An IV order calls for 1000 mL of normal saline to be infused at 167 mL per hour. How many hours will the infusion take, rounded to the nearest hour?

An IV order calls for 1000 mL of normal saline to be infused at 167 mL per hour. How many hours will the infusion take, rounded to the nearest hour?

• A. 5 hours
• B. 6 hours
• C. 7 hours
• D. 8 hours

Answer: (B)

Time needed for an IV infusion equals the total volume divided by the infusion rate. So, 1000 mL ÷ 167 mL/hour ≈ 5.99 hours, which rounds to 6 hours. Checking the math: 6 hours at 167 mL/hour would deliver about 1002 mL, very close to 1000 mL, supporting 6 hours as the correct rounding. Delivering for 5 hours would be only about 835 mL, and 7 hours would be about 1169 mL, farther from the target.

Time needed for an IV infusion equals the total volume divided by the infusion rate. So, 1000 mL ÷ 167 mL/hour ≈ 5.99 hours, which rounds to 6 hours. Checking the math: 6 hours at 167 mL/hour would deliver about 1002 mL, very close to 1000 mL, supporting 6 hours as the correct rounding. Delivering for 5 hours would be only about 835 mL, and 7 hours would be about 1169 mL, farther from the target.