Heart Rate Zone Calculator

How to use this calculator

1. Enter age and resting heart rate.
2. We estimate max HR (220 − age) and heart-rate reserve (max − resting).
3. Zones are calculated as percentages of the reserve added to resting HR.

Inputs explained

Age

Your age in years for the 220 − age max HR estimate.

Resting heart rate

Average resting HR (take after waking, before caffeine).

When to use it

• Setting cardio intensity for warmups, fat burn, and tempo sessions.
• Creating heart-rate-based training plans for running or cycling.
• Quick zone checks when switching devices or training apps.

Tips & cautions

• 220 − age is a general estimate—lab or field tests give more precise max HR.
• Use an average resting HR over several mornings for accuracy.
• Adjust zones based on how you feel; perceived exertion and power/pace are useful cross-checks.
• Age-based max HR may differ significantly from your true max.
• Resting HR fluctuates with stress, sleep, and hydration.
• Not a medical device—consult a clinician for heart conditions.

Worked examples

Deep dive

FAQs

Is 220 − age accurate?

It's a general guideline. Use lab testing for precise training zones.

Which zone is best for fat burn?

Many use ~60–70% of reserve for steady-state fat oxidation. Individual responses vary.

Should I use power or pace instead?

For runners/cyclists, power/pace can be more stable; HR zones are still useful for monitoring effort and recovery.

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