Games & hobbies calculators
Dice odds, dice rolls and tabletop tools.
- Cat Age CalculatorConvert your cat’s age to human years using the vets’ guideline: 15 for the first year, 24 at two, then about 4 years for each year after.
- Coin FlipperFlip virtual coins (heads or tails).
- D&D Dice ProbabilityProbability distribution for d4, d6, d8, d10, d12, d20. Add modifier and optional target (meet or exceed) for tabletop gaming.
- Dice RollerRoll any number of d4, d6, d8, d10, d12, d20 or d100 dice with a modifier. Fair rolls from a secure random source, with each die shown.
Tools for tabletop gaming, probability, and hobby math. Roll dice, see probability distributions for d4 through d20 with modifiers, and get "meet or exceed" chances for target numbers. Fun and useful for D&D, other RPGs, and game design.
Who they're for: Players and GMs who want to know the odds of a roll or the distribution of a die type. Enter the die, optional modifier, and optional target to see percentages and charts.
Common use cases: Checking the probability of rolling at least a certain number on a d20 (e.g. with +5 modifier), comparing d6 vs d8 distributions, and understanding how modifiers shift the "meet or exceed" curve. Results are exact for fair dice; use for planning and curiosity, not real-world prediction.