Heart Rate Zone Calculator
Find your 5 heart rate training zones based on your age or maximum heart rate. Includes the Karvonen formula for heart rate reserve.
Estimated Maximum Heart Rate
190
bpm
Light activity, active recovery, warm-up
95–114 bpm
Karvonen: 125–138
Fat burning, base endurance, long slow runs
114–133 bpm
Karvonen: 138–151
Improved aerobic fitness, moderate cardio
133–152 bpm
Karvonen: 151–164
Speed, power, lactate threshold training
152–171 bpm
Karvonen: 164–177
Maximum effort, sprint intervals
171–190 bpm
Karvonen: 177–190
% of max HR shown. Karvonen zones use heart rate reserve (Max HR − Resting HR).
- 100% free — no account needed
- Runs in your browser
- Nothing is uploaded
Frequently asked questions
Is Heart Rate Zone Calculator really free?
Yes. Heart Rate Zone Calculator is completely free on PureBrowser — every feature, with no account, no trial, and no credit card.
Does Heart Rate Zone Calculator upload my data?
No. Heart Rate Zone Calculator runs entirely inside your browser, so anything you type, paste, or open stays on your own device.
Do I need to sign up or install anything?
Neither. There is no account and nothing to download — open the page and Heart Rate Zone Calculator is ready to use on desktop or mobile.
Does Heart Rate Zone Calculator work offline?
Once the page has loaded, yes. All of the processing happens locally in your browser, so it keeps working without a connection.
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