Blood Sugar Converter
Convert blood glucose levels between mg/dL (US) and mmol/L (international) instantly
Blood Glucose Converter
Enter a value in mg/dL to convert to mmol/L
Quick Presets
Blood Sugar Reference Ranges
| Test / Timing | Normal | Pre-diabetes | Diabetes |
|---|---|---|---|
| Fasting | 70 - 99 mg/dL (3.9 - 5.5 mmol/L) | 100 - 125 mg/dL (5.6 - 6.9 mmol/L) | 126+ mg/dL (7.0+ mmol/L) |
| 2 hrs Post-meal (OGTT) | < 140 mg/dL (< 7.8 mmol/L) | 140 - 199 mg/dL (7.8 - 11.0 mmol/L) | 200+ mg/dL (11.1+ mmol/L) |
| Random | < 140 mg/dL (< 7.8 mmol/L) | -- | 200+ mg/dL (11.1+ mmol/L) with symptoms |
| HbA1c | < 5.7% | 5.7% - 6.4% | 6.5%+ |
Source: American Diabetes Association diagnostic criteria. Always consult your healthcare provider for medical decisions.
Common Blood Sugar Values
| mg/dL | mmol/L | Context |
|---|---|---|
| 70 | 3.9 | Low end of normal fasting |
| 80 | 4.4 | Typical normal fasting |
| 90 | 5.0 | Normal fasting |
| 100 | 5.6 | Upper normal / pre-diabetes threshold |
| 110 | 6.1 | Pre-diabetes range |
| 120 | 6.7 | Pre-diabetes range |
| 126 | 7.0 | Diabetes diagnostic threshold (fasting) |
| 140 | 7.8 | Post-meal upper normal limit |
| 180 | 10.0 | Post-meal diabetes target ceiling |
| 200 | 11.1 | Random test diabetes threshold |
| 250 | 13.9 | Very high |
| 300 | 16.7 | Dangerously high — seek medical attention |
Frequently Asked Questions
What is the difference between mg/dL and mmol/L?
mg/dL (milligrams per deciliter) is used primarily in the United States, while mmol/L (millimoles per liter) is the international standard used in most other countries. They both measure the concentration of glucose in your blood. To convert mg/dL to mmol/L, divide by 18.0182.
What is a normal fasting blood sugar level?
A normal fasting blood sugar level is between 70 and 99 mg/dL (3.9 - 5.5 mmol/L). A fasting level of 100 - 125 mg/dL (5.6 - 6.9 mmol/L) indicates pre-diabetes, and 126 mg/dL (7.0 mmol/L) or higher on two separate tests indicates diabetes.
What should blood sugar be 2 hours after eating?
For most adults without diabetes, blood sugar should be below 140 mg/dL (7.8 mmol/L) two hours after eating. For people with diabetes, the American Diabetes Association recommends a target of less than 180 mg/dL (10.0 mmol/L) two hours post-meal, though individual targets may vary.
Why do different countries use different blood sugar units?
The US adopted mg/dL (mass concentration) early on, while most other countries adopted mmol/L (molar concentration), which is the SI (International System of Units) standard. Both measure the same thing — the amount of glucose in your blood — just expressed differently.