How JustScore is Calculated
JustScore is a proprietary, opinionated rating — this site's own take on a title's quality, blended from IMDb, Rotten Tomatoes, and Metacritic rather than any single source alone.
Each title carries three related numbers, all on a 0–100 scale:
Aggregate Rating
The plain, unweighted mean of whichever rating sources are present. How good the title is, neutrally — never touched by any of the weighting or discounting below.
Concordance
How tightly IMDb, Rotten Tomatoes, and Metacritic agree with each other, via population standard deviation normalized against the maximum possible spread for the number of sources present. Left blank when fewer than two sources exist — agreement isn't a meaningful concept for a single data point.
JustScore
The sortable, single-number blend — this site's actual opinion:
- IMDb is weighted 1.5x over Rotten Tomatoes and Metacritic — audience opinion counted higher than critic aggregators.
- That figure is then discounted by two trust factors: a source-count weight (0.95 for two sources, 1.0 for three — more corroborating sources, more trust) and a concordance curve (
0.7 + 0.3 × √(concordance/100)) that only mildly discounts near-agreement and never discounts below 70% even at total disagreement. The square root front-loads the curve so it's forgiving near the top and steepens toward the bottom, unlike a straight linear interpolation. - With only one source, there's nothing to weigh or discount against, so JustScore simply equals that source's rating.