Target heart rate calculator
Maximum heart rate and training zones from heart rate reserve. Enter a resting rate and the zones become yours.
"220 minus age" has no clear origin and is the most widely repeated formula there is. Tanaka et al. (2001) derived 208 − 0.7 × age from a meta-analysis, and it tracks measured maxima more closely, especially in older people. Zones here use heart rate reserve (Karvonen): supply a resting rate and the same intensity lands on a different number for different people.
Age and resting rate
What you enter is saved in this browser, so it is still here next time
Count for a full minute in the morning before getting up; average a few days.
Tanaka et al. (2001) meta-analysis; closer to measured maxima.
Training zones
Maximum
184 bpm
Heart rate reserve
124 bpm
The other formula gives
185 bpm
Zones by heart rate reserve
| Zone | Intensity | Target |
|---|---|---|
| Very light | 50–60% | 122–134 |
| Light | 60–70% | 134–146 |
| Moderate | 70–80% | 146–159 |
| Hard | 80–90% | 159–171 |
| Maximum | 90–100% | 171–184 |
Zones use the Karvonen method on heart rate reserve, which reflects your resting rate rather than scaling the maximum alone.
Arithmetic on age and resting rate. With a cardiac or blood pressure condition, or on medication, target ranges should be set by a doctor.
Maximum heart rate comes from one of two formulas
Tanaka's is 208 − 0.7 × age; the traditional one is 220 − age. At 35 they give 183.5 and 185, almost the same, shown rounded as 184 and 185. The two meet at 40 (180) and diverge from there — 194 versus 200 at 20, 166 versus 160 at 60. Because 220 − age tends to run below measured values in older people, Tanaka is the default, and the other formula's figure is shown alongside so that when another calculator disagrees you can see where it parted.
Zones are built on heart rate reserve
Reserve is maximum minus resting, and target = resting + reserve × fraction. At 35 with a resting rate of 60 the reserve is 123.5, so the 60–70% zone runs from 60 + 74.1 = 134 to 60 + 86.5 = 146. With a resting rate of 50 the same zone moves to 130–143; with 70, to 138–149. Multiplying the maximum by a percentage gives the same number whatever your resting rate; this page keeps that difference.
The five zones
50–60, 60–70, 70–80, 80–90 and 90–100% of reserve are each computed. At 35 with resting 60 that is 122–134, 134–146, 146–159, 159–171 and 171–184. Boundaries are rounded to whole bpm and each zone carries a short name such as light or moderate. Resting rate is accepted up to 140 and age up to 120. A resting rate above the maximum makes the reserve negative and flips the zones, so such a value is not a measured one.
What this number is not
Both formulas are regressions on population averages, and real maxima at the same age spread by well over ten bpm from person to person. There is no field for a measured maximum — if you have one from a treadmill test, every zone shifts by the difference between it and the figure here. Medication that lowers heart rate, or a cardiac condition, makes the arithmetic inapplicable, and this page has no way of knowing.
Common questions
QHow do I measure resting heart rate?
Count for a full minute in the morning, lying down, before getting up — and average several days. An overnight figure from a watch works too. Coffee, alcohol and short sleep keep the number elevated for days, so discard readings taken when you know the day was unusual.
QIs it true that zone 2 burns fat?
The *proportion* of energy coming from fat is higher at low intensity, but for the same duration a harder effort burns more in *total*. The real argument for zone 2 is that you can sustain it and recover from it, which is what lets weekly volume accumulate.
QCan I use this if I have a heart condition?
This is arithmetic on age and resting rate, not a medical judgement. If you have a cardiac or blood pressure condition, or take medication, your target range should be set by your doctor — beta blockers in particular lower heart rate enough that this calculation no longer applies.
QAt 40 with a resting rate of 65, what is zone 2?
Tanaka gives a maximum of 208 − 28 = 180 and a reserve of 115. The 60–70% zone runs from 65 + 69 = 134 to 65 + 80.5 = 146. Switching to 220 − age changes nothing at 40, since both formulas give 180.
QWhy does my watch show different zones?
Most watches use a percentage of maximum, or their own estimate. At 35, 70% of maximum is 128 while 70% of reserve is 146 — a gap of 18. Neither is wrong; the bases differ. Setting the watch to use resting heart rate brings it close to this page.