Blood Sugar Converter

Q: What is the difference between mg/dL and mmol/L?

mg/dL (milligrams per deciliter) is the blood sugar measurement unit used in the United States, while mmol/L (millimoles per liter) is used in the UK, Canada, Australia, and most other countries. To convert mg/dL to mmol/L, divide by 18. To convert mmol/L to mg/dL, multiply by 18. The exact conversion factor is 18.0182 based on glucose's molecular weight (180.16 g/mol).

Q: What is a normal blood sugar level?

Normal fasting blood sugar is 70-99 mg/dL (3.9-5.5 mmol/L). Prediabetes range is 100-125 mg/dL (5.6-6.9 mmol/L). Diabetes is diagnosed at 126 mg/dL (7.0 mmol/L) or higher. After meals, blood sugar typically stays below 140 mg/dL (7.8 mmol/L) in non-diabetic individuals. These ranges are general guidelines - consult your healthcare provider for personalized advice.

Q: How do I convert 100 mg/dL to mmol/L?

To convert 100 mg/dL to mmol/L, divide by 18.0182. The result is approximately 5.55 mmol/L. This is at the upper end of the normal fasting blood sugar range. The formula is: mmol/L = mg/dL ÷ 18.0182.

Q: What blood sugar level is considered diabetic?

Diabetes is typically diagnosed when fasting blood sugar is 126 mg/dL (7.0 mmol/L) or higher on two separate tests. Random blood sugar of 200 mg/dL (11.1 mmol/L) or higher with symptoms also indicates diabetes. An HbA1c of 6.5% or higher is another diagnostic criterion. Always consult with a healthcare professional for proper diagnosis.

Q: Why do different countries use different blood sugar units?

The US traditionally uses mg/dL (mass concentration), while most other countries adopted the SI unit mmol/L (molar concentration) for standardization. Both measure the same thing - glucose concentration in blood - just with different scales. Medical devices in different countries are calibrated to local standards, which is why conversion is often necessary when traveling or reading international medical literature.

Q: What is hypoglycemia and what are its symptoms?

Hypoglycemia (low blood sugar) occurs when blood glucose falls below 70 mg/dL (3.9 mmol/L). Severe hypoglycemia is below 54 mg/dL (3.0 mmol/L). Symptoms include shakiness, sweating, confusion, rapid heartbeat, hunger, irritability, and in severe cases, loss of consciousness. If you experience these symptoms, consume fast-acting carbohydrates like glucose tablets or fruit juice immediately.

Convert blood sugar levels between mg/dL (US) and mmol/L (UK/International) with instant results, diabetes risk assessment, visual range indicators, and comprehensive glucose reference charts.

Free to useNo sign-up requiredUpdated Jan 2026

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About Blood Sugar Converter

Welcome to the Blood Sugar Converter, your comprehensive tool for converting blood glucose levels between mg/dL (milligrams per deciliter) and mmol/L (millimoles per liter). Whether you are managing diabetes, interpreting lab results, or traveling between countries with different measurement standards, this converter provides instant, accurate conversions with helpful health context.

Understanding Blood Sugar Units

Blood sugar (glucose) levels can be measured in two different units depending on your location:

mg/dL (milligrams per deciliter) - Used primarily in the United States, Japan, France, Egypt, and some other countries. This unit measures the mass of glucose per volume of blood.
mmol/L (millimoles per liter) - Used in the United Kingdom, Canada, Australia, and most other countries worldwide. This SI unit measures the molar concentration of glucose in blood.

The Conversion Formula

Blood Sugar Conversion

mmol/L = mg/dL ÷ 18.0182

mg/dL = mmol/L × 18.0182

The conversion factor 18.0182 is derived from the molecular weight of glucose (180.16 g/mol) divided by 10. For quick mental math, many people simply use 18 as an approximation.

