IV Flow Rate Calculator (ml/hr)
Calculate the infusion pump rate required to deliver a specific volume over a set time.
To deliver ml over .
How to Calculate Flow Rate in ml/hr
In clinical settings, calculating the correct IV flow rate is essential for patient safety. When using an electronic infusion pump, the rate is typically programmed in milliliters per hour (ml/hr). This calculator helps nursing and medical professionals determine the correct pump setting based on the total volume of fluid ordered and the duration of administration.
The Flow Rate Formula
The basic formula to calculate the flow rate for an infusion pump is:
If the time is given in minutes, you must first convert the minutes to hours (by dividing by 60) or use the following variation:
Flow Rate = (Total Volume × 60) ÷ Time (minutes)
Practical Examples
Example 1: Standard Saline Infusion
A physician orders 1,000 ml of Normal Saline to be infused over 8 hours.
- Volume: 1,000 ml
- Time: 8 hours
- Calculation: 1,000 ÷ 8 = 125
- Result: Set the pump to 125 ml/hr.
Example 2: Antibiotic Piggyback
An antibiotic dissolved in 50 ml of D5W needs to be infused over 30 minutes.
- Volume: 50 ml
- Time: 30 minutes (which is 0.5 hours)
- Calculation: 50 ÷ 0.5 = 100
- Result: Set the pump to 100 ml/hr.
Why is Accuracy Important?
Setting the correct flow rate ensures the patient receives medication at the therapeutic rate. Infusing too fast (bolus) can cause toxicity or fluid overload, while infusing too slow may render the medication ineffective or cause line occlusions.