Blood Sugar & HbA1c Calculator
Assess your blood sugar or HbA1c category using the American Diabetes Association (ADA) guidelines. Enter your glucose reading or HbA1c percentage, choose your unit, and get instant, evidence-based feedback and recommendations for your metabolic health.
How to Use This Tool
1. Choose Mode
Blood Sugar or HbA1c
2. Enter Value
Your glucose or HbA1c
3. Select Time/Unit
Fasting/post-meal or %/mmol
4. Get Results
View category & guidance
Blood Sugar & HbA1c Categories
Always consult a healthcare professional for medical advice.
Quick Reference Blood Sugar & HbA1c Table
| Category | Fasting Blood Sugar | HbA1c | HbA1c (mmol/mol) |
|---|---|---|---|
| Normal | < 100 mg/dL | < 5.7% | < 39 |
| Prediabetes | 100–125 mg/dL | 5.7–6.4% | 39–47 |
| Diabetes | ≥ 126 mg/dL | ≥ 6.5% | ≥ 48 |
| Low (Hypoglycemia) | < 70 mg/dL | — | — |
How We Calculated
- Input: We collected your blood sugar or HbA1c reading with units.
- Conversion: If blood sugar was entered in mmol/L, converted to mg/dL. If HbA1c was entered in mmol/mol, converted to %.
- Estimation: If you entered blood sugar, we estimated HbA1c using the formula: eAG = 28.7 × A1C − 46.7 (or the reverse).
- Classification: Applied ADA guidelines to determine your category (Normal, Prediabetes, or Diabetes).
- Result: Displayed your category with both blood sugar and HbA1c values.
Why Trust This Tool?
Based on official standards
No server storage
Use instantly
Works on all devices
Latest health guidelines
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Accuracy & Standards
This calculator uses the American Diabetes Association (ADA) guidelines for both blood sugar and HbA1c classification. The HbA1c conversion uses the validated NGSP/IFCC relationship. The tool is for educational purposes—not a substitute for professional medical advice.
Unit Relationships
1 mmol/L = 18.0182 mg/dL
1% = 10.929 mmol/mol
eAG = 28.7 × A1C(%) − 46.7
Learn About Blood Sugar & HbA1c
What is HbA1c?
HbA1c (glycated hemoglobin) measures your average blood sugar over the past 2–3 months. It's a key indicator for diabetes diagnosis and management, as it reflects long-term glucose control.
Why Both Matter
Blood sugar gives you a snapshot of your current glucose levels, while HbA1c shows the bigger picture. Together, they provide a complete view of your metabolic health.
Managing Your Levels
Healthy diet, regular exercise, weight management, stress reduction, and medication (if prescribed) can help maintain healthy blood sugar and HbA1c levels. Always follow your doctor's advice.
Real-World Examples
- Example 1: Fasting 95 mg/dL → HbA1c 5.2% → Normal
- Example 2: Fasting 110 mg/dL → HbA1c 5.9% → Prediabetes
- Example 3: HbA1c 6.8% → eAG 148 mg/dL → Diabetes
Limitations of This Tool
- Does not replace professional medical diagnosis.
- Single blood sugar reading may not reflect your average.
- HbA1c estimation from blood sugar is an approximation.
- Does not account for factors like anemia, pregnancy, or other conditions affecting HbA1c.
- Always consult a healthcare professional for medical advice.
Trust & Privacy
We take your privacy seriously. This tool:
- Does not store data on any server
- All calculations happen locally in your browser
- No cookies are used for this tool
References
- American Diabetes Association. Standards of Medical Care in Diabetes. DiabetesCare.org.
- Centers for Disease Control and Prevention. Diabetes and Prediabetes. CDC.gov.
- National Institutes of Health. HbA1c and Diabetes. NIH.gov.
- NGSP. HbA1c Conversion and Guidelines. NGSP.org.
Editorial Process
The Healthtus editorial team reviews this tool regularly to ensure accuracy and alignment with the latest diabetes and glucose guidelines. We update the content and references as new research emerges.
Last reviewed: July 2026