Character pool size N and password length L—entropy ≈ L×log₂(N) bits (idealized random model).
Bits = length × log₂(alphabet size), assuming each character is chosen independently and uniformly from a pool of size N ≥ 2 with length ≥ 1. Real passwords deviate (patterns, reuse, biased choices)—treat as an upper‑bound order‑of‑magnitude hint.
This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.