GMI stands for Glucose Management Indicator, which is a metric used to help people with diabetes understand the current state of their glucose management. It is a new term that estimates A1C (a blood test that measures average blood sugar levels over the past 2-3 months) from continuous glucose monitoring (CGM) readings. GMI tells you what your approximate A1C level is likely to be based on the average glucose level from your CGM readings for 14 or more days. To calculate GMI, you need to take the mean glucose reading over the past 10 to 14 days and convert it from mg/dL to a percentage. The GMI formula is GMI (Percentage) = 3.31 + 0.02392 x (glucose reading in mg/dL) . The accuracy of GMI depends on the accuracy of your CGM system. GMI is not the same as A1C, but it provides an estimated A1C level based on CGM data and can avoid some of the limitations of A1C tests. GMI can be highly useful for glucose level management in people with type 1 and type 2 diabetes when evaluated together with other metrics such as A1C and TIR.