Drops-per-Minute (gtt/min)
Enter total infusion volume, time, and IV tubing drop factor to determine the manual drip rate in drops per minute.
Common tubing: microdrip 60 gtt/mL; macrodrip 10, 15, or 20 gtt/mL.
Drops per minute
41.7 gtt/min
Drops per second
0.69 gtt/sec
Equivalent pump rate
125.0 mL/hr
How to Use This Calculator
Identify tubing drop factor
The drop factor (gtt/mL) appears on IV tubing packaging. Microdrip sets are 60 gtt/mL; macrodrip vary by manufacturer.
Enter volume and time
Use the total fluid volume and infusion duration ordered. The calculator converts hours and minutes into total minutes.
Regulate the IV drip
Adjust the roller clamp until the measured drops per minute match the calculated rate. Reassess frequently for accuracy.
Formula
gtt/min = (Volume (mL) / Time (min)) * Drop factor (gtt/mL)
gtt/sec = gtt/min / 60
Full Description
Manual IV administrations rely on gravity and tubing drop factor to regulate flow. Calculating drops per minute prevents under- or over-infusion when infusion pumps are unavailable. Always verify tubing specifications, patient condition, and institutional policies when setting gravity drips, particularly for medications with narrow therapeutic windows.
Frequently Asked Questions
What if the ordered rate is in mL/hr?
Convert mL/hr to gtt/min by dividing by 60 to obtain mL/min, then multiplying by the drop factor.
How often should I recount drops?
Verify the rate every 15 minutes initially and after any patient repositioning, bag change, or equipment adjustment.
Can I use this for medication infusions?
Yes, but double-check calculations with a second clinician, especially for potent medications. Use infusion pumps when available.
What if my tubing drop factor is unknown?
Refer to the package or manufacturer. Estimating can cause significant dosing errors - obtain the correct factor before proceeding.