❤️ Heart Rate Zone Calculator

How the Heart Rate Zone Calculator Works

Heart rate training zones divide your effort into five bands, from very light (zone 1) to maximum effort (zone 5). They are based on your maximum heart rate, which this calculator estimates from your age using one of two formulas: the classic 220 − age, or the Tanaka formula (208 − 0.7 × age), which research found to be more accurate for many adults, especially older ones.

If you also enter your resting heart rate (measured in the morning before getting up), the calculator switches to the Karvonen method, which uses your heart rate reserve and gives zones better tailored to your fitness level. Age-based formulas are population averages and can be off by 10–20 beats per minute for an individual; a lab test gives your true maximum.

Formula

Max HR (classic)  = 220 − age
Max HR (Tanaka)   = 208 − 0.7 × age
Zone target       = Max HR × intensity %
Karvonen target   = Resting HR + (Max HR − Resting HR) × intensity %
Zones: 1 = 50–60%, 2 = 60–70%, 3 = 70–80%, 4 = 80–90%, 5 = 90–100%

How to Use It

1. Enter your age.
2. Optionally enter your resting heart rate for the more personal Karvonen method.
3. Choose the maximum heart rate formula.
4. Use the zone table to guide the intensity of your workouts.

Frequently Asked Questions

What are the five heart rate zones?

Zone 1 (50–60% of max) is very light recovery effort, zone 2 (60–70%) is easy aerobic endurance, zone 3 (70–80%) is moderate aerobic work, zone 4 (80–90%) is hard threshold effort, and zone 5 (90–100%) is maximum effort that can be sustained only briefly.

Is 220 minus age accurate?

It is a rough population estimate and can be off by 10–20 beats per minute for an individual. The Tanaka formula (208 − 0.7 × age) tends to be more accurate for many adults, and a supervised maximal exercise test is the most accurate method.

What is the Karvonen method?

It calculates training zones from your heart rate reserve — the difference between your maximum and resting heart rate — so zones reflect your personal fitness. Fitter people with a lower resting heart rate get correspondingly different targets.

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Formula and content last reviewed: September 2026. All calculations run in your browser — nothing you enter is sent to or stored on our servers.