Heart Rate Zone Formula Explained, With Examples
Every heart rate zone result comes from one formula. Once you understand what goes into it, you can sanity-check any figure you are given, whether by an employer, a bank, a teacher or another website.
The formula
Max HR = 220 − age; zones are percentages of max.
What each input means
- Age: the value you enter in the calculator.
Example
For example, with these inputs:
- Age: 35
the calculator returns:
- Maximum heart rate: 185 bpm
- Zone 2 (fat burn): 111–130 bpm
- Zone 3 (aerobic): 130–148 bpm
- Zone 4 (threshold): 148–167 bpm
How the result changes
The table keeps the other inputs at their example values and changes age.
| Age | Maximum heart rate | Zone 2 (fat burn) | Zone 3 (aerobic) | Zone 4 (threshold) |
|---|---|---|---|---|
| 35 | 185 bpm | 111–130 bpm | 130–148 bpm | 148–167 bpm |
| 17.5 | 203 bpm | 122–142 bpm | 142–162 bpm | 162–182 bpm |
| 26.25 | 194 bpm | 116–136 bpm | 136–155 bpm | 155–174 bpm |
| 43.75 | 176 bpm | 106–123 bpm | 123–141 bpm | 141–159 bpm |
| 52.5 | 168 bpm | 101–117 bpm | 117–134 bpm | 134–151 bpm |
Why it matters
Health numbers are most useful when you track them consistently. A quick calculation turns everyday measurements into something you can act on, whether that is planning meals, training for a run or preparing for a clinic visit.
Any health calculator gives a general estimate. If a result worries you, or you are pregnant, managing a chronic condition or planning a big change in diet or exercise, speak to a doctor, polyclinic or dietitian.
Research has shown that Asians tend to develop conditions such as type 2 diabetes and heart disease at lower body weights than Europeans. That is why the Health Promotion Board recommends lower BMI cut-offs for Singaporeans, with 23 marking the start of moderate risk.
Singapore's tropical climate means you lose more fluid through sweat, even when you are not exercising. Thirst, urine colour and how you feel are good guides, and needs rise during outdoor activity or heat waves.
Related calculations
- Waist-to-Height Ratio Calculator: A ratio above 0.5 suggests increased health risk.
- Protein Intake Calculator: Estimates daily protein needs.
- Steps to Kilometres Calculator: Converts step counts (like your Healthy 365 tracker) to distance.
- Running Pace Calculator: Calculates pace for runs like the Standard Chartered Marathon or IPPT 2.4 km.
Use the Heart Rate Zone Calculator to plug in your own numbers.
Run your own numbers: Heart Rate Zone Calculator