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Hemoglobin A1C normal range (and what it means for nurses)

A normal hemoglobin A1C is 4.0 to 5.6% at UW Medicine (University of Washington Medicine), a range the MagstoneRN app's lab tool uses. 5.7 to 6.4% is prediabetes, and 6.5% or higher is diabetes. A1C reflects average blood glucose over the past 3 months. Ranges differ between labs, so use the range on the patient's report.⁠[1][2][3]

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Quick facts

Hemoglobin A1C reference range and cutoffs
TestRangeUnitApplies to
Hemoglobin A1C⁠[1]4.0-5.6%All ages
Prediabetes⁠[1][2]5.7-6.4%Diagnostic cutoff, not a normal range
Diabetes⁠[1][2]6.5 or higher%Diagnostic cutoff, not a normal range
Common goal in diabetes⁠[1][2]Below 7%Not safe for everyone; see below

A1C is a 3-month average, so it doesn't replace a glucose check

  • A1C measures hemoglobin with glucose attached and reflects average blood glucose over the past 3 months. Glucose from the last 30 days affects it more than earlier months.⁠[2]
  • The test needs no fasting, and experts recommend an A1C test at least twice a year for people with diabetes.⁠[2][4]

Some conditions make A1C read falsely high or low

  • Anything that changes how long red blood cells live, such as recent blood loss, a transfusion, sickle cell disease, or hemodialysis, can change A1C. Iron-deficiency anemia can make it falsely high, and kidney failure or liver disease can also give false results.⁠[2]
  • A hemoglobin variant, a different type of hemoglobin more common in people of African, Mediterranean, or Southeast Asian descent, can interfere with some A1C tests. Interference is suspected when the A1C and the blood glucose results don't match.⁠[2]

A goal below 7% isn't safe for every patient

  • Keeping A1C below 7% lowers the risk of complications for some people with diabetes, but that goal may not be safe if it leads to hypoglycemia.⁠[2]

The Glucose care: clinical reasoning flashcard deck covers hypoglycemia, diabetic ketoacidosis, and hyperosmolar hyperglycemic state. Find the deck in the free app preview.

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How it shows up on nursing exams

  • A1C and fasting glucose answer different questions: A1C is the 3-month average, and a fasting glucose is a single point in time.⁠[2][5]
  • 5.7 to 6.4% is prediabetes and 6.5% or higher is diabetes. An A1C below 7% in a patient with diabetes is a common goal, not a normal result.⁠[1][2]

Practice question

A nurse reviews a hemoglobin A1C of 8.1% for an adult patient with type 2 diabetes. Which statement about this result is accurate?

  1. A. The result shows the patient's blood glucose at the moment of the draw.
  2. B. The result falls in the prediabetes range for an adult patient.
  3. C. The result is valid only if the patient fasted for 8 hours first.
  4. D. The result is above the common goal of below 7% in diabetes.
Show the answer and why

Correct answer: D. The result is above the common goal of below 7% in diabetes.

  • A. Incorrect. A1C is a 3-month average. A glucose check, not an A1C, shows the level at a single point in time.
  • B. Incorrect. Prediabetes is 5.7 to 6.4%. 8.1% is above the diabetes cutoff.
  • C. Incorrect. An A1C test needs no fasting.
  • D. Correct. 8.1% is above the common goal of below 7%. A1C reflects average blood glucose over the past 3 months.

Sources for this question: ⁠[1][2][4]

Memory hook: A1C looks back 3 months: below 5.7 is normal, 5.7 to 6.4 is prediabetes, 6.5 or higher is diabetes.

Questions about hemoglobin A1C

What is a normal A1C?

4.0 to 5.6% at UW Medicine, a range the MagstoneRN app's lab tool uses. NIDDK (the National Institute of Diabetes and Digestive and Kidney Diseases) calls anything below 5.7% normal. Ranges differ between labs, so use the range on the patient's report.⁠[1][2][3]

What A1C means diabetes?

6.5% or higher. 5.7 to 6.4% is prediabetes.⁠[1][2]

Do you need to fast for an A1C test?

No. The A1C test needs no fasting.⁠[2][4]

Study this topic in MagstoneRN

MagstoneRN's Lab values tool lists hemoglobin A1C with UW's prediabetes and diabetes cutoffs and lists its sources.

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Sources for this page

All 5 sources
  1. Hemoglobin A1C by HPLC (reference interval effective October 1, 2024) (opens in a new tab). UW Medicine Laboratory Test Guide. License: Not openly licensed; reference values cited as facts, no text reused. Accessed October 18, 2026.
  2. The A1C Test and Diabetes (last reviewed April 2018) (opens in a new tab). National Institute of Diabetes and Digestive and Kidney Diseases, NIH. License: Public domain (U.S. government work). Accessed November 13, 2026.
  3. How to Understand Your Lab Results (updated September 4, 2025) (opens in a new tab). MedlinePlus, National Library of Medicine. License: Public domain (U.S. government work). Accessed October 18, 2026.
  4. Blood Glucose Test (updated December 30, 2024) (opens in a new tab). MedlinePlus, National Library of Medicine. License: Public domain (U.S. government work). Accessed November 13, 2026.
  5. Diabetes Tests and Diagnosis (last reviewed July 2022) (opens in a new tab). National Institute of Diabetes and Digestive and Kidney Diseases, NIH. License: Public domain (U.S. government work). Accessed November 13, 2026.

MagstoneRN wrote this page from the sources listed here. MagstoneRN has not commissioned an independent clinical review of it.

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Sources: 5 entries, from government health agencies and reputable secondary sources, last accessed November 13, 2026.