A1C and Blood Sugar Targets: Understanding Your Numbers
If you have diabetes or prediabetes, you will hear a lot of numbers: A1C, fasting glucose, after-meal readings, "time in range." This guide explains what each number means, the general targets that major health organizations use, and why your personal targets may be different. Always follow the goals set with your own health care team.
What is the A1C test?
The A1C test, also called hemoglobin A1C or HbA1c, is a blood test that reflects your average blood glucose over roughly the past three months. According to NIDDK, glucose in the blood attaches to hemoglobin, the protein in red blood cells that carries oxygen. The higher your blood glucose has been, the more hemoglobin has glucose attached. Because red blood cells live for about three months, the A1C gives a picture of longer-term control rather than a single moment.
The result is reported as a percentage. You do not need to fast for an A1C test, which makes it convenient.
A1C for diagnosis
For adults who are not pregnant, the American Diabetes Association uses these A1C ranges, also described by NIDDK and the ADA's A1C page:
| A1C result | What it suggests |
|---|---|
| Below 5.7% | Normal |
| 5.7% to 6.4% | Prediabetes |
| 6.5% or higher | Diabetes |
A diagnosis is typically confirmed with a second test unless there are clear symptoms of high blood sugar.
A1C targets if you have diabetes
For many nonpregnant adults with diabetes, the ADA's Standards of Care in Diabetes suggest an A1C goal of less than 7%. However, the ADA emphasizes that goals should be individualized. A lower goal may be appropriate for some people if it can be reached safely without frequent low blood sugar. A less strict goal may be appropriate for people with a history of severe hypoglycemia, limited life expectancy, advanced complications, or other health conditions. Children, older adults, and pregnant people often have different targets.
Your health care provider will typically check your A1C at least twice a year if you are meeting goals, and more often if treatment changes or you are not meeting goals.
Estimated average glucose (eAG)
Some lab reports translate A1C into an "estimated average glucose" in mg/dL, the same unit you see on a home meter. For example, an A1C of 7% corresponds to an estimated average glucose of roughly 154 mg/dL. This can help connect the A1C to your daily readings.
Daily blood glucose targets
Home blood glucose checks or a continuous glucose monitor show what your blood sugar is doing right now. General targets for many nonpregnant adults with diabetes, as described by the ADA and in NIDDK's "Know Your Blood Sugar Numbers", are:
| Timing | Common target |
|---|---|
| Before a meal | 80 to 130 mg/dL |
| 1 to 2 hours after the start of a meal | Below 180 mg/dL |
Again, these are general targets. Your care team may set different numbers based on your age, health, medicines, and risk of low blood sugar.
Continuous glucose monitoring and "time in range"
Continuous glucose monitors (CGMs) measure glucose every few minutes using a small sensor under the skin. Instead of a few snapshots, they show patterns throughout the day and night. CGM reports often include "time in range," the percentage of time glucose stays within a target range, commonly 70 to 180 mg/dL. International consensus guidance used by the ADA suggests that many adults aim for more than 70% of the time in this range, with less than 4% of time below 70 mg/dL. Your provider can help you interpret your CGM data.
Low blood sugar (hypoglycemia)
Blood glucose below 70 mg/dL is generally considered low. Hypoglycemia is most common in people who take insulin or certain diabetes pills that increase insulin release. Symptoms can include shakiness, sweating, fast heartbeat, hunger, irritability, dizziness, and confusion. Severe lows can cause seizures or loss of consciousness.
A common approach recommended by the ADA and CDC is the "15-15 rule": take 15 grams of fast-acting carbohydrate (such as 4 ounces of juice or regular soda, or glucose tablets), wait 15 minutes, and recheck. Repeat if still below 70 mg/dL. Once your level is back in range, eat a snack or meal if your next meal is more than an hour or so away. Talk to your provider about whether you should have glucagon available for severe lows.
High blood sugar (hyperglycemia)
High blood sugar can result from eating more carbohydrates than usual, missing medicine, illness, stress, or less activity. Symptoms may include thirst, frequent urination, fatigue, and blurry vision. Ask your care team what level should prompt you to call them, and whether you should check for ketones, especially if you have type 1 diabetes. Very high glucose with vomiting, rapid breathing, or confusion needs emergency care.
Why A1C and daily readings can disagree
Sometimes the A1C does not match home readings. Possible reasons include:
- Checking only at certain times of day and missing highs or lows.
- Conditions that affect red blood cells, such as anemia, recent blood loss, or some hemoglobin variants. NIDDK notes that certain hemoglobin variants can affect A1C accuracy.
- Kidney disease, pregnancy, or recent transfusion.
- Meter or technique errors.
If your numbers do not add up, share your meter or CGM data with your provider.
Other numbers worth knowing
Blood sugar is not the only measure that matters. The ADA's "ABCs" of diabetes include A1C, blood pressure, and cholesterol, and many guides add "s" for stopping smoking. Many adults with diabetes are advised to keep blood pressure below 130/80 mmHg, though targets are individualized. Regular kidney tests (urine albumin and eGFR) and dilated eye exams are also part of routine care.
Tips for tracking your numbers
- Write down or download readings and bring them to appointments.
- Note what you ate, activity, illness, and medicine timing next to unusual readings.
- Wash and dry your hands before fingerstick checks for accurate results.
- Store test strips properly and check expiration dates.
- Ask about diabetes self-management education to learn how to act on your numbers.
Key takeaways
- A1C shows average blood glucose over about three months; 6.5% or higher indicates diabetes, 5.7% to 6.4% indicates prediabetes.
- Many adults with diabetes aim for an A1C below 7%, but targets should be individualized.
- Common daily targets are 80 to 130 mg/dL before meals and below 180 mg/dL after meals.
- Below 70 mg/dL is low blood sugar; know how to treat it.
Sources
Links to the sources cited above appear in the text. We rely on the Centers for Disease Control and Prevention (CDC), the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), and the American Diabetes Association (ADA).
Related guides: Blood sugar and treatment
- Checking Blood Sugar: Meters and Continuous Glucose Monitors
- Hypoglycemia (Low Blood Sugar): Signs, Treatment, and Prevention
- High Blood Sugar and Diabetic Ketoacidosis (DKA)
- Insulin Basics: Types, Delivery, and Safety
- Metformin and Common Diabetes Medications
- Managing Diabetes When You're Sick
- How to Lower Your A1C: Proven Strategies
- The Dawn Phenomenon: Why Morning Blood Sugar Is High