What is it?
The Heart Rate Zone Calculator estimates your Maximum heart rate and the five training zones, from Zone 1: very light (50–60%) to Zone 5: maximum (90–100%).
Who is it for?
Runners, cyclists and walkers training with a watch or chest strap, and people starting exercise who want to keep effort safe.
How to use it
Enter your Age. Add your Resting heart rate (optional) for more personal zones (the Karvonen method). Measure resting heart rate in the morning before getting up, for a full minute. The answer appears as you type; there is no Calculate button. Tap Copy result to copy it, or Share on WhatsApp to send it.
What each zone is for
- Zone 2 (60–70%): easy, conversational pace. Builds endurance and burns fat as fuel. Most training should be here.
- Zone 3 (70–80%): steady aerobic work, a bit harder to talk.
- Zone 4–5: hard intervals; short bursts only, with full recovery between.
Limits
- “220 minus age” is an average; your real maximum can be 10–15 beats different.
- Medicines like beta-blockers lower heart rate, so zones don’t apply.
- Wrist watches can be off during intervals; chest straps are more accurate.
Stop and get help if you feel chest pain, severe breathlessness or dizziness. If you have heart disease or are starting exercise after a long break, check with a doctor first.
Errors and how to fix them
- A result shows a dash (—): a box is empty or has something that is not a number in it, such as a comma or a letter. Type plain digits; use a dot for decimals.
- The zones look too high or too low for you: age-based maximum heart rate is only an average; it can be 10–20 beats off for one person. Fill in Resting heart rate (optional) for more personal zones.
- Taking heart or blood pressure medicine: some medicines (such as beta blockers) lower your heart rate, so these zones don’t apply. Ask your doctor for your own target.
Open the tool: Heart Rate Zone Calculator
Still stuck?
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Questions, or an error not listed here?
Tell us in the comments: what you were doing, the exact message you saw, and your device and browser. We read every comment and add new fixes to this article.