Drip Rate Calculator
Convert an infusion rate in millilitres per hour (mL/hr) to drops per minute (gtt/min) using the drop factor of your IV tubing.
Enter the infusion rate in mL/hr. Commas accepted (e.g., 1,000).
Select the drop factor from your IV tubing packaging.
How Drip Rate Conversion Works
Converting an infusion rate from millilitres per hour (mL/hr) to drops per minute (gtt/min) depends on the drop factor of your IV tubing set. You divide the hourly rate by 60 to get the rate in mL per minute, then multiply by the drop factor to find how many drops per minute you need to count.
Drop factors vary: macrodrip tubing typically has 10, 15, or 20 drops per mL, while microdrip tubing has 60 drops per mL. The drop factor is printed on the tubing packaging and determines the precision of your infusion. Always check the tubing box before calculating.
Formula
Worked Examples
Example 1: An infusion is ordered at 125 mL/hr. Your tubing has a drop factor of 20 gtt/mL. How many drops per minute?
gtt/min = (125 ÷ 60) × 20
Rate = 125 mL/hr
Divide by 60: 125 ÷ 60 = 2.083 mL/min
Multiply by drop factor: 2.083 × 20 = 41.67
Round to nearest whole drop: 42 gtt/min
Example 2: Running 250 mL/hr on a microdrip set (60 gtt/mL). Calculate drops/min.
Rate = 250 mL/hr, drop factor = 60 gtt/mL (microdrip)
250 ÷ 60 = 4.167 mL/min
4.167 × 60 = 250 gtt/min
Example 3: 50 mL/hr with a macrodrip set of 10 gtt/mL. What is the drip rate?
50 ÷ 60 = 0.833 mL/min
0.833 × 10 = 8.33 gtt/min
Round: 8 gtt/min
When This Calculator Is Used
- •Setting up gravity-fed IV lines without electronic pumps
- •Converting pump rate settings to manual drip counts for verification
- •Emergency IV administration in settings without electronic equipment
- •Education and clinical skills training for manual drip rate calculation
- •Quick double-check before administering manual gravity infusions
Clinical safety note: Always verify the ordered rate, confirm drop factor from the tubing packaging, and count drops manually before and periodically during infusion. This calculator supports calculation checking but does not replace clinical judgement or institutional protocols.
Related Calculators
Frequently Asked Questions
Clinical reminder: Always follow local protocols and consult medication information sheets. These examples are for calculation practice only.
References & Sources
This calculator is based on established drip rate calculation standards from authoritative medical and nursing education sources across Australia, the United States, the United Kingdom, and Canada.