Heart Rate Zone Calculator
Enter your measured maximum heart rate or have it estimated from your age. The calculator splits your heart rate into five training zones from 50 to 100 %, either as a percentage of max HR or using heart rate reserve (Karvonen).
Example: Maximum heart rate: estimate from age (Tanaka) · Age 30 years · Method: percentage of max HR → Maximum heart rate (bpm): 187. Source: doi:10.1016/S0735-1097(00)01054-8, Tanaka H, Monahan KD, Seals DR: Age-predicted maximal heart rate revisited. J Am Coll Cardiol 2001;37(1):153–156. Updated: .
How it is calculated
How the zones are calculated
1. Maximum heart rate (max HR): ideally measured, otherwise estimated as max HR = 208 − 0.7 × age. This formula comes from Tanaka, Monahan and Seals (Journal of the American College of Cardiology, 2001), based on a meta-analysis of 351 studies with 18,712 subjects and a lab study of 514 healthy adults. The popular rule of thumb 220 − age is shown for comparison only: no primary study from which it was derived is documented.
How to calculate heart rate zones
- Enter your measured maximum heart rate or let it be estimated from your age.
- Choose the method: % of max HR or Karvonen; for Karvonen, enter your resting heart rate.
- Read the five training zones with their heart rate ranges.
2. Zones:
- Percentage of max HR: heart rate = percentage × max HR.
- Karvonen (heart rate reserve): heart rate = resting HR + percentage × (max HR − resting HR). Calculating with the difference between resting and maximum heart rate goes back to Karvonen, Kentala and Mustala (1957). It accounts for resting heart rate and therefore gives higher values, especially in the lower zones.
Five zones in 10 % steps (50–60, 60–70, 70–80, 80–90, 90–100 %) are a common convention, not a standard. Training plans and sports watches sometimes use different limits.
Worked example
Age 30: max HR = 208 − 0.7 × 30 = 208 − 21 = 187 bpm (220 − 30 would give 190).
| Zone | Intensity | % of max HR | Karvonen, resting HR 60 |
|---|---|---|---|
| 1 | 50–60 % | 94–112 | 124–136 |
| 2 | 60–70 % | 112–131 | 136–149 |
| 3 | 70–80 % | 131–150 | 149–162 |
| 4 | 80–90 % | 150–168 | 162–174 |
| 5 | 90–100 % | 168–187 | 174–187 |
Karvonen, lower limit of zone 1: heart rate reserve 187 − 60 = 127; 60 + 0.5 × 127 = 123.5 ≈ 124. All values are rounded to whole beats.
Limitations
- Estimation error: max HR varies widely between people of the same age; considerable deviations from the formula are possible.
- Medication and conditions: beta blockers and other drugs lower heart rate, arrhythmias distort it. The zones then do not apply.
- Circumstances: heat, altitude, dehydration, stress and fatigue raise heart rate at the same effort.
The zones are a guide and do not replace medical advice, especially before starting intense training.
More training calculators: running speed with the pace calculator, fitness with the VO2 max calculator, and energy use with the calories burned calculator.
Frequently asked questions
How do I find my exact maximum heart rate?
Most reliably with an exercise test, such as a performance test or a medically supervised exercise ECG. Formulas like 208 − 0.7 × age only give an average.
Which is better: percentage of max HR or Karvonen?
Karvonen includes resting heart rate and so fits the zones a little better to your fitness. The percentage method is simpler and needs no resting heart rate. What matters is sticking to one method.
Why is 220 − age only shown for comparison?
The formula 220 − age is widely used, but no primary study from which it was derived is documented. The formula by Tanaka and colleagues (2001) is based on published data from more than 18,000 people.
How do I measure my resting heart rate?
In the morning right after waking, still lying down, count for 60 seconds or use a heart rate monitor; repeat on several days and take the average.
I take beta blockers – can I use these zones?
No, not without talking to your doctor. Beta blockers lower resting and exercise heart rate, so the formulas do not apply. Your doctor can give you suitable exercise limits.
Sources and legal basis
- doi:10.1016/S0735-1097(00)01054-8: Tanaka H, Monahan KD, Seals DR: Age-predicted maximal heart rate revisited. J Am Coll Cardiol 2001;37(1):153–156
- PMID 13470504: Karvonen MJ, Kentala E, Mustala O: The effects of training on heart rate; a longitudinal study. Ann Med Exp Biol Fenn 1957;35(3):307–315
As of: · Editorial policy
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