🎲 Dice Roller
Roll any dice with standard notation like 2d6+3, 4d6 drop lowest or d20 advantage, and see the exact odds of every total next to your roll.
Try 3d6, 1d20+5, 2d20kh1 (advantage), 4d6kh3, d% or 1d8+1d6+2.
Pick a die or type notation, then Roll.
Odds for 2d6
Range 2–12 · average 7.00
What Dice Roller Does
This dice roller handles everything from a single d6 to full tabletop notation: 2d6+3, 1d20+5, 4d6kh3 (roll four, keep the best three), 2d20kh1 for advantage and 2d20kl1 for disadvantage, percentile dice with d%, and mixed pools like 1d8+1d6+2. Each die is shown after the roll, with dropped dice struck through.
Beside every roll is the exact probability distribution for the notation you typed — computed from every combination of faces, not estimated by simulation — with your result highlighted and the chance of rolling that total or higher. It turns “is 14 a good roll?” into a number.
Every die uses your browser’s cryptographically secure random generator with rejection sampling, so each face is exactly equally likely.
How to Use Dice Roller
- Tap a die (d4 to d100), Advantage or 4d6 drop lowest — or type notation like 2d6+3
- Press Roll or Enter
- See the total and each die, with dropped dice struck through
- Read the exact odds chart and the chance of your total or higher
Formula Used by Dice Roller
Rolling with advantage on a d20
P(at least X) = 1 − ((X − 1) ÷ 20)²
- X
- The number you need to meet or beat
Worked example
You need 10 or higher and roll with advantage.
- Chance one d20 is below 10 = 9/20
- Chance both are below 10 = (9/20)² = 0.2025
- 1 − 0.2025
Result: 79.75%, up from 55% on a single d20.
Average of NdS
Average = N × (S + 1) ÷ 2
Worked example
3d6
- 3 × (6 + 1) ÷ 2
Result: 10.5
Two Six-Sided Dice (2d6)
All 36 combinations are equally likely.
| Total | Ways | Probability |
|---|---|---|
| 2 or 12 | 1 | 2.78% |
| 3 or 11 | 2 | 5.56% |
| 4 or 10 | 3 | 8.33% |
| 5 or 9 | 4 | 11.11% |
| 6 or 8 | 5 | 13.89% |
| 7 | 6 | 16.67% |
d20 With Advantage and Disadvantage
Chance of meeting or beating a target. Averages: normal 10.5, advantage 13.825, disadvantage 7.175.
| Need at least | Normal | Advantage | Disadvantage |
|---|---|---|---|
| 5 | 80% | 96% | 64% |
| 10 | 55% | 79.75% | 30.25% |
| 15 | 30% | 51% | 9% |
| 20 | 5% | 9.75% | 0.25% |
4d6 Drop the Lowest (4d6kh3)
Out of 1,296 equally likely rolls. Average 12.24.
| Result | Rolls out of 1,296 | Probability |
|---|---|---|
| 18 | 21 | 1.62% |
| 16–17 | 148 | 11.42% |
| 13–15 | 463 | 35.73% |
| 10–12 | 437 | 33.72% |
| 3–9 | 227 | 17.52% |
How to Read Your Result
Reading the odds chart
Taller bars are more likely totals. Adding more dice pulls the shape toward a bell curve centered on the average, which is why 3d6 produces far fewer extreme results than 1d20 even though both can reach similar highs.
Advantage is worth the most in the middle
Advantage adds about 25 percentage points when you need a 10 or 11, but under 5 points when you need a 20. Disadvantage is harshest at the same middle targets.
Limitations & Accuracy Notes
- Exploding dice, rerolls, success counting and dice pools with target numbers are not supported.
- Keep-highest or keep-lowest charts are only drawn when the number of face combinations is manageable (up to 200,000).
- Up to 100 dice per term and 1,000 sides per die.
Frequently Asked Questions
Are these dice rolls fair?
How does dice notation work?
How much does advantage help on a d20?
Why is 7 the most common roll with two dice?
What is the average of 4d6 drop the lowest?
What does the chart under my roll show?
References & Further Reading
- Wikipedia — Dice notation — The NdS+c convention