What does my blood glucose reading mean?
Enter the number from your meter, CGM or lab report. You'll see what it means fasting and after a meal — for people without diabetes and for people managing diabetes — and what to do next.
Blood glucose chart at a glance
| Fasting / before a meal | 2 hours after eating | HbA1c | |
|---|---|---|---|
| Normal (no diabetes) | 70–99 mg/dL 3.9–5.5 mmol/L | below 140 mg/dL below 7.8 mmol/L | below 5.7% |
| Prediabetes | 100–125 mg/dL 5.6–6.9 mmol/L | 140–199 mg/dL 7.8–11.0 mmol/L | 5.7–6.4% |
| Diabetes (diagnosis) | 126 mg/dL or more 7.0 mmol/L or more | 200 mg/dL or more 11.1 mmol/L or more | 6.5% or more |
| Target with diabetes* | 80–130 mg/dL 4.4–7.2 mmol/L | below 180 mg/dL below 10.0 mmol/L | below 7% for many adults |
| Low (hypoglycemia) | below 70 mg/dL (3.9 mmol/L) · level 2 below 54 mg/dL (3.0 mmol/L) | ||
*American Diabetes Association (ADA) Standards of Care, most non-pregnant adults; individual targets may differ. Details: blood glucose levels chart.
Convert mg/dL and mmol/L
The US uses mg/dL; most other countries use mmol/L. 1 mmol/L of glucose is about 18 mg/dL.
Conversion table 40–400 mg/dL
Guides
Blood glucose levels
Testing & numbers
Diabetes
Quick answers
What is a normal blood sugar level?
Without diabetes: 70–99 mg/dL (3.9–5.5 mmol/L) after an overnight fast and below 140 mg/dL (7.8 mmol/L) two hours after eating. See What Is Normal Blood Sugar? Ranges by Time of Day.
What blood sugar level is dangerous?
Below 54 mg/dL (3.0 mmol/L) is significant hypoglycemia and needs immediate treatment. Above 240 mg/dL people with type 1 diabetes should check ketones; readings above 300 mg/dL or "HI" on a meter need medical advice the same day, and without known diabetes 250 mg/dL or more is a reason to see a doctor today. Confusion, vomiting or unconsciousness are emergencies — call 911 (US) or your local emergency number.
Can one reading diagnose diabetes?
No. Diabetes is diagnosed with lab tests — fasting glucose, HbA1c or a glucose tolerance test — usually confirmed by a second test. A random value of 200 mg/dL or more with classic symptoms is the exception.
What is LADA?
Latent autoimmune diabetes in adults — a slowly progressing autoimmune form often misdiagnosed as type 2. Read our LADA guide.