Diabetes · Blood test
HbA1c blood test: normal range explained
Also printed as: Glycated Haemoglobin, A1C, Hb A1c
HbA1c shows your average blood sugar over roughly the past two to three months, measured as the share of haemoglobin in your red blood cells that has sugar attached. The adult range commonly printed is 4.0–5.6%, in line with the published cut-off of below 5.7%, but the range printed on your own report is the one that applies.
Last updated 5 sources
What is the normal range for HbA1c?
| Printed for | Range |
|---|---|
| Adults | 4.0–5.6% |
Reference ranges vary between laboratories. Always use the range printed on your own report. Why ranges differ between labs
| Label | Range |
|---|---|
| Normal | <5.7 % |
| Prediabetes | 5.7–6.4 % |
| Diabetes | ≥6.5 % |
These labels are the source's own, not Amara's. Your doctor reads your result with your history and other tests.
Sources:NIDDK, MedlinePlus
What does HbA1c measure?
HbA1c, also called glycated haemoglobin or A1C, measures how much of the haemoglobin in your red blood cells has glucose attached. Red blood cells live for about three months, so the result reflects your average blood sugar over that time rather than on the morning of the test.
Sources:MedlinePlus, Testing.com
Why do doctors order the HbA1c test?
Doctors order HbA1c to check for type 2 diabetes and prediabetes, and to follow blood sugar over time in people who already have diabetes. It is not used to diagnose type 1 diabetes or diabetes that starts in pregnancy. A doctor usually confirms a result in the diabetes range with a second test, unless there are clear symptoms.
Sources:MedlinePlus, NIDDK
What can change your HbA1c result?
Some things can move an HbA1c result, or make it less reliable, without any change in your average blood sugar.
- Low iron, including iron-deficiency anaemia, can make HbA1c read higher than your true average, while haemolytic anaemia or heavy bleeding can make it read lower.
- Haemoglobin variants, such as thalassaemia or sickle cell trait, can interfere with some HbA1c methods.
- Recent blood loss or a blood transfusion changes the age of your red blood cells, which can shift the result.
- Kidney failure and liver disease can affect the result.
- Pregnancy can affect the result, and HbA1c is not used to diagnose diabetes that starts in pregnancy.
- Some medicines, including opioids and some HIV medicines, may affect the result. Do not stop a medicine unless your doctor tells you to.
- A recent meal does not change it, because the test does not need fasting.
Sources:NIDDK, Testing.com, Lab Tests Online UK, MedlinePlus
How do you read HbA1c on your lab report?
Most reports print HbA1c as a percentage. Many also print an estimated average glucose (eAG) in mg/dL, which converts the same result into the units a home glucose meter uses, so it will not match any single reading.
Some reports print a legend instead of one range, with rows such as normal, prediabetes and diabetes. Read your value against the range or legend your own lab printed, and take the result to your doctor with your earlier reports.
UK-style reports print HbA1c in mmol/mol rather than as a percentage. Lab Tests Online UK quotes the WHO figures for those units: below 42 mmol/mol as not diabetes, 42 to 47 as prediabetes and 48 or over as indicative of diabetes, so a report in those units is read against them.
Amara reads HbA1c with the range printed beside it on each report, flags a value outside that range, and shows what changed since your last report. Try it with two sample reports
A sample Amara row for HbA1c: 5.9% on 12 Mar 2026 at Lab A (sample), then 5.5% on 28 Sep 2026 at Lab B (sample), each with its lab's printed range.
Questions people ask about HbA1c
Do I need to fast before an HbA1c test?
An HbA1c test does not need fasting, because it reflects your average blood sugar over the past two to three months rather than your last meal. If other tests on the same form need fasting, such as fasting glucose, follow the lab's instructions for those tests.
What is the difference between HbA1c and fasting blood sugar?
HbA1c reflects your average blood sugar over about three months, while fasting blood sugar is a single reading taken after at least eight hours without food. Because each answers a different question, doctors often read the two together rather than choosing one over the other.
How often should HbA1c be tested?
HbA1c testing frequency depends on your situation. MedlinePlus says people with diabetes are usually tested at least twice a year and people with prediabetes every one to two years, and that for adults with normal results the doctor decides how often, based on age and risk.
Can an HbA1c result be inaccurate?
An HbA1c result can be less reliable when something changes your red blood cells, such as anaemia, a haemoglobin variant like thalassaemia, recent blood loss or a transfusion, kidney failure or liver disease. Your doctor may then rely on other tests, such as fasting glucose.
Why is HbA1c printed in mmol/mol on some reports?
HbA1c is printed in mmol/mol on UK-style reports because that is the standard unit there, while Indian and US reports usually print a percentage. Lab Tests Online UK quotes WHO's figures: 48 mmol/mol or over is indicative of diabetes and 42 to 47 is prediabetes. Read a result against the unit and range its own lab printed.
Sources:NIDDK, Testing.com, MedlinePlus, Lab Tests Online UK
Sources
- Hemoglobin A1C (HbA1c) TestMedlinePlus · medlineplus.gov · Opened
- The A1C Test & DiabetesNIDDK · niddk.nih.gov · Opened
- Hemoglobin A1c Test: Check Your Blood Sugar LevelsTesting.com · testing.com · Opened
- Blood Glucose TestMedlinePlus · medlineplus.gov · Opened
- HbA1c TestLab Tests Online UK · labtestsonline.org.uk · Opened
About this page
Every statement on this page comes from the sources listed above. Ranges are those commonly printed on Indian lab reports; the range printed on your own report is the one that applies.
Published by Amara Health, a product of MetaNova AI Private Limited, Hyderabad.
Amara Health does not provide medical advice, diagnosis or treatment. Information shown by Amara is based on available health records and may contain errors. Review important information against the original report and consult a qualified healthcare professional for medical decisions. Do not use Amara for medical emergencies.
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