In someone without diabetes, normal blood glucose levels are 70–100 mg/dL or 3.9-5.5 mmol/L, while after eating the blood glucose levels never go above 140 mg/dL or 7.8 mmol/L.
Diabetes is diagnosed if someone’s blood glucose is ≥126 mg/dL or ≥7.0 mmol/L when fasting, ≥200 mg/dL or ≥11.1 mmol/L while also having symptoms of diabetes, and/or they have an A1C result ≥6.5%.