Heart Rate Zone Calculator
Calculate heart rate training zones by age. Find your target heart rate ranges for different exercise intensity levels. Health data never leaves your device — every calculation runs locally in your browser.
How to Use the Heart Rate Zone Calculator
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Frequently Asked Questions
How are the zones calculated?
Karvonen method: max HR = 220 − age, reserve = max − resting HR, then zones at 50–60% recovery, 60–70% fat-burn, 70–80% aerobic, 80–90% threshold, 90–100% max of reserve added back to resting. Example: age 35, resting 65 → max 185, reserve 120, Zone 2 ≈137–149 bpm.
Which zone burns the most fat?
Zone 2 (60–70%) burns the highest fat fraction — but higher zones burn more total calories per minute. For fat loss, total weekly volume in Zones 2–3 beats short Zone 5 bursts.
How accurate is 220-minus-age?
±10–12 bpm for most people; medications (beta blockers), fitness, and genetics shift it. For precise training, do a field test or lab VO2max — formulas are starting points.
What zone for a beginner runner?
80% of runs in Zone 2 (conversational pace), 20% harder. Beginners going too hard is the top cause of burnout and injury — slow builds the aerobic base.
When using Heart Rate Zone Calculator, is my health data stored?
No. All calculations run locally in your browser. No health data is transmitted or stored.
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Last updated October 2026