Which finger do I place the pulse oximeter sensor on?

When it comes to which finger you should use a pulse oximeter on, the answer isn’t as cut and dry as one may initially believe. Based on the results of one specific study, it was found that the highest SpO2 value was measured on a subject’s right middle finger.

However, this variance was very slight when compared to the readings of all the other fingers. For this reason, it’s believed that you will obtain similar measurements regardless of which finger you place the probe on. It is still a good practice to use a more uniform digit like the index or middle finger rather than the pinky or thumb as this helps to reduce the margin for error. For more information on which finger you should use, please click here.