Coin Flip and Dice Roller
Flip coins or roll dice for a board game, for deciding who goes first or for a probability lesson. Every coin and die is shown, with the total.
Flip coins
Roll dice
This visit
The list keeps the latest 100 flips and rolls, newest first; the tally counts them all.
Every coin and die comes from your browser’s secure random number generator. Nothing is saved; closing the page clears it.
Coins and dice when there are none to hand
A board game with a missing die, deciding who goes first, choosing between two films, or a probability lesson where the class predicts and then tests: this page flips coins and rolls dice on your screen, shows every one of them, and keeps a tally for this visit.
How to use it
- To flip coins, choose how many, from 1 to 100, and press Flip.
- To roll dice, choose how many, from 1 to 20, and the kind: d4 to d100, or Other for any number of sides from 2 to 1,000.
- Or type the dice the way games write them, such as 3d6 or d20, and the choices above follow.
- Press Roll, or Enter in any of the dice boxes. Each die shows its number, with the total underneath.
Reading the results
- Dice notation: 3d6 means three dice with six sides each; d20 means one die with twenty. Adding a number, as in 3d6+2, isn’t built in: add it to the total yourself.
- The tally counts everything this visit: coins flipped, with heads, tails and the share of heads, and rolls, with every die added together.
- The history lists the latest 100 flips and rolls, newest first. Clear history starts the count again.
How it stays fair
Every coin and every die comes from crypto.getRandomValues, the secure random number generator built into your browser. Random numbers are matched to sides so that each side is exactly as likely as any other: a number that would favor the low sides is thrown away and drawn again. The result is decided before the short animation starts, and the animation is skipped if your device is set to reduce motion.
For a probability lesson
Flip 100 coins a few times and compare the share of heads with one half. Each batch varies, and a run of several heads in a row is normal; over many flips the share tends to settle closer to a half. Two six-sided dice (2d6) make a good next step: totals near the middle come up more often than 2 or 12, because more pairs of faces add up to them.
Good to know
- Nothing is saved; closing the page clears it. Nothing is sent or put in the page address.
- Choosing between more than two things? Spin the Spinner Wheel.
- Planning the lesson? The Lesson Plan Generator lays it out in timed steps.