Offensive and Defensive Rating Calculator
Offensive and Defensive Rating Calculator
Offensive, defensive and net rating in basketball — points scored and allowed per 100 possessions. It takes the possession count from you, because the published ways of estimating one disagree by enough to change the answer.
Points per 100 possessions, from your own possession count
Points ÷ possessions × 100114.2 points from 101.4 possessions; 112.9 allowed from the opponent’s 101.0
Formula, and why the denominator is asked for rather than computed
Defensive rating = 100 × opponent points ÷ opponent possessions
Net rating = offensive rating − defensive rating
- the published definitions
- the NBA’s own stats glossary: offensive rating “Measures a team’s points scored per 100 possessions”, defensive rating “The number of points allowed per 100 possessions by a team”, net rating “Measures a team’s point differential per 100 possessions”. Basketball-Reference’s glossary gives the same in words and prints no formula
- why per 100 and not per game
- because a team that plays fast scores and concedes more of everything, so points per game cannot tell a good offence from a quick one. Dividing by possessions removes tempo, which is why the possession estimate has to be taken seriously
- two denominators, not one
- the NBA’s glossary uses the opponent’s own count for the defensive rating, so the two fields above are separate. The counts are close — each team gets the ball back after the other scores — and some sources use one for both. This page cannot know which, so it asks
- a team rating and a player rating are different things
- these are team ratings. An INDIVIDUAL rating is Dean Oliver’s much longer method from Basketball on Paper; Basketball-Reference’s write-up of it needs the team’s full season line, the opponent’s totals and several derived team quantities, and defers the complete method to the book
- what is deliberately absent
- any conversion of a rating into a price, an implied result probability drawn from a market, or a stake. This page does arithmetic on published figures and nothing else
Worked example
114.2 points from 101.4 possessions; 112.9 allowed from the opponent's 101.0
Offensive rating: 100 × 114.2 ÷ 101.4 = 112.6 points per 100 possessions. Defensive rating: 100 × 112.9 ÷ 101.0 = 111.8, so net rating +0.84
Points per possession: 114.2 ÷ 101.4 = 1.126, which is the rating over 100
Now change nothing but the estimate. The same 114.2 points over Basketball-Reference's longer-form 99.0 possessions is an offensive rating of 115.3 — 2.75 higher, from the same box score
Double the points and the possessions together and the rating does not move; halve the possessions alone and it doubles; set them to 0 and the panel shows nothing
The two possession fields are deliberately unequal, 101.4 against 101.0. A test run with them equal would pass even if both ratings had been computed from one denominator by mistake
The same 114.2 points over five possession estimates
| Possession estimate | Possessions | Offensive rating |
|---|---|---|
| Simple estimate, coefficient 0.40 | 100.58 | 113.5 |
| Simple estimate, coefficient 0.44 (the NBA’s glossary) | 101.45 | 112.6 |
| Simple estimate, coefficient 0.475 (college convention) | 102.21 | 111.7 |
| Basketball-Reference’s longer form, this team only | 99.03 | 115.3 |
What this page computes, and what it will not
| Calculation | Here? | Why |
|---|---|---|
| Team offensive, defensive and net rating from your own possession counts | Yes | The NBA publishes all three definitions and the arithmetic is a division |
| Estimating the possession count for you | No | Two published estimators disagree by 2.4% and move this answer by 2.75 points per 100. The possessions page computes both and prints the gap |
| An individual player’s offensive or defensive rating | No | Oliver’s individual ratings need the team’s and opponent’s full season lines, and the published write-up defers the method to his book |
| Player efficiency rating | No | It needs the league’s own minutes-weighted average rating, which no box score contains. The PER explainer sets out why |
| Converting a rating into a price or an implied match probability | No | Out of scope across this entire site |
Points per 100 possessions, and the estimate underneath it
This page is about basketball, the five-a-side game played to a basket ten feet above the floor. It has no single rule-maker: the Fédération Internationale de Basketball (FIBA) publishes the Official Basketball Rules used by most of the world, the NBA publishes its own rulebook for its own competition, and the NCAA publishes separate rules for United States college play. Where a number on this page is one of theirs rather than plain arithmetic, the body and the edition are named beside it.
Points per game cannot separate a good offence from a fast one: a team that pushes the ball scores and concedes more than one that walks it up without being better at either end. These three ratings divide by possessions instead. The NBA publishes all three in its own stats glossary — “100*((Points)/(POSS)”, “100*((Opp Points)/(Opp POSS))” and “OFFRTG – DEFRTG” — and each is one division.
