Basketball Clock
A game clock and a shot clock on any screen - NBA, FIBA, NCAA or high school lengths, run from a phone or the keyboard.
How to use
- Step 1Pick your rule set under “Rule set”: NBA, FIBA, NCAA men or women, US high school, or a pickup run with one period and no shot clock. The period length, the overtime and the shot clock take the right numbers.
- Step 2Run the game from the keyboard: Space starts and stops both clocks, S puts the full shot clock back after a change of possession, D gives the partial reset, N moves to the next period. The big buttons do the same on a phone.
- Step 3Tap “Share live” and open the view link on the gym screen or a second laptop. It shows the clocks full screen, nobody watching can change them, and only your device sounds the horn.
Game clock by rule set
Almost every argument about a basketball clock is really a question of which rule book is in the gym. The lengths below are the regulation ones; choose the rule set in the settings and the clock, the overtime and the shot clock all change together.
| Rule set | Regulation | Overtime |
|---|---|---|
| NBA | 4 × 12 min | 5 min |
| FIBA (international) and WNBA | 4 × 10 min | 5 min |
| NCAA men | 2 × 20-min halves | 5 min |
| NCAA women | 4 × 10 min | 5 min |
| US high school (NFHS) | 4 × 8 min | 4 min |
| Youth and rec leagues | Usually 4 × 6 to 8 min, often a running clock | Set by the league |
Shot clock by rule set
The shot clock is reset in full on every change of possession. The second, shorter reset exists because the offence does not have to bring the ball up the floor again, and its length differs by rule book.
In the NBA and under FIBA rules the shot clock goes to 14 seconds when the offence rebounds its own missed shot, and on a frontcourt throw-in after a defensive foul the clock is set to 14 if less than that remains. In NCAA basketball the equivalent reset is 20 seconds, and it applies whenever the ball has hit the rim and the offence keeps it in the frontcourt. In every rule set the ball must touch the rim for a reset at all: an air ball the offence recovers does not earn new time.
For US high school, a shot clock is not a national rule. The NFHS opened the door in the 2022-23 season for state associations to adopt a 35-second clock; by the 2025-26 season 32 states used one in some form. The NFHS guidelines keep it simple with a full 35-second reset, so this page's second reset button falls back to a full reset when the high-school rule set is selected.
| Rule set | Shot clock | Second reset |
|---|---|---|
| NBA | 24 s | 14 s after an offensive rebound |
| FIBA and WNBA | 24 s | 14 s after an offensive rebound |
| NCAA men and women | 30 s | 20 s when the ball hit the rim and the offence keeps it in the frontcourt |
| US high school (NFHS), where adopted | 35 s | Full 35 s; the NFHS guidelines have no partial reset |
| Youth and pickup | Usually none | — |
When the clock stops, and when it starts again
- Every whistle stops it: a foul, a violation, a held ball, the ball out of bounds, a timeout. Watch the officials rather than the ball — the whistle and the raised hand are your cue, not the play.
- A made basket does not stop the clock, with two exceptions worth knowing: the NBA stops it after a made field goal in the last two minutes of the fourth quarter and of each overtime, and NCAA men stop it after a made field goal in the last minute of the second half and of each overtime.
- It starts again when a player on the court legally touches the ball after a throw-in, or when the ball is touched after a missed final free throw. It does not start when the official hands the ball over.
- During a free-throw sequence the clock is stopped for all of it and starts on the touch after the last one, if that one misses.
- The shot clock stops and starts with the game clock. Under NBA rules it is switched off entirely once the period has 24 seconds or less left after a change of possession, because the period will end first; this page tells you when you have reached that point.
- At zero the horn sounds and the clock stops on this device. A clock correction is the referee's decision — the console only does what they signal, so stop the clock first and then adjust it by a second or type the exact time.
Running the clock as a table official
One person can run both clocks with a keyboard and almost nobody can do it with a mouse. Put your thumb on the space bar for the game clock and your other hand over S and D for the shot clock, and you never look down to find a button. On a phone, the start and stop button is deliberately the biggest thing on the page.
Start on the touch, stop on the whistle, and do not try to be clever about the half-second — officials would rather correct a clock than watch the table guess. The ±1 s buttons adjust without stopping play, and the mm:ss box sets an exact time when the referee gives you one.
The shot clock is the harder job: reset it in full on every change of possession, use the partial reset only when the ball hit the rim and the offence kept it, and do not reset on an air ball. When the game clock drops below the shot clock the shot clock stops mattering, which is the moment the operator switches it off.
This page shows clocks only. If you also need the score, fouls and timeouts on the same screen, use the basketball scoreboard page: it has the same clock and shot clock with a scoreboard around them.
Questions and answers
Where is the score?
There isn't one here on purpose — this page is the clocks, so they can be as big as the screen allows. The basketball scoreboard page has the same game clock and shot clock with the score, team fouls, the bonus and timeouts around them.
Does the 14-second reset work for college games?
Choose NCAA men or NCAA women in the settings and the shot clock becomes 30 seconds with a 20-second second reset, which is the college rule. The D key and the second button always reset to whatever the selected rule set uses; under high-school rules that is a full 35 seconds.
Can I use it as a practice or drill clock?
Yes. The “Pickup / practice” rule set gives you one period and no shot clock. Tap the time to type any length — 5:00 for a drill, 12:00 for a scrimmage — and Space starts and stops it. Or turn the shot clock on alone and use it as a 24-second trainer.
Can the clock be on the gym screen and the controls on my phone?
That is what the live link is for. Open the view link on the screen, keep the edit link on your phone, and the two stay in step: each device works out the reading from its own clock, so nothing jumps when the network hiccups. The viewing screen never sounds the horn.
Why is there no sound?
Browsers block audio until you have touched the page. Press Start once and the horn works from then on. There are two horns — a long one when the period ends, a short one for the shot clock — and both can be switched off in the settings.