What this calculator does
Delta ratio (delta gap) works out compares the rise in anion gap to the fall in bicarbonate, to spot a mixed acid-base disorder. 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
FormulaDelta ratio = (AG − 12) / (24 − HCO3), where AG = Na − (Cl + HCO3)
The inputs explained
| Field | What to enter |
|---|---|
| Sodium (mEq/L) | A number, measured in mEq/L. Starts at 140. |
| Chloride (mEq/L) | A number, measured in mEq/L. Starts at 100. |
| Bicarbonate (HCO3) (mEq/L) | A number, measured in mEq/L. Starts at 14. |
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 sodium
Every other input is held at the calculator’s starting values while sodium varies. Select any row to load that scenario into the calculator.
How the answer changes with sodium
| Sodium (mEq/L) | Delta ratio | Anion gap used | Reading |
|---|---|---|---|
| 70 | -5.60 | -44.0 mEq/L | Hyperchloremic (normal anion-gap) metabolic acidosis |
| 105 | -2.10 | -9.0 mEq/L | Hyperchloremic (normal anion-gap) metabolic acidosis |
| 140 | 1.40 | 26.0 mEq/L | Pure high anion-gap metabolic acidosis |
| 210 | 8.40 | 96.0 mEq/L | High anion-gap acidosis with a concurrent metabolic alkalosis or pre-existing compensated respiratory acidosis |
| 280 | 15.40 | 166.0 mEq/L | High anion-gap acidosis with a concurrent metabolic alkalosis or pre-existing compensated respiratory acidosis |
| 420 | 29.40 | 306.0 mEq/L | High anion-gap acidosis with a concurrent metabolic alkalosis or pre-existing compensated respiratory acidosis |