350.00040.00010+0+0+0+
20.00340.06290.17220.30200.30030.26680.16120.07030.02120.00390.00120.00030+0+0+
30.00010.00770.04460.17620.23360.26680.25080.16410.07430.02100.00870.00280.00010+0+
40+0.00060.00740.06610.11680.17150.25080.24610.16720.07350.03890.01650.00080+0+
50+0+0.00080.01650.03890.07350.16720.24610.25080.17150.11680.06610.00740.00060+
60+0+0.00010.00280.00870.02100.07430.16410.25080.26680.23360.17620.04460.00770.0001
70+0+0+0.00030.00120.00390.02120.07030.16120.26680.30030.30200.17220.06290.0034
80+0+0+0+0.00010.00040.00350.01760.06050.15560.22530.30200.38740.29850.0830
90+0+0+0+0+0+0.00030.00200.01010.04040.07510.13420.38740.63020.9135

n = 10

n = 10
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.90440.59870.34870.10740.05630.02820.00600.00100.00010+0+0+0+0+0+
10.09140.31510.38740.26840.18770.12110.04030.00980.00160.00010+0+0+0+0+
20.00420.07460.19370.30200.28160.23350.12090.04390.01060.00140.00040.00010+0+0+
30.00010.01050.05740.20130.25030.26680.21500.11720.04250.00900.00310.00080+0+0+
40+0.00100.01120.08810.14600.20010.25080.20510.11150.03680.01620.00550.00010+0+
50+0.00010.00150.02640.05840.10290.20070.24610.20070.10290.05840.02640.00150.00010+
60+0+0.00010.00550.01620.03680.11150.20510.25080.20010.14600.08810.01120.00100+
70+0+0+0.00080.00310.00900.04250.11720.21500.26680.25030.20130.05740.01050.0001
80+0+0+0.00010.00040.00140.01060.04390.12090.23350.28160.30200.19370.07460.0042
90+0+0+0+0+0.00010.00160.00980.04030.12110.18770.26840.38740.31510.0914
100+0+0+0+0+0+0.00010.00100.00600.02820.05630.10740.34870.59870.9044

n = 11

n = 11
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.89530.56880.31380.08590.04220.01980.00360.00050+0+0+0+0+0+0+
10.09950.32930.38350.23620.15490.09320.02660.00540.00070+0+0+0+0+0+
20.00500.08670.21310.29530.25810.19980.08870.02690.00520.00050.00010+0+0+0+
30.00020.01370.07100.22150.25810.25680.17740.08060.02340.00370.00110.00020+0+0+
40+0.00140.01580.11070.17210.22010.23650.16110.07010.01730.00640.00170+0+0+
50+0.00010.00250.03880.08030.13210.22070.22560.14710.05660.02680.00970.00030+0+
60+0+0.00030.00970.02680.05660.14710.22560.22070.13210.08030.03880.00250.00010+
70+0+0+0.00170.00640.01730.07010.16110.23650.22010.17210.11070.01580.00140+
80+0+0+0.00020.00110.00370.02340.08060.17740.25680.25810.22150.07100.01370.0002
90+0+0+0+0.00010.00050.00520.02690.08870.19980.25810.29530.21310.08670.0050
100+0+0+0+0+0+0.00070.00540.02660.09320.15490.23620.38350.32930.0995
110+0+0+0+0+0+0+0.00050.00360.01980.04220.08590.31380.56880.8953

n = 12

n = 12
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.88640.54040.28240.06870.03170.01380.00220.00020+0+0+0+0+0+0+
10.10740.34130.37660.20620.12670.07120.01740.00290.00030+0+0+0+0+0+
20.00600.09880.23010.28350.23230.16780.06390.01610.00250.00020+0+0+0+0+
30.00020.01730.08520.23620.25810.23970.14190.05370.01250.00150.00040.00010+0+0+
40+0.00210.02130.13290.19360.23110.21280.12080.04200.00780.00240.00050+0+0+
50+0.00020.00380.05320.10320.15850.22700.19340.10090.02910.01150.00330+0+0+
60+0+0.00050.01550.04010.07920.17660.22560.17660.07920.04010.01550.00050+0+
70+0+0+0.00330.01150.02910.10090.19340.22700.15850.10320.05320.00380.00020+
80+0+0+0.00050.00240.00780.04200.12080.21280.23110.19360.13290.02130.00210+
90+0+0+0.00010.00040.00150.01250.05370.14190.23970.25810.23620.08520.01730.0002
100+0+0+0+0+0.00020.00250.01610.06390.16780.23230.28350.23010.09880.0060
110+0+0+0+0+0+0.00030.00290.01740.07120.12670.20620.37660.34130.1074
120+0+0+0+0+0+0+0.00020.00220.01380.03170.06870.28240.54040.8864

