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Blood sugar charts by age, risk, and test type

Many factors affect blood sugar levels. Use our blood sugar charts to find out whether your result is within normal range.
Karen Berger medical writer and reviewer headshot
By | Updated on Jun. 30, 2023
Blood sugar testing device: Blood sugar charts

Key takeaways

  • Blood sugar levels fluctuate throughout the day and are influenced by factors such as diet, stress, medication, and exercise. Blood glucose management is a continuous process that involves monitoring trends rather than focusing on singular numbers.

  • People with diabetes must monitor their blood sugar levels regularly, follow a treatment plan that may include dietary changes, exercise, medication, and insulin, and understand their target blood sugar ranges. These measures help prevent complications like heart disease and kidney problems.

  • Blood sugar charts provide general numbers for different groups (by age, during pregnancy, fasting levels, and A1C levels) to help individuals determine if their blood sugar levels are within their target range. Specific ranges vary based on individual health conditions and recommendations from healthcare professionals.

  • Continuous glucose monitoring (CGM) systems offer real-time insights into blood sugar fluctuations. They aid in better diabetes management by allowing for frequent updates on glucose levels and helping individuals maintain their blood sugar within their target range.

In this article:

Blood sugar, also known as blood glucose, is the main sugar in your blood. Blood sugar comes from foods you eat, and the blood carries glucose to your body’s cells for energy. 

People with diabetes have high blood glucose levels. High blood sugar levels can cause complications like heart disease, stroke, and heart attack over time. It can also cause kidney, eye, and nerve problems. 

If you have diabetes, your healthcare provider will give you more information about keeping your blood sugar numbers in a target range. They will also tell you how often and when to check your blood sugar and what to do if your blood sugar is high or low. You may need to make dietary changes and increase your exercise. You may also need to take medication or insulin.

Blood sugar charts

Blood sugar levels naturally fluctuate throughout the day. Blood sugar levels can be affected by many factors, including food intake, stress, medication, exercise, and more. 

“Glucose management will always be a journey, never a destination,” says Stephen Ponder, MD, CDCES, a pediatric endocrinologist at McLane Children’s Hospital in Temple, TX. He is the author of the popular book Sugar Surfing and the 2018 ADCES Diabetes Educator of the Year. Dr. Ponder recommends that patients consider blood sugar levels as continuous trending patterns rather than singular numbers. He explains that blood sugar is a dynamic variable that shifts over time and that blood sugar management is best based on situational factors when a blood sugar trend pattern is recognized. 

Monitoring your blood sugar (with a CGM if possible) can give you great insight into how your blood sugar fluctuates throughout the day and in response to foods, exercise, and other factors. 

The charts below provide general numbers and ranges of numbers. Your healthcare professional will give you a target range, which may be slightly different than the numbers in the charts below. Dr. Ponder notes that diagnostic standards and ranges are based on venipuncture blood samples, not a blood glucose meter or sensors. 

Normal blood sugar levels by age
Age < 6 years old 6-12 years old 13-19 years old 20+ years old
Fasting With diabetes 80-180 mg/dl 80-180 mg/dl 70-150 mg/dl 80-130 mg/dl
Without diabetes Less than 100 mg/dl Less than 100 mg/dl Less than 100 mg/dl Less than 100 mg/dl
1-2 hours after eating With diabetes ~180 mg/dl 140 mg/dl or less 140 mg/dl or less Less than 180 mg/dl
Without diabetes Less than 120 to 140 mg/dl Less than 120 to 140 mg/dl Less than 120 to 140 mg/dl Less than 120 to 140 mg/dl
Bedtime With diabetes 110-200 mg/dl 100-180 mg/dl 90-150 mg/dl 100-140 mg/dl
Without diabetes Less than 100 mg/dl Less than 100 mg/dl Less than 100 mg/dl Less than 100 mg/dl
A1C With diabetes <6.5 to 8% depending on the patient <6.5 to 8% depending on the patient <6.5 to 8% depending on the patient <7 to 8% 

depending on the patient
Without diabetes <5.7% <5.7% <5.7% <5.7%

Download this normal blood sugar levels chart by age here.

RELATED: Learn more about normal blood sugar levels

Gestational diabetes levels
Type Level Blood sugar in mg/dl
Oral glucose tolerance test results 2-hour specimen draw If both the fasting glucose (≥ 126 mg/dl) and 2-hour glucose (≥200 mg/dl) are abnormal, a diagnosis of diabetes is made. If one value is abnormal, the test will be repeated, or a 3-hour test may be performed.
Three-hour glucose tolerance test results Fasting <95 mg/dl
1-hour specimen draw <180 mg/dl ( levels may vary depending on the amount of glucose consumed)
2-hour specimen draw <155 mg/dl (levels may vary depending on the amount of glucose consumed)
3-hour specimen draw <140 mg/dl (levels may vary depending on the amount of glucose consumed)
Non-diabetic pregnant women target Fasting Less than 100 mg/dl
A1C <5.7% (however, A1C levels may fall during normal pregnancy, so this is used as a secondary measurement after blood sugar measurements)
Pre-existing diabetes target levels Fasting <95 mg/dl
1 hour after meal <140 mg/dl 
2 hours after meal <120 mg/dl 
A1C <6 or 7% based on hypoglycemia risk
Gestational diabetes target levels Fasting <95 mg/dl
1 hour after meal <140 mg/dl 
2 hours after meal <120 mg/dl 
A1C <6 or 7% based on hypoglycemia risk

Download this normal blood sugar levels during pregnancy chart here.

