What the A1C Measures, How to Use it, and More

A1C is a healthcare provider-administered blood test that estimates average blood sugar levels over the preceding 2-3 months. You have probably had your A1C checked if you have been diagnosed with prediabetes or diabetes. You and your doctor will be able to see if there are any trends between checkups and assess the efficacy of your current diabetes treatment plan with the help of this useful tool.

However, because A1C is expressed as a percentage, it may be more difficult to understand than the blood sugar readings you're used to seeing on a blood glucose monitor. An A1C calculator can help you understand the relationship between your A1C and your blood sugar averages. Learn more about what your A1C means and what factors influence it before using the calculator.

Use this A1C calculator

Please consult an actual A1C lab test before making any changes to your treatment based on the results of this calculator. Consult your doctor about the specifics of your diabetes self-management plan and the answers to any questions you may have. Nathan et al. (2008) 1473-1478 investigated the connection between A1C and mean glucose levels. * 

The A1C Question: What Exactly Does It Indicate?

If you already check your blood sugar multiple times a day, you may be wondering what sets this test apart. Glycosylated hemoglobin, glycated hemoglobin, and hemoglobin A1C (HbA1c) are all names for the same thing on the A1C test. All these names suggest the substance being quantified: glucose bound to hemoglobin.

The protein hemoglobin is housed within red blood cells; it transports oxygen from the lungs to the rest of the body's cells. When glucose enters the bloodstream, it binds to hemoglobin, a protein that carries oxygen around the body. When blood glucose levels are consistently high, hemoglobin develops a sugar coating, a condition known as glycation.

Hemoglobin cells have a lifespan of about four months, so the A1C percentage represents the average blood sugar levels detected on hemoglobin cells of varying ages (days, weeks, or months). Hemoglobin cells are less likely to be heavily sugar-coated, or "glycated," if blood glucose control has been generally stable, resulting in a lower A1C value.

When should you get an A1C test?

Regular A1C testing may be recommended by your doctor to keep tabs on how your body responds to the medications, insulin pump settings, and other aspects of self-management you're implementing for your diabetes. If your blood glucose levels are normal and stable, your doctor may decide to only order the test once every six months.

Those who have not yet been diagnosed with diabetes may have their A1C levels checked in addition to other diagnostic tools. People who have a high risk of developing diabetes because of genetics or other factors can use this as a starting point to monitor any changes.

What should normal and target A1C levels be?

A lower A1C value indicates a lower concentration of glucose on the hemoglobin. A higher A1C value indicates a higher concentration of glucose on hemoglobin. The levels of glucose in the blood are directly proportional to the A1C, so a higher A1C indicates a higher blood glucose level

A1C ranges

The Centers for Disease Control and Prevention (CDC) defines a healthy A1C as anything less than 5. 7% For a healthy person without diabetes, this is the norm. Levels can rise from 5 to 10 if the body becomes insulin resistant and has trouble using glucose for energy. 7% to 6 Prediabetes affects 4% of the population. Students from 6th to 8th grade Cases of diabetes are diagnosed when the prevalence reaches 5%.

If you have diabetes and your doctor has recommended an A1C test to help you keep track of your condition, you may have noticed that there is some disagreement about what your goal number should be.

A1C goals

Your doctor will help you come up with a personalized A1C target after considering things like:

• Your age
• Hypoglycemia danger
• Ability and motivation to engage in diabetes self-management
• Allowing people with diabetes to afford supplies like test strips, medication, insulin, pumps, and CGMs
• Concerns about your health and aspirations in general

Your doctor will be aware of the potential influences on your A1C levels, such as anemia and sickle cell disease.

Results on the A1C are just that, data, and not good or bad. There are many factors beyond your control when it comes to maintaining healthy blood glucose levels while living with diabetes, including physical pain, emotional stress, a lack of access to timely meals, and other issues. Don't be afraid to check your A1C; in fact, you should inquire about your lab result at every doctor's appointment. More knowledge is better when it comes to managing diabetes on one's own.

Is there a correlation between A1C and mean glucose levels?

Summed reading from multiple glucose meters

A blood glucose meter is necessary for a person with type 1 or type 2 diabetes to monitor their blood sugar on a daily basis and make treatment decisions, despite the fact that an A1C level can provide useful information about average glucose levels over the past few months.

