A1C Chart
An A1C chart converts your haemoglobin A1c percentage into a diabetes risk category and an estimated average blood glucose level. Normal is below 5.7%. Prediabetes falls between 5.7% and 6.4%. Diabetes is diagnosed at 6.5% or above. Reference values follow American Diabetes Association 2024 standards.
Convert Your A1C to Blood Sugar
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This tool is for informational purposes only and does not replace professional medical advice. Formula: eAG (mg/dL) = (28.7 × A1C%) − 46.7 per ADA 2024.
A1C Levels Chart
| A1C Percentage | Category | eAG (mg/dL) | eAG (mmol/L) | Recommended Action |
|---|---|---|---|---|
| Below 5.7% | Normal | Below 117 | Below 6.5 | Maintain a healthy lifestyle. |
| 5.7% – 6.4% | Prediabetes | 117 – 137 | 6.5 – 7.6 | Lifestyle intervention. Retest in 6 to 12 months. |
| 6.5% and above | Diabetes | 137 and above | 7.6 and above | Confirm diagnosis and begin treatment plan with a doctor. |
| 7.0% | ADA Target (adults with diabetes) | 154 | 8.6 | Ongoing management goal. |
| 8.0% and above | Poorly Controlled | 183 and above | 10.2 and above | Intensify treatment and reassess plan. |
Source: American Diabetes Association, Standards of Medical Care in Diabetes 2024
A1C to Estimated Average Glucose — Conversion Line
Hover the chart to see values at any A1C point.
Source: American Diabetes Association 2024 — formula eAG = (28.7 × A1C) − 46.7
A1C to Blood Sugar Conversion Chart
The formula to convert A1C to estimated average glucose is: eAG (mg/dL) = (28.7 × A1C%) − 46.7.
| A1C % | Avg Glucose (mg/dL) | Avg Glucose (mmol/L) |
|---|---|---|
| 4.0% | 68 | 3.8 |
| 4.5% | 82 | 4.6 |
| 5.0% | 97 | 5.4 |
| 5.5% | 111 | 6.2 |
| 6.0% | 125 | 7.0 |
| 6.5% | 140 | 7.8 |
| 7.0% | 154 | 8.6 |
| 7.5% | 169 | 9.4 |
| 8.0% | 183 | 10.2 |
| 8.5% | 197 | 11.0 |
| 9.0% | 212 | 11.8 |
| 9.5% | 226 | 12.6 |
| 10.0% | 240 | 13.4 |
| 10.5% | 255 | 14.2 |
| 11.0% | 269 | 15.0 |
| 11.5% | 283 | 15.8 |
| 12.0% | 298 | 16.6 |
| 12.5% | 312 | 17.3 |
| 13.0% | 326 | 18.1 |
| 13.5% | 341 | 18.9 |
| 14.0% | 355 | 19.7 |
Source: American Diabetes Association — Translating the A1C Assay into Estimated Average Glucose
A1C Targets by Age
The ADA recommends different A1C targets depending on age, health complexity, and risk of hypoglycaemia.
| Patient Group | A1C Target | Clinical Reason |
|---|---|---|
| Children and teens with Type 1 diabetes | Below 7.5% | Balances glycaemic control against hypoglycaemia risk. |
| Most adults | Below 7.0% | Reduces risk of microvascular complications. |
| Older adults — otherwise healthy | Below 7.0% to 7.5% | Standard adult goal applies. |
| Older adults — frail or complex medical needs | Below 8.0% to 8.5% | Avoids dangerous hypoglycaemia episodes. |
| Pregnant women with pre-existing diabetes | Below 6.0% to 6.5% | Protects foetal development. |
Source: American Diabetes Association Standards of Care 2024
How to Lower Your A1C
The interventions below show evidence-based A1C reductions based on published clinical trial data.
| Intervention | Typical A1C Reduction | Timeframe to See Effect |
|---|---|---|
| Regular aerobic exercise at 150 minutes per week | −0.6 to −0.9% | 8 to 12 weeks |
| Low glycaemic index or reduced carbohydrate diet | −0.3 to −2.0% | 3 months |
| Metformin | −1.0 to −1.5% | 3 months |
| GLP-1 agonists (e.g. Ozempic or Wegovy) | −1.5 to −2.0% | 3 to 6 months |
| SGLT-2 inhibitors | −0.5 to −1.0% | 3 months |
| Insulin therapy | −1.5 to −3.5% | 4 to 12 weeks |
Source: ADA Standards of Care 2024 and published clinical trial summaries
What Is A1C?
Before using the A1C chart it helps to understand exactly what the test is measuring and why it reflects 90 days of blood sugar rather than a single moment.
- A1C stands for glycated haemoglobin. Haemoglobin is the protein inside red blood cells that carries oxygen.
