Abstract: This disclosure provides for automatic oxygen titration in high flow and low flow oxygen therapy based on targeted oxygen saturation levels. For example, this disclosure involves an algorithm that can automatically titrate and adjust oxygen fraction (FiO2) of an oxygen therapy medical device based on the peripheral capillary oxygen saturation (SpO2) of the patient to achieve a targeted SpO2. This can allow for continuously monitoring and recording of delivered FiO2 and SpO2. In addition, the administered FiO2 can be adjusted according to patient SpO2 and target SpO2 goals. The disclosure can be adapted to any high flow oxygen device and any low flow oxygen device, such as a flowmeter. In addition, clinicians or other users can be alerted about changes in a subject's oxygenation status with an alarm function.