FIBAInternational Basketball Federation
The Olympics, the World Cup, continental championships and most national leagues run on this rulebook, and so does the rest of this site.
The court · four rulebooks side by side
Basketball Court Dimensions
There is no single set of basketball court dimensions. FIBA, the NBA, the NCAA and US high school rules each paint a different floor, and on the three-point line they differ by nearly half a metre. Every measurement below can be switched between metres and feet.
Checked 20 Aug 2026
| Measurement | FIBA | NBA | NCAA | US high school |
|---|---|---|---|---|
| Court lengthBetween the inner edges of the endlines | 91 ft 10¼ in | 94 ft | 94 ft | 84 ft |
| Court widthBetween the inner edges of the sidelines | 49 ft 2½ in | 50 ft | 50 ft | 50 ft |
| Three-point line, at the top1From the point on the floor below the centre of the ring, to the outer edge of the arc | 22 ft 1¾ in | 23 ft 9 in | 22 ft 1¾ in | 19 ft 9 in |
| Three-point line, in the corner2The same point, measured to the outer edge of the line in the corner | 21 ft 7¾ in | 22 ft | 21 ft 8 in | 19 ft 9 in |
| Lane width3Between the outer edges of the lane lines | 16 ft 1 in | 16 ft | 12 ft | 12 ft |
| Lane depthFrom the inner edge of the endline to the far edge of the free-throw line | 19 ft ¼ in | 19 ft | 19 ft | 19 ft |
| Free-throw line to the backboard4From the far edge of the line to the front face of the board | 15 ft 1 in | 15 ft | 15 ft | 15 ft |
| Free-throw line length5The segment the rulebook defines, centred on the middle of the lane | 11 ft 9¾ in | 12 ft | 12 ft | 12 ft |
| Free-throw circle radiusCentred on the middle of the free-throw line, measured to the outer edge | 5 ft 10¾ in | 6 ft | 6 ft | 6 ft |
| Centre circle radiusFrom the centre of the court to the outer edge of the line | 5 ft 10¾ in | 6 ft | 6 ft | 6 ft |
| No-charge semicircle radius6From the point below the centre of the ring, to the inner edge of the arc | 4 ft 1¼ in | 4 ft | 4 ft | Not marked |
| Ring height7From the floor to the top of the ring | 10 ft | 10 ft | 10 ft | 10 ft |
| Ring inside diameter8Across the inside of the ring | 17¾ in | 18 in | 18 in | 18 in |
| Ring centre to the endlineFrom the inner edge of the endline to the centre of the ring | 5 ft 2 in | 5 ft 3 in | 5 ft 3 in | 5 ft 3 in |
| Backboard to the endlineFrom the inner edge of the endline to the front face of the board | 3 ft 11¼ in | 4 ft | 4 ft | 4 ft |
| Backboard widthAcross the face of the board | 70¾ in | 72 in | 72 in | 72 in |
| Backboard heightTop to bottom of the board | 41¼ in | 42 in | 42 in | 42 in |
| Backboard inner rectangle, width9Across the box painted above the ring | 23¼ in | 24 in | 24 in | 24 in |
| Throw-in line to the endline10From the inner edge of the endline to the mark outside each sideline | 27 ft 3¾ in | Not marked | Not marked | Not marked |
The FIBA figures are metric to begin with, so their imperial forms are not round numbers: “91 ft 10¼ in” is an honest conversion of 28 m, not a figure any rulebook prints. The NBA, NCAA and high school figures are imperial to begin with, and the same applies in reverse.
The four rulebooks
NBANational Basketball Association
A slightly larger floor and a noticeably deeper arc. This is the court almost every broadcast shows.
NCAAUS college basketball
The same floor as the NBA with a narrower lane. The NCAA column follows the men’s rulebook, with the two places the women’s differs called out in the notes. The arc moved to the FIBA distance in 2019-20 for Division I men, 2020-21 for Divisions II and III, and 2021-22 for the women.
US high schoolNational Federation of State High School Associations
A shorter floor, a much closer arc and no restricted-area arc at all. School courts outside the US are usually marked to FIBA, not to this.
Notes
- Three-point line, at the topThe NBA arc is almost half a metre deeper than FIBA’s, which is why the same shot can be a two under one rulebook and a three under the other.
- Three-point line, in the cornerFIBA, the NBA and the NCAA all flatten the corner into a straight run parallel to the sideline, so it sits closer than the top — which is what makes a corner three one of the best shots on the floor. The two short extensions on a US high school line sit exactly on the arc’s radius, so there the corner is the same distance as the top.
- Lane widthThe college and high school lane is more than a metre narrower, which changes what a post player can do inside it and makes the three-second count far less pressing.
- Free-throw line to the backboardThis is the “15 feet” everyone quotes, and it is measured to the board rather than to the ring. The centre of the ring sits 0.375 m in front of the board, which puts the line 4.225 m from it under FIBA rules.
- Free-throw line lengthOn a FIBA or NBA floor the painted line is longer than this, because it runs out to both lane lines — 4.90 m and 16 ft respectively. The NCAA and high school lane is exactly 12 ft, so there the painted line and the rulebook's segment are the same thing.
- No-charge semicircle radiusUS high school rules have no such arc, so a defender standing under the rim can still draw a charge; the identical play on a FIBA court is a blocking foul. NCAA women’s play also removed the marking from 2023-24, wording the rule as “directly beneath the basket” instead, so the NCAA figure on this row is the men’s game only.
- Ring heightTen feet, unchanged since 1891, and the only measurement in this table that all four rulebooks agree on exactly.
- Ring inside diameterFIBA specifies a range of 450–459 mm, so an 18-inch (457 mm) NBA ring is perfectly legal on a FIBA floor.
- Backboard inner rectangle, widthThe box is only a little wider than the ring itself, which is why its top corners are the steadiest aiming point on a bank shot.
- Throw-in line to the endlineOnly FIBA marks it, and it has two uses: play restarts from here after any unsportsmanlike or disqualifying foul, at any point in the game; and in the last two minutes of the fourth quarter and of every overtime, a team that would restart in its own backcourt may, after taking a time-out, elect to throw in from here instead.
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You have the numbers; now the lines
Where a line sits is only half of it. The other half is what turns on it — whether standing on it puts you out, whether a shot is worth two or three, and whether a defender in that spot has drawn a charge or committed a block.