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
Calculates the drops per minute needed to deliver a prescribed volume via gravity IV tubing.
gtt/min = (Volume × Drop Factor) ÷ Time (min)
Determines how long an infusion will take at a given manual drip rate.
Time (min) = (Volume × Drop Factor) ÷ gtt/min
Calculates the total volume delivered over a given time at a known drip rate.
Volume (mL) = (gtt/min × Time (min)) ÷ Drop Factor
Select which variable to solve for, enter the known values and the drop factor from your IV tubing package, and the calculator instantly computes the result. Manual IV administration requires periodic bedside monitoring because gravity flow rates can shift with patient position and IV pole height.
Order: Infuse 1,000 mL over 8 hours using 15 gtt/mL tubing. Calculate the drip rate.
Round to the nearest whole drop when counting at the bedside. Recheck every 15-30 minutes.
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.
Most facilities require rechecking gravity IV rates every 15 to 30 minutes, or whenever the patient is repositioned, ambulates, or the IV pole height changes. Document each rate check and any adjustments made to the roller clamp.