Lessons · IV flow rate (mL/hr)
Dosage calculation
IV flow rate calculation (mL/hr) An IV pump is programmed in milliliters per hour. To find the rate, divide the total volume to be infused by the time in hours. It is the most common IV calculation on the floor.
The formula mL/hr = Volume (mL) ÷ Time (hr)
How to solve it Identify the total volume (mL) and the total time (hr). Divide volume by time. Round to a whole mL/hr the pump can be set to. Common mistakes Mixing minutes and hours - the time here must be in hours. Rounding too early and losing accuracy on longer infusions. Safety check: Double-check the ordered volume and time against the bag and the MAR before programming the pump.
Worked examples
See it solved An order reads: infuse 500 mL of D5W over 3 hours using an IV pump.
What rate (mL/hr) should the pump be set to?
Answer: 167 mL/hr
Step-by-step solution 1. Divide the volume by the time in hours
500 mL ÷ 3 hr
= 166.67 mL/hr
2. Round to a whole mL/hr the pump can be set to
166.67 mL/hr ≈ 167 mL/hr
= 167 mL/hr
An order reads: infuse 1000 mL of lactated Ringer's over 1.5 hours using an IV pump.
What rate (mL/hr) should the pump be set to?
Answer: 667 mL/hr
Step-by-step solution 1. Divide the volume by the time in hours
1000 mL ÷ 1.5 hr
= 666.67 mL/hr
2. Round to a whole mL/hr the pump can be set to
666.67 mL/hr ≈ 667 mL/hr
= 667 mL/hr
An order reads: infuse 50 mL of 0.9% normal saline over 1 hour using an IV pump.
What rate (mL/hr) should the pump be set to?
Answer: 50 mL/hr
Step-by-step solution 1. Divide the volume by the time in hours
50 mL ÷ 1 hr
= 50 mL/hr
2. Round to a whole mL/hr the pump can be set to
50 mL/hr ≈ 50 mL/hr
= 50 mL/hr
Safe number notation Every number on DoseDrill is written the safe way - and here is why it matters:
Always use a leading zero for amounts under 1: write 0.5 mg , never .5 mg . A missing zero is read as 5 - a ten-fold overdose.Never use a trailing zero after a decimal: write 5 mg , never 5.0 mg . A stray zero is read as 50 .Read the full safe-notation guide →
Keep going More worked iv flow rate (ml/hr) examples:
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Practice only - never for real medication. DoseDrill generates problems to help nursing students learn dosage calculation. It must never be used to calculate, prepare, or administer medication to an actual patient. Real administration requires an independent double-check, current drug references, and your facility's policy. A wrong dose can harm or kill - always verify with a licensed professional.