What this calculator does
Corrected calcium for albumin works out adjusts a total calcium reading for a low albumin level, using the Payne formula. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaCorrected Ca = measured Ca + 0.8 × (4.0 − albumin)
The inputs explained
| Field | What to enter |
|---|---|
| Measured total calcium (mg/dL) | A number, measured in mg/dL. Starts at 8.5. |
| Serum albumin (g/dL) | A number, measured in g/dL. Starts at 3. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with measured total calcium
Every other input is held at the calculator’s starting values while measured total calcium varies. Select any row to load that scenario into the calculator.
How the answer changes with measured total calcium
| Measured total calcium (mg/dL) | Corrected calcium | Measured calcium | Reference range for corrected calcium |
|---|---|---|---|
| 4.25 | 5.05 mg/dL | 4.25 mg/dL | 8.5 - 10.2 mg/dL |
| 6.38 | 7.18 mg/dL | 6.38 mg/dL | 8.5 - 10.2 mg/dL |
| 8.5 | 9.30 mg/dL | 8.50 mg/dL | 8.5 - 10.2 mg/dL |
| 12.75 | 13.55 mg/dL | 12.75 mg/dL | 8.5 - 10.2 mg/dL |
| 17 | 17.80 mg/dL | 17.00 mg/dL | 8.5 - 10.2 mg/dL |
| 25.5 | 26.30 mg/dL | 25.50 mg/dL | 8.5 - 10.2 mg/dL |