How to Calculate IV Rates

Many drugs are administered intravenously to patients in hospitals. It is important that the IV flow rate is calculated correctly so that the patient receives the proper amount of medication over the proper amount of time. To calculate the IV rate, you must first know the total volume of the medication being administered and the drop factor specified by the doctor. The most common drop factors are 10 drops/mL, 15 drops/mL, and 60 drops/mL. You also must know the time period the medicine is to be administered over.

Instructions

• 1

  Multiply the volume by the drop factor. For example, a 1,500 mL volume x 10 drop factor = 15,000. Drop factors indicate how many drops it takes to produce a mL of the medication. In the example above, a drop factor of 10 means that every mL of medicine is dispensed over 10 drops dripped into the IV.

• 2

  Divide the number obtained in Step 1 by the timeframe over which the medicine is to be administered. The resulting number is the IV flow rate. For example, if the medicine in Step 1 is to be given over a 12 hour period, 15,000/720 (12 hours x 60 minutes) = 20.83 gtts/minute. Gtts/minute always must be programmed in whole numbers, so you would set the IV at 20 gtts/minute since you never want to round up and give too much medication.

• 3

  Set the IV to the calculated flow rate (20 gtts/min using the above example).