Device Guide · Oura Ring

Oura Ring Metrics Explained

Readiness Score, Sleep Score, and Activity Score — the inputs, the weightings, and what each number actually represents.

Overview

Oura Ring is a finger-worn wearable that uses PPG (photoplethysmography), accelerometry, and thermometry to track sleep, recovery, and activity. The ring form factor improves signal quality compared to wrist devices — the finger's digital arteries provide a stronger, more consistent PPG signal.

Sensor location
Finger (infrared + red LEDs, NTC thermistor, accelerometer)
HRV metric
RMSSD — overnight average during sleep
Sleep staging
Awake / N1 / N2 / N3 / REM (5-stage classification)
Temperature
Nightly deviation from 60-day rolling baseline
Battery life
4–7 days depending on use

Readiness Score (0–100)

Readiness is Oura's daily recovery composite, updated each morning. It weights multiple inputs against your personal baselines rather than population norms.

InputRelative Weight
HRV balance (vs 7-day rolling baseline)Very high
Resting heart rate (vs personal baseline)High
Body temperature deviationMedium-high
Sleep score (prior night)Medium-high
Recovery index (how quickly HRV stabilized during sleep)Medium
Previous day activityLow-medium

Score interpretation: 85–100 = Optimal (green), 70–84 = Good (yellow), below 70 = Pay attention (red).

Sleep Score (0–100)

Sleep Score aggregates the quality and quantity of previous night's sleep. Key contributors: total sleep time, sleep efficiency, restfulness (number and duration of awakenings), REM sleep, and deep sleep. Sleep timing regularity is also factored in newer firmware versions.

Activity Score

Activity Score reflects daily activity against your target — meeting move goals, training frequency, recovery from activity, and avoiding inactivity. Unlike Readiness, it updates throughout the day.

Known limitations

Not medical advice: Device metric explanations are for educational reference. Wearable data should not be used for clinical diagnosis. Consult a qualified clinician for health concerns.