IV Fluid Rate & Drip Rate Calculator
10 (Macro)
15 (Macro)
20 (Macro)
60 (Micro)
Calculation Results:
Flow Rate (Pump Setting)
0 mL/hr
Drip Rate (Gravity)
0 gtt/min
Understanding IV Rate Calculations
In clinical settings, calculating the correct Intravenous (IV) rate is critical for patient safety. Whether you are using an infusion pump or a gravity-fed drip, knowing the volume and the prescribed time allows healthcare providers to deliver medications and fluids accurately.
The Infusion Rate Formulas
There are two primary ways to measure IV flow rates:
- mL/hr (Milliliters per Hour): This is the standard setting for electronic infusion pumps. It is calculated by dividing the total volume by the total hours.
- gtt/min (Drops per Minute): This is used for manual gravity drips. The calculation requires the "Drop Factor" of the IV tubing set (found on the packaging).
Manual Calculation Logic
To calculate the drip rate manually, use the following formula:
(Total Volume in mL × Drop Factor) / Total Time in Minutes = Drops per Minute
Common Drop Factors
IV tubing sets vary by manufacturer and intended use:
| Set Type | Drop Factor (gtt/mL) |
|---|---|
| Macro-drip | 10, 15, or 20 gtt/mL |
| Micro-drip | 60 gtt/mL |
Practical Example
Suppose a physician orders 1,000 mL of Normal Saline to be infused over 8 hours. You are using a macro-drip set with a drop factor of 15 gtt/mL.
- Step 1 (mL/hr): 1,000 mL / 8 hours = 125 mL/hr.
- Step 2 (Time in min): 8 hours × 60 = 480 minutes.
- Step 3 (gtt/min): (1,000 mL × 15) / 480 = 31.25 gtt/min (Round to 31).