Master IV Fluid Calculation Formula for Nursing

The drop factor is the number of drops in one mL of solution, and this will be printed on the IV tubing package. Macrodrip and microdrip refer to the diameter of the needle where the drop enters the drip chamber. The drop factor is needed in order to calculate the drops per minute.

In general, a standard set is called a macrodrip, and it generally has a drop factor of 10, 12, 15, or 20 gtt/ml (drops per milliliter). Macrodrips are used for general adult IV administrations.

A microdrip set is also called a minidrip, and it is 60 gtt/ml. Microdrips are usually used when more exact measurements are required, such as for pediatric patients or ICU patients.

The formula for calculating the drops per minute (gtt/min) is the total volume to infuse (in mL),multiplied by the drop factor, divided by time in minutes, which equals the drops per minute (gtt/min).

The formula for calculating the infusion time is the total volume to infuse divided by milliliters per hour being infused, which will give you the infusion time.

The formula for calculating the number of milliliters per hour is the total volume in milliliters divided by the time (in hours), which will result in the number of milliliters per hour.