Heart Rate Zone Calculator
Calculate your five heart rate training zones in bpm from your age, resting heart rate or measured max heart rate, with the Tanaka and Karvonen formulas.
Estimate based on published formulas, not medical advice. Talk to a health professional about your situation.
Measured in the morning, before getting up. Used by the Karvonen method.
From a supervised stress test or a field test. Replaces the formula.
- Max heart rate used
- – bpm
- Tanaka (2001)
- – bpm
- 220 − age
- – bpm
- Heart rate reserve
- – bpm
| Zone | Intensity | % of HR reserve | Heart rate (bpm) |
|---|
Estimates only. Beta-blockers and other medicines, heart conditions, heat, altitude and fatigue change your heart rate. See a doctor before starting intense exercise, especially if you have a heart condition, chest pain or dizziness.
How to use the heart rate zone calculator
- Enter your Age (years). The tool shows two estimates of your maximum heart rate side by side: 220 − age and Tanaka (2001).
- Enter your Resting heart rate (bpm). Take it in the morning, lying down, before getting up: count your pulse for 60 seconds, or read it from a heart rate monitor, on three mornings and use the average.
- If you know it, enter your Measured max heart rate (bpm, optional). A value from a supervised exercise test is far more accurate than any formula, so it replaces the estimate.
- Choose the Max heart rate formula (Tanaka by default) and the Zone method: Karvonen (heart rate reserve) or % of max heart rate.
- Read the Training zones table: each of the five zones shows its intensity band and its range in beats per minute. The calculation steps are listed below the table.
Everything is calculated in your browser; nothing is sent anywhere. Clear empties the fields.
The formulas
Maximum heart rate (HRmax). The classic rule 220 − age is usually credited to Fox, Naughton and Haskell (1971). It was never derived from a formal study and tends to underestimate HRmax after about 40. Tanaka, Monahan and Seals (Journal of the American College of Cardiology, 2001) pooled 351 studies and more than 18,000 healthy adults and proposed HRmax = 208 − 0.7 × age. At 40 both give 180 bpm; at 60, Tanaka gives 166 bpm instead of 160.
Even the better formula only predicts an average. The standard deviation of these predictions is around 10 bpm, so for two people of the same age, true maximums 20 bpm apart are common.
Percent of max HR. Target = intensity × HRmax. With HRmax 190 bpm, 70 % is 133 bpm.
Karvonen method. Karvonen, Kentala and Mustala (1957) used the heart rate reserve (HRR = HRmax − resting HR): target = resting HR + intensity × HRR. With HRmax 180 and a resting rate of 60, HRR is 120 bpm and 60 % intensity is 60 + 0.6 × 120 = 132 bpm. Because it accounts for your resting rate, this method gives higher, more individual targets for fit people with a low resting heart rate. The American College of Sports Medicine uses heart rate reserve to define moderate (40–59 % HRR) and vigorous (60–89 % HRR) exercise.
The five zones
| Zone | Intensity | Typical use |
|---|---|---|
| 1 | 50–60 % | Recovery, warm-up, cool-down |
| 2 | 60–70 % | Long, easy endurance work; you can talk in full sentences |
| 3 | 70–80 % | Steady aerobic work; talking gets harder |
| 4 | 80–90 % | Threshold intervals; only a few words at a time |
| 5 | 90–100 % | Short, very hard efforts |
This five-zone split is common in fitness and endurance coaching, but it is a convention: other systems use three, six or seven zones, or anchor them to a lactate or ventilatory threshold measured in a lab.
Limits and safety
These zones are estimates, not medical targets. Beta-blockers and some other medicines lower the heart rate response, and heat, dehydration, altitude, caffeine, illness and fatigue raise or lower it. Wrist monitors can also be inaccurate during intervals. Check the zone against how the effort feels.
If you have a heart condition, high blood pressure, diabetes, or if you are starting after a long break, talk to a doctor before any intense exercise; they may suggest a supervised stress test, which also gives you a true maximum. Stop and get help at once for chest pain, unusual breathlessness, palpitations or dizziness.
Frequently asked questions
Which max heart rate formula is more accurate?
For healthy adults, Tanaka (208 − 0.7 × age) fits measured data better than 220 − age, especially after 40. Both still err by about 10 bpm for many people, so a measured maximum is always better.
Should I use Karvonen or % of max HR?
Karvonen is more individual because it uses your resting heart rate, and it is the basis of ACSM intensity ranges. The % of max method is simpler and matches many watches. Use one consistently.
How do I measure my resting heart rate?
Right after waking up, lying still, count your pulse at the wrist or neck for 60 seconds. Repeat on a few mornings and take the average.
Can I find my real maximum heart rate on my own?
All-out field tests exist, but they are strenuous. Do them only if you are healthy and already trained, and ideally after medical advice; a supervised stress test is the safe way.
Why do the zones overlap at the edges?
Each zone ends where the next one starts (for example 70 %). The boundary value belongs to both; aim for the middle of a zone rather than its edge.
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