Formula and method
This calculator uses the values you enter and applies the calculation immediately in your browser. The main output formulas are:
- Estimated max HR:
220-age - Zone 2 low:
(220-age)*0.6 - Zone 2 high:
(220-age)*0.7
Some formulas are undefined for certain input combinations, such as division by zero, equal x-values in a slope calculation, or logarithms of non-positive numbers. In those cases the live tool reports that the result is undefined instead of displaying Infinity or NaN.
Examples
- Example: with Age = 35 years, this calculator returns Estimated max HR = 185 bpm, Zone 2 low = 111 bpm, Zone 2 high = 130 bpm.
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- Try related health & fitness tools when your next step needs another conversion or calculation.
Why your estimated max heart rate might be off
Age-based max heart rate formulas (like 220 minus age) are population averages with a wide individual error margin -- your actual max heart rate could reasonably differ by 10-15 beats per minute from the formula's estimate, especially with a strong training history. If you have a measured max heart rate from a supervised test, use that instead of the formula estimate for more accurate zones. See the heart rate zones guide for how the Karvonen method tries to improve on this.
Embed this tool
Paste this snippet into your own site or blog post to embed a live, working copy of this tool. It links back to the full page on SpecWhale.
Frequently asked questions
Is Heart Rate Zone Calculator free to use?
Yes. Heart Rate Zone Calculator is completely free, has no usage limit, and does not require an account, email, or API key.
Does Heart Rate Zone Calculator store or upload my data?
No. Heart Rate Zone Calculator calculates everything locally in your browser. Nothing you type is sent to a server or stored by SpecWhale.
How accurate is Heart Rate Zone Calculator?
Heart Rate Zone Calculator uses a standard formula (see the Method section above for the exact expression). For high-stakes financial, medical, or legal decisions, confirm the result with a professional or an authoritative source before relying on it.
Can I embed Heart Rate Zone Calculator on my own website?
Yes. Use the "Embed this tool" snippet on this page to add a free, working copy of Heart Rate Zone Calculator to your own blog post or page.
SEO and sharing notes
This page has a single clean canonical URL, descriptive metadata, breadcrumb structured data, and internal links to related tools. Supported calculators and converters can also copy a prefilled share link without changing the canonical index URL.