🩸 Glucose & HbA1c Diagnosis
Estimate average glucose (eAG) from HbA1c and grade it, with the ADA diabetes and prediabetes diagnostic criteria. Browser-side, instant.
Point-of-care A1c is not for diagnosis — use a lab NGSP-standardised method.
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When to use
Translate an A1c into an estimated average glucose and check it against the diagnostic thresholds.
How it works
eAG (mg/dL) = 28.7 × A1c − 46.7. Diabetes A1c ≥ 6.5%, FPG ≥ 126 mg/dL, OGTT 2 h ≥ 200; prediabetes A1c 5.7–6.4%.
Key points
- Point-of-care A1c is not for diagnosis — use a lab NGSP-standardised method.
- Without symptoms, two abnormal results are needed to diagnose.
- Anaemia/haemolysis/transfusion/Hb variants/pregnancy/CKD distort A1c.
- Gestational diabetes uses dedicated criteria.
References
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| HbA1c | 7.0 % |
|---|
→Estimated average glucose (eAG)154 mg/dL (8.5 mmol/L)
- A1c category：Diabetes range (≥ 6.5%, confirm with a repeat test)
- Diagnose diabetes (any one)：A1c ≥ 6.5%; FPG ≥ 126 mg/dL (7.0); OGTT 2 h ≥ 200 (11.1); random ≥ 200 (11.1) + classic symptoms
- Prediabetes：A1c 5.7–6.4%; IFG 100–125 mg/dL (5.6–6.9); IGT 2 h 140–199 (7.8–11.0)
Frequently asked questions
- What is Glucose & HbA1c Diagnosis?
- Estimate average glucose (eAG) from HbA1c and grade it, with the ADA diabetes and prediabetes diagnostic criteria. Browser-side, instant.
- How is Glucose & HbA1c Diagnosis calculated? What is the core formula?
- eAG (mg/dL) = 28.7 × A1c − 46.7. Diabetes A1c ≥ 6.5%, FPG ≥ 126 mg/dL, OGTT 2 h ≥ 200; prediabetes A1c 5.7–6.4%.
- When is Glucose & HbA1c Diagnosis used?
- Translate an A1c into an estimated average glucose and check it against the diagnostic thresholds.
- What are the key clinical points for Glucose & HbA1c Diagnosis?
- Point-of-care A1c is not for diagnosis — use a lab NGSP-standardised method. Without symptoms, two abnormal results are needed to diagnose. Anaemia/haemolysis/transfusion/Hb variants/pregnancy/CKD distort A1c. Gestational diabetes uses dedicated criteria.
- What are the limits and cautions when using Glucose & HbA1c Diagnosis?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- How is Glucose & HbA1c Diagnosis calculated in practice? Can you show a worked example?
- Inputs: HbA1c 7.0 % → Result: Estimated average glucose (eAG) 154 mg/dL (8.5 mmol/L)（A1c category: Diabetes range (≥ 6.5%, confirm with a repeat test), Diagnose diabetes (any one): A1c ≥ 6.5%; FPG ≥ 126 mg/dL (7.0); OGTT 2 h ≥ 200 (11.1); random ≥ 200 (11.1) + classic symptoms, Prediabetes: A1c 5.7–6.4%; IFG 100–125 mg/dL (5.6–6.9); IGT 2 h 140–199 (7.8–11.0)）