Anion Gap Calculator
Anion gap with albumin correction and delta ratio.
Enter your values
Enter the sodium in mmol/L.
Enter the chloride in mmol/L.
Enter the bicarbonate in mmol/L.
Enter the albumin in g/dL.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Anion gap
- 12 mmol/L
- Albumin-corrected gap
- 12 mmol/L
- Interpretation
- Normal
- Delta ratio
- n/a
Working
- 1AG = 140 − (104 + 24) = 12
Quick answer
Anion gap = Na − (Cl + HCO₃); normal is 8–12 mmol/L, and it should be corrected upward by 2.5 for every 1 g/dL that albumin is below 4.
AG = Na⁺ − (Cl⁻ + HCO₃⁻)
At a glance
| What it does | Anion gap with albumin correction and delta ratio. |
|---|---|
| Category | Health |
| Inputs needed | Sodium, Chloride, Bicarbonate, Albumin |
| Main output | Anion gap |
| Formula | AG = Na⁺ − (Cl⁻ + HCO₃⁻) |
| Cost | Free — no sign-up, no download |
How to use the Anion Gap Calculator
- 1Enter sodium, chloride and bicarbonate from the metabolic panel.
- 2Add albumin for correction.
- 3Read the corrected gap and delta ratio.
Inputs explained
- Sodium(mmol/L)
- Enter the sodium in mmol/L.
- Chloride(mmol/L)
- Enter the chloride in mmol/L.
- Bicarbonate(mmol/L)
- Enter the bicarbonate in mmol/L.
- Albumin(g/dL)
- Enter the albumin in g/dL.
Worked example
Using the values the calculator loads with:
Inputs
- Sodium140 mmol/L
- Chloride104 mmol/L
- Bicarbonate24 mmol/L
- Albumin4.0 g/dL
Results
- Anion gap12 mmol/L
- Albumin-corrected gap12 mmol/L
- InterpretationNormal
- Delta ration/a
- AG = 140 − (104 + 24) = 12
Frequently asked questions
Why correct for albumin?
Albumin is the main unmeasured anion. Hypoalbuminaemia masks a raised gap, hiding a true acidosis.
What does the delta ratio tell me?
Below 0.4 suggests a pure normal-gap acidosis; above 2 suggests a coexisting metabolic alkalosis.
What do I need to enter into the Anion Gap Calculator?
Just 4 values: sodium, chloride, bicarbonate, albumin. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Anion Gap Calculator work out the answer?
Anion gap = Na − (Cl + HCO₃); normal is 8–12 mmol/L, and it should be corrected upward by 2.5 for every 1 g/dL that albumin is below 4. It applies the formula AG = Na⁺ − (Cl⁻ + HCO₃⁻) and shows the working so you can check each step by hand.
Is the Anion Gap Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.