Closest CallTwo twenty-sided dice odds (2d20)
The chance of every total from 2 to 40 when you roll two twenty-sided dice and add them.
Every total with two d20s
Two twenty-sided dice have 400 equally likely combinations and average 21. A total of 21 can be made 20 different ways, more than any other, so it comes up 5.00% of the time.
| Total | Ways to roll it | Chance | Chance of this or higher |
|---|---|---|---|
| 2 | 1 | 0.25% | 100.0% |
| 3 | 2 | 0.50% | 99.8% |
| 4 | 3 | 0.75% | 99.3% |
| 5 | 4 | 1.00% | 98.5% |
| 6 | 5 | 1.25% | 97.5% |
| 7 | 6 | 1.50% | 96.3% |
| 8 | 7 | 1.75% | 94.8% |
| 9 | 8 | 2.00% | 93.0% |
| 10 | 9 | 2.25% | 91.0% |
| 11 | 10 | 2.50% | 88.8% |
| 12 | 11 | 2.75% | 86.3% |
| 13 | 12 | 3.00% | 83.5% |
| 14 | 13 | 3.25% | 80.5% |
| 15 | 14 | 3.50% | 77.3% |
| 16 | 15 | 3.75% | 73.8% |
| 17 | 16 | 4.00% | 70.0% |
| 18 | 17 | 4.25% | 66.0% |
| 19 | 18 | 4.50% | 61.8% |
| 20 | 19 | 4.75% | 57.3% |
| 21 | 20 | 5.00% | 52.5% |
| 22 | 19 | 4.75% | 47.5% |
| 23 | 18 | 4.50% | 42.8% |
| 24 | 17 | 4.25% | 38.3% |
| 25 | 16 | 4.00% | 34.0% |
| 26 | 15 | 3.75% | 30.0% |
| 27 | 14 | 3.50% | 26.3% |
| 28 | 13 | 3.25% | 22.8% |
| 29 | 12 | 3.00% | 19.5% |
| 30 | 11 | 2.75% | 16.5% |
| 31 | 10 | 2.50% | 13.8% |
| 32 | 9 | 2.25% | 11.3% |
| 33 | 8 | 2.00% | 9.00% |
| 34 | 7 | 1.75% | 7.00% |
| 35 | 6 | 1.50% | 5.25% |
| 36 | 5 | 1.25% | 3.75% |
| 37 | 4 | 1.00% | 2.50% |
| 38 | 3 | 0.75% | 1.50% |
| 39 | 2 | 0.50% | 0.75% |
| 40 | 1 | 0.25% | 0.25% |
What the chart tells you
- 21 is the most likely total at 5.00%, or 1 in 20. Each step away from 21 takes away one way of rolling the total, so the chances fall in a straight line on both sides.
- More than half of all rolls land from 15 to 27 (54.5%). A single d20 is equally likely to show any face; two added together bunch in the middle.
- A total of 30 or more comes up 16.5% of the time, and 35 or more 5.25%.
- A 40 needs two 20s: 0.25%, or 1 in 400. A 2 is just as rare.
- At least one of the two dice shows a 20 on 9.75% of rolls.
- Both dice show the same number 5.00% of the time, or 1 in 20.
Where this matters
Some tabletop role-playing games resolve actions by rolling two twenty-sided dice and adding them, instead of rolling one. The total is far more predictable than a single die: a target of 21 is slightly better than an even chance (52.5% to reach it or better), while a target of 31 succeeds only 13.8% of the time. This is different from rolling two d20s and keeping the higher one, which is covered on the advantage and disadvantage chart.
More dice odds
- Dice odds library: every chart in one place
- Two dice (2d6) odds chart
- Three dice (3d6) odds chart
- 4d6 drop the lowest: ability score odds
- d20 with advantage and disadvantage
- Five of a kind and other five-dice odds
- Attacker against defender dice odds
- At least one six in 1 to 10 rolls
- Dice calculator: the exact odds for any total with any number of dice, plus a dice roller.
Every figure on this page was computed by counting all possible outcomes. Game names mentioned here are trademarks of their owners; this site is not affiliated with or endorsed by them.