Heart Rate Zones Calculator

5 training intensity zones using the Karvonen formula (with resting heart rate) or the simple 220 − age formula.

Enter inputs

Sport
Measure right after waking up. Leave empty if unknown.

Result

CalcCore
Enter inputs to calculate.
Heart rate zones (open)
Zone % of max BPM Goal

What are heart rate zones

Heart rate zones are ranges of heart rate (HR) that correspond to different levels of physical exertion. Training in different zones produces different effects: from improving overall endurance to developing maximum power output.

The Karvonen formula

If you enter your resting heart rate, the calculator uses the Karvonen formula — it accounts for heart rate reserve (the difference between max HR and resting HR), giving a more accurate and personalized result than a simple formula based only on max HR.

Formula: Target HR = ((HRmax − HRrest) × %intensity) + HRrest
Max HR: 220 − age (simplified estimate)

5 intensity zones

This result is an estimate. The 220-age formula has an error margin of ±10-12 bpm for individuals. For a more precise zone determination, a lab VO2max test or a sports physician consultation is recommended.

FAQ

What are heart rate zones?

Heart rate zones are ranges of heart rate that correspond to different training intensities: from a light warm-up to maximum effort.

What is the Karvonen formula and why is it better?

The Karvonen formula accounts for resting heart rate, making the zone calculation more accurate and personalized compared to a simple formula based only on maximum heart rate.

How do I measure my resting heart rate?

Measure your pulse right after waking up, while still lying in bed, before getting up. Count beats for a full 60 seconds for the most accurate result.

Which zone should I pick for weight loss?

Zone 2 (fat burning, 60-70% of max) is traditionally considered optimal for extended fat-burning sessions, though total calories burned per workout matters more than the specific zone.