Using the Target Heart Rate Calculator
The tool first estimates maximum heart rate as 220 minus age. It subtracts resting heart rate to find the reserve, applies each intensity percentage, then adds resting heart rate back. Enter the lower intensity before the upper intensity so the range has a clear order.
Worked example
Use the example inputs below to reproduce this result. These are the form's starting values, not recommended targets. Changing your inputs updates your result above; this worked example stays fixed for comparison. Results are rounded for display.
Example inputs
- Age (years)
- 30
- Resting heart rate (bpm)
- 60
- Lower intensity (%)
- 50
- Upper intensity (%)
- 70
Example result
- Estimated maximum (bpm)
- 190
- Lower target (bpm)
- 125
- Upper target (bpm)
- 151
Method and assumptions
Karvonen method: resting HR + intensity × (estimated maximum − resting HR), using maximum = 220 − age. Medication and health conditions can affect targets.
Reference: heart.org — method and further reading
Compare like-for-like sessions
Training estimates are more useful when the recorded activity is consistent. Keep the same exercise, measurement method and definition of duration when comparing sessions. Equipment, conditions and effort can change the meaning of similar-looking numbers. A calculator can summarize the entries, but it cannot assess technique, recovery or whether a session is appropriate for you.
Common question
Is 70% of heart-rate reserve the same as 70% of maximum heart rate?
No. The reserve method applies the percentage to the gap between resting and estimated maximum heart rate, then adds the resting rate. Multiplying maximum heart rate alone by 70% follows a different calculation and usually gives a different number.
Guide updated .