Rex says
Same equations the textbooks use — just way less awkward. Pop in your stats and I'll tell you what the number actually means for you.
Try a scenario
Click to load — tweak from there.Inputs
Result
Anion gap (mEq/L)
12.0
Albumin-corrected gap
12.0
Delta gap
0.0
Delta ratio
0.00
Gap including potassium
16.0
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How to use this
- 1Enter sodium (mEq/L).
- 2Enter chloride (mEq/L).
- 3Enter bicarbonate (mEq/L).
- 4Enter albumin (g/dL).
- 5Enter potassium (optional) (mEq/L).
- 6Read your anion gap (meq/l) on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
Compute the serum anion gap from a basic metabolic panel, correct it for hypoalbuminemia, and get the delta gap that helps distinguish mixed acid-base disorders.
Worked example
Using the values the calculator loads with:
Inputs
- Sodium: 140 mEq/L
- Chloride: 104 mEq/L
- Bicarbonate: 24 mEq/L
- Albumin: 4 g/dL
- Potassium (optional): 4 mEq/L
Results
- Anion gap (mEq/L): 12
- Albumin-corrected gap: 12
- Delta gap: 0
- Delta ratio: 0
- Gap including potassium: 16
What each field means
Inputs
- Sodium (mEq/L)
- The sodium used in the calculation, measured in mEq/L. Starts at 140 mEq/L so you have a working example on load.
- Chloride (mEq/L)
- The chloride used in the calculation, measured in mEq/L. Starts at 104 mEq/L so you have a working example on load.
- Bicarbonate (mEq/L)
- The bicarbonate used in the calculation, measured in mEq/L. Starts at 24 mEq/L so you have a working example on load.
- Albumin (g/dL)
- The albumin used in the calculation, measured in g/dL. Starts at 4 g/dL so you have a working example on load.
- Potassium (optional) (mEq/L)
- The potassium (optional) used in the calculation, measured in mEq/L. Starts at 4 mEq/L so you have a working example on load.
Results
- Anion gap (mEq/L)
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Albumin-corrected gap
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Delta gap
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Delta ratio
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Gap including potassium
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What's a normal gap?
Roughly 8–12 mEq/L on modern analyzers when potassium is excluded. Always check your lab's reference range.
Why correct for albumin?
Albumin is the largest unmeasured anion. Low albumin masks a real elevated-gap acidosis.
Accuracy and limitations
- Population formulas describe averages; individual bodies vary, especially at the extremes of height, age, or muscle mass.
- Results do not account for medical conditions, medication, or pregnancy.
- Use this as a directional reference, not a diagnosis — talk to a clinician before acting on it.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Anion Gap Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/anion-gap
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/anion-gap" target="_blank" rel="noopener">Anion Gap Calculator — RevenueLab</a> (2026).</p>
Source: [Anion Gap Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/anion-gap) (2026).