Blood Glucose to HbA1c Calculator
Convert between average blood glucose levels and HbA1c percentage for diabetes monitoring.
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How to use this calculator
The ADA formula converts average plasma glucose in mg/dL to HbA1c percentage. For mmol/L, first multiply by 18.016 to convert to mg/dL before applying the formula.
- 1
Enter your average blood glucose value from recent readings.
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Select the unit: mg/dL (US standard) or mmol/L (international).
- 3
The calculator instantly shows your estimated HbA1c percentage.
- 4
Compare your HbA1c to the normal, pre-diabetes, and diabetic ranges.
Frequently asked questions
What is HbA1c?
HbA1c (glycated hemoglobin) reflects average blood glucose over the past 2–3 months. It is the gold-standard test for diagnosing and monitoring diabetes.
What is a normal HbA1c level?
An HbA1c below 5.7% is considered normal. Between 5.7% and 6.4% indicates pre-diabetes, and 6.5% or above indicates diabetes.
How accurate is this conversion?
The formula is based on the ADA-recommended equation and provides a close estimate, but individual variation exists. Lab-measured HbA1c remains the clinical standard.
Can I use a single glucose reading for this calculation?
The formula is most accurate when using a 30-day or 90-day average of glucose readings, not a single measurement.
Blood Glucose to HbA1c Calculator
Understanding the Relationship Between Blood Glucose and HbA1c
Blood glucose is a snapshot of your sugar level at a single moment, while HbA1c gives a three-month average. For people managing diabetes, knowing how daily glucose readings translate to HbA1c is critical for long-term health planning. This calculator uses the American Diabetes Association formula to bridge those two measurements instantly.
How to Interpret Your HbA1c Result
An HbA1c below 5.7% is normal. Levels between 5.7% and 6.4% indicate pre-diabetes, a reversible condition with lifestyle changes. An HbA1c of 6.5% or higher on two separate tests confirms a diabetes diagnosis. For diagnosed diabetics, a target below 7.0% is generally recommended by the ADA to reduce complications.
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →