HRV Normal Range Calculator

Compares your RMSSD or SDNN reading against age-banded reference ranges from resting short-term recordings. HRV declines with age, so the calculator picks the band that matches your decade and flags whether your value is below, within, or above it.

Nunan D et al. (2010) normative HRV meta-analysis; Shaffer F & Ginsberg JP (2017) overview of HRV metrics and norms.

HRV is highly individual and device-dependent. Population bands are wide — your own night-to-night baseline is a far better reference than any table.

Diagnosing heart conditions. Abnormal or erratic readings, or symptoms like palpitations or dizziness, warrant a conversation with your doctor, not a fitness calculator.

Heart rate variability is the variation in time between consecutive heartbeats. Higher variability generally reflects a well-recovered, adaptable nervous system, while a drop can signal fatigue, stress, or illness. It's one of the most useful recovery signals your watch or ring tracks.

RMSSD captures short-term, beat-to-beat changes driven mainly by your parasympathetic ('rest and digest') system, and it's what most wearables report. SDNN reflects overall variability across a recording. This calculator gives reference ranges for both.

HRV falls steadily with age, so 'normal' depends heavily on how old you are. This tool shows the typical band for your age bracket — but the ranges are wide, and your own baseline matters far more than the population average.

HRV is highly individual and device-dependent. Genetics, fitness, measurement time, and how each device calculates the number all shift the value. Comparing your trend against your own baseline is meaningful; comparing absolute numbers between people usually isn't.

No. A single low morning HRV is normal after hard training, poor sleep, alcohol, or stress. Look at the multi-day trend: a sustained drop is a better cue to back off than any one night.