Matchmaking Rating Calculator

Expected Win % comes directly from the Elo logistic formula, which compares your Player Rating against the Opponent Rating: the wider the gap in the opponent's favor, the lower your expected chance of winning. This holds across the calculator's full 0-5000 rating range — raising Opponent Rating alone always pulls Expected Win % down, never up, whatever your own rating is set to.

K-Factor sets how large a single match's Rating Change can be — it directly scales Change if Win, Change if Loss, and Change if Draw, matching FIDE's own official rating formula (Rating Change = K-Factor × (actual score − expected score), per the FIDE Handbook's Rating Regulations). A K-Factor of 64 (typical for provisional or new accounts) lets one result swing your rating up to four times as far as a K-Factor of 16 (typical for established, converged ratings), even with identical Player and Opponent Ratings. FIDE itself uses 10/20/40 rather than 16/32/64, but the mechanism — a single multiplier scaling every rating update — is identical.

Because New Rating is Player Rating plus a bounded Rating Change, and across the calculator's declared ranges Player Rating is the dominant term in that sum — the Elo correction from a single match, even at a large K-Factor, is a small adjustment relative to a multi-hundred-point rating. This is expected Elo behavior: individual matches nudge a rating, they do not reset it.

No — it implements the classic two-player Elo update only, the same math chess ratings use. Team aggregation, confidence-interval systems like Glicko-2 or TrueSkill, and party-based matchmaking adjustments all require additional machinery this calculator does not include, so treat the result as a 1-v-1 rating estimate rather than a full ranked-ladder model.