A good A1c reading is 4 to 6 percent for someone who does not have diabetes and under 6.5 or 7 percent for someone with diabetes. A person whose A1c is between 5.7 and 6.4 percent may have insulin resistance or be at risk for developing diabetes.
The A1c blood test gives a reading of a person's average blood sugar level over the three months preceding the test. When an A1c result is 5 percent, it means that about 5 percent of the hemoglobin A1c molecules in the blood sample have blood sugar on them.
Studies have shown that keeping the A1c below 7 percent reduces the risk of complications from diabetes, such as kidney disease, nerve damage and eye disease. A diabetic person who has episodes of low blood sugar may stay at a higher A1c, such as 8 percent. The doctor or other health care provider determines an appropriate A1c goal based on the patient's overall health.