Metric

Respiratory Rate

No consumer wearable has a dedicated breath sensor. Every one of them estimates respiratory rate from the same heart-rate sensor already tracking your HRV, and how well that estimate holds up genuinely differs by brand.

Respiratory rate shows up as a quiet number on your sleep summary, usually somewhere between 12 and 20 breaths per minute, and it looks like a direct reading the same way your step count does. It isn't one. Every wrist and ring wearable on this site infers your breathing rate from respiratory sinus arrhythmia, the natural, well-documented rhythm where heart rate speeds up slightly on the inhale and slows on the exhale, captured by the same optical pulse sensor already measuring HRV and resting heart rate. No accelerometer on your chest, no airflow sensor, no direct signal from your lungs at all. That indirect method works better for some brands than others, and the difference isn't marketing, it's published, measured accuracy.

What your device actually calls this

Scientific measurementBreaths per minute, most consumer wearables derive it from respiratory sinus arrhythmia (RSA), the cyclical modulation breathing produces in beat-to-beat heart rate timing. A separate body of research also uses PPG amplitude and baseline-wander modulation, direct changes in the light-absorption waveform breathing causes, though it's not confirmed which specific method each consumer brand actually runs.

Device	What they call it	What it actually measures
Whoop	"Respiratory Rate"	RSA-derived from overnight heart rate data, reported as a median breaths-per-minute figure. Third-party validated in the Journal of Clinical Sleep Medicine within roughly 1 breath per minute of a reference device, the first wrist wearable to have this independently confirmed.
Oura Ring	"Respiratory Rate"	Same RSA-derived approach. Oura's own published comparison against medical-grade research tools reports accuracy within about 1 breath per minute across a full night.
Garmin	"Respiration Rate"	Also RSA-derived, but accuracy depends on getting a clean beat-to-beat signal from the wrist optical sensor, which genuinely degrades at low heart rate, precisely the state you're in overnight when the number matters most. Both Garmin's own user community and independent technical reviews report this as a real, documented weak point.

The honest state of the evidence, not a device-specific finding: a real, substantial body of research exists on wearable respiratory rate estimation, but per-brand third-party validation is uneven. Whoop and Oura both have independently confirmed accuracy figures; Garmin's real-world accuracy gap is documented but the mechanism (signal degradation at low heart rate) is the more reliably established part, not a single clean number. Treat any one brand's stated accuracy as brand-specific, not representative of wearable respiratory rate tracking as a category.

Measurement validity: Uncertain · see the file

Sources: "Breathing Rate Estimation From the Electrocardiogram and Photoplethysmogram," a foundational comparison of ECG- vs PPG-derived respiration estimation; "Toward a Robust Estimation of Respiratory Rate From Pulse Oximeters"; Whoop's own product documentation, cross-referenced against its published third-party validation; Oura's own accuracy blog post; Garmin's own support documentation, cross-referenced against independent community and technical reports. Full study-by-study evidence lives on the Research Desk linked above.