Target Heart Rate Calculator

Maximum heart rate here uses the simplest and most common estimate, 220 − age. The zones themselves use the Karvonen method, which factors in your heart-rate reserve — the gap between max and resting heart rate — rather than just a percentage of max: target = resting + % × (max − resting). Two people with the same maximum but different resting heart rates get different zone boundaries, which is the point: a lower resting heart rate, often a sign of better cardiovascular fitness, shifts the training zones to match.

Zone 1 (50–60%) is easy, conversational effort used for recovery. Zone 2 (60–70%) is the aerobic-base zone most easy training sits in. Zone 3 (70–80%) is a moderate aerobic effort. Zone 4 (80–90%) is threshold work, harder to sustain. Zone 5 (90–100%) is maximum effort, sustainable only briefly. These bands describe how endurance training is commonly structured around intensity — they're a map for reading the table, not an instruction on which zone to train in on a given day.

The 220 − age formula was never a precise law — it's an old approximation, and actual maximum heart rate scatters widely around it for people of the same age, commonly cited with a margin of plus or minus 10 to 15 beats per minute or more. That's a large enough range to shift every zone below it by a meaningful amount. Other prediction formulas exist, such as 208 − 0.7 × age, and they don't fully agree with this one either — which underlines that no age-based formula substitutes for a measured value, only approximates one.

Anyone with a diagnosed heart condition, chest pain or shortness of breath during activity, or a family history of early heart disease should talk to a physician before training toward a percentage of predicted maximum. Certain medications — beta-blockers in particular — blunt the normal heart-rate response to exercise, which makes an age-based estimate unreliable for anyone taking them; effort should be judged differently in that case, on a physician's guidance. The same caution applies to anyone who has been inactive for a long time and is starting structured exercise for the first time.

If precision matters — for competitive training or a medical reason — a supervised graded exercise test measures actual maximum heart rate directly instead of estimating it from age, and is the only way to know the real number rather than a population average. For general training, pairing a zone estimate with the talk test (can you speak in full sentences, in short phrases, or not at all) offers a useful, low-tech sanity check on whether the effort matches the intended zone. A certified trainer or exercise physiologist can help set up either approach.