Dice Roller and Coin Flip
Need a quick, fair roll for a board game, a classroom activity or a tie-break? Roll up to 20 dice at once, choose from 4, 6, 8, 10, 12, 20 or 100-sided dice, or flip a coin up to 100 times.
Last reviewed:
Every result comes from your browser's secure random number generator, and each face has an equal chance. Nothing is sent to a server.
How to use this calculator
- Choose Roll dice or Flip coin.
- Set the number of dice (and sides) or flips.
- Press Roll or Flip.
- Read the total and each result.
Formula and variables
Each die: result = 1 + random whole number below the number of sides Coin: heads or tails with equal probability
- Possible total - from the number of dice (all ones) up to dice × sides (all maximum).
- Fair chance - each face of each die has a probability of 1 ÷ sides.
The random numbers come from the Web Crypto API with rejection sampling, which avoids bias.
Worked example
Rolling two ordinary six-sided dice, as in many board games.
| Dice | 2 |
|---|---|
| Sides | 6 |
| Lowest possible total | 2 |
| Highest possible total | 12 |
| Most likely total | 7 (6 ways out of 36) |
- Each die shows a number from 1 to 6.
- The total of two dice ranges from 2 to 12.
- 7 can be made in six ways, so it is the most common total.
What changes the result
- Number of sides. More sides means a wider range and a smaller chance of each number.
- Number of dice. Adding dice makes totals cluster around the middle.
- Randomness. Rolls are independent. Past results do not change the next roll.
Benefits and practical uses
- Fair, unbiased results.
- Works for board games and tie-breaks.
- No download, no sign-up.
Assumptions and limitations
- Each face has an equal chance.
- Rolls are independent.
- Not meant for gambling, lotteries or any use that needs certified randomness.
Frequently asked questions
Is the dice roller fair?
Yes. It uses your browser's cryptographic random generator and avoids the bias that a simple remainder method can add.
How many dice can I roll?
Up to 20 at a time, with 4, 6, 8, 10, 12, 20 or 100 sides.
Is a coin flip really 50-50?
In this tool, yes. Each flip is heads or tails with equal probability.
Does it remember earlier rolls?
No. Each roll is independent and nothing is stored.
Can I use this to settle a decision?
Yes, for friendly decisions. For anything legal or regulated, use an officially approved method.
References
Page last reviewed on . This calculator gives estimates for planning only; it is not financial advice and not an offer from any lender.