Blood Glucose to A1C Converter
Convert between average blood glucose and HbA1c values for diabetes management: type in either box.
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More optionsLab A1C · %
A CGM app reports a GMI (glucose management indicator) from at least 14 days of readings: GMI % = 3.31 + 0.02392 × mean glucose in mg/dL (Bergenstal et al., Diabetes Care 2018). It runs a little higher than the lab-A1C estimate at the same average, and can differ from your lab A1C.
ExampleEstimated average glucose
108mg/dL
Normal (non-diabetic)A1C 5.4% ≈ 108 mg/dL average glucose.
- Normal under 5.7%
- Prediabetes 5.7–6.4%
- Diabetes range 6.5% and up
- In mmol/L
- 6.0 mmol/L
- A1C in mmol/mol (IFCC)
- 36 mmol/mol
An estimate from the ADAG study average. Only a lab A1C test, reviewed by your doctor, can diagnose diabetes.
How it’s worked outADAG equation (Nathan et al., 2008)
A1C = (average glucose in mg/dL + 46.7) ÷ 28.7
(108.3 + 46.7) ÷ 28.7 = 5.40%
mmol/L = mg/dL ÷ 18.0182 · IFCC mmol/mol = (% − 2.15) × 10.929. Results are approximations; individual variations occur. Always consult your healthcare provider for medical advice and diabetes management.
Frequently Asked Questions
What is HbA1c and why is it important?
HbA1c (glycated hemoglobin) is a blood test that measures your average blood sugar levels over the past 2 to 3 months. It reflects the percentage of hemoglobin proteins in your blood that are coated with sugar. It is a key metric for diagnosing and managing diabetes because it provides a longer-term picture than a single glucose reading.
How does A1C relate to average blood glucose?
A1C and average blood glucose are related through the ADAG equation (Nathan et al., Diabetes Care 2008): estimated average glucose (mg/dL) = 28.7 × A1C − 46.7, or A1C = (Average Glucose in mg/dL + 46.7) / 28.7. For example, an A1C of 7% corresponds to an average blood glucose of approximately 154 mg/dL (8.6 mmol/L). Higher A1C values indicate higher average glucose levels over the past 2-3 months.
What are the target A1C levels?
For most adults with diabetes, the American Diabetes Association recommends a target A1C below 7%. Normal A1C is below 5.7%, prediabetes ranges from 5.7% to 6.4%, and diabetes is diagnosed at 6.5% or higher. Your doctor may set a different target based on your age, health conditions, and risk of hypoglycemia.
How often should A1C be tested?
The ADA recommends A1C testing at least twice a year for people meeting treatment goals, and quarterly for those whose therapy has changed or who are not meeting glycemic goals. Your healthcare provider may recommend more frequent testing if your blood sugar levels are not well controlled.
What factors can affect A1C accuracy?
Several conditions can affect A1C results, including anemia, hemoglobin variants (such as sickle cell trait), kidney disease, liver disease, recent blood transfusions, and certain medications. Pregnancy can also affect A1C readings. If you have any of these conditions, discuss alternative monitoring methods with your healthcare provider.