A court holds the game’s rules in paint.
Lines tell players where to pass, shoot, and defend.
This guide explains what are the lines on a basketball court.
You will learn what is the half court line in basketball, what is the baseline in basketball, what is the key in basketball, and more.
I compare NBA, FIBA, NCAA, and high-school markings and give clear measurements for each.
Court size at a glance
Different leagues use slightly different court sizes.
The NBA and NCAA courts measure 94 by 50 feet.
FIBA courts are 28 by 15 meters, about 91.9 by 49.2 feet.
Many U.S. high school courts are 84 by 50 feet.
The half-court line
The half-court line divides play into frontcourt and backcourt.
Teams have a set time to cross it on offense.
It marks where the jump ball circle sits at center court.
On most courts that circle measures 12 feet across in the NBA and 3.6 metres in FIBA.
The baseline (endline)
The baseline runs along each end of the court behind the basket.
It marks where out-of-bounds calls happen at the ends.
After a made basket, the defense inbounds the ball from the baseline.
Baseline width is the same as the court, normally 50 feet for professional and college floors.
The sidelines
Sidelines run the length of the court.
They define the playable width.
If any part of the player or the ball touches the line, the ball is out.
Game clocks and team benches sit outside the sidelines at most arenas.
The key (the paint)
The rectangular area under the basket goes by many names: the key, paint, or lane.
Its width varies by level. The NBA key is 16 feet wide. The NCAA key follows the NBA size. FIBA uses a slightly narrower lane in metric terms.
The free-throw line sits 15 feet from the plane of the backboard on most courts.
The restricted area (no-charge zone)
The restricted area is a semi-circle painted under the basket.
Its purpose is to limit charging fouls near the hoop.
In the NBA the arc radius is 4 feet from the center of the basket. FIBA uses a similar metric radius of 1.25 metres.
Defenders cannot draw a charge if they stand inside this arc when contact occurs.
The free-throw lane markings
The lane lines and lane spaces tell players where to line up for free throws.
Players stand in marked boxes parallel to the lane.
The shooter stays behind the free-throw line until the ball hits the rim.
Counting, positioning, and rebound responsibilities follow these painted marks.
The three-point arc
The three-point arc separates two-point shots from three-point shots.
NBA distance is 23 feet 9 inches at the top of the arc and 22 feet in the corners.
FIBA and current NCAA distance measure roughly 6.75 metres, about 22 feet 1.75 inches.
High school three-point lines usually sit closer, around 19 feet 9 inches.
The center circle
The center circle marks where the jump ball starts the game.
Only the two jumpers and their opponent’s immediate jumpers enter before the tip.
The diameter differs slightly by rule set. On NBA floors the center circle radius is six feet. FIBA uses a 1.8 metre radius.
Hash marks and the lower defensive box
Some leagues add hash marks near the baseline and key for positional reference.
The NBA uses hash marks to mark the lower defensive box for free-throw rebounding.
Those small lines control where players line up and how officials enforce positioning.
Bench and coaching box markings
Coaching boxes and scorer’s table zones sit outside the playing lines.
They limit where coaches and staff can stand during play.
Violations can result in technical fouls if personnel step into the game area and interfere.
Differences that matter for players and coaches
Three-point spacing changes how offenses set up around the arc.
A wider NBA arc forces more spacing and creates room for drives.
FIBA and NCAA arcs sit closer to the basket, which tightens spacing and emphasizes ball movement.
A smaller high school court reduces transition run length and speeds up fatigue.
Practical notes for arena managers
Mark lines with durable paint and strict measurements.
Check three-point arc accuracy before tournaments. Small errors cause big complaints.
Use certified templates when repainting courts to match league rules.
Keep a ruler and laser measurer in the equipment room for quick checks.
Quick reference: common measurements
- NBA and NCAA court: 94 by 50 ft.
- FIBA court: 28 by 15 m (about 91.9 by 49.2 ft).
- Three-point line: NBA 23.75 ft at top, 22 ft corners; FIBA about 6.75 m.
- Free-throw line: 15 ft from backboard plane.
- Restricted area radius: NBA 4 ft; FIBA about 1.25 m.
Final word
Lines make the court readable for players, coaches, and officials.
They define space, control contact, and shape tactics.
Learn the measurements and the rules and you will read a game faster.
Paint a court right, and the game plays fair and true.
