Target Heart Rate Calculator

Heart-rate training works because the same workout has very different effects depending on how hard your heart is working. Easy sessions in a low zone build your aerobic base and recover you; hard sessions near the top build speed and raise your ceiling. Zone training gives you a language for telling them apart, and it needs two numbers: your maximum heart rate and, ideally, your resting heart rate.

Maximum heart rate is usually estimated from age. The classic formula, 220 minus your age, is simple but imprecise and tends to be wrong at both ends of the age range. The Tanaka formula, 208 minus 0.7 times age, comes from a much larger pooled analysis and is the better default. Both are statistical estimates — if you want a true value, a supervised maximal test is the only way to get one, and it is not advisable without medical clearance.

From there you either take percentages of maximum, or use the Karvonen method, which is more personal because it works from your heart-rate reserve — the gap between resting and maximum. Enter your resting rate, measured first thing in the morning before getting out of bed, and Karvonen will shift every zone up or down accordingly. A well-trained athlete with a resting pulse of 45 will get very different zone boundaries from a sedentary person of the same age, and that difference is exactly what the reserve method captures.

The zones themselves run from 50 percent at the bottom to 100 percent at the top. Zone 2, roughly 60 to 70 percent of maximum, is the one most people under-use: it is the intensity at which you can still hold a conversation, and it is where a great deal of endurance is built. Zone 4 and 5 are for intervals and races. Training almost everything in the middle, Zone 3, is the common mistake — it is hard enough to tire you but not hard enough to drive adaptation, which is why a proper plan spends most of its time easy and a little of its time very hard.

This calculator returns estimates for general information only. It is not medical advice, diagnosis or treatment, and it cannot replace an assessment by a qualified health professional. Individual results vary, and figures such as calorie needs, body-fat percentage and heart-rate zones are approximations based on population averages rather than measurements of you.