Dice & coin flip

Roll dice and flip coins at random with totals.

Dice

Count Sides

Coin

Count

Someone has to go first, and nobody brought a board game box. Or you are playing a tabletop game and the d20 rolled under the couch again. This tool gives you dice and coins that work on any phone or laptop, with the totals worked out for you so nobody has to add up five dice by hand.

How it works

Rolling dice

Set Count for how many dice to throw (1 to 12) and Sides for the type of die (2 to 100). Press Roll and every die appears with its own face value, followed by the Sum and Avg of the throw.

Sides is a free number, not a fixed menu, so it covers dice that are awkward to find physically:

You want	Count	Sides
One ordinary die	1	6
Two dice, board game	2	6
D&D damage roll	3	8
A d100 percentile roll	1	100

Flipping coins

Under Coin, set Count (1 to 50) and press Flip. Each result shows as H (heads) or T (tails), and the line underneath counts how many of each came up. Flipping many at once is handy for a quick look at how streaky randomness really is — twenty flips rarely land on a tidy ten-ten split, and that is normal.

Where the numbers come from

Results use the browser's cryptographic random number generator rather than the ordinary Math.random, and values that would skew the odds are discarded and re-drawn. That last step matters: naively squeezing a random number into a range makes some faces slightly likelier than others. Here every face has an equal chance.

Nothing is sent anywhere — the rolls happen in your browser. Each roll is also independent, so a run of five heads does not make tails "due" on the sixth.

Terms explained

Sides: The number of faces on the die. Six is standard, but tabletop games commonly use 4, 8, 10, 12, 20, and 100.
Sum: The total of every die in the current roll added together.
Avg: The sum divided by the number of dice — the mean face value for that roll.
H / T: Heads and tails. Each coin flip is shown as one letter.
d20: Shorthand for a twenty-sided die. Set Sides to 20 to get one.

Frequently asked questions

Is this really random?

Yes. It uses the browser's built-in cryptographic random generator, and results that would bias the odds are rejected and drawn again. Every face has an equal chance, and each roll is independent of the last.

How many dice can I roll at once?

Up to 12 dice per roll, with anywhere from 2 to 100 sides each. For coins, up to 50 flips at a time. The sum and average are calculated across the whole roll.

Can I roll a die that does not exist physically?

Yes. Type any number from 2 to 100 into Sides. A 3-sided or 7-sided die is impossible to make as a fair physical object, but works fine here.

I flipped ten coins and got eight heads. Is it broken?

No. Eight heads out of ten happens roughly once in every twenty attempts by chance alone. Small samples look lopsided far more often than people expect. Flip 50 at a time and the split will usually sit closer to even.

Does it work offline or on my phone?

Everything runs in your browser with no server call, so once the page has loaded it keeps working without a connection. The layout adapts to phone screens.