Blood Sugar Converter
Convert blood glucose values between mg/dL (US units) and mmol/L (international units). Includes reference ranges for normal fasting, after-meal, and A1C.
Reference Ranges
| Test Type | mg/dL | mmol/L |
|---|---|---|
| Fasting — Normal | 70 – 99 | 3.9 – 5.5 |
| Fasting — Prediabetic | 100 – 125 | 5.6 – 6.9 |
| Fasting — Diabetic | ≥ 126 | ≥ 7.0 |
| 2-hour post-meal — Normal | < 140 | < 7.8 |
| 2-hour post-meal — Diabetic | ≥ 200 | ≥ 11.1 |
How blood sugar units convert
mg/dL ÷ 18 = mmol/L. Factor 18 = glucose molecular weight (180) ÷ 10. Fasting normal: 70-99 mg/dL (3.9-5.5 mmol/L). US uses mg/dL, most world uses mmol/L. Diabetes diagnoses use standardized thresholds.
Frequently asked questions
How accurate are the results?
Formulas used here are validated in population studies but cannot account for individual genetics, body composition, or medical conditions. Treat results as a starting point, not a medical diagnosis.
Should I consult a professional?
If you have specific health concerns, existing conditions, or are planning significant lifestyle changes, consult a qualified healthcare provider (doctor, dietitian, physiologist).
How often should I recalculate?
Recalculate when your weight changes more than 5%, activity level shifts significantly, or every 3-6 months for routine monitoring. Results are snapshots — your body changes daily.
Last updated
For general wellness information only, not medical advice — see our disclaimer.