A1C (HbA1c)
Also called hemoglobin A1C, glycated hemoglobin.
A1C is a blood test that measures how much hemoglobin has glucose attached. It reflects average blood sugar over about the past 3 months. It is reported in % or in mmol/mol. (NIDDK (NIH))
Target
Under 7% (53 mmol/mol) for many nonpregnant adults; the 2019 consensus also gives 7.0% for children, teens and adults 25 or younger with access to full care. Goals are set per person. (ADA Standards of Care 2026, section 6; International consensus on time in range, 2019)
Worked example
An A1C of 7% matches an estimated average glucose of 154 mg/dL (8.6 mmol/L) in the ADAG study table. An A1C of 8% matches 183 mg/dL (10.2 mmol/L).
Related terms
Sources, quoted
- NIDDK (NIH): “The A1C test measures the amount of hemoglobin with attached glucose and reflects your average blood glucose levels over the past 3 months.”
- NIDDK (NIH): “The A1C test is sometimes called the hemoglobin A1C, HbA1c, glycated hemoglobin, or glycohemoglobin test.”
- ADA Standards of Care 2026, section 6: “An A1C goal of <7% (<53 mmol/mol) is appropriate for many nonpregnant adults without severe hypoglycemia or hypoglycemia affecting health or quality of life.”
- International consensus on time in range, 2019: “An A1C target of 7.0% (53 mmol/mol) can be used in children, adolescents, and adults ≤25 years old who have access to comprehensive care”
Every quote above is checked against its source page before each update of this site; last checked 2026-10-06. The worked example is our own arithmetic. This page explains a term; it is not advice for a person's treatment.