# 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 70 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.