Home glucose meters have become widely accessible and, in addition to self-monitoring applications, are now commonly used to support biohacking. Accu-Chek Instant is an easy-to-use and cheaply available device, and thus, it is recommended to use in a known lifestyle change program. Participants and users do not require special knowledge, though have due or undue concerns about changes in blood glucose levels. The study aims to find the minimal magnitude of change in blood glucose level, i.e. the effective resolution of the fore-mentioned device. In addition, we are seeking applicability of the standard Gage R&R study method which is well known in the automotive industry. As Gage R&R requires to incorporate several variance factors into the study, we reproduced typical home applications and daily routines of laymen. Our results on measurement uncertainty turned to be in range with the accuracy specified by the manufacturer, and the Gage R&R method helped us to formulate answer to home user concerns on a layman’s language.