Enter a reference pace above to see training zones.
Training zone calculator
This calculator uses Jack Daniels' VDOT formula, a widely used method in exercise science for estimating running fitness from a single race or time-trial result. Enter a recent 5K or 10K time, and the calculator estimates your VDOT score, then derives five training zones (Jog/Easy, Zone 2, Tempo, Threshold, VO2max) as pace ranges, heart-rate ranges, and lap splits.
Training zones exist because different paces stress your body differently. Running everything at one pace — usually too fast — is one of the most common mistakes recreational runners make. Structuring training across zones, with mostly easy running and a few focused hard sessions, builds aerobic fitness while limiting injury risk.
Say your most recent effort was a 5K in 25:00. That works out to roughly VDOT 38, which puts your easy pace band around 6:15–6:45/km, tempo around 5:35/km, and threshold around 5:20/km. If your max heart rate is 185 bpm and resting is 50 bpm, easy effort should sit around 130–145 bpm — if your watch shows a higher number while you're holding that pace, the pace is probably too fast for the day's conditions, not your fitness. Our guide on pace vs. heart rate covers when to trust which number.
VDOT is a fitness metric developed by exercise physiologist Jack Daniels. It converts a race performance into a single number that predicts equivalent performances at other distances and prescribes training paces.
The zones are estimates based on a validated formula, not a lab test. They're accurate enough to guide day-to-day training, but factors like heat, terrain, and fatigue will shift your actual effort on any given run.
Yes — the calculator needs a real, honest effort (a 5K or 10K time trial or race result from the last few weeks) to estimate your current fitness accurately. Old or non-maximal efforts will skew your zones.
Heart-rate ranges are optional. Leave Max HR and Resting HR blank and the calculator will still show pace-based and lap-split zones.
Yes — fill in the optional Target Race section with a goal distance and time to see your target zones compared side-by-side with your current zones, including how much faster or slower the goal pace is.