Karvonen Target Heart Rate Calculator
Training heart rate zone from the heart rate reserve method, using your resting pulse.
Results
What this tool does
Maximum heart rate here uses the Tanaka estimate of 208 minus 0.7 times age, which fits adults better than the old 220 minus age. Both are population averages and individuals vary widely — if you train by heart rate seriously, a measured maximum beats any formula.
Formula
FC target = (HRmax − HRrest) × intensity + HRrest
Variables
| Symbol | Meaning | Unit |
|---|---|---|
ag | Age | — |
rh | Resting heart rate | bpm |
il | Lower intensity | % |
ih | Upper intensity | % |
ZL | Lower target heart rate | bpm |
ZH | Upper target heart rate | bpm |
HR | Heart rate reserve | bpm |
MX | Estimated maximum heart rate | bpm |
Worked example
- Age35
- Resting heart rate60 bpm
- Lower intensity60 %
- Upper intensity75 %
- Lower target heart rate134 bpm
- Upper target heart rate153 bpm
- Heart rate reserve123.5 bpm
- Estimated maximum heart rate183.5 bpm
Limitations
- This tool is informational only. It does not diagnose, treat or replace a qualified health professional. Speak to a doctor before making decisions about your health.
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
- The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.
Frequently asked questions
How does this differ from percent of maximum heart rate?
The simpler method takes a percentage of maximum heart rate and ignores where your heart sits at rest. Karvonen works from the reserve — the gap between resting and maximum — so a fit person with a low resting pulse gets a different, generally more demanding zone than an unfit one of the same age. It needs an accurate resting rate, measured on waking before getting up.