The Ultimate Blood Sugar Levels Chart: Understanding Your Results (mg/dL & mmol/L)

16 Sep 2025 By Karen Grothe, Ph.D., L.P.

The Ultimate Blood Sugar Levels Chart: Understanding Your Results (mg/dL & mmol/L)

Understanding your blood sugar levels is crucial for maintaining good health, especially if you're managing diabetes or are at risk. This article serves as your comprehensive guide, breaking down what blood sugar levels mean, how to interpret them in both milligrams per deciliter (mg/dL) and millimoles per liter (mmol/L), and when to seek medical advice. We’ll explore normal ranges, what high and low blood sugar levels indicate, and the importance of regular monitoring.

Why Monitoring Blood Sugar Levels is Important

Monitoring your blood sugar isn't just for those with diabetes. It's a vital component of overall health management. Here's why:

Early Detection of Diabetes: Regular monitoring can help identify prediabetes or type 2 diabetes early, allowing for timely intervention.
Management of Existing Diabetes: For individuals with diabetes, tracking blood sugar levels ensures that medication, diet, and exercise are effectively managing the condition.
Preventing Complications: Consistent monitoring and maintenance of healthy blood sugar levels can significantly reduce the risk of long-term complications associated with diabetes, such as heart disease, kidney damage, and nerve damage.
Personalized Health Management: Understanding how your body responds to different foods and activities allows you to tailor your lifestyle for optimal health.
Pregnancy Health: For pregnant women, maintaining healthy blood sugar levels is vital for the health of both the mother and the baby. Gestational diabetes, if left unmanaged, can lead to complications during pregnancy and delivery.

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

Blood sugar levels are typically measured in one of two units:

Milligrams per deciliter (mg/dL): This is the standard unit used in the United States and many other countries.
Millimoles per liter (mmol/L): This unit is primarily used in Canada, Europe, and other parts of the world.

It's essential to understand both units, especially if you travel or use different medical resources. To convert from mg/dL to mmol/L, divide the mg/dL value by 18. For example, 100 mg/dL is equivalent to 5.5 mmol/L. To convert from mmol/L to mg/dL, multiply the mmol/L value by 18. The Dangers Of High Blood Sugar And How To Protect Yourself

Blood Sugar Levels Chart: Normal Ranges

Here’s a detailed blood sugar levels chart outlining the normal, prediabetic, and diabetic ranges, both in mg/dL and mmol/L. These ranges are generally based on guidelines from the American Diabetes Association (ADA) but can vary slightly depending on individual circumstances and medical advice. The Shocking Link Between Stress And Your Blood Sugar Level

Category	Fasting Blood Sugar (mg/dL)	Fasting Blood Sugar (mmol/L)	2-Hour Postprandial (After Meal) (mg/dL)	2-Hour Postprandial (After Meal) (mmol/L)	HbA1c
Normal	Less than 100 mg/dL	Less than 5.6 mmol/L	Less than 140 mg/dL	Less than 7.8 mmol/L	Less than 5.7%
Prediabetes	100 to 125 mg/dL	5.6 to 6.9 mmol/L	140 to 199 mg/dL	7.8 to 11.0 mmol/L	5.7% to 6.4%
Diabetes	126 mg/dL or higher	7.0 mmol/L or higher	200 mg/dL or higher	11.1 mmol/L or higher	6.5% or higher

Note: It's always recommended to consult with a healthcare professional for a personalized diagnosis and management plan.

Understanding Fasting Blood Sugar

Fasting blood sugar is measured after at least eight hours of not eating. It's a crucial indicator of how well your body regulates blood sugar overnight. A normal fasting blood sugar level should be below 100 mg/dL (5.6 mmol/L).

Understanding Postprandial Blood Sugar

Postprandial blood sugar, also known as after-meal blood sugar, is measured two hours after starting a meal. This measurement assesses how your body processes glucose from food. A normal postprandial blood sugar level should be below 140 mg/dL (7.8 mmol/L). How To Read Your A1C Blood Sugar Results Like An Expert

What is HbA1c?

The HbA1c test provides an average of your blood sugar levels over the past 2-3 months. It measures the percentage of blood sugar attached to hemoglobin, the oxygen-carrying protein in red blood cells. It's a valuable tool for assessing long-term blood sugar control.

What Do High Blood Sugar Levels (Hyperglycemia) Mean?

