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Corrected Calcium Calculator

Work out corrected calcium instantly with clear inputs, formula shown and shareable results.

About Corrected Calcium Calculator

Adds 0.8 mg/dL of calcium for every 1 g/dL that albumin falls below 4 g/dL, the standard correction for protein-bound calcium.

Formula

Calcium correction

Corrected Ca (mg/dL) = measured Ca + 0.8 x (4.0 - albumin g/dL); divide by 4.008 for mmol/L

Worked example

With the default values below, Corrected Calcium Calculator returns Albumin-corrected calcium of 9.16. Change any input above and every figure here is recalculated in your browser.

Inputs used

Measured total calciumaccepts 4–16 mg/dL
8.2 mg/dL
Serum albuminaccepts 1–6 g/dL
2.8 g/dL

Results

Albumin-corrected calcium
9.16 mg/dL
Corrected calcium
2.29 mmol/L
Reference band
Within the usual reference range (8.5-10.5 mg/dL)

Step by step

  1. 1Values used
  2. 2Calcium correction
  3. 3Albumin-corrected calcium= 9.16 mg/dL
  4. 4Corrected calcium= 2.29 mmol/L
  5. 5Reference band= Within the usual reference range (8.5-10.5 mg/dL)

Assumptions and limits

  • The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
  • Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
  • This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.

Frequently Asked Questions

Why is correction needed?

Roughly 40% of calcium is albumin-bound, so low albumin lowers total calcium without changing the ionised fraction.

Is ionised calcium better?

Yes, a direct ionised calcium measurement is preferred when available, particularly in critical illness.

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