For adults without diabetes, a good A1C number is below 5.7%. That range corresponds to an estimated average glucose under about 117 mg/dL and reflects healthy blood sugar control over the past 2-3 months. For adults with diabetes, the typical goal is below 7%, though targets are often individualized based on age, health conditions, and risk of hypoglycemia.
What Counts as a Good A1C Number
A1C is reported as a percentage and is interpreted based on cutoffs set by the American Diabetes Association:
| A1C | Category | Estimated Average Glucose | What It Means |
|---|---|---|---|
| Below 5.7% | Normal | Below 117 mg/dL | Healthy — good A1C number |
| 5.7% – 6.4% | Prediabetes | 117-137 mg/dL | Warning stage — reversible |
| 6.5% – 6.9% | Diabetes — early | 140-152 mg/dL | Manage through lifestyle + possible meds |
| 7.0% – 7.9% | Diabetes — moderate | 154-180 mg/dL | Target for most with diabetes |
| 8.0% or higher | Diabetes — elevated | Above 183 mg/dL | Complications risk — needs attention |
Low-to-mid 5s is considered excellent for someone without diabetes. For someone with diabetes, an A1C near 6.5% or slightly above is often a realistic, healthy target.
Early Warning Signs Your A1C May Be Rising
A1C itself is silent — most people with prediabetes have no obvious symptoms. However, the following early warning signs suggest your blood sugar may be creeping up:
- Increased thirst and urination: Especially at night.
- Fatigue after meals: Blood sugar crashes following carb-heavy meals.
- Slow-healing cuts: High glucose impairs immune and tissue repair.
- Darkened skin patches: Acanthosis nigricans, often on the neck or armpits.
- Blurry vision: Fluid shifts in the eye lens from elevated glucose.
- Recurring yeast or urinary infections: Excess glucose feeds bacteria.
Many people have none of these signs even with A1C in the 5.7-6.4% range, which is why routine screening matters more than waiting for symptoms. See our prediabetes symptoms guide for a complete list.
What to Do If Your A1C Number Isn’t “Good”
If your A1C is above 5.7%, the encouraging news is that prediabetes is reversible. The Diabetes Prevention Program — a landmark NIH-funded trial — showed that modest lifestyle changes cut progression to type 2 diabetes by 58%.
Lifestyle Changes That Lower A1C
- Lose 5-7% of body weight. For a 200-pound person, that’s 10-14 pounds.
- Move 150 minutes per week. Brisk walking, cycling, or swimming counts.
- Prioritize fiber and protein. Beans, vegetables, fish, nuts, and whole grains.
- Cut added sugar and refined carbs. Especially sugary drinks and white flour products.
- Sleep 7-9 hours. Short sleep raises cortisol and insulin resistance.
- Manage stress. Chronic stress raises blood sugar through cortisol.
These interventions typically drop A1C by 0.5 to 2 percentage points within 3-6 months. Someone at 6.3% can realistically reach the low 5s. See our prediabetes diet guide for practical food swaps.
Medication Options
If lifestyle changes aren’t enough, your doctor may recommend metformin — especially if you have prediabetes plus BMI above 35, age under 60, or a history of gestational diabetes. For established type 2 diabetes, additional medications like GLP-1 receptor agonists or SGLT2 inhibitors may be added to reach goal.
Individualized A1C Goals
Not everyone needs to aim for the same A1C. The CDC and ADA both recommend individualized targets:
- Below 6.5%: Younger, healthier adults with diabetes and low hypoglycemia risk.
- Below 7.0%: Most adults with diabetes — the standard goal.
- Below 8.0%: Older adults, those with multiple chronic conditions, or high fall/hypoglycemia risk.
- Below 5.7%: Adults without diabetes — maintain healthy habits to stay here.
The “best” A1C number is the one that balances reducing long-term complications with avoiding dangerous low blood sugar episodes.
How Often to Check Your A1C
- Adults 35+ without diabetes: every 3 years with normal results
- Prediabetes: every 1-2 years
- Stable diabetes at goal: every 6 months
- Newly diagnosed or changing treatment: every 3 months
More frequent testing than every 3 months generally doesn’t add useful information because A1C reflects 2-3 months of blood sugar history.
The Bottom Line
A good A1C number is below 5.7% for adults without diabetes, and below 7% for most adults with diabetes — though individualized goals ranging from 6.5% to 8% are common. An A1C of 5.7-6.4% is prediabetes, a reversible warning stage; 6.5% and above is diabetes. Because elevated A1C usually has no symptoms, periodic screening is essential. If your number is higher than you’d like, lifestyle changes — weight loss, activity, better food choices, and sleep — can lower A1C by 0.5 to 2 points within a few months. Work with your doctor to set a target that fits your health profile.
