IV Drip & Medicine Rate Calculator
The total amount of liquid medicine or saline in the bag.
How long the infusion should last.
10 gtt/mL (Macro)
15 gtt/mL (Macro – Standard)
20 gtt/mL (Macro)
60 gtt/mL (Micro – Pediatric)
Check the packaging on your IV tubing set.
Flow Rate (Pump):
— mL/hr
Drip Rate (Gravity):
— gtt/min
Drops per 15 Seconds:
— drops
Understanding Medicine Rates and IV Calculations
In clinical settings, accurately calculating the rate at which medicine or fluids are delivered intravenously (IV) is a critical nursing skill. Whether utilizing an electronic infusion pump or manually regulating flow via gravity using a roller clamp, the correct calculation ensures patient safety and therapeutic efficacy.
How to Calculate IV Drip Rates
The Medicine Rate Calculator helps determine two primary values:
- mL/hr (Flow Rate): Used primarily for electronic infusion pumps. This indicates how many milliliters of fluid are delivered every hour.
- gtt/min (Drip Rate): Used for manual gravity infusion. This indicates how many drops (gtt) fall into the drip chamber per minute.
The IV Rate Formula
To calculate the drip rate manually, healthcare professionals use the following formula:
Drip Rate (gtt/min) = (Total Volume (mL) × Drop Factor (gtt/mL)) ÷ Time (minutes)
Understanding the Inputs
- Total Volume (mL): This is the amount of fluid ordered by the physician (e.g., 1000 mL Normal Saline).
- Time (Hours): The total duration over which the fluid must be infused (e.g., over 8 hours).
- Drop Factor (gtt/mL): This number represents how many drops it takes to make 1 milliliter. This value is printed on the packaging of the IV tubing set.
- Macrodrip (10, 15, 20 gtt/mL): Used for general adult IV therapy and fast infusion rates.
- Microdrip (60 gtt/mL): Used for pediatrics, neonates, or precise medication administration. Note that for microdrip tubing, the gtt/min equals the mL/hr.
Example Calculation
Imagine a patient is prescribed 1000 mL of D5W to be infused over 8 hours. The available tubing is a standard macrodrip with a drop factor of 15 gtt/mL.
- Step 1: Convert hours to minutes. 8 hours × 60 = 480 minutes.
- Step 2: Apply the formula: (1000 × 15) ÷ 480.
- Step 3: 15,000 ÷ 480 = 31.25.
- Result: You would adjust the roller clamp to deliver approximately 31 drops per minute (or roughly 8 drops every 15 seconds).
Safety Considerations
While calculators are helpful tools, clinical judgment is paramount. Always double-check calculations for high-alert medications. If the calculated drip rate seems excessively high or low, verify the order and the tubing factor before initiating the infusion.