Sodium Deficit Calculator
Enter patient weight, sex, current sodium, and target sodium to calculate the total body sodium deficit and safe correction guidance.
Use the Sodium Deficit Calculator
Patient Inputs
Typical hyponatremia range: 100–134 mEq/L
Safe initial target: 125–130 mEq/L
Results
Fill in the inputs and click Calculate.
Total Body Water (TBW)
Na deficit
Delta Na (target − current)
TBW fraction used
Summary
Enter patient weight, sex, current sodium, and target sodium to calculate the total body sodium deficit and safe correction guidance.
How it works
- Enter the patient's weight in kilograms (or pounds — select unit).
- Select sex and age group to determine the TBW fraction.
- Enter the current measured serum sodium (mEq/L).
- Enter the target serum sodium (typically 125–135 mEq/L).
- The calculator applies: Na deficit = TBW × (target Na − current Na).
- Correction rate guidance is shown based on whether the case is acute or chronic.
Use cases
- Estimating sodium replacement needs in symptomatic hyponatremia.
- Determining approximate volume of saline infusion required.
- Teaching clinical pharmacology and fluid/electrolyte physiology.
- Cross-checking manual calculations during clinical rounds.
- Planning correction strategy for acute vs. chronic hyponatremia.
Frequently Asked Questions
Last updated: 2026-09-19 ·
Reviewed by Nham Vu