Key Takeaways
- mg/dL is used in the US, while mmol/L is the international standard
- Conversion formula: mmol/L = mg/dL / 18.018
- Normal fasting blood sugar: 70-100 mg/dL (3.9-5.6 mmol/L)
- The conversion factor 18.018 is based on the molecular weight of glucose
- Always verify readings with your healthcare provider
About the Blood Sugar Unit Converter
The Blood Sugar Unit Converter is a comprehensive online tool designed to help you convert blood glucose readings between mg/dL and mmol/L. Whether you're traveling internationally, using a foreign glucose meter, or comparing readings from different sources, this free calculator provides accurate results instantly.
Understanding Blood Sugar Units
Blood glucose (blood sugar) can be measured in two different units:
- mg/dL (milligrams per deciliter) - Primarily used in the United States, Japan, Israel, and India
- mmol/L (millimoles per liter) - Used in most other countries including the UK, Canada, Australia, and Europe
The Conversion Formula
mmol/L = mg/dL / 18.018
or conversely: mg/dL = mmol/L x 18.018
The conversion factor of 18.018 (often rounded to 18) is derived from the molecular weight of glucose (180.18 g/mol). This factor allows accurate conversion between the two measurement systems.
Blood Sugar Reference Ranges
| Category | mg/dL | mmol/L |
|---|---|---|
| Normal (Fasting) | 70-100 | 3.9-5.6 |
| Prediabetes (Fasting) | 100-125 | 5.6-6.9 |
| Diabetes (Fasting) | 126+ | 7.0+ |
| Normal (2hrs after meal) | Less than 140 | Less than 7.8 |
| Prediabetes (2hrs after meal) | 140-199 | 7.8-11.0 |
| Diabetes (2hrs after meal) | 200+ | 11.1+ |
Medical Disclaimer
This calculator is for informational purposes only and should not be used for medical diagnosis. Blood sugar levels can be affected by many factors including time of day, meals, medications, and stress. Always consult with your healthcare provider for proper diagnosis and treatment recommendations.
How to Use This Calculator
- Enter your blood sugar reading in the input field
- Select the unit you're converting from (mg/dL or mmol/L)
- Click the "Convert" button to see your result
- Use the "Reset" button to clear all fields and start over
Why Do Different Countries Use Different Units?
The difference in measurement units is largely historical. The United States adopted mg/dL (milligrams per deciliter) as part of its medical conventions, while most other countries adopted the SI (International System of Units) standard of mmol/L (millimoles per liter). Neither system is inherently better; they simply represent different ways of expressing the same concentration.
Practical Applications
- International Travel: If you're diabetic and traveling abroad, you may encounter glucose meters that display readings in unfamiliar units
- Medical Records: Converting readings when comparing results from different countries or healthcare systems
- Research: Understanding studies and clinical trials that may use different measurement standards
- Healthcare Communication: Discussing blood sugar levels with international healthcare providers
Frequently Asked Questions
Yes, this calculator is completely free to use with no hidden charges or registration requirements.
The calculator uses the precise conversion factor of 18.018, which is based on the molecular weight of glucose. Results are rounded to one decimal place for practical use and match the precision used in clinical settings.
The conversion factor of 18.018 is derived from the molecular weight of glucose (C6H12O6), which is 180.18 g/mol. When converting from mg/dL to mmol/L, we divide by this factor because mmol/L measures the number of molecules rather than weight.
Absolutely! This calculator is fully responsive and works perfectly on smartphones, tablets, and desktop computers.
Normal fasting blood sugar is typically between 70-100 mg/dL (3.9-5.6 mmol/L). After meals, blood sugar may temporarily rise but should return to normal within 2-3 hours. Consult your healthcare provider for personalized guidance.
Yes! Click the "Copy Widget Code" button above to get the embed code for your website. This allows you to share the calculator with your audience.
Additional Resources
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