Convert HbA1c to average glucose.
HbA1c reports the share of haemoglobin that has been glycated, which reflects average glucose over roughly the preceding two to three months as red cells turn over. The A1c-Derived Average Glucose study produced the linear conversion used here, letting a percentage be read as the mg/dL figure a meter would have averaged. The IFCC value is the same measurement expressed in mmol per mol, the standard unit in much of the world.
Estimated average glucose
eAG in mg/dL = 28.7 x HbA1c - 46.7
Unit conversions
mmol/L = mg/dL / 18.0182; IFCC mmol/mol = (HbA1c - 2.15) x 10.929
Educational estimate only. Not medical advice — discuss results with a qualified clinician before changing treatment, medication or exercise.
Meter averages are biased by when you happen to test — often before meals — while HbA1c integrates every hour including post-meal peaks and overnight. A meter average below the eAG usually means unmeasured highs.
Yes. Anaemia, recent transfusion, pregnancy, haemoglobin variants and chronic kidney disease all distort it, because they change red cell lifespan rather than glucose.