HIIT Timer for Classes — free online circuit timer

Pick the ratio, and the session plans itself

The hard part of HIIT for a class is not the exercises — it is holding an honest work-to-rest ratio for the whole group. The three chips above the timer are the three staples of class-format interval training: 30/30 (a 1:1 ratio everyone can survive), 40/20 (2:1 — the everyday class standard), and 45/15 (3:1, for a group that already moves well). One tap arms the times and six rounds; START does the rest. Because the intervals are enforced by the board and not by your stopwatch thumb, round six is exactly as long as round one — which is the whole discipline of HIIT.

From interval timer to circuit timer

Leave the station list as a single WORK block and this is a straight interval timer. Type in stations — Bikes, Rowers, Kettlebells, Core, Shuttles — and it becomes an online circuit timer: during every rest the big text shows the station the class is moving to, so the transition happens inside the rest window instead of eating your work time. Six stations across twelve rounds simply wraps — every group hits every station twice with nothing retyped.

Built to be read mid-burpee

Numbers on a phone die at ten metres. This board changes the whole screen instead: green background means work, red means rest, and the countdown is huge in the middle. Cast the tab to the gym TV, and the colour flip carries the session even when the whistle is buried under the playlist. The screen stays awake while the timer runs.

Frequently asked questions

Which interval should a new class start with?

Start at 30/30. Equal rest keeps form honest while people learn the movements. When a group can finish all six rounds without form collapsing, step up to 40/20, and save 45/15 for well-conditioned classes — progressing the ratio, not just the exercises, is what makes the programme feel designed rather than random.

How many rounds should a session have?

Six to ten rounds per block is the useful range — enough volume to matter, short enough that quality holds. For a longer session, run two blocks with different stations and give the class two minutes between them rather than stretching one block to fifteen rounds.

Where is the Tabata preset?

The classic 20 seconds on / 10 seconds off × 8 protocol has its own page — the Tabata timer — loaded with 20/10×8 already armed.