Medical

IV Drip Rate Calculator

Calculate drops per minute and mL per hour from an IV prescription. Macro-drip and micro-drip sets supported.

Drops per minute

0

gtt/min

1000 mL over 8 hr @ 20 gtt/mL

Exact drops/min41.7
mL per hour125 mL/hr
mL per minute2.08
Total time480 min
Drop factor20 gtt/mL

Frequently asked questions

The drop factor is the number of drops the IV set delivers per mL — it's a property of the tubing's drip chamber. It's printed on the outer wrapper of every IV set (sometimes inside the chamber). Common values: 10, 15, or 20 drops/mL for adult macro-drip sets; 60 drops/mL for pediatric micro-drip sets. Never assume — always check the wrapper.

Use a pump when: (1) drops/min > 100 (hard to count visually), (2) the medicine has a narrow therapeutic window (insulin, heparin, vasopressors), (3) the patient is paediatric, elderly, or has cardiac/renal failure that requires precise volume control, or (4) hospital policy requires it for that drug. Gravity drips are fine for routine hydration in stable patients.

Count for 15 seconds and multiply by 4. Counting for a full minute is more accurate but takes longer. Use a watch with a clear second hand or your phone stopwatch. Adjust the roller clamp slowly — small movements have big effects.

It will. Patients move, position shifts the drip chamber, evaporation occurs (especially in hot wards). Check the drip every 30-60 minutes and recount. If the bag will run dry significantly earlier or later than scheduled, adjust the clamp or recalculate the rate based on remaining volume and time.

Blood and blood products use a different (larger) drop factor and special filter tubing. Use only the manufacturer's blood-administration set and follow your hospital's blood-transfusion protocol. The drop factor is on the wrapper — usually 10 gtt/mL. The math here applies; the equipment and monitoring differ.

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