- When blood glucose is elevated, glucose molecules attach to haemoglobin in a process called glycation. The higher your blood glucose over time, the more haemoglobin becomes glycated.
- Red blood cells live for approximately 90 to 120 days. The A1C test measures the percentage of haemoglobin that has glucose attached to it, reflecting average glucose levels over that period.
- Because A1C reflects a 90-day average it cannot be manipulated by eating well for a few days before the test, unlike a fasting glucose reading.
A1C Test Frequency Chart
How often you need an A1C test depends on your current health status and whether you are managing diabetes.
| Patient Status | Recommended Frequency | Reason |
|---|---|---|
| No diabetes, normal A1C below 5.7% | Every 3 years | Baseline monitoring for adults over 35 or with risk factors. |
| Prediabetes (5.7% to 6.4%) | Every 6 to 12 months | Monitor for progression toward diabetes. |
| Newly diagnosed diabetes | Every 3 months until stable | Assess how well treatment is working. |
| Diabetes with A1C at goal | Every 6 months | Confirm ongoing control. |
| Diabetes with A1C above target or treatment changes | Every 3 months | Track response to new medication or lifestyle changes. |
Source: American Diabetes Association Standards of Care 2024
A1C Limitations
Certain medical conditions and individual factors can cause A1C results to be misleadingly high or low even when average blood glucose is actually normal.
| Condition or Factor | Effect on A1C Result | Why It Happens |
|---|---|---|
| Iron deficiency anaemia | Falsely high A1C | Fewer red blood cells available means higher proportion appear glycated. |
| Sickle cell disease or trait | Falsely low A1C | Abnormal haemoglobin is not glycated in the same way. |
| Recent blood transfusion | Falsely low A1C | New donor red blood cells have not been exposed to the patient's blood glucose. |
| Pregnancy (especially second and third trimester) | Falsely low A1C | Red blood cell turnover is faster during pregnancy. |
| Chronic kidney disease | May be falsely low or high | Reduced red blood cell lifespan and other metabolic effects. |
| High altitude living | Falsely high A1C | Higher red blood cell count from lower oxygen exposure. |
| Recent severe blood loss or heavy alcohol consumption | Falsely low A1C | Altered red blood cell production and lifespan. |
If you have any of the conditions listed above, ask your doctor whether fructosamine testing or continuous glucose monitoring (CGM) is a more accurate alternative to A1C for you.
Source: American Diabetes Association — A1C and eAG
A1C Goal Planner
Enter your current A1C, your target, and select up to 3 interventions to get an estimated timeline with weekly milestones.
Select up to 3 interventions
Frequently Asked Questions
What is a normal A1C level?
Below 5.7% is classified as Normal in the ADA A1C chart above. Most non-diabetic adults have A1C levels between 4.5% and 5.6%.
Can you lower A1C in 3 months?
Yes — A1C reflects a 90-day average so changes show up within one testing cycle. The intervention chart above shows that dietary changes can reduce A1C by 0.3 to 2.0% and medication can reduce it by 1.0 to 3.5% within 3 months.
What does an A1C of 6.8% mean?
An A1C of 6.8% falls in the diabetes range per ADA 2024 guidelines, as 6.5% and above meets the diagnostic threshold. It sits just above the prediabetes cutoff of 6.4%, so prompt medical evaluation is recommended.
Is A1C the same as blood sugar?
No — A1C reflects a 90-day average of blood glucose levels by measuring glycated haemoglobin. A blood sugar reading shows your glucose level at a single moment in time. For single-reading reference ranges, see the normal blood sugar levels chart. People managing diabetes should also monitor hydration daily — the urine color chart provides a quick visual guide to hydration status and can flag dehydration that worsens blood glucose control.
How often should I get an A1C test?
Adults without diabetes and a normal A1C below 5.7% need testing every 3 years. People with prediabetes should retest every 6 to 12 months, and those with diabetes should test every 3 to 6 months depending on control, as shown in the testing frequency chart above. Diabetes also increases the risk of diabetic retinopathy — the eye chart guide explains visual acuity scores and why diabetic patients are advised to have an annual dilated eye exam.
What causes a falsely high A1C result?
Several conditions can cause falsely high A1C results as detailed in the A1C limitations table above. The most common cause is iron deficiency anaemia, which reduces the number of available red blood cells and makes a higher proportion appear glycated.
Can weight loss lower A1C?
Yes — every 1% of body weight lost is associated with a meaningful reduction in A1C. The intervention chart above shows that dietary changes including reduced carbohydrate intake can lower A1C by 0.3 to 2.0%.
What is a good A1C for a person without diabetes?
Below 5.7% is classified as Normal per the ADA A1C chart above. Most non-diabetic adults have A1C levels between 4.5% and 5.6%.