IV Drip Rate Calculator
Drops per minute=
(Drop Factor/Time in minutes) * Volume
The IV Drip Rate Calculator calculates the amount of drops per minute needed to infuse a volume of IV fluid in a certain amount of time.
The IV drip rate is calculated according to the volume of IV fluid that needs to be infused, the drop factor of the IV plastic dropper, and the amount of time that the fluid is infused.
The volume of fluid is the volume of fluid that needs to be infused in the period of time specified in the time variable. Thus, a bag may be 1000mL but if we're only infusing 200mL into the person, the volume is 200mL, not 1000mL. It's not the total volume in the IV bag, it's the amount of fluid which needs to be infused into the person. So just know the difference between total volume in a bag and volume that needs to be infused.
The drop factor is the amount of drops that makes up 1 milliliter of IV solution. It is specified by IV plastic dropper (the tubing) by the manufacturer. Different kits have different drop factors. Common drop factors are 10 drops per mL and 15 drops per mL. For microdrip tubing, the drop factor is always 60 drops per mL. Again, the drop factor is the number of drops of IV fluid that will give us 1mL of solution. To find this value, read from the IV plastic dropper tubing kit.
The time is the period of time which we want to infuse the IV fluid into the person. This may be 60 minutes (1 hour), 120 minutes (2 hours), 180 minutes (3 hours), etc. The time is always specified in minutes when we are dealing with drops. Because drops are always calculated in drops per minute. When we are dealing with infusion with milliliters (mL), we are calculate that rate in milliliters per hour (mL/hr). When we are dealing with drops, we calculate in drops per minute.
Once we have the volume, drop factor, and time, we calculate the IV drip rate according to the formula, IV drip rate= (drop factor/time) * volume. This will give us the answer in drops per minute (gtt/min).
Once you have this value, then you must manually count the number of drops from the tubing for one minute to make sure that the IV drip rate is outputting the number of drops calculated. This is the manual way of administering IV fluids. And this is not done much anymore. Now these days, most IV is administered via IV pump to make sure the IV infusing is more accurate.
In case you are working on an electronic device where you have to know the amount of drops that are needed in a given time unit, then knowing this formula can be of help.