n = 13

n = 13
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.87750.51330.25420.05500.02380.00970.00130.00010+0+0+0+0+0+0+
10.11520.35120.36720.17870.10290.05400.01130.00160.00010+0+0+0+0+0+
20.00700.11090.24480.26800.20590.13880.04530.00950.00120.00010+0+0+0+0+
30.00030.02140.09970.24570.25170.21810.11070.03490.00650.00060.00010+0+0+0+
40+0.00280.02770.15350.20970.23370.18450.08730.02430.00340.00090.00010+0+0+
50+0.00030.00550.06910.12580.18030.22140.15710.06560.01420.00470.00110+0+0+
60+0+0.00080.02300.05590.10300.19680.20950.13120.04420.01860.00580.00010+0+
70+0+0.00010.00580.01860.04420.13120.20950.19680.10300.05590.02300.00080+0+
80+0+0+0.00110.00470.01420.06560.15710.22140.18030.12580.06910.00550.00030+
90+0+0+0.00010.00090.00340.02430.08730.18450.23370.20970.15350.02770.00280+
100+0+0+0+0.00010.00060.00650.03490.11070.21810.25170.24570.09970.02140.0003
110+0+0+0+0+0.00010.00120.00950.04530.13880.20590.26800.24480.11090.0070
120+0+0+0+0+0+0.00010.00160.01130.05400.10290.17870.36720.35120.1152
130+0+0+0+0+0+0+0.00010.00130.00970.02380.05500.25420.51330.8775

n = 14

n = 14
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.86870.48770.22880.04400.01780.00680.00080.00010+0+0+0+0+0+0+
10.12290.35930.35590.15390.08320.04070.00730.00090.00010+0+0+0+0+0+
20.00810.12290.25700.25010.18020.11340.03170.00560.00050+0+0+0+0+0+
30.00030.02590.11420.25010.24020.19430.08450.02220.00330.00020+0+0+0+0+
40+0.00370.03490.17200.22020.22900.15490.06110.01360.00140.00030+0+0+0+
50+0.00040.00780.08600.14680.19630.20660.12220.04080.00660.00180.00030+0+0+
60+0+0.00130.03220.07340.12620.20660.18330.09180.02320.00820.00200+0+0+
70+0+0.00020.00920.02800.06180.15740.20950.15740.06180.02800.00920.00020+0+
80+0+0+0.00200.00820.02320.09180.18330.20660.12620.07340.03220.00130+0+
90+0+0+0.00030.00180.00660.04080.12220.20660.19630.14680.08600.00780.00040+
100+0+0+0+0.00030.00140.01360.06110.15490.22900.22020.17200.03490.00370+
110+0+0+0+0+0.00020.00330.02220.08450.19430.24020.25010.11420.02590.0003
120+0+0+0+0+0+0.00050.00560.03170.11340.18020.25010.25700.12290.0081
130+0+0+0+0+0+0.00010.00090.00730.04070.08320.15390.35590.35930.1229
140+0+0+0+0+0+0+0.00010.00080.00680.01780.04400.22880.48770.8687

