IV Drip Rate Calculator

Flow Rate is calculated as total volume divided by infusion time, so the two are inversely related: spreading the same total volume over MORE hours means FEWER milliliters need to be delivered each hour, lowering the mL/hr rate. A shorter infusion window packs the same volume into less time, raising the rate. This is the opposite relationship from volume, which raises the flow rate as it increases.

No. Flow Rate in mL/hr depends only on total volume and infusion time -- the tubing's drop factor plays no role in that calculation at all. Drop factor only affects the Drip Rate figure (drops per minute), which translates the same mL/hr flow into a drops-per-minute count specific to whichever tubing is calibrated to deliver it.

Macrodrip sets are calibrated at 10, 15, or 20 drops per mL and are standard for routine adult fluid infusions. Microdrip sets are calibrated at 60 drops per mL -- exactly matching mL/hr to gtt/min -- and are used for pediatric patients, small precise volumes, or medications where slow, closely controlled delivery matters, since counting drops one at a time is more forgiving at a microdrip's finer calibration.

Drip rate (gtt/min) equals total volume multiplied by drop factor, divided by total infusion time in minutes. Equivalently, once you know the mL/hr flow rate, you can convert it to gtt/min by multiplying by the drop factor and dividing by 60. This calculation matters specifically for gravity-fed IV sets without an electronic pump, where the nurse counts drops manually against a watch to maintain the correct rate.