Blood Sugar Chart: Normal Blood Sugar Levels
Without diabetes, a fasting level of 99 mg/dL (5.5 mmol/L) or below is under the prediabetes range. For many adults with diabetes, the ADA target is 80 to 130 mg/dL (4.4 to 7.2 mmol/L) before meals and under 180 mg/dL (10.0 mmol/L) one to two hours after a meal starts. Check a reading below or print the chart.
Where does my reading fall?
The bar uses the five CGM bands from the international consensus (below 54, 54 to 69, 70 to 180, 181 to 250, above 250 mg/dL). A range is not a diagnosis. Nothing you type leaves your browser.
Blood sugar ranges for diagnosis
These are the ranges clinicians use to classify lab results in people who are not pregnant. They are published by the ADA and summarized by the NIDDK. A single result is not a diagnosis.
| Test | Under the prediabetes range (mg/dLmmol/L) | Prediabetes range | Diabetes range |
|---|---|---|---|
| Fasting plasma glucose (no calories for 8 hours) | ≤ 99≤ 5.5 | 100–1255.6–6.9 | ≥ 126≥ 7.0 |
| 2 hours after a 75 g glucose drink (lab test) | ≤ 139≤ 7.7 | 140–1997.8–11.1 | ≥ 200≥ 11.1 |
| Random, with classic symptoms | n/a | n/a | ≥ 200≥ 11.1 |
Sources: NIDDK diagnosis table; ADA Standards of Care 2026, Tables 2.1 and 2.2. Without clear symptoms, diagnosis needs two abnormal results. See also the A1C chart.
Targets for adults who have diabetes
| When | Target (mg/dLmmol/L) | Source |
|---|---|---|
| Before meals | 80–1304.4–7.2 | ADA 2026, Table 6.3 |
| 1 to 2 hours after a meal starts (peak) | < 180< 10.0 | ADA 2026, Table 6.3 |
| CGM time in range | 70–1803.9–10.0, more than 70% of the time | ADA 2026, Table 6.2 |
| CGM time below 70 / below 54 | under 4% / under 1% of the time | ADA 2026, Table 6.2 |
| CGM time above 180 / above 250 | under 25% / under 5% of the time | ADA 2026, Table 6.2 |
These are goals for many nonpregnant adults. The ADA says stricter or looser goals can suit some people. Your care team sets yours.
Low and high warning lines
| Reading (mg/dLmmol/L) | What the source says |
|---|---|
| < 70< 3.9 | ADA hypoglycemia level 1 (down to 54). Treat it: rule of 15. |
| < 54< 3.0 | ADA level 2. The CDC calls it severe and says someone may need to help. |
| ≥ 250≥ 13.9 | CDC: when sick or at this level, test for ketones. See blood sugar of 250. |
| ≥ 300≥ 16.7 | CDC: if it stays here, go to the ER or call 911. See blood sugar of 300. |
Blood sugar levels by age
The diagnosis ranges above do not depend on age. What changes with age is the goal for a person who already has diabetes. The ADA’s framework for older adults gives looser ranges as health becomes more complex, because the risk of low blood sugar can outweigh the benefit of tight control.
| Older adult health status | Fasting or before meals | Bedtime |
|---|---|---|
| Healthy | 80–1304.4–7.2 | 80–1804.4–10.0 |
| Complex or intermediate | 90–1505.0–8.3 | 100–1805.6–10.0 |
| Very complex or poor health | 100–1805.6–10.0 | 110–2006.1–11.1 |
ADA Standards of Care 2026, Table 13.2. For children and teens, and in pregnancy, the care team sets glucose targets; we do not list numbers for them here.
Normal blood sugar for type 2 diabetes
The type of diabetes does not change the ADA targets above. For an adult with type 2 diabetes who is not pregnant, the common targets are the same 80 to 130 before meals and under 180 after. What differs between people is the risk of lows: some medicines can cause them, and others rarely do. That is one reason your goal may differ. Ask your care team what to aim for and how often to check.
How to use a chart well
- Context matters. A reading taken after a walk, a big meal, illness or poor sleep means different things.
- Look for patterns, not single numbers. The blood sugar log makes patterns visible and prints for appointments.
- Meters and sensors can disagree by some percent. Recheck a surprising number, and follow your care team’s plan when symptoms do not match the reading.
- Use the same unit as your meter. The converter handles mg/dL and mmol/L.
Frequently asked questions
What is a normal blood sugar level?
For someone without diabetes, the NIDDK lists a fasting plasma glucose of 99 mg/dL (5.5 mmol/L) or below, and 139 mg/dL (7.7 mmol/L) or below two hours after a 75 g glucose drink in a lab test. For many adults who have diabetes, the ADA gives before-meal targets of 80 to 130 mg/dL and a peak after-meal target under 180 mg/dL. Your care team may set different numbers.
Do normal blood sugar levels change with age?
The ranges used to classify a result do not change with age. The targets for people who already have diabetes can: the ADA gives looser ranges for older adults with complex or poor health. Children, teens and pregnancy have their own targets set by the care team.
What is a normal blood sugar level for a person with type 2 diabetes?
The ADA targets above apply to adults with type 1 or type 2 diabetes who are not pregnant: 80 to 130 mg/dL before meals and under 180 mg/dL one to two hours after a meal starts. They are a starting point, and your care team may adjust them.
Is 140 a good blood sugar after eating?
For an adult with diabetes, 140 mg/dL (7.8 mmol/L) one to two hours after a meal is under the ADA peak target of 180. Without diabetes, the 2-hour lab test for diagnosis uses a different setup (a 75 g glucose drink), so a meal reading is not a diagnosis either way.
Can I diagnose diabetes from one home reading?
No. Diagnosis uses lab tests such as fasting plasma glucose, a glucose tolerance test or A1C, and usually needs two abnormal results. A meter or sensor reading can be a reason to talk to a clinician, not a verdict.
Information only, not medical advice. Your care team may set different targets for you, and only a lab test ordered by a clinician can diagnose diabetes or prediabetes. See our medical disclaimer.
Sources
- NIDDK: Diagnosis of Diabetes and Prediabetes
- ADA Standards of Care in Diabetes—2026, Section 2: Diagnosis and Classification
- ADA Standards of Care in Diabetes—2026, Section 6: Glycemic Goals, Hypoglycemia, and Hyperglycemic Crises
- ADA Standards of Care in Diabetes—2026, Section 13: Older Adults
- Battelino T et al. Clinical targets for CGM data interpretation: international consensus on time in range. Diabetes Care 2019;42:1593
- CDC: Diabetic Ketoacidosis
Last reviewed: by the Diabetes Blogs editorial team. Information only, not medical advice.