By using an accurate glucose meter and testing your blood sugar frequently throughout the day, you can gain useful insight into how your blood sugar levels change throughout the day. The majority of modern blood glucose monitors also calculate averages over the previous 7, 14, 30, or 90 days. To estimate how your meter readings might translate to an A1C, you can use a 90-day moving average in the aforementioned calculator.

The averages generated by glucose meters are dependent on how often you've tested throughout the day, so if you don't have a large sample size (i.e., a lot of readings), the averages will be e unable to test at certain times (i.e., when blood sugar is high or low) or who do not test frequently enough (i.e., when blood sugar is stable) e as when you're sleeping), it may not be as accurate as an A1C test and give you a falsely low reading.

Standardized Mean Glucose (SMG)

To convert your A1C percentage into a more easily understood average, the American Diabetes Association (ADA) suggests using an estimated average glucose (EAG). The above A1C to EAG calculator is based on research conducted by the ADA on the correlation between the two variables. If you're using an A1C calculator, the EAG value will give you an idea of how your blood glucose readings have been averaging in a more intuitive unit of measure, such as that of a blood glucose meter.

This number is only useful for estimating how close your blood glucose levels are to your goal ranges; it should not be used to determine treatment. Increases in both A1C and EAG are seen in people with poorly controlled diabetes. This also means that if your A1C is lower, your EAG will be lower, and that the two values will follow a similar trend.

How do you lower your A1C levels?

• Collaboration with your healthcare provider Check with your doctor to see if your dosage needs to be adjusted. If you haven't seen a Certified Diabetes Educator recently, you should get one recommended to you so that you can start making the little changes that will add up to a big improvement in your health.
• Establish customary practices Maintain a routine with your blood sugar monitoring, medication or insulin injections, and physical activity. This helps establish routines to ensure you don't forget your self-care activities and also helps your doctor spot trends in your blood sugar levels.
• Learn more facts Increase the frequency of your blood sugar checks and aim to check it at least twice a day, preferably two hours after the beginning of a meal. These numbers tell you how well your body processed the meal, and they correlate most closely with your A1C.
• Fast course corrections are required. Low blood sugar before dinner? Try having a snack in the afternoon. Increase your water intake and go for a walk if your blood sugar is high (but only if it's below 250 mg/dL; if it's higher, you shouldn't exercise). Two consecutive blood-sugar-level readings over 250 mg/dL warrant informing your doctor. Taking corrective measures while out of range can speed up the process of regaining range.
• Make sure you're keeping track of your carbohydrates carefully. For more precise servings of carbohydrate-containing foods, a kitchen scale can be helpful. Instead of guessing how many carbohydrates something has, use labels and counting tools to determine the exact amount. Visit a Registered Dietitian Nutritionist for a personalized meal plan and review of your carb counting, and use apps like Calorie King to determine the exact carb content of foods.
• Lessen your worries Finding ways to reduce your stress can help keep your blood sugar levels stable. Get some fresh air, read a good book, have a good laugh with a friend, enroll in a yoga or mindfulness class, or see a therapist. When you have diabetes, all of these things are essential parts of self-care.
• Do more, even if it's just a little bit. It has been proven that if you walk for ten minutes after eating, your blood sugar levels will go up. You can stay active and keep moving by doing things like walking the dog or cleaning the house.

When trying to lower their A1C, many people wonder how long it will take to see results. Getting a better A1C at your next three-month checkup is possible if you stick to your diabetes self-care plan. If you and your doctor continue to work together, and if you follow the advice above, your A1C may continue to drop at each visit.

Extra A1C tests beyond the recommended once every three months are not helpful and are often not covered by insurance. Don't take it personally if your A1C is high despite your best efforts to adhere to your doctor's orders. Once more, many things conspire against easy diabetes management, but if you keep at it, you can see that number drop.

Overall, the A1C test provides a picture of your glucose levels over the course of the past few months. You and your doctor can use this information to gauge the success of your diabetes management plan, but there is no "good" or "bad" number.

You can convert your A1C to an easily understandable EAG number in the same unit of measurement as a blood glucose meter by using an A1C calculator. Don't be afraid to talk with your healthcare professional about setting your unique goals to result in better diabetes management; however, keep in mind that A1C targets can vary from person to person based on age, treatment goals, access to diabetes supplies, and other health issues present.

Research by *Nathan DM, Kuenen J, Borg R, Zheng H, Schoenfeld D, and Heine RJ The A1C assay translated into estimated average glucose values The Management of Diabetes  2008;31(8): 1473-1478  https://www ncbi nlm nih gov/pmc/articles/PMC2742903/