Effective Field Goal Percentage Calculator
Effective Field Goal Percentage Calculator
Effective field goal percentage in basketball — field goals plus half the three-pointers, over field goal attempts. The weighting that prices a made three at one and a half twos, why it is a rule rather than an estimate, and what it leaves out.
Effective field goal percentage from makes, threes and attempts
A made three counts 1.5The NBA’s 2023-24 league average per game: 42.2 field goals made, 12.8 of them threes, from 88.9 attempts
Formula, and why the weight is exactly one half
Equivalently = (2 × FG + 3P) ÷ (2 × FGA) × 100, which is half the points per attempt
- the published definition
- the NBA’s stats glossary gives “(FGM + (0.5 * 3PM)) / FGA”, described as “adjusting for made 3-point field goals being 1.5 times more valuable than made 2-point field goals”; Basketball-Reference’s gives “(FG + 0.5 * 3P) / FGA”. Dean Oliver’s first of four factors is the same expression
- where the 0.5 comes from
- the scoring rules and nothing else. FIBA’s Official Basketball Rules 2024 give a goal from the three-point area 3 points and one from the two-point area 2 at Art. 16.2.1, and the NBA’s Rule 5 Section I says the same. Three over two is one and a half, so a made three is credited as one and a half makes — which is the same as adding half of it. This is the one weighting on this site’s basketball pages derived from a rule rather than fitted to data, and it cannot go out of date
- why a made three and not an attempted one
- because the denominator already counts every attempt once, whether a two or a three. Only the reward differs, so only the makes are reweighted
- what it deliberately does not weigh
- free throws, turnovers and who created the shot. The free throws are the significant omission — see the true shooting percentage calculator. The two coincide only for a line with no threes and no free throws, the degenerate case
Worked example
The NBA's 2023-24 league average per game: 42.2 field goals made, 12.8 of them threes, from 88.9 attempts
Weighted makes: 42.2 + 0.5 × 12.8 = 48.6, and 48.6 ÷ 88.9 = 54.7% against a plain 42.2 ÷ 88.9 = 47.5%, so the three-point shooting is worth 7.2 percentage points
Points from the floor: 2 × 42.2 + 12.8 = 97.2, which is 1.093 per attempt — exactly twice the 0.5467
Set the made threes to 0 and the answer falls to 47.5%, identical to the plain percentage. That is the degenerate case, and it is why this page's test is run with threes in the line rather than without
Double the makes, threes and attempts together and the answer does not move; halve the attempts alone and it doubles
Enter more threes than field goals, or more field goals than attempts, and the panel refuses rather than printing an impossible percentage
Four lines with the same plain field goal percentage
| Field goals | Of which threes | Attempts | Field goal % | Effective field goal % |
|---|---|---|---|---|
| 20 | 0 | 40 | 50.0% | 50.0% |
| 20 | 5 | 40 | 50.0% | 56.3% |
| 20 | 10 | 40 | 50.0% | 62.5% |
| 20 | 20 | 40 | 50.0% | 75.0% |
What each shooting measure includes
| Field goal % | Effective field goal % | True shooting % | |
|---|---|---|---|
| Treats a made three as worth more than a made two | No | Yes | Yes |
| Counts free throws | No | No | Yes |
| Contains a fitted coefficient that could be revised | No | No | Yes, the 0.44 |
| Can exceed 100% | No | Yes | Yes |
| Counts turnovers, or who created the shot | No | No | No |
| NBA 2023-24 league average, by this site’s arithmetic | 47.5% | 54.7% | 58.0% |
The weighting is a rule, not an estimate
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.
A plain field goal percentage counts a made shot as a success and stops, which was adequate when every field goal was worth two points and has not been since. The difference is not small: twenty of forty all from three is sixty points from the floor where twenty of forty from inside is forty. Effective field goal percentage closes that in the simplest way — a made three counts as one and a half makes.
The one and a half is not a judgement or a fit. FIBA’s Official Basketball Rules 2024 state at Art. 16.2.1 that “A goal released from the 3-point goal area counts 3 points” and one from the two-point area counts 2, and the NBA’s Official Rules say the same at Rule 5 Section I items 2 and 3. Three divided by two is one and a half, and adding half a made three to the make count is that same arithmetic. So this is the only weighted shooting figure on this site whose coefficient is published in a rulebook rather than fitted to a season of data, and it is why the number cannot go out of date the way a possession estimate can.
