Free calculator

IV drip rate calculator

Enter the volume, time, and tubing drop factor for a gravity infusion. See the drip-rate formula for the method.

Drip rate

31 gtt/min
1. Start from the flow rate and multiply by the drop factor
( 1000 mL ÷ 480 min ) × ( 15 gtt ÷ 1 mL )
2. Cancel mL and solve
= ( 1000 × 15 ) ÷ 480 gtt/min
= 31.25 gtt/min
3. Round to whole drops (you cannot count part of a drop)
31.25 gtt/min ≈ 31 gtt/min
= 31 gtt/min

Frequently asked questions

What is the IV drip rate formula?

Drip rate (gtt/min) = volume (mL) x drop factor (gtt/mL) divided by time in minutes. For 1000 mL over 8 hours with 15 gtt/mL tubing: (1000 x 15) / 480 = 31 gtt/min.

Where do I find the drop factor?

It is printed on the IV tubing package. Macrodrip sets are usually 10, 15, or 20 gtt/mL and microdrip sets are 60 gtt/mL. If your set is not in the list, choose Other and type the number from the package.

Why is the drip rate rounded to a whole number?

You count whole drops when you time a gravity infusion, so a part drop cannot be delivered. The calculator rounds to the nearest whole gtt/min after showing the exact figure.

What if the answer is less than 1 gtt/min?

A gravity set cannot be counted that slowly, so the rate is not usable. Use an infusion pump, or check whether the volume or the time was entered wrongly.