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Blood Sugar Converter: mg/dL ↔ mmol/L

Instantly convert blood glucose values between mg/dL and mmol/L. Free, accurate (factor 18.0182), and mobile-friendly. Includes a conversion chart and normal range reference.

Educational tool
Instant conversion
Factor 18.0182
Mobile friendly
Disclaimer

Used in the United States

Used in UK, Canada, Australia, and most countries

mmol/L = mg/dL ÷ 18.0182
Converted value —
Range indicator Enter a value above
Conversion factor 18.0182 (molecular weight of glucose ÷ 10)
Medical disclaimer: This tool is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment. The range indicator is based on general ADA guidelines for fasting glucose and may not apply to your individual situation. Always consult a qualified healthcare professional.

How to Use This Blood Sugar Converter

Converting blood glucose values between mg/dL and mmol/L is straightforward with this tool. Simply type your glucose reading into either input field, and the converter will instantly calculate the equivalent value in the other unit. The conversion happens in real time — no need to press a button.

  1. Enter your glucose value in either the mg/dL field (if you have a US lab report) or the mmol/L field (if you have an international report).
  2. View the instant result displayed below the input fields, along with a fasting range indicator based on ADA guidelines.
  3. Compare with the reference tables below to understand where your reading falls within normal, prediabetic, or diabetic ranges.

Tip: You can use a comma or period as the decimal separator. The converter accepts both formats (e.g., "5,6" or "5.6").

Understanding Blood Sugar Units: mg/dL vs. mmol/L

Blood glucose can be measured using two different units, and the one you encounter depends largely on where you live or where your lab test was performed. Both units measure the concentration of glucose in your blood, but they express it differently.

What is mg/dL?

mg/dL stands for milligrams per deciliter. It measures the weight of glucose (in milligrams) present in a fixed volume of blood (one deciliter, or 100 milliliters). This unit is the standard in the United States, Germany, France, Japan, and several other countries.

What is mmol/L?

mmol/L stands for millimoles per liter. It measures the number of glucose molecules (expressed in millimoles) in one liter of blood. This is the international standard used in the United Kingdom, Canada, Australia, and most of the world.

The Conversion Formula

The relationship between these two units is determined by the molecular weight of glucose, which is 180.156 g/mol. Dividing by 10 (to adjust for the deciliter-to-liter ratio) gives us the conversion factor of 18.0182.

Formulas:

mmol/L = mg/dL ÷ 18.0182

mg/dL = mmol/L × 18.0182

Some sources use 18 as a rounded approximation. This tool uses the precise factor 18.0182 for greater accuracy.

Blood Sugar Conversion Chart (mg/dL to mmol/L)

The table below provides a quick reference for converting common blood glucose values between mg/dL and mmol/L. This chart is especially useful when reading lab reports from different countries or comparing glucose readings across different measurement systems.

Common Blood Glucose Conversions — mg/dL to mmol/L
mg/dL mmol/L Clinical Significance
502.8Hypoglycemia (low)
603.3Low — monitor closely
703.9Lower end of normal
804.4Normal fasting range
905.0Normal fasting range
1005.6Upper normal / prediabetes threshold
1106.1Prediabetes range
1206.7Prediabetes range
1267.0Diabetes threshold (fasting)
1407.8Prediabetes (2h post-meal)
1508.3Elevated
18010.0ADA post-meal target limit
20011.1Diabetes (random / 2h OGTT)
25013.9High — consult physician
30016.7Very high — seek medical care
40022.2Dangerously high — emergency

Note: Clinical significance is based on general ADA fasting glucose guidelines. Individual targets may vary. Always consult your healthcare provider for personalized advice.

Normal Blood Sugar Levels: What Do the Numbers Mean?

Understanding where your blood glucose reading falls can help you have more informed conversations with your healthcare provider. The American Diabetes Association (ADA) and the World Health Organization (WHO) provide the following general guidelines for blood sugar levels in adults.

Blood Sugar Reference Ranges (ADA Guidelines)
Test Type Normal Prediabetes Diabetes
Fasting glucose < 100 mg/dL
(< 5.6 mmol/L)		 100–125 mg/dL
(5.6–6.9 mmol/L)		 ≥ 126 mg/dL
(≥ 7.0 mmol/L)
2h after 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 glucose Varies ≥ 200 mg/dL
(≥ 11.1 mmol/L) with symptoms
A1C < 5.7% 5.7–6.4% ≥ 6.5%

Important: These ranges are general guidelines for non-pregnant adults. Targets may differ for children, pregnant women, elderly individuals, and people with specific medical conditions. A diagnosis of diabetes requires confirmation through repeated testing. This information is educational and does not constitute medical advice.

