Calculates five training heart rate zones using the Karvonen method, which factors in your resting heart rate for a more individualized result than a simple percentage of max heart rate.
How it works
Heart rate reserve (max heart rate minus resting heart rate) is calculated, then each zone’s boundaries are set as resting heart rate plus a percentage of that reserve.
What this does not include
This does not include the simpler 2-band moderate/vigorous estimate that ignores resting heart rate — for that quicker version, use this site’s target heart rate calculator instead.
How to use this calculator
- Enter your age and resting heart rate.
A worked example
Age 30, resting heart rate 60: max HR = 220 − 30 = 190. Heart rate reserve = 190 − 60 = 130. Zone 2 works out to 138–151 bpm.
Age 40, resting heart rate 70: max HR = 180. Zone 3 works out to 147–158 bpm.
What the variables mean
| Variable | Meaning |
|---|---|
| Max HR | 220 − age (the same population-average estimate this site’s target heart rate calculator uses) |
| Heart rate reserve (HRR) | Max HR − resting HR |
| Zone boundary | Resting HR + (percentage × HRR) |
Edge cases worth knowing
A resting heart rate at or above the estimated max makes the zones physically impossible — the calculator declines to show a result rather than a nonsensical negative reserve.
Two people with identical max HR can get very different zones here — a fitter person’s lower resting heart rate widens their reserve, shifting every zone boundary, which is exactly why the Karvonen method factors in resting HR at all.
Frequently asked questions
Why does the Karvonen method need resting heart rate?
Two people can share the same max heart rate but have very different fitness levels reflected in resting heart rate — factoring it in gives a more personalized target range than max heart rate percentage alone.
How do I find my resting heart rate?
Measure your pulse first thing in the morning, before getting out of bed, ideally averaged over a few days for consistency.
Which zone should I train in?
It depends on your goal — lower zones suit recovery and base endurance, while higher zones build higher-intensity fitness; most training plans blend several zones across a week.
