what is normal glucose level
Normal glucose levels depend on when you test, but for many adults without diabetes, a fasting blood glucose of about 70 to 99 mg/dL is considered normal, and about 2 hours after eating it is often under 140 mg/dL.
Quick Scoop
| Test time | Common normal range |
|---|---|
| Fasting (before breakfast) | 70–99 mg/dL or about 4.0–5.4 mmol/L | [10][6]
| 2 hours after eating | Under 140 mg/dL | [2][10]
| People without diabetes during the day | Often about 4.0–7.8 mmol/L | [4]
What counts as high
A fasting glucose of 100 to 125 mg/dL is commonly in the prediabetes range, and 126 mg/dL or higher is in the diabetes range if confirmed on repeat testing. After eating, values above the usual target can suggest impaired glucose control, especially if they stay elevated.
When to worry
One reading alone does not diagnose diabetes, because results can vary with food, stress, illness, and testing conditions. If you have symptoms like increased thirst, frequent urination, weight loss, or blurred vision, it is worth getting checked promptly.
Simple example
If your fasting blood sugar is 92 mg/dL, that is generally in the normal range. If it is 112 mg/dL fasting on more than one test, that falls in the prediabetes range.
Bottom line
For a quick rule of thumb: 70–99 mg/dL fasting and under 140 mg/dL 2 hours after eating are common normal targets for people without diabetes.