Correcting for emitted light wavelength variation in blood-oxygen saturation measurements at wearable electronic device

A measurement engine of a wearable electronic device may compensate for wavelength variations of light emitted as part of blood-oxygen saturation measurements. In some cases, determining an estimated blood-oxygen saturation value is based at least partially on temperature data that may be used to compensate for temperature-based wavelength variations of the emitted light, drive current data that may be used to compensate for drive-current-based wavelength variations of the emitted light, and/or calibration information that may be used to compensate for manufacturing variability across different light emitters. In various embodiments, the measurement engine may use temperature data, the drive current data, and/or calibration information in a variety of ways to determine estimated blood-oxygen saturation values, including using lookup tables or calibration curves, applying functions, and the like.