A 750 mL bag of normal saline is to be infused at 125 mL/h. How long will the infusion take?

A 750 mL bag of normal saline is to be infused at 125 mL/h. How long will the infusion take?

• A. 4 hours
• B. 5 hours
• C. 6 hours
• D. 7 hours

Answer: (C)

The time for an IV infusion is found by dividing the total volume to be infused by the infusion rate, since the rate tells you how many milliliters pass per hour. With a 750 mL bag and a rate of 125 mL per hour, the calculation is 750 ÷ 125 = 6. Because the rate is in mL per hour, the result is in hours. So the infusion will take six hours. This also checks out because 125 mL/hour × 6 hours = 750 mL, matching the bag’s volume.

The time for an IV infusion is found by dividing the total volume to be infused by the infusion rate, since the rate tells you how many milliliters pass per hour. With a 750 mL bag and a rate of 125 mL per hour, the calculation is 750 ÷ 125 = 6. Because the rate is in mL per hour, the result is in hours. So the infusion will take six hours. This also checks out because 125 mL/hour × 6 hours = 750 mL, matching the bag’s volume.