Your heart rate tells you how hard your body is working. Resting heart rate is a simple fitness marker – well-trained athletes often have 40–60 bpm – and the reserve between resting and maximum sets your training zones.
How to use the Heart Rate Calculator
- Age (years)
- Measured maximum heart rate (0 = estimate)
- Do you know your resting heart rate?
- Resting heart rate (bpm)
- Pulse count in 15 seconds
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Enter your age (or a measured maximum) and your resting heart rate – or count your pulse for 15 seconds.
Inputs explained
| Field | What to enter |
|---|---|
| Age (years) | A number |
| Measured maximum heart rate (0 = estimate) | A number |
| Do you know your resting heart rate? | Choose one: Yes, No – I’ll count my pulse for 15 seconds |
| Resting heart rate (bpm) | A number |
| Pulse count in 15 seconds | A number |
What each result means
- Heart rate reserve = [Maximum heart rate] – [Resting heart rate]
- Zone 1 – Very light (50–60%) from = round([Resting heart rate] + 0.5×[Heart rate reserve])
- up to = round([Resting heart rate] + 0.6×[Heart rate reserve])
- Zone 2 – Light / fat burning (60–70%) from = round([Resting heart rate] + 0.6×[Heart rate reserve])
- up to = round([Resting heart rate] + 0.7×[Heart rate reserve])
- Zone 3 – Moderate / aerobic (70–80%) from = round([Resting heart rate] + 0.7×[Heart rate reserve])
- up to = round([Resting heart rate] + 0.8×[Heart rate reserve])
- Zone 4 – Hard / anaerobic (80–90%) from = round([Resting heart rate] + 0.8×[Heart rate reserve])
- up to = round([Resting heart rate] + 0.9×[Heart rate reserve])
- Zone 5 – Maximum (90–100%) from = round([Resting heart rate] + 0.9×[Heart rate reserve])
- up to = round([Resting heart rate] + 1.0×[Heart rate reserve])
Example values
How the main result changes when Age changes and everything else stays at the example values above:
| Age (years) | Heart rate reserve (bpm) |
|---|---|
| 17.5 | 125 |
| 26.25 | 122 |
| 35 | 118 |
| 43.75 | 114 |
| 52.5 | 108 |
| 70 | 93 |
Formula
HRmax = 192 − 0.007 × age² (Gellish) or measured · RHR = 15-s count × 4 · HRR = HRmax − RHR · Target = RHR + % × HRR
Worked example
Inputs — Age (years): 35; Measured maximum heart rate (0 = estimate): 0; Do you know your resting heart rate?: Yes; Resting heart rate (bpm): 65.
Results — Maximum heart rate = 183 bpm; Resting heart rate = 65 bpm; Resting heart rate rating = Normal (60–100 bpm); Heart rate reserve = 118 bpm; Zone 1 – Very light (50–60%) from = 124 bpm; up to = 136 bpm; Zone 2 – Light / fat burning (60–70%) from = 136 bpm; up to = 148 bpm; Zone 3 – Moderate / aerobic (70–80%) from = 148 bpm; up to = 160 bpm; Zone 4 – Hard / anaerobic (80–90%) from = 160 bpm; up to = 172 bpm; Zone 5 – Maximum (90–100%) from = 172 bpm; up to = 183 bpm.
Key terms
- Heart rate reserve
- HRmax minus resting heart rate.
Frequently asked questions
What is a normal resting heart rate?
60–100 bpm for adults; athletes are often lower.
When should I measure resting heart rate?
In the morning before getting out of bed.
Why use heart rate reserve?
It personalises zones using your resting heart rate.
Is a low resting heart rate good?
Usually yes for fit people, but see a doctor if you have dizziness.