Renal & Electrolytes

Corrected Calcium Calculator

Total calcium adjusted for low albumin; an ionized calcium is more reliable in the critically ill.

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Turn on JavaScript to use this calculator, or open it in the web app.

Formula

Corrected Ca = Total Ca + 0.8 × (4.0 - Albumin)

How it is used

• Normal corrected calcium is 8.5 to 10.5 mg/dL.
• Roughly 50% of serum calcium is bound to albumin. Low albumin falsely lowers total calcium measurements.

Same formula as the app. Open it in the web app.

Related one-pagers

• Electrolyte ImbalancesCorrected Ca = Ca + 0.8 × (4.0 − albumin g/dL). Example: Ca 7.6, albumin 2.0 → 9.2 mg/dL, not truly low.
• ABG Interpretation in 6 Steps
• CRRT (Continuous Renal Replacement)

Related calculators

• Anion Gap
• BUN/Cr Ratio
• Corrected Sodium (Hyperglycemia)
• Creatinine Clearance (Cockcroft-Gault)
• CRRT Effluent Dose (mL/kg/h)
• Fractional Excretion of Sodium (FENa)
• Fractional Excretion of Urea (FEUrea)
• Free Water Deficit

For education and exam preparation only. Follow your institution’s protocols. For education and exam preparation only. Verify results independently and follow your institution’s protocols. Not a substitute for clinical judgment.