Tool 43/54·Charts & Guides
Normal, prediabetes, and diabetes blood glucose ranges — fasting, post-meal, and A1C — across all age groups.
Medical Disclaimer
This chart is for educational reference only and does not constitute medical advice. Blood sugar targets vary by individual. Always consult a licensed healthcare provider for diagnosis, treatment, or interpretation of your results.
Units
Age Group
Values in mg/dL · Source: American Diabetes Association Standards of Care 2024
| Condition | Fasting(8+ hrs no food) | 2-hr Post-Meal(after eating) | Random(any time) | A1C(3-month avg) |
|---|---|---|---|---|
| Normal Normal | 70–99mg/dL | <140mg/dL | 70–139mg/dL | <5.7% |
| Prediabetes Prediabetes 5–10% weight loss can prevent or delay progression to T2D | 100–125mg/dL | 140–199mg/dL | 140–199mg/dL | 5.7–6.4% |
| Diabetes Type 1 Diabetes ADA target ranges; individualize with your physician | 80–130mg/dL | <180mg/dL | Variesmg/dL | <7.0% |
| Diabetes Type 2 Diabetes Less stringent targets (A1C <8%) may suit some individuals | 80–130mg/dL | <180mg/dL | Variesmg/dL | <7.0% |
To convert between units use these simple formulas:
Example: 100 mg/dL ÷ 18 = 5.6 mmol/L
Normal Fasting
70–99 mg/dL
Prediabetes Fasting
100–125 mg/dL
Diabetes Fasting
≥126 mg/dL
A1C reflects average blood glucose over 2–3 months. One percentage point equals roughly 29 mg/dL (1.6 mmol/L) in average glucose.
Low (Hypoglycemia)
<70 mg/dL
Treat with fast-acting carbs immediately
High (Hyperglycemia)
>240 mg/dL
Contact your healthcare provider
Blood sugar — or blood glucose — is the concentration of glucose in your bloodstream. Your body regulates it tightly using insulin, a hormone produced by the pancreas. When this system breaks down, levels can remain chronically elevated, damaging blood vessels, nerves, and organs over time. Knowing what numbers are healthy for your age and situation is the first step toward prevention and management.
How These Ranges Are Determined
The ranges in this chart are based on the American Diabetes Association (ADA) Standards of Medical Care in Diabetes 2024 and World Health Organization (WHO) diagnostic criteria. Diagnostic thresholds (e.g., fasting ≥126 mg/dL for diabetes) are the same regardless of age; however, treatment targets are individualized — particularly for children and older adults — based on hypoglycemia risk and overall health status.
Diagnostic thresholds for diabetes are universal, but treatment targets shift with age and life stage. Children going through puberty experience temporary insulin resistance driven by growth hormones, which can make blood sugar harder to control. Teens with Type 1 diabetes must balance tight control with the real risk of hypoglycemia during sports and erratic schedules. Adults in their prime benefit from strict targets to prevent long-term complications. Older adults, especially those with multiple chronic conditions, may tolerate slightly higher levels to avoid dangerous low-sugar episodes that increase fall and cardiovascular risk.
What you eat has a direct, measurable effect on your blood glucose within minutes of a meal. Refined carbohydrates — white bread, sugary drinks, candy — are digested rapidly, causing a sharp post-meal spike. Foods rich in fiber, protein, and healthy fats slow digestion and blunt the glucose rise. Practical strategies include:
When to See a Doctor
If your fasting blood sugar is consistently 100 mg/dL or higher, or your post-meal readings exceed 140 mg/dL regularly, speak with a healthcare provider. Early intervention — through diet, exercise, and sometimes medication — can prevent or significantly delay the progression from prediabetes to Type 2 diabetes. Do not use this chart to self-diagnose or change medications.
01
A normal fasting blood sugar (measured after at least 8 hours without food) is between 70 and 99 mg/dL (3.9–5.5 mmol/L) for most adults. A reading of 100–125 mg/dL (5.6–6.9 mmol/L) indicates prediabetes, while 126 mg/dL (7.0 mmol/L) or higher on two separate tests points to diabetes.
02
Yes, slightly. The diagnostic thresholds set by the American Diabetes Association are the same across age groups, but clinical targets for people already managing diabetes are adjusted. Older adults (60+) with complex health profiles may have more relaxed A1C targets (under 8%) to reduce the risk of dangerous hypoglycemia, whereas children with Type 1 diabetes aim for under 7%.
03
For people without diabetes, blood sugar should return below 140 mg/dL (7.8 mmol/L) two hours after a meal. A reading of 140–199 mg/dL (7.8–11.0 mmol/L) at the 2-hour mark suggests impaired glucose tolerance (prediabetes). Levels of 200 mg/dL (11.1 mmol/L) or above at 2 hours indicate diabetes.
04
Blood sugar below 70 mg/dL (3.9 mmol/L) is considered hypoglycemia and can cause shakiness, confusion, or loss of consciousness — treat immediately with fast-acting carbohydrates. Readings above 240 mg/dL (13.3 mmol/L) are generally considered high and may require medical attention. Levels consistently above 180 mg/dL (10.0 mmol/L) after meals can cause long-term organ damage if left unmanaged.
05
A1C (glycated hemoglobin) reflects your average blood sugar over the past 2–3 months. It is expressed as a percentage. Below 5.7% is normal, 5.7–6.4% indicates prediabetes, and 6.5% or higher on two tests confirms diabetes. For people already diagnosed with diabetes, most guidelines recommend keeping A1C below 7% to reduce complication risk.
06
Diet is one of the most powerful levers for managing blood sugar. Foods high in refined carbohydrates and added sugars cause rapid glucose spikes. Eating balanced meals rich in fiber, lean protein, and healthy fats slows glucose absorption and reduces post-meal peaks. Even small changes — like choosing whole grains over white bread, or adding vegetables to every plate — can measurably improve fasting levels and A1C over time.