Blood sugar levels for adults aged 30 to 45
Identical published thresholds. This is the age band in which a first abnormal result most often turns up on a routine health check.
Nothing here can diagnose you, and nothing here is a treatment plan. Blood glucose results are interpreted by a doctor alongside your history, your symptoms and a repeat test — a single number on a screen is not a diagnosis. If any reading concerns you, or if you feel unwell, see a doctor rather than a website.
The criteria below are the same at 32 as at 62. What changes across this decade and a half is the probability of finding something — this is the band in which a company health check or a pre-employment panel most commonly produces a first raised fasting glucose.
Two things are worth knowing before reading such a result. First, a single value is not a diagnosis; the published criteria require confirmation, normally a repeat of the same test on another day. Second, a fasting value in the 100–125 mg/dL band is the prediabetes range on ADA criteria but sits below WHO's impaired-fasting-glucose threshold of 110 mg/dL — so the identical result can be flagged on one report and not on another.
Neither point is a reason to relax and neither is a reason to panic. Both are reasons to take the report to a doctor rather than to a search engine.
The published criteria — unchanged for this age band
This is the same table that appears on every page of this site, because the thresholds genuinely are the same. If a chart shows you a different range for this age, that chart is not quoting a health authority.
| Result | Published value | Same value in mmol/L |
|---|---|---|
| Fasting plasma glucose — at least 8 hours with no food | ||
| Normal | 99 mg/dL or below | 5.5 mmol/L or below |
| Prediabetes | 100 to 125 mg/dL | 5.6 – 6.9 mmol/L |
| In the diabetes range | 126 mg/dL or above | 7.0 mmol/L or above |
| 2 hours into a 75 g oral glucose tolerance test | ||
| Normal | 139 mg/dL or below | 7.7 mmol/L or below |
| Prediabetes | 140 to 199 mg/dL | 7.8 – 11.0 mmol/L |
| In the diabetes range | 200 mg/dL or above | 11.1 mmol/L or above |
| HbA1c | ||
| Normal | below 5.7% | — |
| Prediabetes | 5.7% to 6.4% | — |
| In the diabetes range | 6.5% or above | — |
| Random (any time of day) | ||
| In the diabetes range | 200 mg/dL or above with the classic symptoms of high blood glucose | 11.1 mmol/L or above |
A result in the diabetes range is not a diagnosis. Published criteria require confirmation — normally a repeat of the same test on a separate day, unless someone has unmistakable symptoms with a clearly raised glucose. Your doctor makes that call, not a chart.
Source: American Diabetes Association, Standards of Care in Diabetes — Diagnosis and Classification of Diabetes. Diabetes Care 2025;48(Suppl. 1):S27–S49. Link
Source: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health — Diabetes Tests & Diagnosis. Link
And the WHO version
| Category | Fasting plasma glucose | 2 h after a 75 g glucose load |
|---|---|---|
| Diabetes | 7.0 mmol/L (126 mg/dL) or above | 11.1 mmol/L (200 mg/dL) or above |
| Impaired fasting glucose (IFG) | 6.1 – 6.9 mmol/L (110–125 mg/dL) | below 7.8 mmol/L (140 mg/dL), if measured |
| Impaired glucose tolerance (IGT) | below 7.0 mmol/L (126 mg/dL) | 7.8 – 11.0 mmol/L (140–199 mg/dL) |
WHO also accepts a random plasma glucose of 11.1 mmol/L (200 mg/dL) or above, in the presence of symptoms, and — since the 2011 consultation — an HbA1c of 6.5% or above. WHO is explicit that an HbA1c below 6.5% does not rule diabetes out.
Source: World Health Organization / International Diabetes Federation. Definition and diagnosis of diabetes mellitus and intermediate hyperglycaemia: report of a WHO/IDF consultation. Geneva: WHO, 2006. Link
PeakForm is a training and accountability programme. It is not a treatment for diabetes or prediabetes, it is not a substitute for your doctor's advice, and nothing on this site should be acted on before speaking to one.
Common questions
What is a normal fasting blood sugar level?
What is a normal sugar level after eating?
Does the normal blood sugar range change with age?
Is one high reading enough to diagnose diabetes?
What is the normal blood sugar level for adults aged 30 to 45?
Thresholds from the ADA Standards of Care, NIDDK and the WHO/IDF 2006 consultation. General information only — NOT medical advice, and never a diagnosis. Only a doctor can interpret your results and diagnose or treat diabetes. If a reading concerns you, see a doctor rather than a website. Every threshold, equation and glycemic index value used on this site is listed with its publication on the data & method page.