How to use the IV Drip Rate Calculator
- Enter the volume to infuse (mL).
- Enter the infusion time.
- Select the drop factor printed on the IV set packaging.
- Read the flow rate in mL/hr and drops/minute.
Formulas
mL/hr = Volume (mL) ÷ Time (hr)
Drops/min = Volume (mL) × Drop factor (gtt/mL) ÷ Time (min)
Example: 1,000 mL over 8 hours with a 20 gtt/mL set → 125 mL/hr and 1000 × 20 ÷ 480 ≈ 42 drops/min.
Drop factors
- Macro-drip sets: 10, 15 or 20 drops/mL — adult infusions.
- Micro-drip sets: 60 drops/mL — paediatrics and precise small volumes. With a 60 gtt/mL set, drops/min equals mL/hr.
Frequently asked questions
Who should use this calculator?
It is a learning and double-checking aid for trained nurses and students. Always follow the prescription, hospital protocols and infusion pump settings.