IV Drip Rate Calculator (gtt/min)
For a gravity infusion you count drops. Enter the volume, the time, and the drop factor printed on the tubing package.
Shows the work. Answer, formula, and numbered steps, rounded the way nursing exams expect. For study and exam practice, not for patient care.
Formula
gtt/min = volume × drop factor ÷ minutes.
Fill in the fields and press Calculate to see the answer and every step.
For study and exam practice, not for patient care.
Rounding: A drop can't be split, so drip rates round to a whole gtt/min.
Terms: gtt, Drop factor, Macrodrip, Microdrip, IVPB
Worked examples
Infuse 500 mL of 5% dextrose in water over 2 hours by gravity. The tubing delivers 20 gtt/mL.
- Volume
- 500 mL
- Infusion time
- 120 minutes
- Drop factor
- 20 gtt/mL
Formula gtt/min = volume × drop factor ÷ minutes.
- gtt/min = volume × drop factor ÷ minutes.
- 500 mL × 20 gtt/mL ÷ 120 minutes = 83.33 gtt/min.
- A drop cannot be split, so round to a whole number: 83 gtt/min.
Answer 83 gtt/min
Infuse 500 mL of 0.45% sodium chloride over 10 hours by gravity with microdrip tubing (60 gtt/mL).
- Volume
- 500 mL
- Infusion time
- 600 minutes
- Drop factor
- 60 gtt/mL
Formula gtt/min = volume × drop factor ÷ minutes.
- gtt/min = volume × drop factor ÷ minutes.
- 500 mL × 60 gtt/mL ÷ 600 minutes = 50 gtt/min.
- 50 gtt/min is exact, so no rounding is needed.
Answer 50 gtt/min
FAQ
What is the IV drip rate formula?
gtt/min = volume (mL) × drop factor (gtt/mL) ÷ time (minutes). Convert hours to minutes first by multiplying by 60.
What drop factors are common?
Macrodrip tubing is usually 10, 15, or 20 gtt/mL; microdrip tubing is 60 gtt/mL. The drop factor is printed on the tubing package.
Why is the microdrip rate the same number as mL/hr?
With 60 gtt/mL tubing, multiplying by 60 drops and dividing by 60 minutes cancel, so the gtt/min equals the mL/hr.