What counts as fluid input?

All fluid entering the body: IV infusions, oral intake (water, juice, soup), nasogastric (NG) feeds, blood products (packed red cells, FFP, platelets), and drug infusions delivered in saline or dextrose.

What counts as fluid output?

All fluid leaving the body: urine (measured via catheter or urinal), nasogastric drainage, wound or surgical drains, stool (especially watery/liquid), vomit, and insensible losses (sweat, respiration — commonly estimated at 500–1000 mL/day).

What is a normal 24-hour fluid balance?

A balance close to zero (±200–500 mL) is generally considered neutral. Clinical targets depend on the patient's condition — euvolemia is the usual goal, but some patients may require a deliberate positive (e.g., dehydration) or negative (e.g., fluid overload) balance.

Does this tool store patient data?

No. All calculations run in your browser and nothing is sent to a server or stored anywhere. Data clears when you reload the page or click Reset.

Can I use milliliters and liters interchangeably?

Enter all volumes in the same unit — this calculator uses milliliters (mL) throughout. Convert liters to mL by multiplying by 1000 before entering (e.g., 1.5 L = 1500 mL).

Fluid Balance Calculator

Name: Fluid Balance Calculator
Availability: InStock
Author: Nham Vu

Enter all fluid inputs and outputs to calculate net 24-hour fluid balance instantly.

Fluid Inputs

No inputs added yet.

Fluid Outputs

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24-Hour Balance Summary

Total Inputs

Total Outputs

Net Fluid Balance

No entries yet

Outputs Balance bar Inputs

Entry added

Summary

Enter all fluid inputs and outputs to calculate net 24-hour fluid balance instantly.

How it works

Enter each fluid input (IV fluids, oral, NG feeds, blood products) and click Add.
Enter each fluid output (urine, nasogastric drainage, wound drainage, stool, vomit) and click Add.
The calculator sums all inputs and outputs automatically.
Net balance = Total Inputs − Total Outputs. A positive value indicates fluid gain; negative indicates fluid loss.
Remove any entry with the delete button if it was entered in error.
Reset clears all entries for a new patient or new 24-hour period.

Use cases

ICU and ward nurses tracking hourly and 24-hour fluid balance for patients.
Physicians assessing fluid status in sepsis, heart failure, or post-operative patients.
Rapid calculation of fluid balance during patient handovers.
Teaching student nurses and junior doctors how to document intake and output.
Monitoring patients on diuretics or IV fluid resuscitation.
Documenting fluid management in critically ill pediatric patients.

Frequently Asked Questions

Last updated: 2026-07-22 · Reviewed by Nham Vu