Blood Sugar Levels Chart: Understanding mg/dL and mmol/L

23 Aug 2025

Blood Sugar Levels Chart: Understanding mg/dL and mmol/L Understanding your blood sugar levels is crucial for managing diabetes or prediabetes and mai...

Blood Sugar Levels Chart: Understanding mg/dL and mmol/L

Understanding your blood sugar levels is crucial for managing diabetes or prediabetes and maintaining overall health. This article provides a comprehensive blood sugar levels chart, explaining the differences between mg/dL (milligrams per deciliter) and mmol/L (millimoles per liter), and what your numbers mean. We will explore target ranges for different groups, the implications of high and low blood sugar, and strategies for keeping your blood glucose levels stable.

Why is Monitoring Blood Sugar Important?

Blood sugar, or glucose, is the main sugar found in your blood, and it comes from the food you eat. Your body uses glucose for energy. Maintaining healthy blood glucose levels is essential for preventing both short-term and long-term complications. Consistently high blood sugar, a condition known as hyperglycemia, can damage organs, nerves, and blood vessels. Conversely, low blood sugar, or hypoglycemia, can lead to dizziness, confusion, and even loss of consciousness. Regular monitoring allows you to make informed decisions about diet, exercise, and medication (if prescribed) to keep your blood sugar within a healthy range.

Understanding the Units: mg/dL vs. mmol/L

Blood sugar levels are typically measured in two units:

Related reading: Postprandial Blood Sugar How To Prevent Spikes 2 Hours After Eating

  • Related reading: Struggling To Control Blood Sugar A Dietitian S Daily Plan To Help

    mg/dL (milligrams per deciliter): This is the standard unit used in the United States and some other countries. It represents the weight of glucose in a specific volume of blood.

  • mmol/L (millimoles per liter): This unit is used more commonly in Canada, Europe, and other parts of the world. It represents the number of glucose molecules in a specific volume of blood.

Related reading: What Does Your A1C Level Really Mean Plus A1C To Blood Sugar Conversion

To convert between the two units, you can use the following formulas:

  • mg/dL to mmol/L: Divide mg/dL by 18
  • mmol/L to mg/dL: Multiply mmol/L by 18

For instance, a blood sugar level of 100 mg/dL is equivalent to approximately 5.6 mmol/L.

Blood Sugar Levels Chart: Target Ranges

The following chart provides general guidelines for target blood sugar levels at different times of the day. It's essential to discuss your individual target range with your healthcare provider, as it may vary depending on your age, health condition, and medication regimen.

Category Fasting Blood Sugar (mg/dL) Fasting Blood Sugar (mmol/L) 2 Hours After Eating (mg/dL) 2 Hours After Eating (mmol/L) A1C
Normal (Non-Diabetic) Less than 100 Less than 5.6 Less than 140 Less than 7.8 Less than 5.7%
Prediabetes 100-125 5.6-6.9 140-199 7.8-11.0 5.7%-6.4%
Diabetes 126 or higher 7.0 or higher 200 or higher 11.1 or higher 6.5% or higher

Note: A1C is a blood test that reflects your average blood sugar levels over the past 2-3 months.

Understanding High Blood Sugar (Hyperglycemia)

Hyperglycemia occurs when your blood sugar is too high. This can happen if you:

  • Eat too many carbohydrates
  • Don't get enough exercise
  • Don't take enough insulin or oral diabetes medication (if prescribed)
  • Are stressed or ill

Symptoms of hyperglycemia can include:

  • Increased thirst
  • Frequent urination
  • Blurred vision
  • Fatigue
  • Headaches

Long-term complications of uncontrolled hyperglycemia include:

  • Heart disease
  • Kidney disease
  • Nerve damage (neuropathy)
  • Eye damage (retinopathy)
  • Foot problems

It's critical to manage blood sugar effectively through diet, exercise, and medication (if needed) to prevent these complications. Regularly monitor your blood glucose levels and work closely with your healthcare team to adjust your treatment plan as needed.

Understanding Low Blood Sugar (Hypoglycemia)

Hypoglycemia occurs when your blood sugar is too low. This can happen if you:

  • Take too much insulin or oral diabetes medication
  • Skip meals or don't eat enough carbohydrates
  • Exercise strenuously without adjusting your medication or food intake
  • Drink alcohol, especially on an empty stomach

Symptoms of hypoglycemia can include:

  • Shakiness
  • Sweating
  • Dizziness
  • Confusion
  • Rapid heartbeat
  • Hunger
  • Irritability
  • In severe cases, loss of consciousness or seizures

If you experience symptoms of hypoglycemia, it's crucial to act quickly. The "15-15 rule" is a common guideline: consume 15 grams of fast-acting carbohydrates (such as glucose tablets, fruit juice, or regular soda), wait 15 minutes, and then check your blood sugar again. If your blood sugar is still low, repeat the process.

Strategies for Maintaining Healthy Blood Sugar Levels

  • Follow a Balanced Diet: Focus on whole foods, including fruits, vegetables, whole grains, and lean protein. Limit processed foods, sugary drinks, and saturated and trans fats. Pay attention to carbohydrate intake and portion sizes.

  • Engage in Regular Physical Activity: Aim for at least 30 minutes of moderate-intensity exercise most days of the week. Exercise helps improve insulin sensitivity and lower blood sugar.

  • Monitor Your Blood Sugar Regularly: If you have diabetes, check your blood sugar as directed by your healthcare provider. Keep a log of your readings and discuss them with your doctor.

  • Take Medications as Prescribed: If you have diabetes, follow your doctor's instructions carefully regarding medication dosage and timing.

  • Manage Stress: Stress can affect blood sugar levels. Practice stress-reduction techniques such as yoga, meditation, or deep breathing.

  • Get Enough Sleep: Lack of sleep can also impact blood sugar. Aim for 7-8 hours of quality sleep each night.

  • Stay Hydrated: Drink plenty of water throughout the day. Dehydration can affect blood sugar.

  • Work with a Healthcare Professional: Partner with your doctor, diabetes educator, and registered dietitian to develop a personalized diabetes management plan.

Tools and Resources for Blood Sugar Management

Numerous tools and resources are available to help you manage your blood sugar effectively:

  • Blood Glucose Meters: These devices allow you to check your blood sugar at home.
  • Continuous Glucose Monitors (CGMs): CGMs provide real-time blood glucose readings and alert you to highs and lows.
  • Diabetes Apps: Many apps help you track your blood sugar, food intake, and exercise, and can provide personalized insights.
  • Diabetes Education Programs: These programs offer education and support for people with diabetes.
  • Registered Dietitians: A registered dietitian can help you create a diabetes-friendly meal plan.
  • Online Resources: The American Diabetes Association (ADA) and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) websites provide reliable information about diabetes.

The Importance of Individualized Care

Remember, blood sugar targets can vary depending on individual factors such as age, overall health, and the presence of other medical conditions. Therefore, it's essential to work closely with your healthcare team to establish a personalized blood sugar management plan that meets your specific needs. Regular monitoring and adjustments to your diet, exercise, and medication (if needed) are crucial for achieving and maintaining optimal blood sugar control.