Sodium Deficit (Hyponatremia, Teaching)
Na deficit (mEq) ≈ TBW (L) × (target Na − current Na); TBW ≈ 0.6×kg (men) or 0.5×kg (women).
Calculator
How it works
Many teaching sources approximate total body sodium deficit as total body water multiplied by the desired rise in serum sodium concentration.
TBW (L) ≈ 0.6 × weight (men) or 0.5 × weight (women) Na deficit (mEq) ≈ TBW × (target Na − current Na)
Limits
Does not model acute water shifts, SIADH nuances, or hypertonic saline infusion math; not for self-directed therapy.
Educational tool only—not for diagnosis or treatment decisions.