What is a normal urine output rate?

Normal urine output in adults is 0.5–1.0 mL/kg/hr. Values below 0.5 mL/kg/hr for more than 6 hours indicate oliguria, which may signal acute kidney injury or inadequate perfusion.

What counts as oliguria?

Oliguria is defined as urine output below 0.5 mL/kg/hr sustained for ≥6 hours, or below 0.3 mL/kg/hr for ≥12 hours (KDIGO staging). This calculator flags any reading under 0.5 mL/kg/hr as oliguric.

Polyuria in the ICU context is urine output exceeding 2.5 mL/kg/hr. It can indicate diabetes insipidus, excessive IV fluids, recovering ATN, or diuretic therapy.

How do I measure the collection period?

For hourly nursing checks, enter 1 hour and the volume drained in that hour. For 8-hour or 24-hour totals, enter the corresponding decimal hours (8 or 24) and the cumulative volume.

Does this calculator work for pediatric patients?

Yes, but pediatric thresholds differ. Normal output for children is 1–2 mL/kg/hr; oliguria is defined as <1 mL/kg/hr. This tool uses adult thresholds only — apply clinical judgment for pediatric cases.

Urine Output Rate Calculator

Calculate urine output rate in mL/kg/hr and get clinical interpretation for oliguria, normal, or polyuria thresholds.

Patient Data

Urine Volume Collected (mL)

Patient Weight (kg)

Collection Period (hours)

Result

Enter values on the left and click Calculate.

Urine Output Rate

mL/kg/hr

Adult Thresholds (ICU)

Category	Range (mL/kg/hr)
Oliguria	< 0.5
Normal	0.5 – 1.0
High-normal	1.0 – 2.5
Polyuria	> 2.5

Summary

Calculate urine output rate in mL/kg/hr and get clinical interpretation for oliguria, normal, or polyuria thresholds.

How it works

Enter the total urine volume collected in milliliters.
Enter the patient body weight in kilograms.
Enter the collection time period in hours.
The calculator divides volume by (weight × time) to get mL/kg/hr.
A clinical interpretation label is shown based on standard ICU thresholds.

Use cases

ICU nurses monitoring hourly urine output via Foley catheter.
Intensivists assessing fluid resuscitation adequacy and renal perfusion.
Nephrology teams tracking early signs of acute kidney injury (AKI).
Post-operative care teams evaluating hydration status.

Frequently Asked Questions

Last updated: 2026-09-20 · Reviewed by Nham Vu