Calculated Serum Osmolality
Median calculated serum osmolality is 281 mmol/kg across US adults, with 90% of adults between 273 and 290 mmol/kg.
Unit: mmol/kg · 12 groups · age and sex · 1 source
Filed under panels: Renal Function , Electrolyte Panel · topics: Metabolic , Renal , Electrolytes
Calculated Serum Osmolality by age and sex
| Age (years) | Males (mmol/kg) | Females (mmol/kg) |
|---|---|---|
| 20-29 | median 281 middle 90% 275 to 288 | median 278 middle 90% 271 to 286 |
| 30-39 | median 281 middle 90% 273 to 288 | median 279 middle 90% 270 to 287 |
| 40-49 | median 281 middle 90% 275 to 289 | median 279 middle 90% 272 to 286 |
| 50-59 | median 281 middle 90% 273 to 291 | median 282 middle 90% 272 to 291 |
| 60-69 | median 282 middle 90% 274 to 291 | median 283 middle 90% 274 to 291 |
| 70+ | median 284 middle 90% 274 to 294 | median 284 middle 90% 270 to 293 |
Download Calculated Serum Osmolality percentiles (CSV) Values at full stored precision; tables on this site may round for display. Licensed under CC BY 4.0.
Population Distribution
NHANES calculates serum osmolality from sodium, glucose, and blood urea nitrogen rather than measuring it with an osmometer. These survey-weighted percentiles describe the full US adult population and are not clinical laboratory intervals.
Frequently Asked Questions
Was serum osmolality measured directly?
No. NHANES calculated this value from sodium, glucose, and blood urea nitrogen on the chemistry analyzer.
What formula did NHANES use?
NHANES documents the formula as 1.86 times sodium, plus glucose divided by 18, plus BUN divided by 2.8, plus 9.
Are these clinical reference intervals?
No. They are population percentiles for a calculated chemistry value and are not laboratory decision limits.
Data Sources
Cite this data
LabNorms. Calculated Serum Osmolality population percentiles by age and sex. Data: NHANES 2017-March 2020 Pre-Pandemic. https://labnorms.com/analytes/serum-osmolality/. Licensed under CC BY 4.0. Accessed [date].
Download Calculated Serum Osmolality percentiles (CSV) Values at full stored precision; tables on this site may round for display. Licensed under CC BY 4.0.