d20 tool
d20 Roller
Set the count, add a modifier, roll. Handles anything from a single d20 up to 100 of them at once.
Total
Tap to roll, or press R.
One d20 against two
Rolling more dice does not just raise the ceiling, it changes the shape. One d20 is flat. Two d20 bunches hard around 21.
- Lowest
- 2
- Highest
- 40
- Average
- 21.00
- Most likely
- 21
- Chance of 21
- 5.0%
2d20 distribution. Peak at 21 (5.0%). Ends at 2 and 40, each 0.250%.
Every total on 2d20
| Total | Chance | Odds | This or higher |
|---|---|---|---|
| 2 | 0.250% | 1 in 400 | 100.0% |
| 3 | 0.500% | 1 in 200 | 99.8% |
| 4 | 0.750% | 1 in 133 | 99.2% |
| 5 | 1.00% | 1 in 100 | 98.5% |
| 6 | 1.25% | 1 in 80 | 97.5% |
| 7 | 1.50% | 1 in 67 | 96.2% |
| 8 | 1.75% | 1 in 57 | 94.8% |
| 9 | 2.00% | 1 in 50 | 93.0% |
| 10 | 2.25% | 1 in 44 | 91.0% |
| 11 | 2.50% | 1 in 40 | 88.8% |
| 12 | 2.75% | 1 in 36 | 86.2% |
| 13 | 3.00% | 1 in 33 | 83.5% |
| 14 | 3.25% | 1 in 31 | 80.5% |
| 15 | 3.50% | 1 in 29 | 77.2% |
| 16 | 3.75% | 1 in 27 | 73.8% |
| 17 | 4.00% | 1 in 25 | 70.0% |
| 18 | 4.25% | 1 in 24 | 66.0% |
| 19 | 4.50% | 1 in 22 | 61.8% |
| 20 | 4.75% | 1 in 21 | 57.2% |
| 21 | 5.00% | 1 in 20 | 52.5% |
| 22 | 4.75% | 1 in 21 | 47.5% |
| 23 | 4.50% | 1 in 22 | 42.8% |
| 24 | 4.25% | 1 in 24 | 38.2% |
| 25 | 4.00% | 1 in 25 | 34.0% |
| 26 | 3.75% | 1 in 27 | 30.0% |
| 27 | 3.50% | 1 in 29 | 26.2% |
| 28 | 3.25% | 1 in 31 | 22.8% |
| 29 | 3.00% | 1 in 33 | 19.5% |
| 30 | 2.75% | 1 in 36 | 16.5% |
| 31 | 2.50% | 1 in 40 | 13.8% |
| 32 | 2.25% | 1 in 44 | 11.2% |
| 33 | 2.00% | 1 in 50 | 9.00% |
| 34 | 1.75% | 1 in 57 | 7.00% |
| 35 | 1.50% | 1 in 67 | 5.25% |
| 36 | 1.25% | 1 in 80 | 3.75% |
| 37 | 1.00% | 1 in 100 | 2.50% |
| 38 | 0.750% | 1 in 133 | 1.50% |
| 39 | 0.500% | 1 in 200 | 0.750% |
| 40 | 0.250% | 1 in 400 | 0.250% |