radialtimers.com
Forty seconds of work, twenty of rest, ten rounds, ten minutes end to end. The window is long enough for a full set or a circuit station, and every change announces itself with a chime, so the work keeps your full attention.
The 40/20 split is for training that needs a bit of setup: a kettlebell to pick up, a band to loop, a box to step to. Forty seconds fits a proper set of 10 to 15 reps at a steady tempo, and twenty seconds is enough to put one thing down and pick up the next. This page runs ten rounds with a chime at every change and finishes on the tenth work block, which puts the clock at 9 minutes 40 seconds. Each work dial sheds a ring every 2 seconds.
Run any of these twice with a 2 minute rest between and you have a twenty-two minute session with a real training effect.
Lay out every piece of equipment before starting so the twenty seconds is rest, not searching. Fullscreen the dial on a screen you can see from the floor and from standing; the chime tells you when to switch, so you never have to watch for it. For a group class, put the timer on the big screen, or share a Room link so each phone shows the same countdown from wherever people are stood.
Five minutes of easy movement before the first round, timed on the 5 minute timer: marching, arm circles, bodyweight squats at half depth. Afterwards, three or four minutes of walking and stretching. Both can be added as blocks to the same cycle in Cycles, so one press covers the whole session.
Rushing the reps to "fit more in" is the usual one: forty seconds at a controlled tempo beats forty seconds of bouncing. Picking ten moves that all hammer the same muscle leaves the last four rounds useless; alternate push, pull, legs, core. Skipping the rest chime for one more rep breaks the rhythm for the rest of the circuit. And if form falls apart at 30 seconds every round, choose a lighter load or move to the 30/10 split.
For maximal sprints, the 20/10 Tabata. For circuit stations that need a longer effort, 45/15. For heavy lifts, drop the intervals and use a plain 90 second timer between sets. The guide on interval and HIIT timing compares them in detail.
Forty seconds fits a controlled set or a timed station, and twenty is enough to reset for the next. For shorter, sharper efforts, the HIIT 30/10 and Tabata pages cover those splits.
Yes. Fullscreen turns the whole display into the dial, and the chime at each change carries even when your back is to the screen.
Add it as a browser source in OBS; the background stays transparent. Change t for any length.
A radial timer is a free online countdown timer you set in one click: pick a length, press Start, and an alarm sounds at zero. Run several timers at once, take one fullscreen, or pop one out picture-in-picture to float over other apps. Every timer keeps counting in a background tab, and any timer exports as a video. No download, no sign-up.
Its dial draws the countdown as 20 concentric rings, one for each twentieth of the duration. Rings empty one by one, outermost first, so a glance shows how far along you are without reading a digit.
Yes. The countdown follows the clock, so it stays on time while you work in another tab and still chimes at zero. The picture-in-picture popout keeps a small dial in view the whole way.
Yes. Any timer exports as an MP4 or a transparent WebM of the whole countdown, up to 4K and 60 fps, in 16:9, vertical, or square.
Yes. In OBS, add a browser source pointing at radialtimers.com/overlay?t=25m and a transparent dial counts down over your scene. Change t for any length, like 90s or 3h.
As many as you need. Each timer gets its own dial and runs on its own, which suits interval workouts, several dishes on the stove, or a room of activity stations.