METHOD: FORMULA Calculation of IV Drip Rate Using Gravity Flow The physician orders 1 liter of D5 W over 12 hours (83 mL/hr) Drop factor 12 drops = 1 mL Formula: Flow rate drops/minute Volume in mL/h X drop factor = Flow rate in drops per minute 60 minutes/h 83 X 12 = 996 = 16.6 or 17 drops per minute 60 60 In summary, 17 drops per minute will deliver 83 mL per hour.
17 METHOD: FORMULA IV FLOW RATES FOR PIGGYBACK MEDICATION PER GRAVITY. The patient is to receive Zincef 1 g in 50 mL D5W over 30 minutes Formula: Volume in mL X drop factor = Flow rate in drops/minute Time in minutes 50 mL X 15 gtts = 750 = 25 gtts per minute 30 minutes 30 In summary, 25 gtts per min will deliver 50 mL D5W over 30 minutes. METHOD FORMULA: Calculating The Infusion Time EX. 1000 mL of D5W is to infuse at 125 mL/hour. How many hours will it take for this liter of fluid to be completed? Formula for Infusion Time Total volume to infuse = Infusion time (h) mL/h 1000 mL = 8 hours 125 mL/h In summary, 1000 mL at 125 mL/hour will take 8 hours.