Health
A1C (Hemoglobin A1C)
A blood test reflecting average blood glucose levels over 2–3 months, expressed as a percentage. Normal is below 5.7%; 5.7–6.4% indicates prediabetes; 6.5%+ is diagnostic of diabetes.
Because glucose binds to hemoglobin in proportion to its blood concentration, A1C captures a longer-term average than a single fasting reading. It maps to an estimated average glucose (eAG), letting clinicians track control between visits.
Key Formula & Relationship
Below 5.7% Normal · 5.7%–6.4% Prediabetes · 6.5%+ Diabetes Diagnostic Threshold
Reviewed by the Calculover Editorial Team for mathematical and practical accuracy.
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