IV Drug Calculation Tutorial

Last updated on April 30th, 2015 at 10:29 pm


Volume/Time – IV mL Rate Questions

Given a certain amount of liquid and a time period, what is the necessary IV flow rate in mL/hr? Measurement used when IV regulated electronically by infusion pump.


Volume (mL)
Time (hr)
 =  Y (Flow Rate in mL/hr)

Example: Infuse 250 mL over the next 120 minutes by infusion pump.

Volume (mL)
Time (hr)
 =  Y (Flow Rate in mL/hr)

Convert 120 minutes to hours.

  • min → hr    ( ÷ by 60 )
  • 120 min ÷ 60 = 2 hr
250 mL
2 hr
 =  125 mL/hr

Example: Ordered 1000 mL D5W IV to infuse in 10 hours by infusion pump.

Volume (mL)
Time (hr)
 =  Y (Flow Rate in mL/hr)
1000 mL
10 hr
 =  100 mL/hr




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Anna Curran. RN, BSN, PHN

Anna Curran. RN-BC, BSN, PHN, CMSRN I am a Critical Care ER nurse. I have been in this field for over 30 years. I also began teaching BSN and LVN students and found that by writing additional study guides helped their knowledge base, especially when it was time to take the NCLEX examinations.

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