A1C Calculator

Convert A1C to estimated average glucose and back.

A1C <-> eAG conversion

mg/dL + mmol/L

Range classification

A1C conversion

Convert between HbA1c and estimated average glucose (eAG).

A1C%

A1C

5.8%

eAG

120mg/dL

eAG

6.7mmol/L

A1C ranges4.0% to 10.0%

5.8%

4.0%5.7%6.5%10.0%

Normal

4.0%-5.7%

Prediabetes

5.7%-6.5%

Diabetes

6.5%-10.0%

Range classificationPrediabetes range

Educational estimate only. Use lab results and your clinician for diagnosis or treatment decisions.

What A1C represents

A1C estimates average blood glucose over roughly 2-3 months by measuring glycated hemoglobin.

Uses the standard ADAG conversion formula between A1C and estimated average glucose. Individual factors can change real values.

Use this as an educational reference and confirm interpretation with lab tests and clinician guidance.