Free Water Deficit Calculator

Free Water Deficit Calculator

Calculate free water deficit in hypernatremia and determine treatment

Free Water Deficit Results

Free Water Deficit

0
mL
Volume of free water needed

Hypernatremia Severity

Calculation Method

Free Water Deficit Formula:

FWD = TBW × [(Current Na⁺ / Target Na⁺) - 1]

Where:

• TBW = Total Body Water = 0 L

• Current Na⁺ = 0 mEq/L

• Target Na⁺ = 0 mEq/L

• FWD = 0 mL

Treatment Recommendations

Free Water Deficit Information

Mild Hypernatremia: Na⁺ 145-150 mEq/L - Usually asymptomatic

Moderate Hypernatremia: Na⁺ 150-160 mEq/L - May cause confusion, weakness

Severe Hypernatremia: Na⁺ >160 mEq/L - Can cause seizures, coma

Note: Correct hypernatremia slowly (0.5-1 mEq/L/hour) to avoid cerebral edema. Monitor closely during correction.

Scroll to Top