IV Flow Rate Calculator (mL/hr)
Convert volume and time to mL/hr for pump programming and infusion checks.
Understanding this tool
Why nurses use it
Infusion pumps are programmed in mL/hr. Nurses convert volume and time into an hourly rate for pump setup and to verify that an running infusion matches the prescription.
When to use it
Use whenever an IV order states total volume over a set number of hours — maintenance fluids, antibiotics, or fluid replacement.
Calculate
How to use this calculator
- Enter total volume (mL) from the bag or order.
- Enter infusion time in hours.
- Program the pump to the calculated mL/hr.
- Document start time and expected completion.
How the calculation works
mL/hr = Volume ÷ Time (hours). This is a direct rate: how many millilitres must run each hour to finish on time.
Formula used by this tool — verify units before applying at the bedside.
Worked example
Limitations & clinical notes
- Confirm pump library drug entry matches prescribed concentration.
- Account for line priming volume separately if required.
References
Key sources: INS — Infusion therapy standards of practice.
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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.