Device research record
Apple Watch Series 7
Signals and sensors
From the device record. Fields the source does not state are left out.
- Maker
- Apple
- Form factor
- Wrist
- Series
- Series 7
- Family
- Apple Watch
- Signals recorded
- PPG, Accelerometer, ECG
- Also called
- Watch Series 7, Apple Watch S7
What published studies show
Results quoted from 5 published validation studies, each against a clinical reference. A result applies to the model and protocol tested, not to every model the brand sells. From the wearable accuracy database (v1.0.0).
Blood oxygen (SpO2)4 studies
| Device tested | Result | Reference | Sample | Study |
|---|---|---|---|---|
| Apple Watch Series 7 | 3.5% (rest)Root-mean-square error | Medical-grade pulse oximeter | n = 36, Rest, COPD outpatients | Støve et al. (2023)Funding not reported |
| Apple Watch Series 7 | 2.2% (RMSE 2.9%)Mean absolute error | Medical-grade pulse oximeter | n = 49, Spot readings, with and without chronic pulmonary disease | Jiang et al. (2023)Independent |
| Apple Watch Series 7 | 2.9%Root-mean-square error | Medical-grade pulse oximeter | n = 49, Spot readings, with and without chronic pulmonary disease | Jiang et al. (2023)Independent |
| Apple Watch Series 7SaO2 < 88% | Arms 5.82% (SaO2 < 88%)Root-mean-square error | Arterial blood gas (SaO2) | Controlled hypoxia, SaO2 < 88% subset | Jiang et al. (2026)Funding not reported |
| Apple Watch Series 7detecting clinically significant hypoxia | 34.8% (spec 97.5%)Sensitivity | Medical-grade pulse oximeter | n = 200, Hospital ward, COVID-19 inpatients | Rajakariar et al. (2024)Independent |
- Apple Watch Series 73.5% (rest)
Root-mean-square error · vs Medical-grade pulse oximeter · n = 36, Rest, COPD outpatients
Støve et al. (2023) Funding not reported
- Apple Watch Series 72.2% (RMSE 2.9%)
Mean absolute error · vs Medical-grade pulse oximeter · n = 49, Spot readings, with and without chronic pulmonary disease
Jiang et al. (2023) Independent
Root-mean-square error · vs Medical-grade pulse oximeter · n = 49, Spot readings, with and without chronic pulmonary disease
Jiang et al. (2023) Independent
- Apple Watch Series 7Arms 5.82% (SaO2 < 88%)
Root-mean-square error, SaO2 < 88% · vs Arterial blood gas (SaO2) · Controlled hypoxia, SaO2 < 88% subset
Jiang et al. (2026) Funding not reported
- Apple Watch Series 734.8% (spec 97.5%)
Sensitivity, detecting clinically significant hypoxia · vs Medical-grade pulse oximeter · n = 200, Hospital ward, COVID-19 inpatients
Rajakariar et al. (2024) Independent
VO2max estimate1 study
| Device tested | Result | Reference | Sample | Study |
|---|---|---|---|---|
| Apple Watch Series 7 | 15.79% (ICC 0.47)Mean absolute percentage error | Indirect calorimetry | n = 19, Graded cycle ergometer test | Caserman et al. (2024)Independent |
- Apple Watch Series 715.79% (ICC 0.47)
Mean absolute percentage error · vs Indirect calorimetry · n = 19, Graded cycle ergometer test
Caserman et al. (2024) Independent
Comparisons
Head-to-head comparisons for this brand.
- Whoop vs Apple Watch: What the Sleep-Lab Studies Found
- Garmin vs Apple Watch: PPG, ECG & Battery Compared
- Apple Watch Ultra 2 vs Garmin Fenix 8: Specs Guide
- Fitbit vs Apple Watch: PPG Sensor Accuracy and Health Features
- Samsung Galaxy Watch vs Apple Watch: PPG Sensor and Health Features
- Oura Ring vs Apple Watch: Finger PPG vs Wrist PPG Accuracy
- Google Pixel Watch vs Apple Watch: PPG Sensor and Health Ecosystem
- Withings vs Apple Watch: ScanWatch 2 ECG, SpO2 and PPG Compared
Datasets recorded with this device
- WatchMyHeart
Apple Watch 7 + Galaxy Watch 4 resting ECG (n=93)