Blood Sugar Ranges and Health Categories

Understanding where your blood sugar falls on the health spectrum is crucial for managing your health. Here are the standard fasting blood glucose ranges:

Category	mg/dL Range	mmol/L Range	Health Indication
Severe Hypoglycemia	< 54	< 3.0	Medical emergency - seek help immediately
Hypoglycemia	54 - 69	3.0 - 3.8	Low blood sugar - consume fast-acting carbs
Normal	70 - 99	3.9 - 5.5	Healthy fasting blood sugar range
Prediabetes	100 - 125	5.6 - 6.9	Elevated - lifestyle changes recommended
Diabetes	126 - 179	7.0 - 9.9	Diagnostic threshold for diabetes
High	180 - 249	10.0 - 13.8	High - requires monitoring and management
Very High	≥ 250	≥ 13.9	Very high - seek medical attention

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Important: These ranges are general guidelines for fasting blood glucose. Post-meal readings are typically higher. Always consult your healthcare provider for personalized targets and medical advice.

How to Use This Converter

Enter your value: Type your blood sugar reading into the input field. The converter accepts various number formats including decimals.
Select direction: Choose whether to convert from mg/dL to mmol/L or vice versa.
Set precision: Select how many decimal places you want in your result.
View results: Click Convert to see your converted value along with a visual indicator showing where your level falls on the glucose health spectrum.

Quick Reference Conversions

mg/dL	mmol/L	Category
70	3.9	Normal (lower)
80	4.4	Normal
90	5.0	Normal
100	5.6	Prediabetes threshold
110	6.1	Prediabetes
120	6.7	Prediabetes
126	7.0	Diabetes threshold
140	7.8	Diabetes
180	10.0	High
200	11.1	High

Why Different Countries Use Different Units

The difference in blood sugar measurement units is largely historical. The United States adopted the mass concentration method (mg/dL) early in medical practice. When the International System of Units (SI) was developed, most countries transitioned to molar concentration (mmol/L) for standardization. However, some countries, particularly the US, continued using mg/dL due to established medical infrastructure and familiarity.

Tips for Managing Blood Sugar

Test regularly: Follow your healthcare provider's recommendations for testing frequency.
Keep a log: Record your readings to identify patterns and trends.
Know your targets: Work with your doctor to establish personalized blood sugar goals.
Understand timing: Fasting levels are typically taken in the morning before eating. Post-meal levels are measured 1-2 hours after eating.
Watch for symptoms: Learn to recognize signs of high and low blood sugar.

Frequently Asked Questions

What is the difference between mg/dL and mmol/L?

mg/dL (milligrams per deciliter) is the blood sugar measurement unit used in the United States, while mmol/L (millimoles per liter) is used in the UK, Canada, Australia, and most other countries. To convert mg/dL to mmol/L, divide by 18. To convert mmol/L to mg/dL, multiply by 18. The exact conversion factor is 18.0182 based on glucose's molecular weight (180.16 g/mol).

What is a normal blood sugar level?

Normal fasting blood sugar is 70-99 mg/dL (3.9-5.5 mmol/L). Prediabetes range is 100-125 mg/dL (5.6-6.9 mmol/L). Diabetes is diagnosed at 126 mg/dL (7.0 mmol/L) or higher. After meals, blood sugar typically stays below 140 mg/dL (7.8 mmol/L) in non-diabetic individuals.

How do I convert 100 mg/dL to mmol/L?

To convert 100 mg/dL to mmol/L, divide by 18.0182. The result is approximately 5.55 mmol/L. This is at the upper end of the normal fasting blood sugar range.

What blood sugar level is considered diabetic?

Diabetes is typically diagnosed when fasting blood sugar is 126 mg/dL (7.0 mmol/L) or higher on two separate tests. Random blood sugar of 200 mg/dL (11.1 mmol/L) or higher with symptoms also indicates diabetes. An HbA1c of 6.5% or higher is another diagnostic criterion.

Why do different countries use different blood sugar units?

The US traditionally uses mg/dL (mass concentration), while most other countries adopted the SI unit mmol/L (molar concentration) for standardization. Both measure the same thing - glucose concentration in blood - just with different scales.

What is hypoglycemia and what are its symptoms?

Hypoglycemia (low blood sugar) occurs when blood glucose falls below 70 mg/dL (3.9 mmol/L). Severe hypoglycemia is below 54 mg/dL (3.0 mmol/L). Symptoms include shakiness, sweating, confusion, rapid heartbeat, hunger, irritability, and in severe cases, loss of consciousness.

Additional Resources

Reference this content, page, or tool as:

"Blood Sugar Converter" at https://MiniWebtool.com/blood-sugar-converter/ from MiniWebtool, https://MiniWebtool.com/

by miniwebtool team. Updated: Jan 29, 2026

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