Boxing round timer
Pick a real round structure — professional, amateur or beginner — or build your own, and run it. You get a ten-second warning, then work and rest phases that call themselves.
Round structure
The clock
The countdown reads real time rather than counting ticks, so it stays accurate within a round even if you switch tabs — though a frozen tab cannot call the bell on time. See what those rounds cost you →
The standard round structures
| Format | Rounds | Work / rest |
|---|---|---|
| Pro championship | 12 | 3:00 / 1:00 |
| Pro non-title | 10 | 3:00 / 1:00 |
| Amateur & Olympic | 3 | 3:00 / 1:00 |
| Beginner bag work | 3 | 2:00 / 1:00 |
Why the clock reads real time
Most browser timers count intervals: tick, subtract a second, repeat. Browsers deliberately throttle that in background tabs to save battery, so a timer built this way runs slow the moment you switch away — and you find out when your round ran four minutes. This one records the moment each phase should end and compares against the system clock, so backgrounding the tab has no effect on when the bell goes.
Honest caveats
The timing is exact; what it cannot do is make the work hard. Structure is the easiest part of training to get right and the least important — three rounds done properly beat twelve rounds spent pacing around a bag. The clock tells you when to work, not how hard.
Curious what a session costs you in energy terms? The boxing calorie calculator uses published MET values, and the punch stats calculator turns the rounds you just did into accuracy and work rate.
Common questions
How long are professional rounds compared to amateur ones?+−
Both are three minutes with a one-minute rest. The difference is how many: professional championship bouts run twelve rounds, non-title fights commonly ten, while elite amateur and Olympic bouts are three. Men’s amateur bouts moved to three three-minute rounds in 2009 and women’s followed in December 2016.
Why three minutes?+−
It comes from the Marquess of Queensberry rules of 1867, which set three-minute rounds with a minute between them and replaced the older format of fighting until a man went down. It has survived for over a century and a half largely unchanged, which is unusual for any sporting convention.
How should a beginner structure bag rounds?+−
Start at three rounds of two minutes with a full minute of rest, which is the third preset here. Two minutes of honest work on a bag is much harder than it sounds when your technique is still forming, and the failure mode for beginners is not insufficient volume — it is form collapsing under fatigue and grooving bad habits. Add rounds before you add length.
Will the timer keep time if I switch tabs?+−
Within a round, yes. Browsers throttle background timers, so a clock that counts ticks drifts badly the moment you look away; this one reads the actual system clock and works out how much time is left, so the countdown itself stays accurate. What it cannot do is fire a bell while the tab is frozen — if you background it mid-round, the phase change lands when the tab wakes up rather than at the exact second. Keep it visible if you are relying on it to call the round.
The bell is free. The engine behind it is $49.
Twelve weeks of periodized work on the muscles that keep a fighter sharp in the eleventh round, not just the first.