Kinsa thermometers were not designed with Basal Body Temperature, or BBT tracking in mind, and so we don't recommend using them for this purpose.
Typical fever thermometers, including ours, measure to the tenth place of a degree.
BBT thermometers on the other hand are designed to measure to the hundredth place. This increased accuracy is better for capturing the subtle changes in body temperature caused by hormonal changes.
If you're looking for a thermometer to use for fertility tracking, we recommend purchasing a dedicated BBT thermometer.