Calculate IV rate as gtt/min
Formulas
To calculate rate as drops/minute (gtt/min) using minutes:
- V = Volume
- C = Calibration
- M = Minutes
To calculate rate as gtt/min using hours:
- V = Volume
- C = Calibration
- H = Hours
To convert milliliters/hour (mL/hr) to gtt/min:
- R = Rate
- C = Calibration
Examples
1. Give a 50 milliliter (mL) IVPB over 30 minutes using IV tubing with a calibration of 10 drops/milliliter (gtt/mL). How many drops per minute should this IVPB be set for?
- Volume = 50 mL
- Calibration = 10
- Minutes = 30 min
The answer is 16.7 or 17 gtt/min.
2. Using IV tubing alone (calibrated at 60 gtt/mL), prepare an IV to infuse 1 liter over 8 hours. How many drops per minute should the IV be set for?
- Volume = 1000 mL
- Calibration = 60
- Hours = 8
The answer is 125 gtt/min.
3. The doctor orders an IV to infuse at 125 mL/hr. Calculate the flow rate using 10 gtt/mL tubing.
- Rate = 125
- Calibration = 10
The answer is 20.8 or 21 gtt/min.