Read the other way, the measure is half the points per field goal attempt, and the result panel prints both: they must always be in that exact ratio — 54.7% against 1.093 points per attempt on the default line. That identity says what the figure is, a scoring rate per shot rescaled so “all twos, all made” lands on 100%, and it explains the values above 100% that surprise people and are correct.
Read the formula for what it leaves out. There is no turnover term, so a player who loses the ball before shooting is not charged for it; no term for who created the shot, so an open lay-up fed by someone else and a contested fadeaway off the dribble count identically; and nothing about defence at either end. It is a shooting-efficiency figure and nothing wider, which is why it is reliable at the thing it does measure. The significant omission is free throws, and it is deliberate: including them would mean deciding how much of a possession an attempt consumes, which is a fitted coefficient and the thing this page is free of. If you want them counted, the true shooting percentage calculator does it at 0.44 each and prints what that costs; for the rules behind the 0.5, with their article numbers, the three-point line and shot clock interpreter. No governing body publishes a good-or-bad threshold for this figure, and none is invented here. It is interpretable only against a position, a competition and a season, so the honest use of it is comparing players in the same role in the same competition, from one source.
Frequently asked questions
How do you calculate effective field goal percentage?
Add half the made three-pointers to the made field goals and divide by the field goal attempts. For 42.2 field goals including 12.8 threes from 88.9 attempts: 42.2 + 0.5 × 12.8 = 48.6, and 48.6 ÷ 88.9 = 54.7%. The NBA’s own stats glossary gives the same formula.
Why is a made three counted as one and a half?
Because the rules make it worth one and a half times as much. FIBA’s Official Basketball Rules 2024 give a three-point goal 3 points and a two-point goal 2 at Art. 16.2.1, and the NBA’s Rule 5 Section I says the same. Three over two is one and a half. Unlike the 0.44 in true shooting percentage, this coefficient is a rule rather than an estimate.
Can effective field goal percentage be over 100%?
Yes. A player who attempts only threes and makes them all is at 150%, because the scale’s 100% means two points per attempt rather than every shot made. It looks wrong and is right; it is the price of putting a points-per-shot figure on a percentage scale.
Is effective field goal percentage one of the four factors?
Yes, and the heaviest. Dean Oliver’s four factors of basketball success are effective field goal percentage, turnover rate, offensive rebounding rate and free throw rate, and his published weights are 40%, 25%, 20% and 15%. A 2023 paper reproducing the work calls that weighting “somewhat ad hoc”, so the 40% is not on the same footing as the formula.
What is a good effective field goal percentage?
There is no published threshold and none is invented here. By this page’s arithmetic on Basketball-Reference’s published league-average row the NBA’s 2023-24 average was 54.7% — but a centre shooting at the rim and a guard shooting from range are not on one scale, and the league figure has moved a long way between eras as three-point volume has risen.
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.
- “Dean Oliver’s Four Factors Revisited”, arXiv:2305.13032, read 12 Oct 2026. States Oliver’s approximation as POSS = FGA + TOV − ORB + μ·FTA, with μ “the proportion of free throws that end the possession of the ball”; attributes μ = 0.44 to Kubatko et al. (2007) on 2003-06 data; refits μ = 0.42 for 2022-23, “no longer accurate in 2023”; cites Zimmermann (2016) using 0.475 for the NCAA; and states that “the exact number of possessions can not be deduced” from a box score. Quotes Oliver’s four-factor weights of 40/25/20/15%, calling them “somewhat ad hoc”. Cites Oliver D, Basketball on Paper, Potomac Books, 2004. Its figures are image-only.
- Fédération Internationale de Basketball. Official Basketball Rules 2024, v1.0 — approved at Mies, 26 April 2024, “Valid as of 1st October 2024”; read 12 Oct 2026. Art. 2.1 (the 28 m by 15 m court); Art. 2.5.4 (the 6.75 m three-point arc and the 0.90 m sideline setback); Art. 8.1 and 8.7 (four 10-minute quarters, five-minute overtimes); Art. 16.2.1 (the 1, 2 and 3 point values); Art. 29.1.1 and 29.2.2/29.2.3/29.2.7 (24 seconds, reset to 14). The court diagrams returned as captions only, so no figure here is from one.
- National Basketball Association. Official Rules, Rule No. 5 Section I items 2-3 (two points inside the arc, three outside) and Section II items 1-2 (“All periods of regulation play in the NBA will be twelve minutes.”, five-minute overtimes); Rule No. 7 Section I (“The shot clock shall start at 24 seconds”) and Section IV-d-1 (reset to 14 seconds after a missed attempt “that contacts the basket ring”). official.nba.com, read 12 Oct 2026.