Electrolyte Panel
The electrolyte panel groups sodium, potassium, chloride, bicarbonate, calcium, phosphorus, and calculated serum osmolality from the standard chemistry profile. Together they describe fluid balance, acid-base status, renal handling, mineral physiology, and the concentration of dissolved particles. The summary table below shows each analyte's population range (P5 to P95) and median for US adults age 20 and over.
Also listed under Metabolic , Renal , Electrolytes .
Population Reference Ranges (US adults, age 20+)
| Analyte | P5–P95 | Median (P50) | Unit |
|---|---|---|---|
| Sodium | 136–144 | 141 | mmol/L |
| Potassium | 3.6–4.7 | 4.1 | mmol/L |
| Chloride | 97–106 | 101 | mmol/L |
| Bicarbonate | 22–29 | 26 | mmol/L |
| Calcium | 8.7–9.9 | 9.3 | mg/dL |
| Phosphorus | 2.7–4.4 | 3.6 | mg/dL |
| Calculated Serum Osmolality | 273–290 | 281 | mmol/kg |
Population percentiles for US adults age 20 and over (NHANES 2017-2020), pooled across sex and age. These describe where values sit in the population, not clinical reference intervals.
Frequently Asked Questions
Why are electrolytes shown together as a panel?
Sodium, potassium, chloride, and bicarbonate reflect overlapping fluid, renal, and acid-base physiology. Calcium and phosphorus add mineral context, while calculated serum osmolality summarizes contributions from sodium, glucose, and BUN.
Why are electrolyte distributions so narrow?
The body regulates these analytes through hormones, kidney handling, and cellular buffering. Their population distributions are generally compact, although each analyte has its own pattern.
What do the values in the summary table represent?
Each row shows the population range (5th to 95th percentile) and the median for US adults age 20 and over, pooled across sex and age from NHANES 2017-2020. They describe where values sit across the population, not clinical reference intervals set by a laboratory. The per-analyte pages break these down further by sex and age group.