How to use the anion gap calculator
Calculate the anion gap from serum sodium, chloride and bicarbonate levels. Enter sodium, chloride, bicarbonate in the fields above; the anion gap is computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “anion gap”, “blood acid base anion gap”, “sodium minus chloride and bicarbonate”, “calculate anion gap”, “find anion gap”.
Formula
Variables
- na — Sodium (mmol/L)
- cl — Chloride (mmol/L)
- hco3 — Bicarbonate (mmol/L)
Worked example
With sodium = 140 mmol/L, chloride = 104 mmol/L, bicarbonate = 24 mmol/L, the calculator gives anion gap ≈ 12 mmol/L.
Frequently asked questions
What is the anion gap calculator used for?
Calculate the anion gap from serum sodium, chloride and bicarbonate levels. It helps with questions such as “anion gap”, “blood acid base anion gap”, “sodium minus chloride and bicarbonate”.
What is the formula for the anion gap calculation?
Anion gap (mmol/L) = na-(cl+hco3). Here na is sodium (mmol/L), cl is chloride (mmol/L), hco3 is bicarbonate (mmol/L).
What inputs do I need for the anion gap calculator?
You need sodium in mmol/L, chloride in mmol/L, bicarbonate in mmol/L. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the anion gap calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the anion gap result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.