Target heart rate calculator

Frequently asked questions

Why does this calculator use 208 − 0.7 × age instead of the older 220 − age shortcut?

The Tanaka formula — 208 − 0.7 × age — was developed from a larger, more representative dataset and tends to be more accurate for adults over 40, where the older shortcut increasingly overestimates maximum heart rate.

What is the Karvonen method and when should I use it?

The Karvonen method factors in your resting heart rate by working from heart-rate reserve (max HR minus resting HR) rather than max HR alone. It tends to give more personalized zone boundaries, particularly for people with lower resting heart rates due to training. Enter your resting heart rate in the field to enable it.

How do I find my resting heart rate accurately?

Measure it first thing in the morning before getting out of bed, using a finger on your wrist or neck and counting beats for 60 seconds. Taking the average over several days gives a more stable value than any single measurement.

Do medications affect these zone estimates?

Yes. Beta-blockers and certain other medications reduce maximum heart rate, which makes age-based estimates unreliable. If you take medications that affect heart rate, consult a physician before using heart-rate zones to guide exercise intensity.