Lesson 4: Drip Rates

Drip Rate Calculation

To calculate the drops per minute for an infusion by gravity, follow the steps in Table 8.6.

Table 8.6 Calculating the Drops per Minute (gtts/min) for an Infusion by Gravity
Steps Additional Information
1. Verify the physician order. An order may read:

Example 1: Give NS IV 125 ml/hr.

Example 2: Give 1000 ml of NS IV over 8 hours.

2. Determine the drop factor on the IV administration set. The drop factor is the amount of drops (gtts) per minute. IV tubing is either macro tubing (10, 15, or 20 gtts/min) or micro tubing (60 gtts/min). The drop factor (or calibration of the tubing) is always on the packaging of the IV tubing.
3. Complete the calculation using the formula. Use the formula:

Infusion rate (ml/hr) X IV  drop factor (gtts/min) = drops per minute
60 (Administration time is always in minutes)

To calculate ml/hr, divide 1000 ÷ 8 = 125 ml/hr.

Example: Infuse IV NS at 125 ml/hr. IV tubing drop factor is 20 gtts/min.

125 X 20 = 41.6 gtts/min, round up to 42 gtts/min (Round down or up to the nearest whole number)
4. Regulate IV infusion using the roller clamp. Observe and count the drips in the drip chamber and regulate for 42 gtts/min (one full minute). Alternatively, divide 42 by 4 (rounded down from 10.4 to 10 gtts/min) to count for 15 seconds. The gtts/min should be assessed regularly to ensure the IV is infusing at the correct rate (e.g., every 1 to 2 hours, if the patient accidentally bumps the IV tubing, or if a patient returns from another department).

Regulating IV tubing is a roller clamp

Regulate IV tubing by using a roller clamp

Data source: Fulcher & Frazier, 2007; Perry et al., 2014

This video is a demonstration of how you can calculate a Dopamine drip:


Creative Commons License The Drip Rate Calculation is taken from "https://opentextbc.ca/clinicalskills/chapter/8-2-types-of-iv-therapy/8.3 IV Fluids, IV Tubing, and Assessment of an IV System" by British Columbia Institute of Technology (BCIT) is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

Creative Commons License The video "Dopamine Infusion Drug Calculation" work is licensed under a Creative Commons Attribution 3.0 Unported License.

Creative Commons License All other material in this work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. If you would like  to use this material, please provide attribution as follows: Richmond, J. (2016). https://www.ceces.ca/courses/med-math/. Continuing Education Centre for Emergency Services.