Training Zone Calculator

How this is worked out

Heart-rate zones. If you give a resting heart rate, zones are calculated on heart rate reserve (the Karvonen method): each zone is a percentage of the gap between resting and maximum, added back onto resting. Without one, zones fall back to a straight percentage of maximum.

Where you haven’t measured a maximum, we estimate it with Tanaka’s formula (208 − 0.7 × age). That is a population average with a spread of roughly ±10 bpm, so a proper max test or a hard race finish is always worth more than the estimate.

Pace zones. Your race result is scaled to a 60-minute effort using the same Riegel exponent as the race predictor; that pace is treated as threshold, and every other zone is a fixed multiplier of it.

Information only — not medical advice. These are estimates from population-level formulas, not a substitute for professional assessment. See our full disclaimer.