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Calculate my heart rate zones

One reference heart rate, clear ranges. Compare the methods before focusing on the beats.

What is it for?

Turn your heart-rate references into heart-rate zones. Read your intensities on your watch knowing which method produced them.

How it works

  1. Choose a maximum heart rate reference or an age estimate.
  2. Explore five %HRmax zones, or compare reserve percentages using your resting heart rate.
  3. Save the result and method; an estimate is not a measured threshold.

Editable example

5 zones · %HRmax · Reference value

HRmax used
180 bpm
Your heart rate bands · 5 zones · %HRmax
Your heart rate bands
Zone or bandWhole beatsPercentage
Z1 · Very light90–107 bpm90 ≤ HR < 10850–60 %
Z2 · Light108–125 bpm108 ≤ HR < 12660–70 %
Z3 · Moderate126–143 bpm126 ≤ HR < 14470–80 %
Z4 · Hard144–161 bpm144 ≤ HR < 16280–90 %
Z5 · Maximum162–180 bpm162 ≤ HR ≤ 18090–100 %

Lower boundary included; upper boundary excluded, except at 100%. Displayed beats are the whole numbers within each band. Detailed boundaries display up to three decimal places; calculations retain their precision.

Zones are references, not a prescription or measured thresholds. Heat, fatigue and sensor readings can affect the picture. Pay attention to how you feel; do not aim for the maximum zone to validate this calculation.

If medication or a heart condition affects your heart rate, use targets agreed with your healthcare professional.

The words on this page, made clear

Choose a term for its definition and an illustrated example.

Understand the calculation

%HRmax: heart rate = percentage × maximum heart rate. The five bands 50–60, 60–70, 70–80, 80–90 and 90–100% follow the convention described by Polar. %reserve (Karvonen): heart rate = resting HR + percentage × (HRmax − resting HR). The same percentages compare calculations here; reserve bands do not inherit HRmax zone names. Age estimation uses 208 − 0.7 × age, as presented by Mayo Clinic. Calculation boundaries remain visible; each whole bpm belongs to only one band.

Updated on October 8, 2026

Your questions, answered

Do I need an account to calculate?

No. Results and methods are freely available.

What does saving keep?

Your inputs, result and method version, in your private resources. Your plan and personal records are not changed.

Do these zones change my profile or plan?

Saving keeps the calculation private. Adopting references in your profile is a separate action: whole, dated personal values, a preview, then confirmation. The age formula never replaces a known HRmax. Existing sessions and watch settings stay unchanged.

Source and limitations