Timing & Pacing
8 calculators
Interval structure, session duration, rest periods and the clock arithmetic behind common training formats: Tabata, EMOM, work-to-rest ratios and hiking time estimation.
These are scheduling calculations rather than physiological ones. They answer how long something takes and how the time divides, which is the part most easily got wrong in the middle of planning a session.
- Sleep Cycle Calculator Calculate bedtimes for complete 90-minute sleep cycles based on your desired wake time.
- Eating Window Clock Work out when a chosen eating window closes and how long the remaining gap runs.
- HIIT Work-Rest Ratio Calculator Calculate total HIIT session time and work-to-rest ratio from your interval structure.
- Hiking Time Calculator (Naismith's Rule) Estimate hiking time from distance and ascent using Naismith's 1892 rule.
- Tabata Timer Setup Calculator Calculate total workout time for Tabata and custom interval training protocols
- EMOM Round Calculator Calculate total rep volume across EMOM-style workouts with fixed reps per minute.
- Rest Time Between Sets Calculator Find evidence-based rest intervals matched to your training goal—endurance, hypertrophy, or strength.
- Workout Duration Calculator Estimate total session time from sets, work and rest intervals, and warm-up duration.
Interval formats and what defines them
The Tabata protocol is a specific structure from Izumi Tabata's 1996 study: eight rounds of 20 seconds of work and 10 seconds of rest, four minutes in total. The term is now applied loosely to any short interval format, but the original protocol had fixed durations and a fixed intensity, and the published findings apply to that structure rather than to the general idea.
EMOM — every minute on the minute — inverts the usual accounting: the work is fixed and the rest is whatever remains of the minute. Finishing a set in 35 seconds buys 25 seconds of rest, so as fatigue slows the work, the rest shrinks automatically.
Work-to-rest ratios describe the relationship rather than the absolute durations. A 1:3 ratio means three times as long recovering as working, and the same ratio can describe a 15-second sprint or a four-minute effort.
Duration estimates
Naismith's rule, published in 1892, estimates walking time as one hour per 5 km plus an additional hour per 600 m of ascent. It remains in use because it is simple and reasonably calibrated for steady walking on paths; it makes no allowance for descent, terrain, load or rests, and Langmuir's corrections exist to address some of those.
Session duration arithmetic multiplies sets by the time each takes, including the rest between them, which is where most session plans overrun. A commonly used planning figure is around two and a half minutes per set including rest, though the real figure varies widely with the exercise and rest interval chosen.
Common questions
What is the actual Tabata protocol?
Eight rounds of 20 seconds of work followed by 10 seconds of rest, totalling four minutes. It comes from Izumi Tabata's 1996 study, which used a fixed high intensity on a cycle ergometer. The word is now attached to almost any short interval format, but the published results describe that specific structure and intensity. The timer here follows the original 20/10 × 8 pattern.
What does EMOM mean?
Every minute on the minute: a set begins at the top of each minute, and whatever remains of that minute after the work is finished becomes the rest. The structure makes rest self-adjusting — a set finished in 30 seconds leaves 30 seconds of recovery, and as fatigue slows the work the rest shrinks with it. That is what makes the format progressively harder without changing the load.
How long will a hike take?
Naismith's rule allows one hour per 5 km of distance plus one hour per 600 m of ascent, which for 12 km with 700 m of climb gives about 3 hours 30 minutes of walking. It assumes steady walking on reasonable ground and includes no time for rests, navigation, difficult terrain or descent. Adding a margin for those is a matter of judgement rather than arithmetic.