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HbA1c Converter

Convert HbA1c percentage to estimated average glucose (eAG) in mg/dL and mmol/L — or go the other direction — plus see the IFCC mmol/mol value and where your result falls on the ADA diabetes scale.

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NGSP vs. IFCC: the % figure (e.g. 6.0%) is the NGSP unit used in the US, UK, and most of the world. Some labs, especially in parts of Europe, report IFCC mmol/mol instead. Both are shown below.

How to Use This Calculator

Choose whether you're entering an HbA1c percentage from a lab result, or an average glucose reading from a continuous glucose monitor or meter log, and every other value updates instantly — HbA1c %, estimated average glucose in both mg/dL and mmol/L, IFCC mmol/mol, and your ADA category. For the full explanation of what HbA1c actually measures, why the eAG formula works the way it does, and a worked example for every calculation on this page, see the "How to Use the HbA1c Converter" section of our complete guide.

Read the full guide first for the best context: what HbA1c actually measures biologically, how the eAG formula was derived, the difference between NGSP and IFCC units, and a detailed worked example for every calculation on this page are all covered in our HbA1c Converter Guide 2026 →

This calculator provides general estimates for informational and educational purposes only. It is not medical advice and does not diagnose diabetes or prediabetes. HbA1c results can be affected by certain blood conditions, and a single result is not a substitute for clinical evaluation by a doctor.