Probability Calculator
Understand the odds. Master the strategy.
Select Total
21
Selected Total
Statistics for 21
Ways to Roll
20 / 400
Probability
5.00%
Odds
1 in 20.0
Probability Distribution (2d20)
2
0.3%
1/400
3
0.5%
2/400
4
0.8%
3/400
5
1.0%
4/400
6
1.3%
5/400
7
1.5%
6/400
8
1.8%
7/400
9
2.0%
8/400
10
2.3%
9/400
11
2.5%
10/400
12
2.8%
11/400
13
3.0%
12/400
14
3.3%
13/400
15
3.5%
14/400
16
3.8%
15/400
17
4.0%
16/400
18
4.3%
17/400
19
4.5%
18/400
20
4.8%
19/400
21
5.0%
20/400
22
4.8%
19/400
23
4.5%
18/400
24
4.3%
17/400
25
4.0%
16/400
26
3.8%
15/400
27
3.5%
14/400
28
3.3%
13/400
29
3.0%
12/400
30
2.8%
11/400
31
2.5%
10/400
32
2.3%
9/400
33
2.0%
8/400
34
1.8%
7/400
35
1.5%
6/400
36
1.3%
5/400
37
1.0%
4/400
38
0.8%
3/400
39
0.5%
2/400
40
0.3%
1/400
💡 Strategy Tip
21 is the most common roll (10% chance) - it functions like '7' in traditional craps. It wins on come-out but ends point phase.