Heart Rate Zone Calculator

Q: Simple vs Karvonen — which should I use?

Use Karvonen if you know your resting HR. It personalizes zones using heart-rate reserve. Otherwise, simple percent of max HR is fine.

Q: How accurate is 220 − age?

It’s a quick estimate and varies by person. If you have a lab-measured or sport-tested max HR, use that instead.

Get your zones using the simple method (percent of max HR) or the Karvonen method when you provide your resting heart rate.

Age

Resting HR (optional)

Method

Max HR uses the common estimate: 220 − age.

Estimated Max HR

— bpm

Fat Burn (50–69%)

— bpm

Cardio (70–84%)

— bpm

Peak (85–100%)

— bpm

FAQ

Simple vs Karvonen — which should I use?

Use Karvonen if you know your resting HR — it personalizes zones using heart-rate reserve. Otherwise, the simple % of max HR works fine for a quick estimate.

How accurate is 220 − age?

It’s a quick estimate and can vary by person. If you have a lab-measured or sport-tested max HR, use that value instead.

How do I measure resting HR?

Measure first thing in the morning before getting up, or use a wearable’s “resting” metric averaged over multiple days.