Ethanol mg/dL → mmol/L
Convert ethanol from mg/dL to mmol/L
Sources last checked: 2026-11-03
Ethanol mg/dL → mmol/L
Convert ethanol from mg/dL to mmol/L
Converts units only; reference ranges depend on the laboratory, the assay and the patient.
What is the Ethanol mg/dL → mmol/L?
Blood ethanol is reported in mg/dL by laboratories in the USA, Turkey and parts of Europe, and in mmol/L in the UK and in SI-based toxicology literature. This converter multiplies by 0.2171, the factor that follows from the molar mass of ethanol (46.07 g/mol) and matches the AMA Manual of Style SI table. It converts a serum or plasma concentration; it does not produce a per-mille (‰) or breath-alcohol value.
When to use it
- Reading UK or SI-based toxicology papers and poisoning references after a result in mg/dL
- Estimating how much of a raised measured osmolality ethanol can explain (osmolal gap), which requires molar units
- Comparing results from laboratories that report different units
- Exam questions on toxic alcohols and the osmolal gap
When not to use it
- Converting to per-mille (‰) or legal blood-alcohol figures — ‰ is a mass fraction in whole blood, and this factor alone does not get there
- Breath-alcohol readings, which are a different matrix and unit
- Methanol, ethylene glycol or isopropanol — each has its own molar mass and therefore its own factor
How it is calculated
Ethanol (mmol/L) = ethanol (mg/dL) × 0.2171
Clinical pearls and limitations
- Converts units only; reference ranges depend on the laboratory, the assay and the patient.
- 1 mg/dL ≈ 0.217 mmol/L; 100 mg/dL ≈ 21.7 mmol/L.
- Hospital assays usually measure serum or plasma. Serum contains more water than whole blood, so a serum value is higher than the whole-blood value of the same sample — keep track of which matrix a figure refers to.
- Ethanol is osmotically active and raises measured osmolality; in mmol/L its expected contribution can be compared with the osmolal gap on the same scale, which is why the SI unit is convenient in suspected toxic-alcohol ingestion.
- Interpretation (intoxication, tolerance, legal limits) depends on context, jurisdiction and sample matrix; take thresholds from the relevant guideline or legal source, not from a converted number.
Frequently asked questions
How do I convert ethanol from mg/dL to mmol/L?
Multiply by 0.2171. For example, 80 mg/dL × 0.2171 = 17.4 mmol/L and 150 mg/dL × 0.2171 = 32.6 mmol/L.
Where does the factor 0.2171 come from?
Ethanol has a molar mass of 46.07 g/mol. 1 mg/dL is 10 mg/L, and 10 ÷ 46.07 = 0.2171 mmol/L.
Can I convert mg/dL into per-mille (‰)?
Not with this factor alone. Per-mille as used in German-speaking countries is a mass of ethanol per mass of whole blood, whereas a hospital mg/dL result is usually a serum or plasma concentration per volume. Moving between them needs a matrix conversion and a density, which forensic laboratories apply under their own rules.
Evidence and guidelines
Have a follow-up question?
Medelix answers clinical questions from current guidelines and studies — every statement with its source.
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<p><a href="https://medelix.ai/en/calculators/ethanol-mg-dl-to-mmol-l">Ethanol mg/dL → mmol/L calculator by Medelix</a></p>For healthcare professionals and medical students. These tools support, and do not replace, clinical judgement. Always check results against the original source and your local protocols.