A possession count is an estimate, not a count. No league publishes one alongside its box score: the NBA’s own stats glossary defines possessions in words — “The number of possessions played by a player or team” — and prints no formula for them at all, and defines pace as “The number of possessions per 48 minutes” with no formula either. Every possession figure you have read was reconstructed from field goal attempts, free throw attempts, offensive rebounds and turnovers, and the published reconstructions do not agree with each other. That is why this page asks you for the count rather than working one out. On the NBA’s 2023-24 league-average line the simple estimate gives 101.4 possessions and Basketball-Reference’s longer form 99.0, so the same 114.2 points come out at an offensive rating of 112.6 or 115.3 depending on which formula produced the denominator — 2.75 points per 100 possessions, created by nothing that happened on the court. Moving only the free throw coefficient across the published range from 0.40 to 0.475 spans another 1.8 points. The possessions and pace calculator will produce a count two ways and print the gap if you do not have one.
Three cautions. The defensive rating uses the opponent’s possession count rather than yours, which is why there are four fields; the two are close, and some sources collapse them into one. These are TEAM ratings: an individual player’s rating is Oliver’s far larger method from Basketball on Paper, needing the team’s and opponent’s full season lines, and this page does not attempt it — nor, for the reasons the player efficiency rating explainer sets out, a player efficiency rating. And nothing here converts a rating into a price or a stake.
Frequently asked questions
How do you calculate offensive rating?
Divide the points by the possessions and multiply by 100. For 114.2 points from 101.4 possessions: 100 × 114.2 ÷ 101.4 = 112.6 points per 100 possessions. The NBA’s own stats glossary gives offensive rating as “100*((Points)/(POSS)” and describes it as a team’s points scored per 100 possessions.
Why does this calculator ask me for the possessions?
Because no league publishes a possession count and the published estimators disagree. On the NBA’s 2023-24 league-average line the two common formulas give 101.4 and 99.0, turning one points total into a rating of 112.6 or 115.3. Your source already used one of them; using its number keeps this page reconcilable with it.
Should the two possession counts be the same?
They are close but not identical, and the NBA’s glossary treats them separately: defensive rating is “100*((Opp Points)/(Opp POSS))”. Each team gets the ball back after the other scores, so over a full game the counts converge; over part of one they diverge. Some sources average them into one figure.
Is this the same as a player’s offensive rating?
No. These are team ratings and a one-line division. An individual rating is Dean Oliver’s much longer method from Basketball on Paper, whose published write-up needs the team’s full season line, the opponent’s totals and several derived team quantities and defers the rest to the book. None of that is on the box score in front of you.
What is a good offensive rating?
It depends on the era and the competition, and no governing body publishes a threshold. By this page’s arithmetic on Basketball-Reference’s published league-average row the NBA’s 2023-24 average was about 112.6 on the 0.44 estimate; the same calculation on a 1990s average would be much lower, because scoring efficiency has risen. Compare within a season.
Related calculators
References
- National Basketball Association. Stats Glossary, nba.com, read 12 Oct 2026. The source for this site’s true shooting percentage, effective field goal percentage and offensive, defensive and net rating formulas, each quoted verbatim on the page that uses it. Possessions and pace are defined in WORDS with NO FORMULA at all. Usage percentage is “(FGA + Possession Ending FTA + TO) / POSS” and turnover ratio “(TO * 100) / (POSS)” — neither the 0.44 form.
- Sports Reference LLC. Basketball-Reference.com Glossary, read 12 Oct 2026. True shooting attempts “FGA + 0.44 * FTA”, eFG% “(FG + 0.5 * 3P) / FGA”, TOV% “100 * TOV / (FGA + 0.44 * FTA + TOV)”, Pace “48 * ((Tm Poss + Opp Poss) / (2 * (Tm MP / 5)))”. Its team Possessions entry instead uses 0.4 on free throw attempts and 1.07 on an estimated offensive-rebound term, and averages both teams’ estimates — so one page carries 0.4 and 0.44 for the same quantity. Offensive and defensive rating carry no formula here.
- Sports Reference LLC. “Calculating Individual Offensive and Defensive Ratings.” States that the ratings were “developed by Dean Oliver in his 2004 book Basketball on Paper” and refers readers to the book for full details. The individual ratings need the team’s full season line, the opponent’s made and attempted field goals and free throws, points, turnovers and offensive rebounds, and team possessions. No team possession formula appears on the page. Read 12 Oct 2026.
- Squared Statistics. “Analyzing NBA Possession Models.” squared2020.com, 10 July 2017, read 12 Oct 2026. Quotes the NBA’s own estimator with its .436 coefficient and the NBA’s stated basis for it — “approximately 43.6% of all free throws are possession-ending”, which “may change from year to year”. Counts 2016-17 possessions from play-by-play and scores both formulas against the count; the figures and the refitted 0.4328 and 1.2228 are quoted on this site’s possessions page. Its per-team tables are images, so no row here comes from one.
- Sports Reference LLC. 2023-24 NBA Season Summary, read 12 Oct 2026. The Per Game Stats table’s League Average row, used as this page’s default inputs so no worked example rests on an invented box score: FG 42.2, FGA 88.9, 3P 12.8, FTA 21.7, ORB 10.6, DRB 33.0, TOV 13.6, PTS 114.2. Its own Advanced table was absent from the fetched text, so every Pace, rating or percentage figure here is this site’s own arithmetic on that row.