Calculate a player’s raw on-court scoring differential, reverse a target, and optionally normalize it by minutes or possessions.
How the Plus Minus Calculator Works
Basketball plus-minus compares team scoring and opponent scoring only during the minutes a player is on the court. Positive values mean the player’s team outscored the opponent in that window; negative values mean it was outscored.
Formula: Raw plus-minus = on-court team points – on-court opponent points; per 36 = raw plus-minus / minutes x 36; per 100 = raw plus-minus / possessions x 100
Choosing the Right Inputs
Use synchronized scoring totals covering exactly the player’s stints. Optional minutes and possessions must cover those same stints. Do not substitute the final game score unless the player was on the court for the entire game.
| Team points | Opponent points | Raw +/- | Meaning |
|---|---|---|---|
| 52 | 47 | +5 | Team won the player’s minutes by five |
| 41 | 50 | -9 | Team lost the player’s minutes by nine |
| 80 | 80 | 0 | Even scoring during the stint |
| 48 | 44 | +4 | At 40 possessions, +10.0 per 100 |
Understanding Your Results
Raw plus-minus leads, followed by both scoring totals and the team’s share of all points in the stint. Optional minutes add a per-36 rate and optional possessions add a per-100 rate.
Worked Example
If a player’s team scores 52 points and allows 47 while that player is on the court, the raw plus-minus is +5. Over 18 minutes and 50 possessions, that equals +10.0 per 36 and +10.0 per 100.
Assumptions and Limitations
Plus-minus is strongly affected by teammates, opponents, rotations, score effects, and small samples. It records what happened during a stint but does not by itself identify why the differential occurred.
Sources
NBA. Stats Glossary.