IV Drip Rate Calculator (gtt/min)
Calculate the gravity IV drip rate (drops per minute) needed to deliver a specific volume of fluid over a set time using the IV giving set drop factor.
Calculator
Educational use only. Always verify the prescription, patient identity, infusion time, and drop factor before administering. Follow local protocols and clinical judgment.
How it Works
To calculate an IV drip rate (gtt/min) for a gravity infusion, you need the total volume (mL), the infusion time (hours), and the giving set drop factor (gtt/mL). The calculator converts the infusion time to minutes (hours × 60) and then applies the standard drops-per-minute formula. Results are rounded to a whole drop because partial drops can't be counted reliably.
Formula
Worked Examples
Example 1: How many drops per minute for 1000 mL over 8 hours using 20 gtt/mL?
Time in minutes = 8 × 60 = 480 min
Total drops = 1000 × 20 = 20,000 drops
gtt/min = 20,000 ÷ 480 = 41.67
Example 2: How many gtt/min for 500 mL over 4 hours using 15 gtt/mL?
Time in minutes = 4 × 60 = 240 min
Total drops = 500 × 15 = 7,500 drops
gtt/min = 7,500 ÷ 240 = 31.25
Example 3: How many gtt/min for 250 mL over 2 hours using a microdrip 60 gtt/mL set?
Time in minutes = 2 × 60 = 120 min
Total drops = 250 × 60 = 15,000 drops
gtt/min = 15,000 ÷ 120 = 125
When This Calculator Is Used
- •Gravity IV infusions using drip chambers and manual drip rate adjustment
- •Clinical settings without IV pumps or when pumps are unavailable
- •Emergency and transport situations requiring manual flow rate calculation
- •Double-checking and verifying IV pump settings for safety
- •Nursing, paramedic, and clinical education on IV flow rate calculations
Clinical safety note: Always confirm the order, verify the correct fluid, double-check the drop factor on your tubing, and reassess the patient throughout the infusion. Follow local protocols for drip rate monitoring and adjustment.
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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 pharmaceutical and nursing IV drip rate calculation standards from authoritative medical and educational sources.