The drops-per-minute formula
Drops per minute (gtt/min) is calculated directly from the total volume to be infused, the total time it should take, and the drop factor of the IV administration set: gtt/min = (Total Volume in mL × Drop Factor in gtt/mL) ÷ Total Time in minutes.
Why this matters
This one-step version of the formula is handy when you already know the full volume and total run time, rather than an hourly flow rate. It’s commonly used when setting up a gravity IV drip without a pump, so the caregiver can count drops against a clock or watch.
Note: This tool is for general educational reference only and does not replace a clinician’s order or facility policy.
Last reviewed August 2026