Are these zones medical advice?

No—consult a medical professional before starting new training.

Can I customize max HR?

Yes—override the formula with your lab-tested or wearable-derived max.

Heart-Rate Zones

Enter your age (and optionally your resting HR). Choose a formula and zone method to get Z1–Z5 targets in bpm. Use Karvonen (HRR) for zones relative to your fitness.

Max HR method Zone calculation

Age (years) Resting HR (bpm) (optional) Zone scheme

Estimated Max HR

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Heart-Rate Reserve (HRR)

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HRR = Max HR − Resting HR (used by Karvonen)

Zone	Intensity	% Range	Target (bpm)

Calories estimator (uses MET)

Weight Duration (min) MET

Estimated calories

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Per minute

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Formula: kcal = MET × body-weight(kg) × time(hours). When using pounds, we convert to kg automatically.

Help & FAQ — Heart Rate Zones Calculator

How to use

Enter age and optionally resting heart rate.
Choose a formula (Karvonen, Fox, or custom max).
Review the calculated zone ranges and export/share if needed.

Use cases

Plan cardio workouts with target zones.
Set heart-rate ranges for endurance training.

Tips & FAQs

Are these zones medical advice?: No—consult a medical professional before starting new training.
Can I customize max HR?: Yes—override the formula with your lab-tested or wearable-derived max.

Formats & limits

Input age: 10–90 years
Outputs 5 training zones plus warm-up/cool-down bands
Intended for healthy adults; adjust with professional guidance

Privacy

Calculations run locally in your browser; no data leaves your device.

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Updated

15 October 2025