Blood Glucose 16 tested - mmol/L or mg/dL?
Most meters outside the US show mmol/L. A reading of 16 is far more likely to be 16 mmol/L than 16 mg/dL.
If it is 16 mmol/L
= 288 mg/dL. Fasting without diabetes: Diabetes range · With diabetes before a meal: High — check ketones
Full explanation for 288 mg/dL →If it really is 16 mg/dL
That is 0.9 mmol/L — severely low, below the level 2 hypoglycemia threshold of 54 mg/dL (3.0 mmol/L). Most meters show "LO" below 20 mg/dL. If the person is shaky, sweaty, confused or drowsy, treat it as a severe low: 15–20 g of fast-acting carbohydrate if they can swallow safely; if not, glucagon if available, recovery position and call 911 (US) or your local emergency number.
Full explanation for 16 mg/dL →Check for ketones
- With type 1 diabetes or on insulin: test for ketones (urine strip or blood ketone meter).
- Drink water, follow your sick-day plan and take correction insulin as prescribed.
- Do not exercise if ketones are moderate or high — it can push glucose higher.
- Without known diabetes: see a doctor today.
If you don't have diabetes — reading 16 mmol/L (288 mg/dL)
16 mmol/L (288 mg/dL) is in the diabetes range whether fasting or after a meal. A random reading of 11.1 mmol/L = 200 mg/dL or more together with typical symptoms (thirst, frequent urination, weight loss) is enough for a diagnosis — see a doctor today.
Fasting prediabetes cut-off: the ADA uses 5.6 mmol/L (100 mg/dL); the WHO uses 6.1 mmol/L (110 mg/dL). This site follows the ADA.
Fasting (8+ hours without food)
Diabetes range2 hours after eating (or glucose tolerance test)
Diabetes rangeIf you have diabetes — reading 16 mmol/L (288 mg/dL)
16 mmol/L (288 mg/dL) is high. Above 13.3 mmol/L = 240 mg/dL, people with type 1 diabetes or on insulin should check for ketones (see the box above).
Before a meal / fasting
High — check ketones1–2 hours after a meal
High — check ketonesTargets for most non-pregnant adults (American Diabetes Association (ADA) Standards of Care). Your own targets may be different — for example in pregnancy, for children, older adults or people prone to lows. See pregnancy targets.
288 mg/dL as an average: HbA1c 11.7%
If 288 mg/dL were your average glucose over two to three months, it would match an HbA1c of about 11.7% (above the common treatment goal of below 7%). A single reading says little about your HbA1c — it is the long-term average that counts. Learn more in how to measure blood sugar.
Make sure the number is right
- Wash and dry your hands before a finger-stick: fruit juice or sugar on the skin can raise the result a lot.
- Home meters may differ from a lab value by up to about 15%. At 288 mg/dL that means roughly 245–331 mg/dL.
- CGM sensors measure tissue fluid and lag 5–15 minutes behind blood when glucose changes quickly — confirm lows with a finger-stick.
Check another reading
Nearby values
Sources: ADA Standards of Care · ADA: Hyperglycemia · ADAG study (HbA1c and average glucose) · WHO: Definition and diagnosis of diabetes · MedlinePlus: Blood glucose test
This page explains one reading in general terms. It is not a diagnosis or a treatment instruction. Follow the plan agreed with your doctor or diabetes team.