An IV set has a calibration of 15 gtt per mL. If the ordered rate is 25 gtt per minute, what is the rate in milliliters per minute?

An IV set has a calibration of 15 gtt per mL. If the ordered rate is 25 gtt per minute, what is the rate in milliliters per minute?

• A. 0.90 mL/min
• B. 1.25 mL/min
• C. 1.67 mL/min
• D. 2.50 mL/min

Answer: (C)

Converting IV flow from drops per minute to milliliters per minute uses the drop factor, which tells how many drops equal one milliliter. Here, 15 gtt per mL means 15 drops = 1 mL. At 25 drops per minute, the volume per minute is 25 divided by 15, so 25/15 = 1.666..., which rounds to 1.67 mL per minute. Verifying the check: 1.67 mL/min × 15 gtt/mL ≈ 25 gtt/min, which matches the ordered rate. So the rate is 1.67 mL/min.

Converting IV flow from drops per minute to milliliters per minute uses the drop factor, which tells how many drops equal one milliliter. Here, 15 gtt per mL means 15 drops = 1 mL. At 25 drops per minute, the volume per minute is 25 divided by 15, so 25/15 = 1.666..., which rounds to 1.67 mL per minute. Verifying the check: 1.67 mL/min × 15 gtt/mL ≈ 25 gtt/min, which matches the ordered rate. So the rate is 1.67 mL/min.