MMR CalculatorHonest MMR estimates for League of Legends

A three-tier inverse-variance estimator that combines win behavior and lobby composition into a confidence interval — not a fake-precise scalar.

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Methodology

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Lobby-composition signal

Tier 2 looks up the current rank of every other participant in your last 20 ranked games. Opponents are weighted higher than teammates, and recent games count more.

Honest uncertainty

Every estimate is a (mu, sigma) pair combined via inverse-variance weighting. New or sparse accounts get a wide 90% CI rather than a confidently wrong number.

Built on Cloudflare

SvelteKit on Cloudflare Workers, D1 for the cache, KV for hot lookups, a Durable Object rate limiter for the Riot API, and cron snapshots feeding a future LP-delta tier.