Heart Rate Zones

Five training zones via Karvonen or % of max HR.

100% private — no uploads Free & unlimited Read tutorial

See how it works

Watch a quick simulation of this tool in action — no file needed.

How to use Heart Rate Zones

Follow these steps — everything happens instantly in your browser.

  1. 1

    Step 1. Enter your age and resting heart rate.

  2. 2

    Step 2. Pick a method: Karvonen (uses HRR) or % of max HR.

  3. 3

    Step 3. Read your max HR and five zones with bpm ranges.

Why use this tool

Private by design

All processing happens locally in your browser. Open DevTools → Network and you'll see zero file uploads. Ever.

Instant

No upload wait, no queue, no server round-trip. Results appear the moment you drop a file.

Free & unlimited

No accounts, no watermarks, no daily caps. Use it as many times as you like, forever.

Works everywhere

Desktop, tablet or phone — every tool is responsive and installable as a PWA for offline use.

Frequently asked questions

Everything you might want to know about heart rate zones.

Want to learn more?

Read our complete Heart Rate Zones tutorial with tips, use cases, and FAQs.