💧 IV Therapy Calculator

IV Drip Rate Calculator

Calculate IV flow rates in drops per minute (gtt/min) and mL/hr. Supports all standard drip sets and both basic and advanced calculation modes.

⚠️ Clinical reference only. Verify all calculations with a pharmacist or supervising clinician before administration.

Volume to Infuse (mL)

Infusion Time

Time Unit

Drop Factor (gtt/mL)

Ordered Dose

Dose Unit

Patient Weight (kg)

Drug Concentration

Concentration Unit

Total Volume (mL)

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📋 Drop Factor Quick Reference

Set Type	Drop Factor	Common Use	gtt/min for 100mL/hr
Macro drip	10 gtt/mL	Blood, colloids, rapid infusions	17 gtt/min
Macro drip	15 gtt/mL	Standard IV fluids (many brands)	25 gtt/min
Macro drip	20 gtt/mL	Most common macro set	33 gtt/min
Micro drip	60 gtt/mL	Pediatrics, small volumes, precise rates	100 gtt/min

Frequently Asked Questions

What is the formula for IV drip rate?

The standard formula: gtt/min = (Volume in mL × Drop Factor) ÷ Time in minutes. For mL/hr: mL/hr = Total Volume ÷ Total Hours. For example, 500 mL over 4 hours = 125 mL/hr. With a 20 gtt/mL set: (500 × 20) ÷ 240 = 41.7, rounded to 42 gtt/min.

When do you use a micro drip vs macro drip set?

Micro drip sets (60 gtt/mL) are used when you need precise control over small volumes — pediatric patients, concentrated medications, or infusion rates below 50 mL/hr. Macro drip sets (10–20 gtt/mL) are used for higher-volume infusions where absolute precision is less critical. When in doubt, micro drip sets provide more control.

Should I always round drip rates to a whole number?

Yes. You cannot count fractions of drops, so always round gtt/min to the nearest whole number. For mL/hr on infusion pumps, most facilities round to the nearest whole number or one decimal place, per institutional policy.

How do I verify my IV drip rate is correct?

Count the drops for 15 seconds and multiply by 4, or count for 60 seconds. Compare to the ordered rate. If using a pump, the pump does the counting — verify the rate and volume are programmed correctly and cross-check against the order. Two-nurse verification is standard for high-alert medications.