Heart rate zone calculator: Zone 2 by age

UNDERSTAND THE METHOD

How to use this calculator

Choose an equation or enter a measured maximum. Add resting heart rate to calculate reserve-based (Karvonen) zones. Enter zero for resting heart rate to calculate percentages of maximum heart rate. The five zones run from 50% to 100% in 10% steps, and Zone 2 is 60–70% of maximum heart rate, or of heart-rate reserve when you add a resting rate.

What the result can tell you

Age equations estimate group averages and can differ substantially from an individual test. Medication, illness, and other factors can change your heart-rate response. These ranges do not establish that an intensity is safe for you. The Gulati equation comes from a study of women.

Heart-rate zones by age, and what Zone 2 means

Heart-rate monitor makers such as Polar split effort into five zones of maximum heart rate. Zone 1 (very light) is 50–60%, Zone 2 (light) is 60–70%, Zone 3 (moderate) is 70–80%, Zone 4 (hard) is 80–90% and Zone 5 (maximum) is 90–100%. For example, at age 40 the Tanaka equation gives a maximum of 208 − 0.7 × 40 = 180 bpm, so Zone 2 is 108–126 bpm.

Maximum heart rate and Zone 2 by age (bpm)

Age	Maximum, Tanaka	Zone 2, Tanaka	Maximum, Fox (220 − age)	Zone 2, Fox
20	194	116–136	200	120–140
25	190.5	114–133	195	117–137
30	187	112–131	190	114–133
35	183.5	110–128	185	111–130
40	180	108–126	180	108–126
45	176.5	106–124	175	105–123
50	173	104–121	170	102–119
55	169.5	102–119	165	99–116
60	166	100–116	160	96–112
65	162.5	98–114	155	93–109
70	159	95–111	150	90–105

Fox (220 − age) gives a higher maximum than Tanaka below age 40 and a lower one above it; the two agree at 40. The next table shows all five zones from the Tanaka maximum. Each bound is the percentage of maximum heart rate rounded to a whole beat, and neighboring zones share their boundary.

Five heart-rate zones by age, Tanaka maximum (bpm)

Age	Zone 1	Zone 2	Zone 3	Zone 4	Zone 5
20	97–116	116–136	136–155	155–175	175–194
30	94–112	112–131	131–150	150–168	168–187
40	90–108	108–126	126–144	144–162	162–180
50	87–104	104–121	121–138	138–156	156–173
60	83–100	100–116	116–133	133–149	149–166
70	80–95	95–111	111–127	127–143	143–159

The American Heart Association puts moderate activity at about 50–70% of maximum heart rate and vigorous activity at about 70–85%, so Zones 1 and 2 match its moderate range.

You can also check effort without a monitor. On a scale of 0 to 10, where 0 is sitting and 10 is the hardest you can go, moderate activity feels like a 5 or 6 and vigorous activity starts at a 7 or 8. The talk test is quicker: at moderate effort you can talk but not sing, and at vigorous effort you cannot say more than a few words without pausing for a breath.

If you enter a resting heart rate, the calculator uses heart-rate reserve instead (the Karvonen method): resting rate + (maximum − resting) × percentage. At age 40 with a resting rate of 60 bpm, 60–70% of reserve is 132–144 bpm, higher than the 108–126 bpm from maximum alone. The two bases are not interchangeable: by ACSM's cut points, 60–70% of heart-rate reserve is vigorous, while 60–70% of maximum heart rate is light to moderate. That is why the zone names above apply only to percentages of maximum.

In exercise science, Zone 2 training means steady effort below the first lactate threshold, the point where lactate in the blood starts to rise. A fixed percentage only estimates that point. In a study of 165 recreational runners, the first lactate threshold sat at about 81% of measured maximum heart rate on average, with wide differences between people, and estimates were less accurate when maximum heart rate came from an age equation.

Age equations estimate a group average, and your own maximum can be well above or below it. Medicines, illness and other factors change how your heart rate responds. These zones do not show that an intensity is safe for you.

Common questions

What is Zone 2 heart rate?

In the five-zone model used by heart-rate monitor makers such as Polar, Zone 2 is 60–70% of maximum heart rate. At age 40, with a Tanaka maximum of 180 bpm, that is 108–126 bpm. In exercise science, Zone 2 means effort below your first lactate threshold, which varies from person to person, so a percentage is only an estimate.

How can I tell I am in Zone 2 without a heart-rate monitor?

Only roughly. The American Heart Association counts 50–70% of maximum heart rate as moderate activity, which covers Zone 1 and Zone 2 (60–70%). The CDC describes moderate activity as a 5 or 6 on a 0 to 10 effort scale, and its talk test says you can talk but not sing. So a moderate feel puts you somewhere in that whole band, not in Zone 2 alone. If you can only say a few words before pausing for breath, the CDC counts that as vigorous effort (CDC, How to Measure Physical Activity Intensity). Zone 2 in the exercise-science sense, below the first lactate threshold, is best measured in a lab.

When should I enter zero for resting heart rate?

Enter zero to calculate ranges as percentages of maximum heart rate. Enter a resting heart rate to calculate heart-rate-reserve ranges.

Do these zones show that an intensity is safe for me?

No. Age equations estimate group averages and can differ from an individual result. Medicines, illness, and other factors can change heart-rate response.

Sources & limitations9 sources

Sources checked September 12, 2026. These notes identify methods and assumptions. They have not received an independent clinical review.

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