HbA1c Converter Calculator

Convert HbA1c percentage to average blood glucose levels. Understand your diabetes risk with instant, accurate conversions.

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Quick Facts

Normal Range
Below 5.7%
Healthy blood sugar control
Prediabetes Range
5.7% - 6.4%
Increased diabetes risk
Diabetes Diagnosis
6.5% or higher
On two separate tests
Target for Diabetics
Below 7%
ADA recommendation

Your Results

Calculated
HbA1c
0%
Your input value
Average Glucose
0 mg/dL
US measurement
Average Glucose
0 mmol/L
International measurement

Key Takeaways

  • HbA1c measures your average blood sugar over 2-3 months
  • Normal HbA1c is below 5.7%, prediabetes is 5.7-6.4%, diabetes is 6.5%+
  • Each 1% increase in HbA1c equals roughly 28.7 mg/dL higher average glucose
  • The ADA recommends diabetics maintain HbA1c below 7%
  • Regular testing helps track long-term blood sugar management

What Is HbA1c?

HbA1c (glycated hemoglobin or A1c) is a blood test that measures your average blood sugar levels over the past 2-3 months. Unlike daily glucose testing, HbA1c provides a long-term picture of how well your body is managing blood sugar.

When glucose enters your bloodstream, it attaches to hemoglobin (the protein in red blood cells that carries oxygen). The HbA1c test measures what percentage of your hemoglobin is "glycated" or coated with sugar. Since red blood cells live about 3 months, the test reflects your average blood sugar during that period.

The HbA1c to Blood Glucose Conversion Formula

eAG (mg/dL) = (28.7 x HbA1c) - 46.7
eAG = Estimated Average Glucose
HbA1c = Your A1c percentage

To convert to mmol/L (international units), divide the mg/dL result by 18:

eAG (mmol/L) = eAG (mg/dL) / 18

Understanding HbA1c Ranges

HbA1c Average Glucose (mg/dL) Average Glucose (mmol/L) Classification
4% 68 3.8 Normal
5% 97 5.4 Normal
5.6% 114 6.3 Normal
5.7% 117 6.5 Prediabetes
6.0% 126 7.0 Prediabetes
6.4% 137 7.6 Prediabetes
6.5% 140 7.8 Diabetes
7.0% 154 8.6 Diabetes
8.0% 183 10.2 Diabetes
9.0% 212 11.8 Diabetes
10.0% 240 13.3 Diabetes

Pro Tip: Setting Your Target

While the general target for diabetics is below 7%, your doctor may set a different goal based on your age, health conditions, and hypoglycemia risk. Some people may aim for below 6.5%, while others may have a higher target of 8% to prevent dangerous low blood sugar episodes.

Why HbA1c Matters

  • Long-term tracking: Unlike daily glucose tests, HbA1c shows how well you've managed blood sugar over months
  • Complication risk: Higher HbA1c is linked to increased risk of diabetes complications (eye, kidney, nerve damage)
  • Treatment effectiveness: Helps doctors assess if your current treatment plan is working
  • No fasting required: Can be taken at any time of day, unlike fasting glucose tests

Factors That Can Affect HbA1c Accuracy

  • Anemia or blood disorders
  • Recent blood transfusions
  • Kidney or liver disease
  • Certain medications
  • Pregnancy
  • Some hemoglobin variants (common in certain ethnic groups)