n = 15

n = 15
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.86010.46330.20590.03520.01340.00470.00050+0+0+0+0+0+0+0+
10.13030.36580.34320.13190.06680.03050.00470.00050+0+0+0+0+0+0+
20.00920.13480.26690.23090.15590.09160.02190.00320.00030+0+0+0+0+0+
30.00040.03070.12850.25010.22520.17000.06340.01390.00160.00010+0+0+0+0+
40+0.00490.04280.18760.22520.21860.12680.04170.00740.00060.00010+0+0+0+
50+0.00060.01050.10320.16510.20610.18590.09160.02450.00300.00070.00010+0+0+
60+0+0.00190.04300.09170.14720.20660.15270.06120.01160.00340.00070+0+0+
70+0+0.00030.01380.03930.08110.17710.19640.11810.03480.01310.00350+0+0+
80+0+0+0.00350.01310.03480.11810.19640.17710.08110.03930.01380.00030+0+
90+0+0+0.00070.00340.01160.06120.15270.20660.14720.09170.04300.00190+0+
100+0+0+0.00010.00070.00300.02450.09160.18590.20610.16510.10320.01050.00060+
110+0+0+0+0.00010.00060.00740.04170.12680.21860.22520.18760.04280.00490+
120+0+0+0+0+0.00010.00160.01390.06340.17000.22520.25010.12850.03070.0004
130+0+0+0+0+0+0.00030.00320.02190.09160.15590.23090.26690.13480.0092
140+0+0+0+0+0+0+0.00050.00470.03050.06680.13190.34320.36580.1303
150+0+0+0+0+0+0+0+0.00050.00470.01340.03520.20590.46330.8601

n = 16

n = 16
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.85150.44010.18530.02810.01000.00330.00030+0+0+0+0+0+0+0+
10.13760.37060.32940.11260.05350.02280.00300.00020+0+0+0+0+0+0+
20.01040.14630.27450.21110.13360.07320.01500.00180.00010+0+0+0+0+0+
30.00050.03590.14230.24630.20790.14650.04680.00850.00080+0+0+0+0+0+
40+0.00610.05140.20010.22520.20400.10140.02780.00400.00020+0+0+0+0+
50+0.00080.01370.12010.18020.20990.16230.06670.01420.00130.00020+0+0+0+
60+0.00010.00280.05500.11010.16490.19830.12220.03920.00560.00140.00020+0+0+
70+0+0.00040.01970.05240.10100.18890.17460.08400.01850.00580.00120+0+0+
80+0+0.00010.00550.01970.04870.14170.19640.14170.04870.01970.00550.00010+0+
90+0+0+0.00120.00580.01850.08400.17460.18890.10100.05240.01970.00040+0+
100+0+0+0.00020.00140.00560.03920.12220.19830.16490.11010.05500.00280.00010+
110+0+0+0+0.00020.00130.01420.06670.16230.20990.18020.12010.01370.00080+
120+0+0+0+0+0.00020.00400.02780.10140.20400.22520.20010.05140.00610+
130+0+0+0+0+0+0.00080.00850.04680.14650.20790.24630.14230.03590.0005
140+0+0+0+0+0+0.00010.00180.01500.07320.13360.21110.27450.14630.0104
150+0+0+0+0+0+0+0.00020.00300.02280.05350.11260.32940.37060.1376
160+0+0+0+0+0+0+0+0.00030.00330.01000.02810.18530.44010.8515

n = 17

n = 17
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.84290.41810.16680.02250.00750.00230.00020+0+0+0+0+0+0+0+
10.14470.37410.31500.09570.04260.01690.00190.00010+0+0+0+0+0+0+
20.01170.15750.28000.19140.11360.05810.01020.00100.00010+0+0+0+0+0+
30.00060.04150.15560.23930.18930.12450.03410.00520.00040+0+0+0+0+0+
40+0.00760.06050.20930.22090.18680.07960.01820.00210.00010+0+0+0+0+
50+0.00100.01750.13610.19140.20810.13790.04720.00810.00060.00010+0+0+0+
60+0.00010.00390.06800.12760.17840.18390.09440.02420.00260.00050.00010+0+0+
70+0+0.00070.02670.06680.12010.19270.14840.05710.00950.00250.00040+0+0+
80+0+0.00010.00840.02790.06440.16060.18550.10700.02760.00930.00210+0+0+
90+0+0+0.00210.00930.02760.10700.18550.16060.06440.02790.00840.00010+0+
100+0+0+0.00040.00250.00950.05710.14840.19270.12010.06680.02670.00070+0+
110+0+0+0.00010.00050.00260.02420.09440.18390.17840.12760.06800.00390.00010+
120+0+0+0+0.00010.00060.00810.04720.13790.20810.19140.13610.01750.00100+
130+0+0+0+0+0.00010.00210.01820.07960.18680.22090.20930.06050.00760+
140+0+0+0+0+0+0.00040.00520.03410.12450.18930.23930.15560.04150.0006
150+0+0+0+0+0+0.00010.00100.01020.05810.11360.19140.28000.15750.0117
160+0+0+0+0+0+0+0.00010.00190.01690.04260.09570.31500.37410.1447
170+0+0+0+0+0+0+0+0.00020.00230.00750.02250.16680.41810.8429

n = 18

n = 18
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.83450.39720.15010.01800.00560.00160.00010+0+0+0+0+0+0+0+
10.15170.37630.30020.08110.03380.01260.00120.00010+0+0+0+0+0+0+
20.01300.16830.28350.17230.09580.04580.00690.00060+0+0+0+0+0+0+
30.00070.04730.16800.22970.17040.10460.02460.00310.00020+0+0+0+0+0+
40+0.00930.07000.21530.21300.16810.06140.01170.00110+0+0+0+0+0+
50+0.00140.02180.15070.19880.20170.11460.03270.00450.00020+0+0+0+0+
60+0.00020.00520.08160.14360.18730.16550.07080.01450.00120.00020+0+0+0+
70+0+0.00100.03500.08200.13760.18920.12140.03740.00460.00100.00010+0+0+
80+0+0.00020.01200.03760.08110.17340.16690.07710.01490.00420.00080+0+0+
90+0+0+0.00330.01390.03860.12840.18550.12840.03860.01390.00330+0+0+
100+0+0+0.00080.00420.01490.07710.16690.17340.08110.03760.01200.00020+0+
110+0+0+0.00010.00100.00460.03740.12140.18920.13760.08200.03500.00100+0+
120+0+0+0+0.00020.00120.01450.07080.16550.18730.14360.08160.00520.00020+
130+0+0+0+0+0.00020.00450.03270.11460.20170.19880.15070.02180.00140+
140+0+0+0+0+0+0.00110.01170.06140.16810.21300.21530.07000.00930+
150+0+0+0+0+0+0.00020.00310.02460.10460.17040.22970.16800.04730.0007
160+0+0+0+0+0+0+0.00060.00690.04580.09580.17230.28350.16830.0130
170+0+0+0+0+0+0+0.00010.00120.01260.03380.08110.30020.37630.1517
180+0+0+0+0+0+0+0+0.00010.00160.00560.01800.15010.39720.8345

n = 19

n = 19
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.82620.37740.13510.01440.00420.00110.00010+0+0+0+0+0+0+0+
10.15860.37740.28520.06850.02680.00930.00080+0+0+0+0+0+0+0+
20.01440.17870.28520.15400.08030.03580.00460.00030+0+0+0+0+0+0+
30.00080.05330.17960.21820.15170.08690.01750.00180.00010+0+0+0+0+0+
40+0.01120.07980.21820.20230.14910.04670.00740.00050+0+0+0+0+0+
50+0.00180.02660.16360.20230.19160.09330.02220.00240.00010+0+0+0+0+
60+0.00020.00690.09550.15740.19160.14510.05180.00850.00050.00010+0+0+0+
70+0+0.00140.04430.09740.15250.17970.09610.02370.00220.00040+0+0+0+
80+0+0.00020.01660.04870.09810.17970.14420.05320.00770.00180.00030+0+0+
90+0+0+0.00510.01980.05140.14640.17620.09760.02200.00660.00130+0+0+
100+0+0+0.00130.00660.02200.09760.17620.14640.05140.01980.00510+0+0+
110+0+0+0.00030.00180.00770.05320.14420.17970.09810.04870.01660.00020+0+
120+0+0+0+0.00040.00220.02370.09610.17970.15250.09740.04430.00140+0+
130+0+0+0+0.00010.00050.00850.05180.14510.19160.15740.09550.00690.00020+
140+0+0+0+0+0.00010.00240.02220.09330.19160.20230.16360.02660.00180+
150+0+0+0+0+0+0.00050.00740.04670.14910.20230.21820.07980.01120+
160+0+0+0+0+0+0.00010.00180.01750.08690.15170.21820.17960.05330.0008
170+0+0+0+0+0+0+0.00030.00460.03580.08030.15400.28520.17870.0144
180+0+0+0+0+0+0+0+0.00080.00930.02680.06850.28520.37740.1586
190+0+0+0+0+0+0+0+0.00010.00110.00420.01440.13510.37740.8262

