IV Pump Rate & Flow Rate Calculator
Calculate infusion rates in mL/hr and drip rates in gtt/min for intravenous therapy.
10 (Macro)
15 (Macro)
20 (Macro)
60 (Micro)
Pump Infusion Rate:
Drip Rate (Gravity):
Total Time:
Understanding IV Pump Rate Calculations
In clinical settings, accurately calculating the rate of intravenous fluids is a critical safety task. Nurses and healthcare providers must often convert a physician's order into specific pump settings (mL/hr) or manual drip rates (gtt/min) for gravity-fed lines.
The Core Formulas
Depending on whether you are using an electronic infusion pump or a gravity drip, you will use one of the following formulas:
1. Pump Rate Formula (mL/hr)
This is the simplest calculation used for infusion pumps. You only need the total volume and the total time in hours.
Formula: Total Volume (mL) / Total Time (hr) = mL/hr
2. Drip Rate Formula (gtt/min)
When an infusion pump is unavailable, you must calculate the number of drops per minute based on the tubing's drop factor.
Formula: (Total Volume (mL) x Drop Factor (gtt/mL)) / Time in Minutes = gtt/min
Common Drop Factors
| Tubing Type | Drop Factor | Common Usage |
|---|---|---|
| Macrodrip | 10, 15, or 20 gtt/mL | Routine adult fluid administration. |
| Microdrip | 60 gtt/mL | Pediatrics, critical care, or high-potency meds. |
Practical Example
Order: Infuse 500 mL of Normal Saline over 4 hours using 15 gtt/mL tubing.
- Pump Rate: 500 mL / 4 hrs = 125 mL/hr
- Total Minutes: 4 hrs x 60 = 240 minutes
- Drip Rate: (500 mL x 15) / 240 min = 7500 / 240 = 31.25 gtt/min (rounded to 31)
Clinical Safety Tips
- Always double-check calculations with a colleague if administering high-alert medications.
- Ensure the "Drop Factor" on the calculator matches the physical tubing package being used.
- Monitor the IV site regularly for signs of infiltration or phlebitis, especially at high flow rates.
- If the calculated gtt/min is a decimal, round to the nearest whole number as you cannot count partial drops.