Enter the volume to infuse, the infusion time and the drop factor printed on the IV tubing to get the drip rate in gtt/min and the equivalent pump rate in mL/hr.
Important: this tool only does the arithmetic (gtt/min = volume × drop factor ÷ minutes). It does not check whether an order is appropriate. Always follow the prescriber's order, the tubing package label and your facility's protocol, and double-check high-alert infusions.
gtt/min = volume (mL) × drop factor (gtt/mL) ÷ time (min). For 1,000 mL over 8 hours with 15 gtt/mL tubing: 1,000 × 15 ÷ 480 = 31.25, so about 31 drops per minute. The flow rate is 1,000 ÷ 8 = 125 mL/hr.
Macrodrip sets deliver 10, 15 or 20 drops per mL and are used for routine adult infusions. Microdrip sets deliver 60 drops per mL, so the drip rate equals the mL/hr rate – useful for small, precise volumes.
With 15 gtt/mL tubing it is about 31 gtt/min (125 mL/hr).
Divide the volume in mL by the time in hours. 500 mL over 4 hours is 125 mL/hr.
Because 60 drops per mL and 60 minutes per hour cancel out.