What Are Normal Fasting Blood Glucose Levels?
Reference values in health come from large population studies (NHANES, WHO). They provide a framework for interpreting your results, but your personal context matters most. Normal <100 mg/dL. Prediabetes 100-125. Diabetes ≥126. Values are current as of 2026 and reviewed periodically to keep you informed.
When to use this calculator
- Students and professionals in healthcare and endocrinology
- Validate lab results against standard reference ranges
- Educational reference for understanding diabetes classification
- Quick reference in clinical and personal health management
- Understanding fasting glucose interpretation and diagnosis criteria
Calculation Example
- Typical fasting glucose value
- Classification result
How it works
1 min readNormal health values come from large-scale population studies (NHANES, WHO, CDC). They vary by age, sex, ethnicity, and region. These are reference guidelines; your personal medical history always takes precedence.
How It's Calculated
Fasting blood glucose is classified as:
This calculator applies the standard classification to your glucose reading, checking for typical ranges and alerting you to unusually high or low values.
Normal Reference Values for Adults
| Parameter | Normal Range |
|---|---|
| Blood Pressure | <120/80 mmHg |
| Resting Heart Rate | 60-100 bpm |
| Body Temperature | 36.1-37.2°C |
| SpO2 | 95-100% |
| Fasting Glucose | 70-100 mg/dL |
| HbA1c | <5.7% |
| Total Cholesterol | <200 mg/dL |
| LDL Cholesterol | <100 mg/dL |
| HDL Cholesterol | >40 (M) / >50 (F) |
Important Notes
This calculator is a reference tool only. For critical decisions (medical, financial, legal), consult a qualified healthcare professional. Values and formulas are current as of 2026 and reviewed periodically.
Frequently asked questions
What is a normal fasting blood glucose level?
Normal fasting glucose is less than 100 mg/dL. Values of 100-125 mg/dL indicate prediabetes, and ≥126 mg/dL suggest diabetes. These thresholds are based on international guidelines from the WHO and CDC.
How do I prepare for a fasting glucose test?
Fast for 8-10 hours before the test (water is allowed). Avoid eating, drinking, and strenuous exercise during this period. Most fasting tests are done in the morning after an overnight fast.
What does it mean if my fasting glucose is 110?
A fasting glucose of 110 mg/dL falls in the prediabetes range (100-125 mg/dL). This is higher than normal but below the diabetes threshold. Consult your doctor about lifestyle changes and monitoring.
Can medications affect fasting glucose levels?
Yes, many medications (statins, beta-blockers, diuretics, corticosteroids) can affect glucose levels. Always inform your doctor of all medications before testing and discussing results.
When should I see a doctor about elevated fasting glucose?
See your doctor if your fasting glucose is consistently above 100 mg/dL, if you have symptoms of diabetes, or if you have a family history of diabetes or cardiovascular disease.
Is fasting glucose testing accurate for diabetes diagnosis?
Fasting glucose is a reliable screening tool, but diagnosis typically requires confirming results. Additional tests like HbA1c or oral glucose tolerance test may be needed for confirmation.
What causes elevated fasting blood glucose?
Common causes include insulin resistance, type 2 diabetes, stress, certain medications, pregnancy (gestational diabetes), and metabolic disorders. A doctor can help identify the underlying cause.
Do fasting glucose levels differ between men and women?
The standard reference ranges are the same for men and women. However, pregnancy can affect glucose metabolism, and women may develop gestational diabetes during pregnancy with different diagnostic criteria.