Sodium Correction Rate Calculator

Written by Great Medico

Updated September 24, 2026 •2 min read

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Fluid and electrolyte decisions often start with a small equation and a careful unit check. Sodium Correction Rate Calculator makes that calculation visible without pretending the number replaces bedside assessment.

What this calculator does

Sodium Correction Rate Calculator uses Age / sex category, Weight, Serum sodium, Replacement fluid, Fluid sodium, and Aimed sodium change to calculate estimated serum-sodium change per liter. Where supported, it also shows Correction flow, Total body water, and Fluid sodium so the primary result is easier to check. It follows the exact field flow and engine behavior in this plugin rather than describing a different calculator with the same name. Fluid and electrolyte formulas are sensitive to units, timing, ongoing losses, kidney function, and rapidly changing physiology. They are most useful as structured estimates alongside repeat measurements and bedside assessment.

How to use it

Enter or select Age / sex category, Weight, Serum sodium, Replacement fluid, Fluid sodium, and Aimed sodium change. Use the units offered by the calculator and keep paired laboratory or treatment values from the same clinical episode whenever the formula assumes that. If an entry is unknown, do not substitute a guess simply to obtain a number.

How the calculation works

The engine estimates total body water from weight and the selected age/sex factor, identifies the sodium concentration of the chosen replacement fluid, and applies an Adrogué–Madias-style change per liter: (fluid sodium − serum sodium) ÷ (TBW + 1). It also estimates the flow needed to reach the entered aimed change.

Example

Using the sample values prefilled in this calculator, the primary result is 0.674 mmol/L per L (Serum sodium change per liter), Correction flow is 741.4 mL/h, and Total body water is 42 L. This example demonstrates the plugin’s own calculation path; replace the sample inputs with verified values before interpreting a real result.

How to interpret the result

Read the output as serum sodium change per liter from the implemented formula. Compare it with measured values, volume status, ongoing inputs/losses, and serial trends; treatment decisions should not rely on the calculator in isolation.

Limitations and notes

Predictive sodium-change formulas can perform poorly when urine output, electrolyte-free water clearance, ongoing infusions, or kidney function change. Frequent measured sodium values are required during active correction.