Calculated Osmolality by age and sex
What’s typical for calculated osmolality at every adult age, from a U.S. government health survey of 5,619 people, next to the usual ranges labs print.
NHANES August 2021–August 20235,619 adultsAI-verified against cited sources. Awaiting expert review
What’s typical at one age
Pick a sex and an age to see the spread among U.S. adults like that, and type a result to see where it falls.
U.S. women aged 40–49
409 people in NHANES, August 2021–August 2023.
Women aged 40–49, 409 people: median 277, middle half 275 to 280, middle 90% 272 to 284 mOsm/kg. Usual range 275 to 295.
- Median (half are lower)
- 277 mOsm/kg
- Middle half of people
- 275 to 280
- Middle 90% of people
- 272 to 284
- Usual range a lab prints
- 275 to 295
Shaded: the middle 90% and middle half of people. Dark line: the median. The bracket above: the usual range.
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Across adult life
NHANES describes the US civilian, non-institutionalized population, not a 'healthy' reference group. People with disease, on medication, fasting or not (except fasting-subsample markers), smokers and so on are all included. A percentile says where a value sits among Americans of that sex and age, not whether it is normal.
Use the left and right arrow keys to read each age. Shift moves five years.
Reference data derived from CDC/NCHS National Health and Nutrition Examination Survey (NHANES), cycles August 2021-August 2023. Analysis by bloodtesttracker.com; not endorsed by CDC, NCHS or HHS.
Every percentile
Download this table (CSV)The 25th percentile means a quarter of people in that group had a lower result. In mOsm/kg. A dash means too few people were measured for the survey to publish that number.
Women
| Age | People | 2.5th | 5th | 10th | 25th | Median | 75th | 90th | 95th | 97.5th |
|---|---|---|---|---|---|---|---|---|---|---|
| 18–29 | 402 | – | 272 | 273 | 274 | 277 | 279 | 280 | 281 | – |
| 30–39 | 444 | – | 271 | 272 | 274 | 277 | 279 | 281 | 283 | – |
| 40–49 | 409 | – | 272 | 273 | 275 | 277 | 280 | 282 | 284 | – |
| 50–59 | 469 | 270 | 272 | 275 | 277 | 280 | 282 | 285 | 286 | 288 |
| 60–69 | 732 | 269 | 272 | 275 | 278 | 281 | 283 | 286 | 287 | 289 |
| 70–79 | 438 | – | 269 | 273 | 278 | 282 | 285 | 288 | 289 | – |
| 80+ | 155 | – | – | 273 | 279 | 282 | 285 | 288 | – | – |
| All adults | 3,049 | 270 | 271 | 273 | 275 | 278 | 282 | 285 | 286 | 288 |
Men
| Age | People | 2.5th | 5th | 10th | 25th | Median | 75th | 90th | 95th | 97.5th |
|---|---|---|---|---|---|---|---|---|---|---|
| 18–29 | 359 | – | 273 | 275 | 277 | 279 | 281 | 284 | 285 | – |
| 30–39 | 346 | – | 274 | 275 | 277 | 279 | 281 | 283 | 284 | – |
| 40–49 | 322 | – | 272 | 274 | 277 | 280 | 282 | 285 | 287 | – |
| 50–59 | 378 | – | 273 | 274 | 278 | 280 | 283 | 286 | 287 | – |
| 60–69 | 597 | 267 | 272 | 274 | 278 | 281 | 283 | 286 | 287 | 289 |
| 70–79 | 425 | – | 272 | 275 | 279 | 282 | 285 | 288 | 289 | – |
| 80+ | 143 | – | – | 275 | 279 | 284 | 288 | 291 | – | – |
| All adults | 2,570 | 271 | 273 | 275 | 277 | 280 | 283 | 286 | 287 | 289 |
About these numbers
- NHANES describes the US civilian, non-institutionalized population, not a 'healthy' reference group. People with disease, on medication, fasting or not (except fasting-subsample markers), smokers and so on are all included. A percentile says where a value sits among Americans of that sex and age, not whether it is normal.
- Assays differ between labs and between NHANES cycles. Values from a commercial lab can sit a few percent higher or lower than NHANES for the same blood. Earlier cycles were bridged to the 2021-2023 method with NCHS equations where NCHS recommends it.
- Age 80 and over is top-coded at 80 in public NHANES files, so the 80+ cell mixes everyone 80 and older.
- 2021-2023 (cycle L) had a 25.7% exam response rate and no race/income oversampling; NCHS advises caution when combining it with earlier cycles.
- NHANES LBXSOSSI, calculated by the analyzer as 1.86 x Na + glucose/18 + BUN/2.8 + 9. 2021-2023 only, for the same reason as sodium (weak sodium bridging).
Reference data derived from CDC/NCHS National Health and Nutrition Examination Survey (NHANES), cycles August 2021-August 2023. Analysis by bloodtesttracker.com; not endorsed by CDC, NCHS or HHS.
Centers for Disease Control and Prevention (CDC). National Center for Health Statistics (NCHS). National Health and Nutrition Examination Survey Data. Hyattsville, MD: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, August 2021-August 2023. https://wwwn.cdc.gov/nchs/nhanes/
The usual adult range
Labs print one adult range for calculated osmolality, whatever your age.
- 18+275–295 mOsm/kg