Blood sugar reference
Blood sugar levels: diagnostic ranges and monitoring targets
Understand the difference between laboratory criteria used to diagnose diabetes and individualized blood sugar targets used for day-to-day monitoring.
Diagnostic laboratory ranges and daily monitoring targets answer different questions. A home meter reading cannot diagnose diabetes, and personal targets should be set with a qualified healthcare professional.
Diagnosis is different from daily monitoring
Clinicians diagnose diabetes using standardized laboratory tests such as A1C, fasting plasma glucose, or an oral glucose tolerance test. People already managing diabetes may use a meter or continuous glucose monitor to follow individualized treatment targets.
ADA laboratory criteria for diagnosis
| Laboratory test | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| A1C | Below 5.7% | 5.7–6.4% | 6.5% or higher |
| Fasting plasma glucose | Below 100 mg/dL | 100–125 mg/dL | 126 mg/dL or higher |
| 2-hour oral glucose tolerance test | Below 140 mg/dL | 140–199 mg/dL | 200 mg/dL or higher |
Typical monitoring targets for many adults with diabetes
The American Diabetes Association suggests the following targets for many nonpregnant adults with diabetes. Your targets may be different based on age, other conditions, medications, pregnancy, and your treatment plan.
| Timing | Typical target |
|---|---|
| Before a meal | 80–130 mg/dL (4.4–7.2 mmol/L) |
| 1–2 hours after starting a meal | Below 180 mg/dL (below 10.0 mmol/L) |
Make each logged reading more useful
- Record whether the reading was fasting, before a meal, or after a meal.
- For post-meal readings, note the time from the start of the meal.
- Use the unit shown by your meter: mg/dL or mmol/L.
- Add brief context such as activity, illness, or medication only when your care plan calls for it.
- Look for repeated patterns and discuss them with your healthcare team rather than changing treatment yourself.
Primary sources
We link directly to the organizations responsible for the medical guidance used on this page.
A useful next step
Keep BP and blood sugar records organized.
CardioLog helps families record readings, notice patterns, and export a clear report—100% offline, with no account required.
Continue reading
Related CardioLog guides
Blood pressure reference
Blood pressure chart
For most adults, normal blood pressure is below 120/80 mm Hg. A single reading does not confirm a diagnosis; healthcare professionals look at repeated, correctly taken measurements and your individual health situation.
Read guideHome measurement guide
Accurate home BP readings
Accurate home readings depend on a validated upper-arm monitor, the correct cuff size, five quiet minutes of rest, supported posture, and consistent technique.
Read guideCaregiver guide
Tracking BP for parents
A good caregiver record is consistent, respectful, and easy for a healthcare professional to review. Track only what is useful, keep each person’s history separate, and follow the measurement plan provided by their care team.
Read guide