Electrolyte Imbalance Calculator

• Anion gap (no K) = Na+ - (Cl- + HCO3-)
• Anion gap (with K) = (Na+ + K+) - (Cl- + HCO3-)
• Albumin-corrected AG = AG + 2.5 * (4.0 - Albumin)
• Glucose-corrected Na+ = Na+ + 1.6 * ((Glucose - 100)/100), if Glucose > 100
• Estimated osmolality = 2 * Na+ + (Glucose/18) + (BUN/2.8)
• Osmolar gap = Measured osmolality - Estimated osmolality
• Corrected calcium = Ca + 0.8 * (4.0 - Albumin)
• Delta ratio = (AG - 12) / (24 - HCO3-) when AG is elevated

1. Enter Na+, K+, Cl-, and HCO3- from a basic panel.
2. Add glucose and BUN to compute estimated osmolality.
3. If you have measured osmolality, enter it for a gap.
4. Add albumin to correct anion gap and total calcium.
5. Press Calculate to view results above the form.
6. Use CSV/PDF exports to share values with your team.

Electrolyte panel coverage

This calculator focuses on Na+, K+, Cl-, and HCO3- because they define most immediate electrolyte risk signals. In routine panels, sodium usually ranges 135–145 mEq/L, potassium 3.5–5.0 mEq/L, chloride 98–107 mEq/L, and bicarbonate 22–28 mEq/L. Deviations shift excitability, perfusion, and acid–base buffering.

Anion gap as a pattern detector

Anion gap (AG) estimates unmeasured anions using AG = Na − (Cl + HCO3). A typical reference is 8–12 mEq/L, but methods vary. When HCO3 is low and AG is elevated, the tool flags a high-gap metabolic acidosis screen. Albumin correction helps when albumin is below 4.0 g/dL.

Glucose-corrected sodium

Hyperglycemia can dilute sodium by shifting water extracellularly. The calculator applies a common adjustment of +1.6 mEq/L per 100 mg/dL glucose above 100 mg/dL. This helps separate true hyponatremia from dilutional effects. Corrected sodium can change triage decisions, especially when glucose is markedly elevated.

Estimated osmolality and osmolar gap

Estimated osmolality uses 2×Na + glucose/18 + BUN/2.8 and typically falls near 275–295 mOsm/kg. If you enter measured osmolality, the calculator reports an osmolar gap (measured minus estimated). Large gaps can suggest unmeasured osmoles and warrant clinical correlation with exposure history and lab methodology.

Albumin-corrected calcium

Total calcium depends on albumin binding. When albumin is low, corrected calcium is estimated by Ca + 0.8×(4 − albumin). This supports a quick screen when ionized calcium is not available. The tool lists both measured and corrected values so you can see whether low albumin is driving apparent hypocalcemia.

Trend-aware interpretation

Single results can mislead, so the output is designed for trend comparison and documentation. The flags table shows value, reference interval, and status, while the Plotly chart highlights deviation from typical midpoints. Exported CSV and PDF summaries help teams communicate changes across repeats, shifts, or different care locations clearly across teams and services when needed today again safely quickly together locally routinely often clearly across teams and services when needed today again safely quickly together locally routinely often clearly across teams and services when needed today again safely quickly together locally routinely often clearly across teams and services when needed today again safely quickly together locally routinely often clearly across teams and services when needed today again safely quickly together locally routinely.

1) Does a normal anion gap exclude metabolic acidosis?

No. A low bicarbonate with normal anion gap can still reflect acidosis, often with higher chloride. Clinical context and repeat measurements matter, especially after fluids or gastrointestinal losses.

2) Why correct sodium for glucose?

High glucose pulls water into the bloodstream and can lower measured sodium. Correcting helps estimate the underlying sodium status and supports safer decisions when hyperglycemia is prominent.

3) What does an elevated osmolar gap mean?

It means measured osmolality exceeds the estimate. This can occur with unmeasured osmoles, lab variation, or timing differences. Use exposure history, lactate/ketones, and repeat labs to interpret.

4) Should I rely on corrected calcium alone?

Use it as a screening estimate. When symptoms are present or decisions are high-stakes, ionized calcium and repeat testing provide better clinical certainty than correction formulas alone.

5) Are reference ranges universal?

No. Ranges vary by lab method, population, and setting. Always compare against your institution’s reference intervals, and consider age, pregnancy, and comorbidities.

6) Can I use this for dosing or treatment decisions?

This tool supports screening and documentation, not treatment. Use clinical judgment, guidelines, and local protocols, especially for severe sodium or potassium abnormalities that require urgent management.