A1C to Estimated Average Glucose (eAG) Conversion

The A1C test (also called HbA1c or glycated hemoglobin) measures your average blood sugar over the past 2 to 3 months. It is one of the most important tests for managing diabetes and assessing long-term glucose control. The table below shows the relationship between A1C percentages and estimated average glucose (eAG) values.

A1C to Estimated Average Glucose (eAG) Conversion Table
A1C (%) eAG (mg/dL) eAG (mmol/L) Category
5.0975.4Normal
5.51116.2Normal
5.71176.5Prediabetes threshold
6.01267.0Prediabetes
6.51407.8Diabetes threshold
7.01548.6Diabetes
7.51699.4Diabetes
8.018310.2Diabetes
9.021211.8Diabetes (poorly controlled)
10.024013.4Diabetes (poorly controlled)

Formula: eAG (mg/dL) = (28.7 × A1C) − 46.7. Source: ADA / Nathan et al., Diabetes Care, 2008.

Frequently Asked Questions About Blood Sugar Conversion

To convert blood sugar from mg/dL to mmol/L, divide the mg/dL value by 18.0182. For example, if your fasting blood glucose is 100 mg/dL, the conversion would be: 100 ÷ 18.0182 = 5.55 mmol/L. This is the standard conversion used by laboratories and medical professionals worldwide.
To convert blood sugar from mmol/L to mg/dL, multiply the mmol/L value by 18.0182. For example, 7.0 mmol/L × 18.0182 = 126.13 mg/dL. This is the reverse of the mg/dL to mmol/L conversion.
According to the American Diabetes Association (ADA), a normal fasting blood sugar level is below 100 mg/dL (5.6 mmol/L). Levels between 100–125 mg/dL (5.6–6.9 mmol/L) indicate prediabetes, and a fasting level of 126 mg/dL (7.0 mmol/L) or higher on two separate tests indicates diabetes. The CDC also uses these same thresholds for classification.
The difference is historical and relates to the adoption of the International System of Units (SI). The United States, along with a few other countries, continues to use mg/dL (a mass concentration unit), while most of the world has adopted mmol/L (a molar concentration unit) as recommended by the SI system. Both are scientifically valid and measure the same thing — the concentration of glucose in blood — just expressed differently.
The conversion factor is derived from the molecular weight of glucose (C₆H₁₂O₆), which is 180.156 g/mol. Dividing by 10 (to convert from grams per liter to milligrams per deciliter) gives 18.0156, often rounded to 18.0182 in clinical practice. Many sources use 18 as a quick approximation, which is sufficient for most purposes. This tool uses the more precise factor for accuracy.
A1C (glycated hemoglobin or HbA1c) is a blood test that reflects your average blood sugar levels over the past 2 to 3 months. Unlike a single glucose reading, A1C provides a longer-term picture of blood sugar control. An A1C below 5.7% is considered normal, 5.7–6.4% indicates prediabetes, and 6.5% or higher indicates diabetes. The formula to estimate average glucose from A1C is: eAG (mg/dL) = (28.7 × A1C) − 46.7.
No. This is an educational unit conversion tool only. It does not provide medical advice, diagnosis, or treatment recommendations. The range indicators shown are based on general ADA guidelines and may not apply to your individual situation. Always consult a qualified healthcare professional for medical decisions about your blood sugar levels.
Blood sugar levels above 250 mg/dL (13.9 mmol/L) are considered very high and require medical attention. Levels above 300 mg/dL (16.7 mmol/L) can be dangerous and may lead to diabetic ketoacidosis (DKA) in people with type 1 diabetes. Levels above 400 mg/dL (22.2 mmol/L) are a medical emergency. If you experience extremely high blood sugar along with symptoms like excessive thirst, frequent urination, nausea, or confusion, seek emergency medical care immediately.

Sources & References

  1. American Diabetes Association. "Standards of Care in Diabetes — 2025." Diabetes Care, vol. 48, Supplement 1, 2025. diabetesjournals.org/care
  2. Centers for Disease Control and Prevention (CDC). "Diabetes Testing." cdc.gov/diabetes/diabetes-testing
  3. World Health Organization (WHO). "Diabetes Fact Sheet." who.int
  4. Nathan DM, et al. "Translating the A1C Assay Into Estimated Average Glucose Values." Diabetes Care, 2008;31(8):1473-1478. PubMed
  5. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). "The A1C Test & Diabetes." niddk.nih.gov

Editorial Policy & Legal Information

All content on Calcule Sua Saúde is written and reviewed by our editorial team with a commitment to accuracy, clarity, and evidence-based information. We reference peer-reviewed studies, official health organizations (ADA, CDC, WHO), and established medical literature. This content is regularly reviewed and updated to reflect the latest guidelines.

Last reviewed:  |  Medically reviewed content — For educational purposes only.