NCLEX-RN cheat sheet
Adult lab values and vital signs: quick sheet
Common adult reference ranges and the therapeutic ranges the exam expects you to know. Ranges vary slightly between laboratories.
Reviewed by a licensed nurse · 22 October 2026
Chemistry
| Test | Typical range | Unit |
|---|---|---|
| Sodium | 135 to 145 | mEq/L |
| Potassium | 3.5 to 5.0 | mEq/L |
| Chloride | 98 to 106 | mEq/L |
| Calcium (total) | 8.6 to 10.2 | mg/dL |
| Magnesium | 1.7 to 2.2 | mg/dL |
| Phosphorus | 2.5 to 4.5 | mg/dL |
| BUN | 10 to 20 | mg/dL |
| Creatinine | 0.6 to 1.2 | mg/dL |
| Fasting glucose | 70 to 99 | mg/dL |
Typical adult ranges. Always use the reference range of the lab that ran the test.
Hematology and coagulation
| Test | Typical range | Therapeutic target |
|---|---|---|
| WBC | 5,000 to 10,000 /mm3 | |
| Platelets | 150,000 to 400,000 /mm3 | |
| Hemoglobin (female) | 12 to 16 g/dL | |
| Hemoglobin (male) | 14 to 18 g/dL | |
| INR | 0.8 to 1.1 | 2 to 3 on warfarin (higher for some valves) |
| aPTT | 30 to 40 seconds | 1.5 to 2.5 times control on heparin |
Arterial blood gas
| Value | Typical range | Note |
|---|---|---|
| pH | 7.35 to 7.45 | |
| PaCO2 | 35 to 45 mmHg | Respiratory |
| HCO3 | 22 to 26 mEq/L | Metabolic |
| PaO2 | 80 to 100 mmHg |
Drug levels
| Drug | Usual therapeutic range | Unit |
|---|---|---|
| Digoxin | 0.5 to 2.0 | ng/mL |
| Lithium | 0.6 to 1.2 | mEq/L |
Adult vital signs
| Measure | Typical range | Note |
|---|---|---|
| Heart rate | 60 to 100 /min | |
| Respiratory rate | 12 to 20 /min | |
| Blood pressure | Below 120/80 | Normal category |
| Temperature | 36.5 to 37.5 C | 97.7 to 99.5 F |
| SpO2 | 95 to 100% | COPD target often 88 to 92% |
Educational content for exam preparation. It is not clinical guidance and does not replace your facility's policies, current professional guidelines or the advice of a qualified clinician.
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