--- title: "A1C levels: normal range, prediabetes and the eAG chart" description: "What your A1C result means: below 5.7% is normal, 5.7% to 6.4% is prediabetes. The CDC's A1C to average glucose chart, and when the test misleads." canonical: https://glucosebench.com/a1c-levels alternate_html: https://glucosebench.com/a1c-levels language: en-US last_updated: 2026-09-27 type: guia --- # Your A1C result, read against the NIH's cutoffs and the CDC's chart 1. [Home](https://glucosebench.com/) 2. [Blood sugar basics](https://glucosebench.com/blood-sugar) 3. Your A1C result, read against the NIH's cutoffs and the CDC's chart An A1C is one number standing in for months of blood sugar. Reading it well means knowing three cutoffs, the chart that turns it into mg/dL, and the handful of situations where it reads wrong. By **GlucoseBench editorial team**Updated September 27, 2026 ![Your A1C result, read against the NIH's cutoffs and the CDC's chart](https://glucosebench.com/img/guia-a1c-levels-640.webp) Short answer A normal A1C is below 5.7%. From 5.7% to 6.4% is prediabetes, and 6.5% or above is diabetes, per NIDDK, the National Institute of Diabetes and Digestive and Kidney Diseases. It reflects your average blood sugar over the past 3 months, per NIDDK and the CDC's A1C page (the CDC's general testing page says 2 or 3 months), and you don't need to fast for it. A result in the diabetes range gets confirmed with a second measurement unless there are clear symptoms. For most people who already have diabetes, the CDC puts the goal at 7% or less, which its chart equates to an estimated average glucose of 154 mg/dL. ## A1C ranges and what each one means Only the A1C is here. The fasting, glucose tolerance and random test cutoffs are side by side in our diabetes tests guide. A1C result Category What NIDDK says about it Below 5.7% Normal "A normal A1C level is below 5.7 percent." If you have risk factors, ask your doctor whether and when to test again. 5.7% to 6.4% Prediabetes A risk factor for type 2 diabetes. Lifestyle changes such as weight loss or being active most days of the week may prevent or delay it. 6.5% or above Diabetes Needs a second measurement to confirm it, unless there are clear symptoms of diabetes. Source: NIDDK, "The A1C Test & Diabetes" (last reviewed April 2018), read on September 27, 2026. The CDC's "Diabetes Testing" page, read the same day, uses the same three ranges. NIDDK says the A1C shouldn't be used to diagnose type 1 diabetes, gestational diabetes or cystic fibrosis-related diabetes. ## A1C to average blood sugar (eAG) Estimated average glucose (eAG) turns the A1C percentage into mg/dL, the unit a home meter shows. The CDC's chart runs from 6% to 12% in whole-point steps, and we haven't filled in anything between them. A1C Estimated average glucose (eAG) 6% 126 mg/dL 7% 154 mg/dL 8% 183 mg/dL 9% 212 mg/dL 10% 240 mg/dL 11% 269 mg/dL 12% 298 mg/dL Source: CDC, "A1C Test for Diabetes and Prediabetes" (May 15, 2024), read on September 27, 2026. The CDC notes that the estimate "may not account for any spikes or lows." NIDDK adds that eAG "will not match daily glucose readings because it's a long-term average." ## When an A1C can read too high or too low ### Very low iron NIDDK: "A falsely high A1C result can occur in people who are very low in iron", for example people with iron-deficiency anemia. ### Kidney failure or liver disease Both are on NIDDK's list of other causes of false A1C results. ### Changes to red blood cells Recent blood loss, sickle cell disease, erythropoietin treatment, hemodialysis or a transfusion can change A1C levels, because they change how long red blood cells last. ### Hemoglobin variants If you're of African, Mediterranean or Southeast Asian descent, or have relatives with sickle cell anemia or a thalassemia, you may carry a hemoglobin variant that interferes with some A1C tests. Most carriers don't know it. Doctors may suspect it when the A1C and blood glucose results don't match. NIDDK's tests page adds that "most A1C tests used in the United States are not affected by the most common variants." ### Some medicines, and pregnancy The CDC's list of things that can falsely raise or lower a result also includes "certain medicines, including opioids and some HIV medications," and early or late pregnancy. ### Where the blood is analyzed Tests run in a doctor's office or clinic, called point-of-care tests, "should not be used for diagnosis," per NIDDK. A diagnostic A1C goes to a lab using an NGSP-certified method. ## How much an A1C moves on its own Even one tube of blood won't give the exact same A1C twice. NIDDK's example: "an A1C reported as 6.8 percent on one test could be reported in a range from 6.4 to 7.2 percent on a repeat test from the same blood sample." Stricter quality control has made results more precise than they used to be, but that's still the spread NIDDK describes. Timing matters too. The A1C is a long-term average, yet NIDDK says blood glucose levels within the past 30 days "have a greater effect on the A1C reading than those in previous months," and the test doesn't show "sudden, temporary increases