What is the Heart Rate Zone Calculator?
The Karvonen method uses heart-rate reserve so the resting pulse influences the zone estimate.
The Calcwise Heart Rate Zone tool is designed to give a fast answer while keeping the arithmetic visible. Enter the requested values, check the units, and the result updates in your browser. Your calculator entries are not sent to a Calcwise server.
How to use this calculator
- Enter values using the units shown beside each field. In the interactive calculator, each field also shows a plain-language example or meaning guide.
- Check that the values describe the same period or situation where relevant.
- Read the main result and the supporting figures shown beside it.
- Use the reset button to return to the example values.
Inputs used
- Age — Adults 18–80
- Resting heart rate
Heart Rate Zone Calculator formula
The formula is shown so you can understand the relationship between the inputs instead of treating the result as a black box.
Worked example
At age 30 with resting HR 65, the 60–70% zone is roughly 140–153 bpm.
Your own result may differ because it uses the exact values you enter. For comparisons, keep the method and units consistent from one calculation to the next.
Important assumptions and limitations
General adult exercise estimate only. Medications and health conditions can change heart-rate response.
Calculator outputs are estimates unless the underlying arithmetic is exact by definition. For decisions involving tax filing, lending, health, contracts or institutional grading rules, use the calculator as a first check and confirm the final decision with the relevant authoritative source.
Frequently asked questions
What does the Heart Rate Zone Calculator calculate?
The Karvonen method uses heart-rate reserve so the resting pulse influences the zone estimate.
What formula does the Heart Rate Zone Calculator use?
Max HR ≈ 220 − age; target = resting HR + intensity × (max HR − resting HR)
Is the Heart Rate Zone Calculator result exact?
General adult exercise estimate only. Medications and health conditions can change heart-rate response.
How should I use the Heart Rate Zone Calculator result?
Use the result as a practical estimate or planning check. Keep the inputs consistent, read the assumptions on this page, and verify important financial, academic or health decisions with the appropriate official or professional source when needed.
Pro mode: Custom max-HR zones
Use a measured or clinician-provided maximum heart rate instead of an age estimate.
Enable Pro mode above the input form to reveal the advanced scenario fields. The normal result stays visible, and a separate Pro analysis appears underneath so you can compare the basic answer with the deeper model.
Advanced options
- Custom maximum heart rate (bpm)