Hyperglycemia, or high blood sugar, occurs when there's too much glucose in the blood. It can be caused by various factors, including:

Diet: Consuming a diet high in carbohydrates and sugars.
Lack of Exercise: Physical inactivity can lead to insulin resistance.
Stress: Stress hormones can elevate blood sugar levels.
Illness: Infections can cause a temporary rise in blood sugar.
Medications: Certain medications, such as steroids, can increase blood sugar.
Insufficient Insulin: In people with diabetes, insufficient insulin dosage can cause hyperglycemia.

Symptoms of hyperglycemia include frequent urination, increased thirst, blurred vision, fatigue, and slow-healing sores. If left untreated, it can lead to serious complications like diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS), both of which require immediate medical attention.

What Do Low Blood Sugar Levels (Hypoglycemia) Mean?

Hypoglycemia, or low blood sugar, occurs when the glucose level in the blood drops too low. It's more common in people with diabetes who are taking insulin or certain oral medications. Causes of hypoglycemia include:

Excessive Insulin: Taking too much insulin can cause a rapid drop in blood sugar.
Skipping Meals: Not eating enough can deplete blood sugar stores.
Intense Exercise: Strenuous physical activity can lower blood sugar.
Alcohol Consumption: Alcohol can interfere with the liver's ability to release glucose.

Symptoms of hypoglycemia include shakiness, sweating, dizziness, hunger, confusion, irritability, and in severe cases, loss of consciousness. It's essential to treat hypoglycemia promptly by consuming a fast-acting carbohydrate source, such as juice, glucose tablets, or hard candy. If untreated, severe hypoglycemia can lead to seizures or coma.

Factors Affecting Blood Sugar Levels

Many factors can influence blood sugar levels, including:

Food Intake: The type and quantity of food consumed directly impact blood sugar.
Physical Activity: Exercise increases insulin sensitivity and can lower blood sugar.
Stress: Hormones released during stress can raise blood sugar.
Sleep: Poor sleep can affect insulin sensitivity and blood sugar control.
Hydration: Dehydration can concentrate blood sugar, leading to higher readings.
Medications: Various medications can either raise or lower blood sugar.
Menstrual Cycle: Hormonal changes during the menstrual cycle can affect blood sugar in women.
Time of Day: Blood sugar levels often vary throughout the day due to hormonal fluctuations and meal timings.

Tips for Maintaining Healthy Blood Sugar Levels

Maintaining healthy blood sugar levels is a proactive approach to overall well-being. Here are some tips to help:

Balanced Diet: Focus on a diet rich in whole grains, lean proteins, healthy fats, and plenty of fruits and vegetables. Limit processed foods, sugary drinks, and excessive carbohydrates.
Regular Exercise: Aim for at least 150 minutes of moderate-intensity exercise per week. This can include brisk walking, jogging, cycling, or swimming.
Consistent Meal Times: Eating meals at consistent times each day can help regulate blood sugar levels.
Portion Control: Be mindful of portion sizes to avoid overeating.
Stay Hydrated: Drink plenty of water throughout the day to maintain proper hydration.
Manage Stress: Practice stress-reducing techniques such as meditation, yoga, or deep breathing exercises.
Monitor Blood Sugar Regularly: If you have diabetes or are at risk, regularly check your blood sugar as directed by your healthcare provider.
Get Enough Sleep: Aim for 7-8 hours of quality sleep each night to support healthy blood sugar regulation.
Limit Alcohol: If you choose to drink alcohol, do so in moderation and with food to prevent hypoglycemia.

When to Seek Medical Advice

It’s crucial to consult with a healthcare professional in the following situations:

Consistently High Blood Sugar Levels: If you consistently have blood sugar levels above the normal range.
Frequent Episodes of Hypoglycemia: If you experience frequent episodes of low blood sugar, especially if they are severe or unexplained.
Symptoms of Diabetes: If you experience symptoms of diabetes, such as increased thirst, frequent urination, unexplained weight loss, or blurred vision.
Changes in Medication: Before making any changes to your diabetes medication regimen.
Pregnancy: If you are pregnant and have diabetes or develop gestational diabetes.

Regular check-ups and open communication with your healthcare provider are essential for effective diabetes management and overall health.

Conclusion

Understanding your blood sugar levels and knowing how to interpret them in both mg/dL and mmol/L is a fundamental aspect of health management. By using the blood sugar levels chart provided, you can better understand your results and take proactive steps to maintain healthy blood sugar levels. Remember, this guide is for informational purposes only and does not substitute professional medical advice. Always consult with your healthcare provider for personalized recommendations and treatment plans. Through consistent monitoring, a balanced lifestyle, and appropriate medical care, you can effectively manage your blood sugar and live a healthy life.