Rex says
Same equations the textbooks use — just way less awkward. Pop in your stats and I'll tell you what the number actually means for you.
Try a scenario
Click to load — tweak from there.Inputs
Result
Estimated max HR
190
Zone 1 (recovery)
125–138 bpm
Zone 2 (endurance)
138–151 bpm
Zone 3 (tempo)
151–164 bpm
Zone 4 (threshold)
164–177 bpm
Zone 5 (VO2 max)
177–190 bpm
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter age.
- 2Enter resting hr (optional, for karvonen).
- 3Read your estimated max hr on the right — it updates as you type.
- 4Hit Share to keep the scenario or send it to someone.
About this calculator
Estimates max heart rate (220 − age) and the standard training zones.