Step 1: Convert inputs to common units.
Step 2: Solve equation.
gtt/min = (V × DF) / T
gtt/min = (1000 × 15) / 480
Result = 31.3 gtt/min
Manual IV drip rate calculations are essential when using gravity-fed IV tubing without an electronic pump. The nurse adjusts the roller clamp while counting drops in the drip chamber to achieve the prescribed flow rate.
This calculator can solve for drip rate (gtt/min), infusion time, or volume depending on which values are known. The drop factor is determined by the IV tubing manufacturer and is printed on the tubing package.
Calculate IV Drip Rate ↑Order: Infuse 1,000 mL over 8 hours using 15 gtt/mL tubing.
gtt/min = (1000 × 15) / 480 = 31.25 gtt/min
Count the drops falling in the drip chamber for 15 seconds and multiply by 4. Adjust the roller clamp until you reach the target gtt/min. Recheck the rate every 15-30 minutes and after any patient repositioning.
Gravity-fed IVs rely on the height difference between the IV bag and the insertion site to create flow. Changes in the IV pole height, patient position, or kinks in the tubing will alter the drip rate. This is why manual IVs require periodic monitoring.