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Heart-Rate Zone Calculator

Free to use, with no sign up. Your entries stay in this browser; calculations run on your device.

Maximum heart rate

Enter your age to see an adult heart-rate estimate.

HRmax ≈ 220 − age, or Tanaka HRmax ≈ 208 − 0.7 × age. A measured HRmax overrides either age estimate. Tanaka et al., 2001.

AHA moderate and vigorous ranges

Enter valid values to see the AHA ranges.

Target = fraction × HRmax. AHA moderate intensity: 50–70% of HRmax; vigorous: 70–85% of HRmax. These are general guides. AHA target heart rates.

Your chosen target method

Add resting heart rate to use Karvonen, or leave it blank for % of HRmax.

With resting HR: Karvonen target = HRrest + fraction × (HRmax − HRrest). Without resting HR: fraction × HRmax. Karvonen, Kentala and Mustala, 1957.

The Karvonen comparison applies 50–70% and 70–85% to heart-rate reserve. Those are different numbers from AHA's percentages of maximum; they are not AHA intensity bands for reserve. Age formulas can miss your individual maximum. Medicines and health conditions can change your heart-rate response.

For general information only; not medical advice.

How to use this tool

Enter your age and choose a maximum heart-rate formula. Add a measured maximum to override it, and resting heart rate to compare Karvonen targets.

Frequently asked questions

Which maximum heart-rate formula should I use?

220 minus age and Tanaka 208 minus 0.7 times age are population estimates, not measurements. Choose either or enter a measured maximum from an appropriate test.

What changes when I add resting heart rate?

The chosen target method becomes Karvonen: resting heart rate plus a fraction of the difference between maximum and resting heart rate. The separate AHA ranges still use percentages of maximum.

Are percentages of maximum and reserve interchangeable?

No. The same percentage produces different bpm values. AHA moderate and vigorous ranges refer to maximum heart rate; the reserve comparison is labelled separately.

Why might these ranges differ from my watch?

A watch may use a different maximum, resting heart rate, formula or set of zone boundaries. These adult estimates are general guides, and medicines or health conditions can affect your response.