Lab values
Normal CBC Values
Adult reference ranges in US units with the SI equivalent. Ranges differ a little between labs; use your lab’s printed range.
| Test | US units | SI units | Notes |
|---|---|---|---|
| WBC | 4,500–11,000/mm³ | 4.5–11.0 × 10⁹/L | |
| RBC | 4.7–6.1 million/mm³ (men), 4.2–5.4 million/mm³ (women) | 4.7–6.1 × 10¹²/L (men), 4.2–5.4 × 10¹²/L (women) | |
| Hemoglobin | 14–18 g/dL (men), 12–16 g/dL (women) | 140–180 g/L (men), 120–160 g/L (women) | |
| Hematocrit | 42–50% (men), 37–47% (women) | 0.42–0.50 L/L (men), 0.37–0.47 L/L (women) | |
| Platelets | 150,000–400,000/mm³ | 150–400 × 10⁹/L | |
| Absolute neutrophil count | 2,500–8,000/mm³ | 2.5–8.0 × 10⁹/L | Below 500 (some protocols 1,000): neutropenic precautions SI: Below 0.5 × 10⁹/L (some protocols 1.0): neutropenic precautions |
Study the labs
- ABG Interpretation in 6 StepspH, PaCO₂, HCO₃⁻, compensation, anion gap and oxygenation, with worked examples
- Electrolyte ImbalancesNa, K, Ca, Mg and phos: normals, ECG clues, safe replacement, hyperkalemia steps
- Pediatric Assessment and EmergenciesPAT, vital signs, airway infections, febrile seizures, dehydration, arrest, choking and abuse
Other lab values
- Chemistry
- Coagulation
- Arterial blood gas
- Liver and pancreas
- Cardiac
- Therapeutic drug levels
- Urine
- Pregnancy and postpartum
- Newborn
- Pediatric vital signs by age
- Pediatric labs that differ from adults
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Sources
- MedlinePlus Medical Encyclopedia ranges (National Library of Medicine, reviewed 2024–2026); ABIM laboratory reference ranges (January 2026) for hemoglobin, hematocrit and potassium; Merck Manual for ionized calcium; the heparin label for the aPTT target; ASHP/IDSA 2020 vancomycin guideline
For education and exam preparation only. Follow your institution’s protocols. Typical adult values for study. Follow your local protocols and medical direction.