Zone 2 Heart Rate: Calculator and Chart by Age

Zone 2 heart rate chart by age

The chart applies the same arithmetic the calculator runs to every decade: maximal heart rate from 208 - 0.7 x age [1], Zone 2 as 70 to 80 percent of it, and the Karvonen band for a resting heart rate of 60 bpm [3]. Your own resting pulse shifts the Karvonen column; enter it above.

Values in beats per minute, rounded. The age formula has an individual scatter of about 10 bpm [1, 2], so a measured maximal heart rate always beats the estimate. The chart is a reference, not a training prescription.

How the calculator works

Three inputs, two published formulas, no hidden factors. Every step is shown so you can check the arithmetic yourself.

1. 1Enter your age. The calculator estimates your maximal heart rate as 208 - 0.7 x age, the Tanaka equation from a meta-analysis of 351 studies and a lab sample of 514 healthy adults [1].
2. 2If you have a measured maximal heart rate from a lab test or a genuine all-out effort, enter it. It replaces the estimate, because the age formula scatters by about 10 bpm from person to person [2].
3. 3Zone 2 by percent of maximal heart rate is 70 to 80 percent of that number. This is the band most endurance coaches mean when they say Zone 2, and it is what the chart above uses.
4. 4If you add your resting heart rate, the calculator also runs the Karvonen method: resting pulse plus 60 to 70 percent of the difference between maximal and resting heart rate [3]. Because it uses your own resting value, it adapts to your fitness.
5. 5Read the band as a starting point and confirm it with the talk test: in Zone 2 you can speak in full sentences, but you would rather not sing. If the band and the talk test disagree, the talk test wins.

What Zone 2 actually is, and why the definitions differ

Physiologically, Zone 2 is the highest intensity at which your muscles still run mostly on fat and your blood lactate stays roughly flat, typically below about 2 mmol/L. San-Millan and Brooks measured this in professional cyclists and in less fit adults: the trained group oxidised far more fat at the same relative intensity and kept lactate low much longer, which is what a large aerobic base looks like in the lab [4]. Heart rate is only a proxy for that state. Coaches translate it into a band because nobody trains with a lactate meter on every ride. The catch is that the translation is not standardised. The five-zone scale that Garmin, Polar and Apple ship by default sets Zone 2 at 60 to 70 percent of maximal heart rate. Most endurance coaching models place the physiological Zone 2 higher, around 70 to 80 percent of maximal heart rate or 60 to 70 percent of heart-rate reserve. That is the band this calculator uses, and it is why your watch may call the same effort Zone 3. In elite endurance training the bulk of the volume, roughly 80 percent, sits in this easy region, with the remaining 20 percent hard [5]. That distribution, not the exact bpm, is the point.

Karvonen or percent of maximal heart rate: which method to use

Both methods start from your maximal heart rate. Without a measurement the calculator estimates it with 208 - 0.7 x age [1]. That equation replaced the older 220 minus age rule, which underestimates the maximum in older adults. It is still a population average: in the Norwegian HUNT study of 3,320 healthy adults the standard error of the age formula was about 11 bpm, so a real 40-year-old can have a maximum of 170 or 190 and both are normal [2]. The percent-of-maximum method multiplies that number by 0.70 and 0.80. The Karvonen method, published in 1957, works with your heart-rate reserve instead, the gap between resting and maximal heart rate, and places Zone 2 at 60 to 70 percent of that reserve above your resting pulse [3]. Because a fitter person has a lower resting pulse and therefore a larger reserve, the Karvonen band sits slightly higher for them and slightly lower for someone with a high resting pulse. The two methods usually land within 5 to 10 bpm of each other. When they disagree, prefer Karvonen if your resting pulse was measured properly, lying down after waking, and prefer a measured maximal heart rate over any formula.

The talk test: the check that beats every formula

Every band on this page is an estimate. Your body gives a more direct signal. In Zone 2 you can hold a conversation in full sentences, breathing through your nose is possible for most people, and you finish the session feeling you could have gone on. If you can only manage short phrases, you are above Zone 2. If you could sing comfortably, you are below it. Beginners often find that the heart rate that passes the talk test is lower than the formula band, because their aerobic base is small; after a few months the same heart rate feels easier and the band grows into the formula. Use the calculator for the first weeks, then let the talk test and, if you have one, a resting heart rate trend refine it. A lactate test at a sports-medicine institute pins the real threshold if you want the exact number.

How much Zone 2 per week, and why it is worth it

The American College of Sports Medicine recommends at least 150 minutes of moderate or 75 minutes of vigorous aerobic activity per week for healthy adults, in sessions of 30 to 60 minutes, and defines moderate as 40 to 59 percent and vigorous as 60 to 89 percent of heart-rate reserve [7]. Zone 2 as defined here sits at the boundary between the two. The reason to accumulate it is the link between cardiorespiratory fitness and survival: in a Cleveland Clinic cohort of 122,007 adults followed for a median of 8.4 years, the least fit fifth had roughly five times the mortality of the fittest, and there was no fitness level above which the benefit stopped [6]. That is observational data, not proof that training causes the difference, but it is the strongest reason to build a base. A practical starting point for most people is three sessions of 30 to 45 minutes per week, walking briskly, cycling or on a rower, and adding time before adding intensity. How Zone 2 and harder VO2max intervals fit together is covered in our guide.

Frequently asked questions