Tabletop games calculators
6 free tools
The little bits of math that come up at the game table, all in one spot. Roll any dice notation you throw at it, check the odds before you gamble on a big attack, roll up a D&D character, and settle who goes first without hunting for a physical d20.
Type standard dice notation like 2d6+3 or 1d20, mix dice types, and see every die plus the total.
Roll six D&D ability scores with the classic 4d6-drop-lowest method and see each die, the totals, and your overall modifier.
Add up monster XP, apply the encounter multiplier for the group size, and compare it to your party's difficulty thresholds.
Find the odds of rolling an exact sum, at least a total, or at most a total with any number of dice.
Work out your new Elo rating after a win, draw, or loss, with the expected score and the points you gained or lost.
Enter each combatant's name and initiative modifier, roll a d20 for everyone, and get a turn order sorted from highest to lowest.
Frequently asked questions
Are the dice rolls actually random?
They use your browser's cryptographic random generator when it's available, which is far better than a plain Math.random() for feeling fair. Nothing is stored or sent anywhere — every roll happens on your device.
Do I need to know D&D to use these?
Not for the dice and Elo tools. The ability-score, encounter, and initiative helpers assume 5e-style rules, but each one explains what it's doing so you can follow along even if you're new.
Can I use these for other games besides D&D?
Yes. The dice roller and probability tool work for any game that uses polyhedral dice, and the Elo calculator suits chess, board games, or any head-to-head league you're running.