Quick answer. In an adult without diabetes, normal blood sugar when fasting is 3.9 to 5.5 mmol/L (70 to 99 mg/dL). Two hours after eating, normal is below 7.8 mmol/L (140 mg/dL). A fasting value from 5.6 to 6.9 is considered prediabetes, so-called hidden sugar. 7.0 mmol/L or more when fasting, measured twice, is the threshold for diabetes. For HbA1c, normal is below 5.7%, and 6.5% or more means diabetes. A single number from a glucometer is not a diagnosis, but a reason for a laboratory check.
You measured your blood sugar, there’s a number on the screen, and now you don’t know whether to relax or to worry. That’s the most common reason people here search for “upper limit of blood sugar,” “normal blood sugar values” or “blood sugar after eating.” In this guide we’ve gathered all the values in one place: fasting, after a meal, HbA1c, for pregnant women, children and older adults, in both units you’ll come across on lab results and meters.
The numbers come from the international guidelines our doctors use too: the World Health Organization, the American Diabetes Association (ADA, 2026 standards) and the guidelines of the Ministry of Health. Where they differ, we’ll also tell you why.
























