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Cardio As of 2026-04-24

How Resting Heart Rate Calculator works

Methodology for the Resting Heart Rate Calculator: formulas, coefficients, data sources, assumptions, and known limitations.

Scope

Classifies resting heart rate, estimates relative cardio-fitness age, and suggests a training target to improve RHR.

Formula

Classification lookup by sex and age band. Cardio-age estimate maps RHR to the age where that RHR is the median.

Coefficients

Parameter Value Note
Athlete (M, 30s) 49–55 bpm
Excellent (M, 30s) 56–61 bpm
Average (M, 30s) 66–69 bpm
Poor (M, 30s) 82+ bpm

Data sources

  1. Cooper Institute fitness norms — Resting Heart Rate. — Source of the age- and sex-banded RHR percentile tables.
  2. Nauman J, Janszky I, Vatten LJ, Wisloff U. Temporal changes in resting heart rate and deaths from ischemic heart disease. JAMA. 2011;306(23):2579-2587. — PMID 22187277. Population-level link between RHR change and ischemic heart disease mortality.

Assumptions

  • Reading is taken upon waking, before caffeine or activity.

Approximation range

Population norms carry ~4–6 bpm standard deviation within each age band.

Limitations

  • Beta-blockers and other meds shift RHR independently of fitness.
  • Atrial fibrillation and other arrhythmias invalidate any RHR classification.

Reproducibility

Male, 35, RHR 58: classification 'Excellent'.

Change log

  • 2026-04-24: methodology page first published.
General fitness estimates — not medical advice. Consult a healthcare professional for medical decisions.