or decreases in blood glucose levels." Keep that in mind when a sales page quotes an A1C. The GLPro sales video, which our review found is about a different product, says "88% lowered their A1C below 5.7 in under 60 days." A Glucore testimonial says "my A1C dropped to 6.1!" and BloodArmor's page talks about "improvements in hemoglobin A1c (HbA1c)." None of them names a lab, gives test dates or shows a repeat result, so none can be checked. ## What research on supplements shows about A1C The NIH's complementary health center (NCCIH) summed up the research in its fact sheet "Diabetes and Dietary Supplements" (November 2023). For chromium, a 2022 review of 16 studies (868 participants) "suggested that chromium supplementation may help improve" HbA1c in people with type 2 diabetes. For vitamins, a 2022 review of 178 studies found the improvements seen with vitamin D "were small and less than the minimal amount needed for a clinical difference," and its authors concluded that "nutritional supplements may not be helpful for blood glucose control." That's thin ground for any product that talks about A1C, and it's why nothing on this site is sold or recommended as a way to lower one. If you take diabetes medication, NCCIH says to tell your health care providers about any herbal supplements you're taking. We'd go further and ask before you start one. ## A1C goals after a diabetes diagnosis "For most people with diabetes, the A1C goal is 7% or less," says the CDC, and your doctor sets your own goal from your full medical history. NIDDK adds that some people with diabetes can reduce the risk of complications by keeping their A1C below 7 percent. And if lifestyle changes and medicine bring someone below 6.5%, the CDC is careful to say that "this doesn't mean that their condition went away"; it usually means blood sugar is well managed. Lower isn't automatically better. NIDDK warns that keeping an A1C below 7 percent "may not be safe if it leads to problems with hypoglycemia," and that 7 to 8 percent, or even higher, may suit people with limited life expectancy, long-standing diabetes, severe hypoglycemia or advanced complications. Your target is a decision you make with your doctor. Once you have diabetes, experts recommend an A1C test at least twice a year. ## Frequently asked questions **What is a normal A1C level?** Below 5.7%, according to NIDDK and the CDC. From 5.7% to 6.4% is prediabetes, and 6.5% or above is diabetes. **How do you calculate average blood sugar from an A1C?** You don't need a formula. NIDDK says estimated average glucose (eAG) is calculated from your A1C, and some labs report it with the result. The CDC's chart gives the pairs: 6% is 126 mg/dL, 7% is 154 mg/dL and 8% is 183 mg/dL. **Is an A1C of 6.5 diabetes?** 6.5% is where the diabetes range starts. NIDDK says any test used to diagnose diabetes needs a second measurement to confirm it, unless there are clear symptoms. **Do you have to fast for an A1C test?** No. You can eat and drink beforehand, and the blood can be drawn at any time of day. **Can a supplement lower my A1C?** Don't count on it. NCCIH found weak evidence for a handful of supplements and none for most, and for vitamin D the change in HbA1c was below what makes a clinical difference. A supplement shouldn't stand in for anything your doctor prescribed. **How often should A1C be checked?** With diabetes, at least twice a year, and more often if you aren't meeting your goals, per NIDDK and the CDC. Without diabetes, the CDC says your doctor recommends a retesting schedule based on your age and risk factors. ## Related pages Blood sugar basics ### [Prediabetes: a number worth acting on, usually without a symptom](https://glucosebench.com/prediabetes) Prediabetes means your blood sugar is higher than normal but not high enough for a type 2 diabetes diagnosis. Read more Blood sugar basics ### [Which blood test diagnoses diabetes? All four, compared](https://glucosebench.com/diabetes-tests) Type 2 diabetes and prediabetes are diagnosed with blood tests: the A1C, the fasting plasma glucose test, the oral glucose tolerance test (OGTT) and, when there are… Read more Blood sugar basics ### [Fasting blood sugar: three cutoffs and one blood draw](https://glucosebench.com/fasting-blood-sugar) The CDC's cutoffs for fasting blood sugar: 99 mg/dL or below is normal, 100 to 125 mg/dL is prediabetes, and 126 mg/dL or above is diabetes. Read more Blood sugar basics ### [Lowering an A1C: medicine, meals, movement and weight](https://glucosebench.com/how-to-lower-a1c) An A1C comes down the same way daily blood sugar does: diabetes medicine taken as prescribed, a meal plan, regular physical activity and, if you have overweight, some… Read more Updated September 27, 2026. [See our full method](https://glucosebench.com/how-we-choose) --- ## GlucoseBench - GlucoseBench, published by Grupo Marfre Automação e Tecnologia (Contagem, Brazil) - Email: contact@glucosebench.com - Home: https://glucosebench.com/ - llms.txt: https://glucosebench.com/llms.txt · llms-full.txt: https://glucosebench.com/llms-full.txt · sitemap: https://glucosebench.com/sitemap.xml