IV Flow Rate Calculator

IV fluid

IV Flow Rate= Volume of Fluid/Time


The IV Flow Rate Calculator calculates the amount of milliliters per hour that an IV needs to be set to in order to infuse a certain volume of IV fluid in a certain period of time.

The IV flow rate is calculated according to the formula, IV flow rate= volume/time.

The volume of fluid is the volume of fluid that needs to be infused in the period of time specified in the time variable. This may not necessarily be the total volume which is present in an IV bag which is hung. It is the amount of fluid which needs to be infused. Thus, a bag of IV solution may be 1000mL but if we're only infusing 200mL into the person, the volume is 200mL, not 1000mL. So, to repeat, it's not the total volume in the IV bag, it's the amount of fluid which will be infused into the person. So just know the difference between total volume in a bag and volume that needs to be infused. The volume for this calculator can either be in milliliters (which is the default value) or liters.

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 hours when we are dealing with a pump. When we are dealing with infusion with milliliters (mL), we calculate that rate in milliliters per hour (mL/hr). The time unit is always in hours. When we are dealing with drops, we calculate in drops per minute. For this calculator, the time can be entered in either hours, minutes, or days, but the calculated value is always converted into milliliters per hour, because IV pumps always use milliliters per hour.

Once we have the volume of fluid we are infusing and the time that we are going to infuse it in, we calculate the IV drip rate according to the above formula.

In case you are working on an electronic device that uses flow rate wiht milliliters per hour, then knowing this formula can be of help.

Related Resources

Parkland Formula Calculator

IV (Macro) Drip Rate Calculator

IV Micro Drip Rate Calculator