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Calcimator

Intake & Output Balance Calculator

Calculate 24-hour fluid balance from all intake sources (oral, IV, other) and output sources (urine, drains, other).

About this calculator

Intake and output (I&O) tracking is a routine nursing measurement that sums every fluid a patient takes in against every fluid that leaves the body over a set period, typically 24 hours. This calculator sums three intake sources -- oral intake, IV fluids, and other intake (tube feeds, blood products, irrigation) -- and three output sources -- urine output, drain output, and other output (emesis, wound drainage, stool, insensible losses) -- then reports net balance as total intake minus total output. A positive balance means the patient is retaining more fluid than is measurably leaving the body, which can reflect appropriate fluid resuscitation or can signal fluid overload depending on the clinical picture; a negative balance means measured output exceeds intake, which can reflect appropriate diuresis or can signal dehydration.

Net balance alone does not diagnose either condition -- it is one data point nurses and physicians track alongside weight, vital signs, and labs. This calculator's balance-per-hour figure simply divides the 24-hour net balance by 24 for an average hourly rate; it does not track intake and output as they occur throughout the day, so it should not be read as a real-time trend, only as a same-period average.

Inputs

mL
mL
mL
mL
mL
mL

Results

Net Balance

500 mL

Balance Per Hour

20.8 mL/hr

Total Intake2,500 mL
Total Output2,000 mL
Positive Balance1 (0=Negative, 1=Positive)
How to Use This Calculator
  1. Enter all intake sources: oral intake (mL), IV fluids (mL), and other intake (mL).
  2. Enter all output sources: urine output (mL), drain output (mL), and other output (mL).
  3. Read the fluid balance (mL): positive = net fluid retention, negative = net fluid loss.
  4. Review 24-hour totals and running balance to identify trends in fluid status.
  5. Document results in the medical record and report significant imbalances per facility protocol.

How the result changes with Urine Output

Urine OutputNet BalanceBalance Per Hour
9001,400 mL58.3 mL/hr
1,350950 mL39.6 mL/hr
2,700-400 mL-16.7 mL/hr
4,500-2,200 mL-91.7 mL/hr

What each input means

Oral Intake
Total oral fluid intake over 24 hours in milliliters (water, juice, soup, etc.).
IV Fluids
Total intravenous fluid intake over 24 hours in milliliters.
Other Intake
Other fluid intake (tube feeds, blood products, irrigation) in mL.
Urine Output
Total urine output over 24 hours in milliliters.
Drain Output
Total output from surgical drains, NG tube, chest tube, etc. in mL.
Other Output
Other fluid losses (emesis, wound drainage, stool, insensible losses) in mL.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Oral Intake = 1500, IV Fluids = 1000, Other Intake = 0, Urine Output = 1800 = 6 input(s) provided
  2. Calculate Net Balance
    Net Balance
    500 = 500
  3. Calculate Balance Per Hour
    Balance Per Hour
    20.8 = 20.8
  4. Calculate Total Intake
    Total Intake
    2500 = 2500
  5. Calculate Total Output
    Total Output
    2000 = 2000

Engine last updated . Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.

Frequently Asked Questions

What does a positive fluid balance mean?

A positive net balance means total measured intake exceeded total measured output over the period -- the patient is retaining more fluid than left the body through the tracked routes. Depending on the clinical context this can be an intended result of fluid resuscitation, or it can be an early sign of fluid overload, especially in patients with heart or kidney impairment, so it is interpreted alongside other clinical findings rather than as a diagnosis on its own.

Why are insensible losses like sweating and breathing not entered as a separate input?

This calculator groups less-precisely-measurable losses -- insensible losses along with emesis, wound drainage, and stool -- into the single "Other Output" field rather than breaking each one out, since insensible losses in particular are typically estimated rather than directly measured at the bedside. Enter a reasonable estimate for these combined losses in that field if tracking them.

Does adding IV fluids change the total output or only the total intake?

Only total intake -- IV fluids, oral intake, and other intake are summed separately from urine output, drain output, and other output, with no cross-term between the two sides. Total output depends only on the three output fields; entering more IV fluids never changes it, it only raises total intake and, through that, the net balance.

Is the balance-per-hour figure a real-time fluid trend?

No -- it is simply the 24-hour net balance divided by 24, giving an average hourly rate over the tracked period. It does not reflect how intake and output actually varied hour to hour, so a large intake early in the day followed by heavy output later would show the same average balance-per-hour as a steady rate throughout -- it is a same-period average, not a running or real-time trend.

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