About DnD Calculator
DnD Calculator is a collection of free calculators for fifth edition tabletop roleplaying games. It started from a simple frustration: the rules are easy to learn, but working out encounter budgets, hit points for a multiclass character or the real value of advantage mid-session slows the game down.
What makes these calculators different
- Both rule sets. Every calculator supports the 2014 rules and the 2024 revision. One switch changes the rules across the whole site.
- Exact math. Probabilities are calculated exactly, not estimated by simulation, so a 9.75% chance really is 9.75%.
- Shows the working. Each page explains the rule behind the numbers, with the tables you need at the table.
- Fast and free. No sign-up, no app to install, and it works on a phone at the table.
Where the rules come from
The calculators use the game mechanics published in the System Reference Documents 5.1 and 5.2 and the core fifth edition rules. Creature names in our monster picker come from the SRD 5.1. You can read the full licensing details on the SRD attribution page.
DnD Calculator is an independent fan project. It is not affiliated with, endorsed, sponsored, or approved by Wizards of the Coast.
Who runs this site
DnD Calculator is built and maintained by GEMWEB, a small web studio based in Lamia, Greece, run by people who play and run fifth edition games.
Found a mistake or want a new calculator?
Rules questions, bug reports and ideas for new tools are always welcome. Send us a message and we will take a look.