Cheatsheets
6 printable references · updated as the blueprint changes
Reduction of Risk
Lab values, ranked by how often they are tested
Updated Jul 12, 2026
If you memorise nothing else, memorise the first six rows.
- Potassium
- 3.5 – 5.0 mEq/L
- Sodium
- 135 – 145 mEq/L
- Calcium
- 9.0 – 10.5 mg/dL
- Magnesium
- 1.3 – 2.1 mEq/L
- Hemoglobin
- 12 – 18 g/dL
- Platelets
- 150,000 – 400,000/mm³
- INR (on warfarin)
- 2.0 – 3.0
- Digoxin
- 0.5 – 2.0 ng/mL
- Lithium
- 0.6 – 1.2 mEq/L
- BUN
- 10 – 20 mg/dL
- Creatinine
- 0.6 – 1.2 mg/dL
- pH
- 7.35 – 7.45