IV Flow Rate Calculator (mL/hr)
Calculate the infusion rate for intravenous fluids accurately.
Calculated Flow Rate:
0 mL/hr
How to Calculate Flow Rate in mL/hr
In clinical settings, ensuring the correct infusion rate for medications and fluids is critical for patient safety. The "mL/hr" (milliliters per hour) flow rate determines how much fluid a patient receives over a sixty-minute period.
The Step-by-Step Calculation Process
To calculate the flow rate manually, follow these steps:
- Identify the Total Volume: Determine the total amount of fluid to be infused in milliliters (mL).
- Determine the Time: Determine the total time over which the fluid should be delivered.
- Convert Time (if necessary): If the time is given in minutes, divide the number of minutes by 60 to convert it into hours. Alternatively, use the formula: (Volume / Minutes) × 60.
- Divide Volume by Time: Divide the volume by the hours to find the mL/hr rate.
Practical Example
Scenario: A physician orders 500 mL of Normal Saline to be infused over 4 hours.
- Total Volume: 500 mL
- Time: 4 hours
- Calculation: 500 mL / 4 hr = 125 mL/hr
Scenario with Minutes: An antibiotic of 100 mL is to be infused over 30 minutes.
- Total Volume: 100 mL
- Time: 0.5 hours (since 30 / 60 = 0.5)
- Calculation: 100 mL / 0.5 hr = 200 mL/hr
Common Infusion Rate Terms
While mL/hr is the standard for infusion pumps, you may also encounter "gtt/min" (drops per minute). The mL/hr rate is used to program electronic pumps, while gtt/min is used for manual gravity infusions where a "drip factor" (the number of drops per mL) must be considered.
Why Accuracy Matters
Calculating the correct flow rate prevents fluid overload or under-infusion. Pediatric patients and those with cardiac or renal conditions are particularly sensitive to infusion rates, making precise calculation using tools like this calculator essential for healthcare professionals.