Electrolytes & renal — paediatric reference ranges
11 reference ranges. Values vary by laboratory, assay and age — always check the range printed on your own report.
| Test | Specimen | Reference range |
|---|---|---|
| Sodium | Plasma | 135–145 mmol/L |
| Potassium | Plasma | 3.5–5.0 mmol/L (neonate up to 6.0) |
| Chloride | Plasma | 98–106 mmol/L |
| Bicarbonate | Plasma | 22–26 mmol/L |
| Urea | Plasma | 2.5–6.5 mmol/L |
| Creatinine | Plasma | Infant 18–35; child 27–62 µmol/L (age-dependent) |
| Glucose (fasting) | Plasma | 3.5–5.5 mmol/L |
| Calcium (total) | Plasma | 2.2–2.7 mmol/L |
| Ionised calcium | Plasma | 1.1–1.3 mmol/L |
| Magnesium | Plasma | 0.7–1.0 mmol/L |
| Phosphate | Plasma | 1.3–2.3 mmol/L (higher in infants) |
Common questions
What is the normal sodium level in children?
Sodium (Plasma): 135–145 mmol/L.
Which electrolytes & renal tests are covered?
Sodium, Potassium, Chloride, Bicarbonate, Urea, Creatinine, Glucose (fasting), Calcium (total), Ionised calcium, Magnesium, Phosphate.
About this page
Compiled from standard paediatric references. Interpret against the child's clinical state and the ranges used by your own institution or laboratory.
Spotted something wrong? Report an error on this page — corrections from clinicians are welcome and are reviewed before any change is published.
Last reviewed 2026-08-12.