Normal Lab Values for Nursing and NCLEX (Printable Chart)

By Chris Mulder, CRNA · Reviewed September 2026

The normal lab values nursing students need for the NCLEX, in one printable chart. Reference ranges vary slightly between labs; always follow your facility's values in practice.

Electrolytes

Sodium (Na)	135-145 mEq/L
Potassium (K)	3.5-5.0 mEq/L
Chloride (Cl)	98-106 mEq/L
Calcium (total)	9.0-10.5 mg/dL
Magnesium (Mg)	1.3-2.1 mEq/L
Phosphorus	3.0-4.5 mg/dL

Complete blood count (CBC)

WBC	5,000-10,000/mm³
RBC	Male 4.7-6.1; female 4.2-5.4 million/mm³
Hemoglobin	Male 14-18; female 12-16 g/dL
Hematocrit	Male 42-52%; female 37-47%
Platelets	150,000-400,000/mm³

Coagulation

PT	11-12.5 seconds
INR	0.8-1.1 (on warfarin: usually 2-3)
aPTT	30-40 seconds (on heparin: 1.5-2.5x control)

Arterial blood gases (ABGs)

pH	7.35-7.45
PaCO₂	35-45 mmHg
HCO₃	22-26 mEq/L
PaO₂	80-100 mmHg
SaO₂	95-100%

Kidney, glucose, and metabolic

BUN	10-20 mg/dL
Creatinine	0.6-1.2 mg/dL
Fasting glucose	70-99 mg/dL
Hemoglobin A1C	Less than 5.7%
Serum osmolality	275-295 mOsm/kg
Urine specific gravity	1.005-1.030

Liver and protein

Albumin	3.5-5.0 g/dL
Total bilirubin	0.3-1.0 mg/dL
ALT	4-36 units/L
AST	0-35 units/L

Lipids

Total cholesterol	Less than 200 mg/dL
LDL	Less than 100 mg/dL
HDL	Greater than 40 (men), greater than 50 (women) mg/dL
Triglycerides	Less than 150 mg/dL

Therapeutic drug levels

Digoxin	0.5-2.0 ng/mL (lower targets often used in heart failure)
Lithium	0.6-1.2 mEq/L (toxic above 1.5)
Phenytoin	10-20 mcg/mL
Theophylline	10-20 mcg/mL
Magnesium sulfate (preeclampsia)	4-7 mEq/L

Other high-yield values

BNP	Less than 100 pg/mL
CD4 count	500-1,500 cells/mm³

Memory tips

Potassium 3.5-5: "K is 3.5 to 5, keep the heart alive."
Sodium 135-145: think "1-3-5, 1-4-5."
ABGs: ROME. Respiratory Opposite, Metabolic Equal (pH vs CO₂ or HCO₃ direction).

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Frequently asked questions

Which lab values should I memorize for the NCLEX?

Prioritize electrolytes (sodium, potassium, calcium, magnesium), CBC, coagulation (PT/INR, aPTT), ABGs, glucose and A1C, BUN and creatinine, and therapeutic levels for digoxin and lithium.

Does the NCLEX give you lab reference ranges?

Sometimes a case study or exhibit includes reference ranges, but you should not count on it. Know the common normal ranges.

About the author

Chris Mulder, CRNA is a certified registered nurse anesthetist with about 15 years in nursing: 3 years as a medical ICU nurse and 12+ years in anesthesia. He has written nursing and CRNA exam prep books for over 10 years and founded Nurse Dojo to make NCLEX prep something students actually stick with.

CRNA, 12+ years
Former MICU RN
Published nursing author

Content is checked against the current NCSBN test plan and standard nursing references. It is for exam study, not clinical decision-making.