Heart rate zones (Zone 1–5)

Calculate all 5 training zones (Zone 1 Recovery to Zone 5 VO₂max) with Karvonen and %HRmax. From age and resting HR, with Zone 2 highlighted as the star zone.

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Note: Estimated heart-rate ranges do not replace spiroergometry. The most accurate thresholds come from lactate or VO₂max tests.

Age (years)Resting heart rate (bpm) — optional, for KarvonenMeasure in the morning before getting up, for about 1 minute. Without it the calculator uses the simpler %HRmax method.

Please enter your age.

Frequently Asked Questions

Methodology

How does the calculator work?

Enter your age in years
Optional: enter your resting HR (morning, before getting up)
All 5 zones show up immediately as bpm ranges
Zone 2 is highlighted — the most important zone for aerobic base
Switch between Karvonen and %HRmax via the method picker

HRmax = 220 − age. Karvonen: resting HR + (HRmax − resting HR) × zone factor. %HRmax: HRmax × zone factor. Zone 1 = 50–60 %, Zone 2 = 60–70 %, Zone 3 = 70–80 %, Zone 4 = 80–90 %, Zone 5 = 90–100 %.

1Which method fits?

Both methods give you all 5 zones — they only differ in how the absolute bpm values are computed.

Karvonen (HRR + resting HR): Karvonen uses heart-rate reserve (HRR = HRmax − resting HR) and adds the resting HR back on top. Accounts for individual fitness — more accurate than the plain HRmax formula.

%HRmax (220 − age): %HRmax takes x % of HRmax (220 − age). Works without resting HR but is rougher — HRmax varies by ±10 bpm individually.

2What are heart-rate zones?

Intensity bands defined by %HRmax or %HRR. The 5-zone model is the standard in Garmin, Polar and Apple Watch and splits training into Recovery (Z1), Aerobic Base (Z2), Tempo (Z3), Threshold (Z4) and Maximal/VO₂max (Z5).

3How should I split training time across the zones?

Classic "polarised training": ~80 % of cardio time in Z1–2, ~20 % in Z4–5, Z3 kept thin ("grey zone"). For pure health/longevity goals, 150 minutes of Zone 2 per week is enough.

4Why is Zone 2 so popular?

Zone 2 builds mitochondrial density and fat-oxidation capacity — the foundation for every higher intensity. Peter Attia, Iñigo San Millán and other longevity researchers recommend Zone 2 as the most important cardio zone for VO₂max and metabolic health.

5What if my real HRmax differs from the formula?

220 − age is a rule of thumb with ±10 bpm spread. If you know your actual HRmax from a test (e.g. ramp test), mentally shift the calculator: if you are 5 bpm above the estimate, push all zones up by 5 bpm. Smartwatches with a chest strap usually give the most accurate live HRmax estimate.

6Can I use these values with a smartwatch?

Yes. On Garmin/Apple/Polar set the calculated ranges as custom HR zones. Note: wrist-based optical HR is less accurate during running than a chest strap — use a chest strap for threshold and VO₂max intervals.