Estimate five exercise zones with the Karvonen heart-rate-reserve method. It runs through the validated Universal Tools Runtime and keeps calculation history under the same access controls as other tools.
Formula source: Estimated maximum heart rate = 220 − age; target = resting HR + intensity × heart-rate reserve.
How to use this tool
- Select units or currency where available.
- Enter realistic values within the validated ranges.
- Run the calculator, review the explanation and print or export the result if needed.
Important: Medications and health conditions may change safe exercise intensity.
Examples
Example calculation
Enter sample values, run the calculator and compare the result with the displayed formula explanation.
Frequently asked questions
Is this result professional advice?
No. The result is an educational estimate and should be checked with an appropriately qualified professional before important decisions.
Can I keep a calculation history?
Signed-in users can access private calculation history and printable reports. Retention follows the Tool Runtime configuration.