24-Hour Fluid Balance Calculator
Sum intake and output to calculate net fluid balance over a shift or 24-hour period.
Understanding this tool
Why nurses use it
Twenty-four-hour fluid balance (intake minus output) tracks hydration status in heart failure, AKI, post-operative care, and sepsis resuscitation. Nurses chart I&O; this tool sums totals quickly.
When to use it
Use at end of shift or 24-hour period when reviewing oral + IV intake against urine and other losses.
Calculate
How to use this calculator
- Sum all intake (oral, IV, enteral) for the period.
- Sum all measurable output (urine, drains, vomit, etc.).
- Calculate net balance and trend with weight and clinical exam.
How the calculation works
Net balance = Total intake − Total output (mL). Positive balance suggests fluid retention; negative suggests deficit — interpret with diagnosis and ongoing losses.
Formula used by this tool — verify units before applying at the bedside.
Worked example
Limitations & clinical notes
- Insensible losses and third-spacing are not captured.
- 24-hour totals should align with charted I&O documentation.
References
Key sources: NICE — Intravenous fluid therapy in adults.
Don’t miss new nursing tools
Subscribe for alerts when we add calculators, clinical scores, and reference updates to NurseOnShift.
Disclaimer: This calculator is for educational and bedside double-check purposes only. It does not replace institutional protocols, prescriber orders, pharmacist verification, or clinical judgment. Always follow your local policies — especially for high-risk medications, infusions, pediatrics, and critical care. If the patient is acutely unwell, escalate immediately rather than relying on any calculator output.