Free Water Deficit Calculator
Calculate the free water deficit (FWD) to estimate the amount of water needed to correct hypernatremia. This tool uses the standard formula based on body weight, current sodium, and target sodium.
Was this calculator helpful?
How to use this tool?
- 1 Enter the requested data in the fields above carefully.
- 2 Click the calculate button to process the information instantly.
- 3 Analyze the detailed result and the formula explanation presented below.
- 4 You can print, share, or even embed the calculator on your own site for free.
Unlike traditional static calculators, our tools adapt to specific user needs. They include detailed explanations of the formulas used, ensuring transparency in results. Furthermore, our design is focused on user experience, eliminating distractions and focusing on what really matters: your data and conclusions.
Previous Results
| Result | Inputs | Date |
|---|
Frequently Asked Questions
Free water deficit is the estimated volume of water needed to correct hypernatremia (high sodium levels). It helps guide fluid replacement therapy.
The formula is: Deficit = Total Body Water (TBW) × (1 - Target Na⁺ / Current Na⁺). TBW is estimated as 0.6 × weight (kg) for males and 0.5 × weight for females.
Normal serum sodium levels range from 135 to 145 mEq/L. Hypernatremia is defined as sodium > 145 mEq/L.
Advertisement
Advertisement