For adults. This is an educational estimate—not an exercise prescription, fitness clearance, diagnosis, or safety limit.
| Zone | Intensity | Target BPM |
|---|---|---|
| Zone 1 | 50–60% | — |
| Zone 2 | 60–70% | — |
| Zone 3 | 70–80% | — |
| Zone 4 | 80–90% | — |
| Zone 5 | 90–100% | — |
Both predict a population average, not a personal ceiling. The Tanaka equation was derived from a meta-analysis and laboratory validation in healthy adults. Neither equation proves that maximal exertion is safe.
For display, final zone boundaries are rounded to the nearest whole beat per minute. Calculations use the unrounded maximum-heart-rate value.
There is no universal five-zone naming system. Watches, coaches, labs, and apps may use different inputs and boundaries. This page uses 50–60%, 60–70%, 70–80%, 80–90%, and 90–100% as transparent comparison bands.
Warm up and cool down gradually. Stop exercise and seek appropriate medical help for chest pain or pressure, fainting, marked dizziness or confusion, unusual or extreme shortness of breath, or a fast or uneven heartbeat that feels concerning. Follow local emergency guidance when symptoms may be urgent.
Heart rate can be changed by medication, illness, dehydration, heat, altitude, caffeine, stress, poor sleep, and sensor error. Wrist optical sensors may lag or misread during movement. A normal-looking number does not override symptoms.
For a 40-year-old using the AHA simple estimate:
Using percentage of maximum, the AHA general moderate range is approximately 90–126 bpm (50–70%), and the vigorous range is approximately 126–153 bpm (70–85%).
If the same person has a resting heart rate of 60 bpm and selects heart-rate reserve, a 60–70% range becomes:
This difference is expected: 60–70% of heart-rate reserve is not the same calculation as 60–70% of maximum heart rate.
Method note: the calculator retains decimal precision internally and rounds displayed BPM to the nearest whole number. It does not infer fitness, diagnose rhythm problems, evaluate wearable accuracy, or prescribe workout duration.
A simple method multiplies maximum heart rate by the desired intensity. The heart-rate-reserve method first subtracts resting heart rate from maximum heart rate, multiplies that reserve by the desired intensity, then adds resting heart rate back.
Maximum heart rate is the highest rate reached during maximal effort. Equations such as 220 − age or 208 − 0.7 × age estimate a population average. Your measured maximum may differ, and you should not attempt maximal exercise merely to obtain a number unless that testing is appropriate for you.
The American Heart Association describes moderate-intensity activity as about 50–70% of maximum heart rate and vigorous activity as about 70–85%. These are broad guides, not personalized medical prescriptions.
The terms are commonly used together. The calculation adds resting heart rate to a selected percentage of the difference between maximum and resting heart rate.
Devices may use different maximum-heart-rate estimates, resting-heart-rate averages, zone boundaries, rounding rules, lactate-threshold estimates, or automatic updates. Check the chosen method and inputs before comparing numbers.
Yes. Beta blockers, some calcium channel blockers, and other medicines can change heart-rate response. Ask a qualified health professional for an appropriate exercise target if you take heart-rate-altering medicine or have a heart condition.
No. The calculation runs in your browser, and this tool does not upload, save, or track the values you enter.