RELATED: Learn more about gestational diabetes

What do my fasting blood sugar levels mean?
Demographic Risk Fasting blood sugar in mg/dl Action needed
Adults with diabetes Dangerously high A dangerously high number will vary, depending on your target ranges and treatment plan. Your healthcare professional will give you more information. Check ketones if required/Seek emergency medical care as outlined on your treatment plan
High >130 mg/dl, or possibly higher, depending on your target range Follow the treatment plan provided by your healthcare professional
Normal 70-130 mg/dl depending on your target range Follow your treatment plan provided by your healthcare professional
Low <70 mg/dl depending on your target range Follow your treatment plan provided by your healthcare professional
Dangerously low <54 mg/dl but may vary depending on your range Emergency intervention with glucagon and emergency medical care may be required depending on the patient’s status. Patients who are able to eat should consume fast-acting carbs as detailed in their treatment plan.
Adults without diabetes High A fasting blood sugar of 100-125 mg/dl is considered high, and in the prediabetes range

A fasting blood sugar of 126 mg/dl or more is considered high and in the diabetes range

 Consult your healthcare provider. Adults with prediabetes may be able to lower blood sugar with lifestyle changes such as a healthy diet and exercise (and possibly medication). Adults with diabetes generally will need medication, diet, and exercise, and some patients will need insulin.
Normal 70-100 mg/dl Consult your healthcare provider- generally, no action is required.
Low <70 mg/dl Consult your healthcare provider

Download this fasting blood sugar levels chart here.

The chart below converts A1C levels into an average blood sugar level. You can access this calculator to find your average blood sugar level if your exact A1C is not listed in the chart. 

What do my A1C levels mean?
Diagnosis A1C percentage (for adults) Estimated average glucose (EAG)
Normal <5.7% 114 mg/dl for A1C of 5.6%
Prediabetic 5.7-6.4% 117 to 137 mg/dl
Diabetic 6.5% or higher 140 mg/dl for A1C of 6.5%
7% 154 mg/dl
7.5% 169 mg/dl
8% 183 mg/dl
8.5% 197 mg/dl
9% 212 mg/dl
9.5% 226 mg/dl
10% 240 mg/dl

Download this A1C average blood sugar chart here.

Blood glucose tests

Your healthcare professional will likely order labwork, such as a fasting blood glucose test and an A1C test. The frequency of labwork depends on your medical condition (nondiabetic vs prediabetes or diabetes), age, risk factors, and other variables. 

A fasting blood glucose test is done after not eating for at least 8 to 12 hours. The hemoglobin A1C level is a measure of blood sugar control over about three months. Sometimes, a healthcare professional can check your blood sugar level and/or A1C in the office using a finger stick. You can read more about blood sugar testing at the American Diabetes Association website.

How to monitor blood sugar

Your doctor will tell you how often to check your blood sugar at home. Checking blood sugar at home can be done in several ways. You can use a blood glucose monitor to check your blood sugar. This method uses a finger stick device (called a lancing device) to get a drop of blood. Then, you put a drop of blood on a test strip, which is inserted into the monitor. The monitor will then give you a reading of your blood sugar. 

Another method of checking blood sugar is continuous glucose monitoring or CGM. This method places a sensor on the body, with a tiny attachment that goes under the skin. CGMs monitor interstitial blood sugar, the sugar found in fluid between cells. The data is transmitted to a receiver or an app on the patient’s mobile phone. Data is updated frequently. Depending on which CGM you use, your glucose data is updated every one to five minutes. This is especially useful in patients who use insulin and need frequent readings to make treatment decisions.

Your healthcare provider will give you a treatment plan. You will have a target blood sugar range. Depending on your diagnosis, your provider will give you more information on what to do if your blood sugar is too low (for example, consume 15 grams of fast-acting carbohydrates such as Smarties or glucose tablets), or if your blood sugar is too high (administer insulin, if your condition requires insulin). 

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FAQs

When and why should you monitor your blood sugar?

Your healthcare provider will tell you how often to monitor your blood sugar. People with diabetes, especially those who use insulin, will need to monitor blood sugar much more frequently than those with prediabetes or normal blood sugar. People with normal blood sugar may only require periodic testing, for example, once yearly, at their physical examination. Maintaining blood sugar in the target range is important in preventing long-term complications. 

How do blood sugar levels correlate to A1C?

Blood sugar levels can be converted to an average A1C and vice versa. There are many calculators online that can convert these numbers. For example, an A1C of 6.3% translates to an average blood sugar of 134 mg/dl. You can talk more with your healthcare professional about your numbers and what they mean. 

A patient may have an excellent A1C but have lots of highs and lows, while another could have an excellent A1C and have a very steady number that is usually in the target range. People who use a CGM can benefit from aiming for a time in range of at least 70%. The time in range is the amount of time spent in your target blood sugar range—not too high or too low. Having consistent normal blood glucose levels can help prevent long-term complications from diabetes.

What are dangerous blood sugar levels?

Blood sugar can be dangerously high—or dangerously low. Your healthcare provider will give you individual target ranges and tell you when to take action on dangerously high or low blood sugar levels. These numbers, especially high numbers, differ by individual. Hypoglycemia (low blood sugar) is generally defined as a blood sugar less than 70 mg/dl, but it can vary depending on the individual. Severe hypoglycemia may occur if your blood sugar drops to a level where you need help recovering—your healthcare provider may prescribe glucagon that a family member or caregiver can use in a low blood sugar emergency. 

What should your blood sugar levels be in the morning?

For people without diabetes, normal fasting blood sugar is less than 100 mg/dl. Diabetic patients will have target ranges recommended by their healthcare provider, generally between 70 to 180 mg/dl, depending on age and other factors.

What are the target blood sugar levels for Type 1 vs. Type 2 diabetes?

Regardless of which type of diabetes you have, it is important to stay in the target range as much as possible to avoid long-term complications. Your healthcare provider will tell you your target ranges and give you more information on how to stay in the appropriate ranges.

 

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