Heart rate zones calculator
Same formula as the Overload app
This heart rate zones calculator estimates your HRmax from age or from a known value, and splits it into five training zones from easy to VO2max. Choose Tanaka's age formula or type in a tested HRmax, optionally add your resting heart rate for the more precise Karvonen method, and read off the bpm range for every zone, ready to guide an easy run, a tempo session or an interval workout.
HRmax
187bpm
Heart rate zones
| Zone | Range (bpm) |
|---|---|
| Easy | 122 – 139 |
| Aerobic | 140 – 154 |
| Tempo | 155 – 164 |
| Threshold | 165 – 171 |
| VO2max | 172 – 187 |
How it works
Without a known HRmax, the calculator uses Tanaka's 2001 formula, 208 minus 0.7 times age, which fits a wide range of ages better than the older 220-minus-age rule and is the estimate this tool defaults to.
Zone boundaries are set as fixed percentages of HRmax by default: roughly 65, 75, 83, 88 and 92 percent mark the bottom of each successive zone. Switching on Karvonen changes the calculation to percentages of heart rate reserve, HRmax minus resting heart rate (Karvonen 1957), which shifts every zone up for someone with a low resting heart rate.
Karvonen tends to be more accurate for well-trained runners with a notably low resting heart rate, since it accounts for individual cardiovascular fitness rather than treating everyone at the same age as identical.
Frequently asked questions
How do I calculate my heart rate zones?
Start from your HRmax, either estimated by age with 208 minus 0.7 times age or measured directly, then split it into percentage bands from easy to hard. This calculator does that split automatically and shows the bpm range for each of the five zones.
What is the Karvonen method?
Karvonen zones use heart rate reserve, the gap between your resting and maximum heart rate, instead of a flat percentage of HRmax. Two people with the same HRmax but different resting heart rates get different zone boundaries, which better reflects real cardiovascular fitness.
Is the age-based HRmax formula accurate for everyone?
It's a population average with real individual variation of ten beats per minute or more either way. If you have a measured HRmax from a max effort test or a running watch, switch to the known HRmax option here for a more personal result.
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These values are training estimates. They are not medical advice.
Overload estimates HRmax from your runs
Overload tracks your heart rate across every run and shows exactly how much time you spend in each zone. Free on iOS and Android.