n = 20

n = 20
Probability of success (p) →
x ↓
.01.05.10.20.25.30.40.50.60.70.75.80.90.95.99
00.81790.35850.12160.01150.00320.00080+0+0+0+0+0+0+0+0+
10.16520.37740.27020.05760.02110.00680.00050+0+0+0+0+0+0+0+
20.01590.18870.28520.13690.06690.02780.00310.00020+0+0+0+0+0+0+
30.00100.05960.19010.20540.13390.07160.01230.00110+0+0+0+0+0+0+
40+0.01330.08980.21820.18970.13040.03500.00460.00030+0+0+0+0+0+
50+0.00220.03190.17460.20230.17890.07460.01480.00130+0+0+0+0+0+
60+0.00030.00890.10910.16860.19160.12440.03700.00490.00020+0+0+0+0+
70+0+0.00200.05450.11240.16430.16590.07390.01460.00100.00020+0+0+0+
80+0+0.00040.02220.06090.11440.17970.12010.03550.00390.00080.00010+0+0+
90+0+0.00010.00740.02710.06540.15970.16020.07100.01200.00300.00050+0+0+
100+0+0+0.00200.00990.03080.11710.17620.11710.03080.00990.00200+0+0+
110+0+0+0.00050.00300.01200.07100.16020.15970.06540.02710.00740.00010+0+
120+0+0+0.00010.00080.00390.03550.12010.17970.11440.06090.02220.00040+0+
130+0+0+0+0.00020.00100.01460.07390.16590.16430.11240.05450.00200+0+
140+0+0+0+0+0.00020.00490.03700.12440.19160.16860.10910.00890.00030+
150+0+0+0+0+0+0.00130.01480.07460.17890.20230.17460.03190.00220+
160+0+0+0+0+0+0.00030.00460.03500.13040.18970.21820.08980.01330+
170+0+0+0+0+0+0+0.00110.01230.07160.13390.20540.19010.05960.0010
180+0+0+0+0+0+0+0.00020.00310.02780.06690.13690.28520.18870.0159
190+0+0+0+0+0+0+0+0.00050.00680.02110.05760.27020.37740.1652
200+0+0+0+0+0+0+0+0+0.00080.00320.01150.12160.35850.8179

Tip: click any value to highlight its row and column.

How to read this table

  1. Find the block for your number of trials n.
  2. Go to the row for x and the column for p.
  3. The cell is P(X = x). Add cells to get the probability of a range of values, or use the cumulative table.
  4. 0+ means a probability that is positive but below 0.00005; 1− means one that is below 1 but above 0.99995.

Worked example

In a Phase II trial of 10 patients where the true response rate is 20%, the chance of exactly 2 responses is in the n = 10 block, row x = 2, column p = .20: 0.3020. The chance of no responses at all is 0.1074.

This is the calculation behind single-arm Phase II designs such as Simon's two-stage design, which choose sample sizes and response thresholds from binomial probabilities.

Click the underlined links to highlight the value in the table.

Calculator

For values between the rows and columns of the table. Results update as you type.

Formula and how the values were computed

P(X = x) = C(n, x) px (1 − p)n − x

Each cell is computed exactly from the binomial formula and rounded to four decimals.

Frequently asked questions

What are the conditions for a binomial distribution?

A fixed number of trials n, two outcomes per trial, the same probability of success p on every trial, and independent trials.

What if n is larger than 20?

Use the calculator above, which handles any n. When np and n(1 − p) are both at least about 10, the normal approximation with mean np and variance np(1 − p) also works well.

Related calculators and tutorials