HbA1c to Average Glucose Converter — Free Online Calculator
Input
Estimated Average Glucose
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Estimated Average Glucose
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About This Calculator
The HbA1c (glycated hemoglobin) to estimated average glucose (eAG) converter translates HbA1c percentage to the corresponding average blood glucose level over the past 2–3 months. This relationship was established by the A1C-Derived Average Glucose (ADAG) study. HbA1c is used for diabetes diagnosis, monitoring, and treatment target assessment.
Formula
Interpretation
| HbA1c (%) | Classification | eAG (mg/dL) |
|---|---|---|
| < 5.7% | Normal | < 117 |
| 5.7 – 6.4% | Prediabetes | 117 – 137 |
| ≥ 6.5% | Diabetes | ≥ 140 |
References
Frequently Asked Questions
How often should HbA1c be measured?
For patients with stable diabetes, HbA1c should be measured every 6 months. For patients with changing therapy or not meeting glycemic goals, it should be measured quarterly. HbA1c reflects average glucose over the preceding 2–3 months based on red blood cell lifespan.
What conditions can falsely affect HbA1c?
Conditions that affect red blood cell turnover can falsify HbA1c: hemolytic anemia, chronic blood loss, and recent transfusion cause falsely low values; iron deficiency anemia and splenectomy cause falsely high values. Hemoglobin variants (HbS, HbC) may interfere depending on the assay method.
What is the ADA recommended HbA1c target?
The ADA recommends a general target of < 7.0% (53 mmol/mol) for most non-pregnant adults with diabetes. More stringent targets (< 6.5%) may be appropriate for younger patients, while less stringent targets (< 8.0%) may be acceptable for older patients or those with significant comorbidities.
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⚠ Medical Disclaimer
This tool is for educational and informational purposes only. It is not intended to replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional for clinical decisions.