mg/dL ↔ mmol/L conversion (glucose) — reference tables & tips
Use this tool to convert blood glucose units instantly. Below you’ll find quick reference tables and practical notes on interpreting readings (fasting vs after meals).
The conversion formula (glucose)
Note: Some labs use a more precise factor (18.0182). For everyday conversion, 18 is the standard shortcut.
| Direction | Formula | Example |
|---|---|---|
| mg/dL → mmol/L | mmol/L = mg/dL ÷ 18 | 100 mg/dL → ~5.6 mmol/L |
| mmol/L → mg/dL | mg/dL = mmol/L × 18 | 7.0 mmol/L → ~126 mg/dL |
Quick reference table (common glucose values)
| mg/dL | mmol/L (approx.) |
|---|---|
| 70 | 3.9 |
| 80 | 4.4 |
| 90 | 5.0 |
| 100 | 5.6 |
| 110 | 6.1 |
| 120 | 6.7 |
| 126 | 7.0 |
| 140 | 7.8 |
| 160 | 8.9 |
| 180 | 10.0 |
| 200 | 11.1 |
Fasting vs after meals: why context matters
A single number can mean different things depending on when it was taken:
- Fasting (usually morning, before food): reflects baseline glucose regulation.
- Post‑meal (1–2 hours after eating): reflects how your body handles carbohydrate intake.
This page provides unit conversion only. If you’re monitoring diabetes or suspect an issue, use the reference ranges provided by your lab/clinician.
Interesting blood sugar facts (quick wins)
- Same value, two unit systems: mg/dL is mass concentration; mmol/L is molar concentration.
- Glucose uses “÷18” — other blood analytes have different conversion factors.
- Fingerstick vs lab: different measurement methods can produce slightly different results.
Blood sugar converter FAQ
Q:How do I convert mg/dL to mmol/L for glucose?
For glucose, mmol/L = mg/dL ÷ 18 (more precisely ÷ 18.0182). Example: 100 mg/dL ≈ 5.6 mmol/L.
Q:How do I convert mmol/L to mg/dL?
For glucose, mg/dL = mmol/L × 18 (more precisely × 18.0182). Example: 7.0 mmol/L ≈ 126 mg/dL.
Q:Why are there two units for blood sugar?
Different countries and labs use different reporting standards. The US commonly uses mg/dL, while many other countries use mmol/L.
Q:Is this a medical diagnosis tool?
No. This converter only converts units. Interpretation of glucose numbers depends on context (fasting vs after meals), individual health, and lab standards. For diagnosis and treatment, follow your clinician’s guidance.