Zone 2 heart rate calculator
This calculator needs JavaScript. The quick-reference table below works without it, and the formula is just above it.
How it works
There are two common ways to find zone 2. % of max heart rate takes 60 to 70% of your maximum. Karvonen uses your heart-rate reserve, the gap between resting and max, so a fitter heart with a low resting rate gets a range that suits it. Without a tested max, both estimate it from your age with the Tanaka formula. That's closer for most adults than 220 minus age, but it can still be off by 10 beats or more. Brands draw their zones differently; these are the bands Auralo uses by default.
max HR = 208 − 0.7 × age (unless you enter yours)
% of max: zone 2 = 0.60 × max to 0.70 × max
Karvonen: zone 2 = rest + 0.60 × (max − rest) to rest + 0.70 × (max − rest)
Quick reference
| Age | Estimated max HR | Zone 2, % of max | Zone 2, Karvonen at resting HR 60 |
|---|---|---|---|
| 20 | 194 bpm | 116–136 bpm | 140–154 bpm |
| 25 | 190 bpm | 114–133 bpm | 138–151 bpm |
| 30 | 187 bpm | 112–131 bpm | 136–149 bpm |
| 35 | 184 bpm | 110–129 bpm | 134–147 bpm |
| 40 | 180 bpm | 108–126 bpm | 132–144 bpm |
| 45 | 176 bpm | 106–123 bpm | 130–141 bpm |
| 50 | 173 bpm | 104–121 bpm | 128–139 bpm |
| 55 | 170 bpm | 102–119 bpm | 126–137 bpm |
| 60 | 166 bpm | 100–116 bpm | 124–134 bpm |
| 65 | 162 bpm | 97–113 bpm | 121–131 bpm |
| 70 | 159 bpm | 95–111 bpm | 119–129 bpm |
How Auralo does this
Auralo sets your zones from your age, or from your resting heart rate (Karvonen), a lactate threshold or your own numbers, and keeps Karvonen in step with your 30-day resting heart rate. During a run your Watch shows your zone and how close you are to today's strain target, with a tap on the wrist near the top of it.
Questions
Why does my zone 2 feel too easy?
That's normal. Zone 2 should feel easy enough to talk in full sentences. If it feels hard, your estimated max may be too high; try the Karvonen method or a tested max.
Which method is better?
Karvonen, if you know your resting heart rate, because it accounts for your fitness. A tested max heart rate beats any formula.
Why is my Garmin or WHOOP zone different?
Brands use different formulas and zone edges. Pick one method and stick with it, so your training compares week to week.
Is this medical advice?
No. It's wellness information. If you have a heart condition or take medicines that affect heart rate, ask your doctor for your range.
Sources
- Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol 2001;37(1):153–156.
- Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate. Ann Med Exp Biol Fenn 1957;35(3):307–315.
Wellness information, not medical advice. If you have a health condition, follow your clinician's guidance.