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Corrected calcium calculator

Calculate albumin-adjusted total calcium in mmol/L and mg/dL, or solve for measured calcium or albumin.

Enter the numeric value in the selected unit. This selector changes how the value is interpreted.

Enter the numeric value in the selected unit. This selector changes how the value is interpreted.

Adjusted calcium (mmol/L)
2.300
Adjusted calcium (mg/dL)
9.218
Measured calcium (mmol/L)
2.100
Albumin (g/L)
30.00

Estimates for information only. Not financial, medical, legal or engineering advice. See the Terms.

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How this calculator works

The equation adjusts measured total calcium to an albumin concentration of 40 g/L. Select the units before entering each number. Albumin in g/dL is multiplied by 10. The adjusted value remains an estimate of total concentration; it is not a measurement of the ionized fraction. The result is an estimate for information only and is not medical advice.

Formula

Adjusted calcium (mmol/L) = measured calcium + 0.02(40 - albumin in g/L). mg/dL = mmol/L × 4.0078000000000005.

Worked example

Measured calcium 2.1 mmol/L with albumin 30 g/L gives 2.300 mmol/L. At albumin 40 g/L, the adjustment is zero.

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Frequently asked questions

Is this an ionized concentration?

No. Protein binding and pH affect the ionized fraction. Use an appropriate laboratory measurement when clinically indicated.

Can the adjustment lower the result?

Yes. The cited equation subtracts a correction when albumin exceeds 40 g/L.

How are mg/dL values converted?

The calculation uses the molar mass of calcium. The same SI equation is used after conversion, avoiding inconsistent constants between unit systems.

Sources

Written byAmira MansourCalculator writer. Builds and tests Mathulate calculators against published sources.
Reviewed byPriya Natarajan, RDRegistered dietitian. Checks health calculators against public health guidance.

Last updated .

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