Your target heart rate is the beats-per-minute range to aim for during exercise. Estimate your maximum heart rate as 220 − age, then train at a percentage: 50–70% for moderate (aerobic / "fat-burn") work and 70–85% for vigorous (cardio) work. If you know your resting heart rate, the Karvonen method personalises the zones using your heart-rate reserve. This calculator gives both.
Reviewed: June 20, 2026 · Author: Naveen P N, Founder — AI Calculator · Verified against: the 220−age estimate and the Karvonen heart-rate-reserve formula, recomputed in code. General guidance, not medical advice.
The formulas
The simple method takes a flat percentage of your estimated maximum. The Karvonen method is more individual: it works from your heart-rate reserve — the gap between maximum and resting — and adds the resting rate back. Because fitter people have lower resting rates, Karvonen shifts their zones accordingly. Both are estimates; the 220−age rule alone can be off by 10–12 bpm in either direction.
Worked example — age 30, resting 60
Scenario: a 30-year-old with a resting heart rate of 60 bpm.
The estimated max is 190 bpm. By percent-of-max, moderate exercise sits at 95–133 and vigorous at 133–162. Using Karvonen with a resting rate of 60 (reserve 130), the same percentages shift up: 50% is 125, 70% is 151, and 85% is 171 bpm. Karvonen tends to give slightly higher targets, reflecting that your working range starts above your resting rate, not from zero.
Frequently Asked Questions
Max HR = 220 − age, then take 50–70% (moderate) or 70–85% (vigorous). Age 30 → 95–133 and 133–162 bpm.
An estimate of maximum heart rate in bpm. Age 40 → 180. An average — real max varies ±10–12 bpm.
Target = (max − resting) × intensity + resting. Max 190, rest 60 → 70% = 151 bpm. More personal.
Moderate (50–70%) burns a higher share from fat, but vigorous burns more total calories. Mix both.
General guidance only. Medications and conditions change real numbers — check with a doctor if unsure.