HbA1c to Average Glucose Calculator
Convert HbA1c percentage to estimated average glucose (eAG) in mg/dL and mmol/L using the ADAG study formula. Classify your A1c level.
Blood Sugar Converter
Convert blood sugar levels between mg/dL and mmol/L. View normal, prediabetic, and diabetic ranges with color-coded classifications.
⚠️ Medical Disclaimer: This converter is for educational purposes only. Do not self-diagnose. Consult your healthcare provider for interpretation of blood glucose results.
mg/dL
mg/dL
100
=
mmol/L
5.5
Prediabetes
Fasting glucose classification
mg/dL⧉
100
Milligrams per deciliter
mmol/L⧉
5.5
Millimoles per liter
Classification⧉
Prediabetes
Based on fasting criteria
Fasting Glucose Ranges
Low (Hypoglycemia)
< 70 mg/dL (< 3.9 mmol/L)
Normal
70–99 mg/dL (3.9–5.5 mmol/L)
Prediabetes
100–125 mg/dL (5.6–6.9 mmol/L)
Diabetes
≥ 126 mg/dL (≥ 7.0 mmol/L)
Quick Conversion Table
| mg/dL | mmol/L | Fasting Classification |
|---|---|---|
| 40 | 2.2 | Low (Hypoglycemia) |
| 50 | 2.8 | Low (Hypoglycemia) |
| 60 | 3.3 | Low (Hypoglycemia) |
| 70 | 3.9 | Normal |
| 80 | 4.4 | Normal |
| 90 | 5 | Normal |
| 100 | 5.5 | Prediabetes |
| 110 | 6.1 | Prediabetes |
| 120 | 6.7 | Prediabetes |
| 126 | 7 | Diabetes Range |
| 140 | 7.8 | Diabetes Range |
| 160 | 8.9 | Diabetes Range |
| 180 | 10 | Diabetes Range |
| 200 | 11.1 | Diabetes Range |
| 250 | 13.9 | Diabetes Range |
| 300 | 16.6 | Diabetes Range |
| 400 | 22.2 | Diabetes Range |
Planning notes, formulas, and examples
About the Blood Sugar Converter
This converter changes blood glucose values between mg/dL and mmol/L using the standard glucose unit-conversion factor. It also shows broad fasting and random-glucose interpretation bands so the converted value can be read in context.
The main use case is practical unit translation: a meter, lab report, article, or travel context may use a different unit than the one you are used to. The page is not a diagnosis engine, but it can help prevent simple unit mistakes.
When This Page Helps
People who monitor glucose often run into both mg/dL and mmol/L in devices, lab reports, and guidelines. A direct converter with the usual fasting and random thresholds helps avoid simple misreading of the number when the unit changes.
How to Use the Inputs
- Enter your blood glucose value in either mg/dL or mmol/L.
- The converter quickly shows the equivalent in the other unit.
- Select whether this is a fasting or random reading.
- View the color-coded classification (normal, prediabetic, diabetic).
- Refer to the conversion table for common values.
Formula used
mg/dL to mmol/L: divide by 18.0182
mmol/L to mg/dL: multiply by 18.0182
Fasting Glucose Ranges:
• Normal: < 100 mg/dL (< 5.6 mmol/L)
• Prediabetes: 100–125 mg/dL (5.6–6.9 mmol/L)
• Diabetes: ≥ 126 mg/dL (≥ 7.0 mmol/L)
Random Glucose:
• Normal: < 140 mg/dL (< 7.8 mmol/L)
• Impaired: 140–199 mg/dL (7.8–11.0 mmol/L)
• Diabetes: ≥ 200 mg/dL (≥ 11.1 mmol/L)Example Calculation
Result: 6.1 mmol/L — Prediabetes range
110 mg/dL ÷ 18.0182 = 6.1 mmol/L. For a fasting reading, this falls in the prediabetes range (100 –125 mg/dL or 5.6–6.9 mmol/L). The ADA recommends follow-up testing and lifestyle modifications at this level.
Tips & Best Practices
- For fasting glucose, don't eat or drink (except water) for at least 8 hours before the test.
- Glucometer accuracy can vary by ±15% — lab values are more precise.
- A single reading doesn't confirm diabetes; multiple readings and an HbA1c test are needed for diagnosis.
- Post-meal glucose peaks 1–2 hours after eating and should return near fasting levels within 3 hours.
- Store this converter on your phone if you travel to countries using a different glucose unit.
- Hypoglycemia (low blood sugar) is generally defined as < 70 mg/dL (< 3.9 mmol/L).
Understanding Blood Glucose Measurement
Glucose concentration in blood can be expressed as mass concentration (mg/dL, milligrams per deciliter) or molar concentration (mmol/L, millimoles per liter). The conversion factor of 18.0182 comes from the molecular weight of glucose (180.156 g/mol), divided by 10 to convert between deciliters and liters.
Diagnostic Criteria for Diabetes
The American Diabetes Association uses three criteria for diagnosing diabetes (any one is sufficient): fasting glucose ≥126 mg/dL (7.0 mmol/L), 2-hour post-load glucose ≥200 mg/dL (11.1 mmol/L) during an OGTT, or HbA1c ≥6.5%. The test should be repeated on a separate day to confirm unless symptoms of hyperglycemia are present.
Self-Monitoring Best Practices
For people with diabetes, the ADA recommends checking glucose before meals and at bedtime. Target ranges are individualized, but general goals are 80–130 mg/dL (4.4–7.2 mmol/L) before meals and <180 mg/dL (<10.0 mmol/L) 1–2 hours after eating. Consistent monitoring and pattern recognition are key to effective management.
Sources & Methodology
Last updated:
Methodology
This page converts glucose values between mg/dL and mmol/L using the standard glucose conversion factor of 18.0182. It then compares the converted result with broad fasting or random-glucose threshold bands for low glucose, normal range, prediabetes or impaired range, and diabetes range.
The output is a unit converter with guideline-style reference bands, not a stand-alone diabetes diagnosis. Diagnosis and treatment decisions depend on the type of test, repeat confirmation, symptoms, and the full clinical context.
Sources
- Standards of Care in Diabetes (American Diabetes Association)
- SI Units and Clinical Laboratory Data (World Health Organization) — General unit-conversion context for laboratory measurements.
Frequently Asked Questions
Historical convention. The US adopted mg/dL (mass concentration) while much of the world adopted mmol/L (molar concentration) following the push toward SI units in the 1970s. The conversion factor (18.0182) reflects the molecular weight of glucose.
Fasting glucose is measured after at least 8 hours without food. Random glucose is taken at any time regardless of meals. Fasting glucose is the standard screening test for diabetes. Random glucose is used in emergency settings or when fasting isn't practical.
For fasting: below 100 mg/dL (5.6 mmol/L) is normal. For 2 hours after eating: below 140 mg/dL (7.8 mmol/L). These are ADA guidelines for non-pregnant adults. Optimal fasting levels are typically 70–99 mg/dL.
The ADA recommends lifestyle changes: losing 5–7% of body weight, getting 150 minutes of moderate exercise per week, and following a balanced diet. These changes can reduce the risk of developing type 2 diabetes by up to 58%. Regular follow-up testing is also recommended.
They measure different things. HbA1c reflects average glucose over 2–3 months and doesn't require fasting. Fasting glucose is a snapshot of current levels. Both are used for diagnosis. HbA1c is often preferred for monitoring long-term blood sugar control.
Yes. Physical and emotional stress triggers cortisol and adrenaline release, which can raise blood sugar by 50+ mg/dL temporarily. This is why it's important to take readings in a calm state and use multiple readings for clinical decisions.
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