Blood Sugar Chart & Checker
Last updated: 2026-06-25
A normal fasting blood sugar is below 100 mg/dL. 100-125 is impaired fasting glucose (prediabetes), and 126 or higher is the suspected-diabetes range.
Enter whichever value you have — fasting glucose, 2-hour post-meal glucose or HbA1c — and the tool classifies it as normal, prediabetes or suspected diabetes. Results are for reference only, not a diagnosis.
Enter your blood sugar
Blood sugar category
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This result is a reference category for a single reading, not a diagnosis. A diabetes diagnosis is made by a clinician based on repeat tests and symptoms. For authoritative criteria see the American Diabetes Association.
How to use
- Choose the test — pick fasting glucose, 2-hour post-meal glucose or HbA1c.
- Enter the value — type your result. Glucose is in mg/dL and HbA1c is in percent.
- View the result — press Check to see the category (normal, prediabetes or suspected diabetes) and an explanation.
Normal blood sugar and diabetes criteria
Blood sugar is interpreted differently depending on when it is measured. The most common tests are fasting glucose (after 8 or more hours without food), 2-hour post-meal glucose (two hours after the start of a meal), and HbA1c (reflecting average blood sugar over the past 2-3 months). The chart below shows widely used classification thresholds.
| Test | Normal | Prediabetes | Suspected diabetes |
|---|---|---|---|
| Fasting glucose | below 100 mg/dL | 100-125 (impaired fasting glucose) | 126 or higher |
| 2-hour post-meal glucose | below 140 mg/dL | 140-199 (impaired glucose tolerance) | 200 or higher |
| HbA1c | below 5.7% | 5.7-6.4% | 6.5% or higher |
A fasting glucose below 70 mg/dL is a tendency toward hypoglycemia; if you have cold sweats, trembling or dizziness, take some sugar right away and consult a clinician if it recurs. "Prediabetes" is an important window when lifestyle changes can bring numbers back to normal, so diet, exercise and weight management matter.
A single result cannot confirm diabetes. A diagnosis is made by a clinician using repeat testing on different days or several tests together. To see normal blood pressure and blood sugar side by side, read the Normal blood pressure & blood sugar at a glance guide.
Frequently asked questions (FAQ)
What is a normal fasting blood sugar?
A normal fasting glucose (after 8 or more hours without food) is below 100 mg/dL. 100-125 mg/dL is impaired fasting glucose (prediabetes), and 126 mg/dL or higher is the suspected-diabetes range.
What is HbA1c?
HbA1c reflects your average blood sugar over the past 2-3 months. Below 5.7% is normal, 5.7-6.4% is prediabetes, and 6.5% or higher is the suspected-diabetes range. It can be measured regardless of meals.
What is the 2-hour post-meal glucose threshold?
Two hours after the start of a meal, glucose below 140 mg/dL is normal, 140-199 mg/dL is impaired glucose tolerance (prediabetes), and 200 mg/dL or higher is the suspected-diabetes range.
Does one high reading mean I have diabetes?
No. A diabetes diagnosis is usually confirmed with repeat testing, and a clinician weighs symptoms and several tests together. This tool gives a reference category for your input, not a diagnosis.
What if blood sugar is too low (hypoglycemia)?
A fasting glucose below 70 mg/dL is a tendency toward hypoglycemia. If you have cold sweats, trembling or dizziness, take some sugar quickly, and if it recurs, consult a healthcare professional.
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Last updated: 2026-06-25