Heart Rate Reserve Calculator — Training Zones
Calculate heart rate reserve and training zones from resting and max heart rate. Plan easy, tempo, and threshold efforts with zone targets.
This calculator uses the heart rate reserve (HRR) method, also known as the Karvonen formula: target heart rate = resting heart rate + (maximum heart rate − resting heart rate) × intensity. Enter your maximum and resting heart rate to see zone ranges for recovery, easy, tempo, threshold, and maximum efforts.
If you do not know your maximum heart rate, start with the maximum heart rate calculator for a rough age-based estimate, then bring that number back here. A field test or lab measurement is more accurate if your zones feel consistently too easy or too hard.
Resting heart rate is best measured first thing in the morning before getting out of bed, or after sitting quietly for a few minutes. A lower resting heart rate often reflects better aerobic fitness, which shifts your zones upward compared with a simple percentage-of-max estimate.
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