How to Practice Calculations for Microdrops Per Minute

By Gabrielle David; Updated April 25, 2017
Calculating microdrops per minute takes practice.

Practice makes perfect, and perfection is needed when calculating IV flow as microdrops per minute, especially if drugs are being administered. "Microdrops," abbreviated as µgtts, indicates that the administration set being used takes 60 tiny drops to make 1 mL of fluid. Microdrop sets, also known as 60-drop sets or pediatric sets, are used for precise fluid and medication administration, especially when an infusion pump isn't available. Doctors, nurses, paramedics and other medical professionals who deal with intravenous solution administration should all be comfortable calculating microdrops per minute. Constructing problems and solving them will increase your proficiency and confidence.

Review the formula for calculating IV rates: Volume to be infused in milliliters divided by time in minutes multiplied by drip factor. For microdrop sets, the drip factor is always 60.

Write simple problems and solve them, such as "How many µgtts per minute are required to infuse 100mL per hour?"

The solution is 100 mL / 60 minutes x 60 gtts = 100 µgtts per minute.

Recognize the shortcut. When time in minutes is 60 and the drip factor is 60, they cancel out. To infuse 100 mL per hour, you must infuse 100 µgtts per minute. Infusing 160 mL per hour requires a rate of 160 µgtts per minute.

Make more complicated problems. For example, determine how many µgtts you must infuse per minute to infuse 120 mL over three hours. Here is the solution:

120 mL / 180 minutes x 60 gtts = 40 µgtts per minute.

To calculate how many µgtts per minute are required to infuse 60 mL over 45 minutes, this is the solution:

60 mL / 45 minutes x 60 gtts = 80 µgtts per minute.

Work backwards, calculating how many mL per specified time period would be administered at different microdrop rates. For example, determine how many mL will be infused in an hour at 40 µgtts per minute. Here is the solution:

40 µgtts per minute = Volume / Minutes x Drip = V / 60 x 60 = 40 mL per hour.

Calculate how many mL will be infused in 2 hours at 70 µgtts per minute. Here is how to do it:

70 µgtts per minute = Volume / Minutes x Drip = V / 120 x 60 = 35 mL per hour.


Practice often to maintain proficiency.

Take advantage of textbook and workbook problems.

Use online and smart phone applications that do automatic calculations to verify your answers.


Fluid and medication administration miscalculations can be fatal.

Ask competent professionals to verify your calculations.

Always verify the administration set drip factor.

About the Author

Gabrielle David has been a writer, columnist and editor for a weekly newspaper for more than 30 years. A paramedic, she has been in emergency medical services for more than 20 years, teaches CPR and basic emergency medical technician courses and is the training director for her ambulance service.