Free resources · Dosage calculations
Drip rate (gtt/min)
Counting drops per minute for gravity tubing with a known drop factor.
Worked example: learn the method
Ungraded teaching example with different numbers from the practice exercise. For study only, not clinical use.
50 mL is to infuse over 20 minutes using tubing with a drop factor of 20 gtt/mL. What is the drip rate?
(Volume × drop factor) ÷ time in minutes = gtt/min
- Multiply volume by the drop factor: 50 mL × 20 gtt/mL = 1000 gtt
- Divide by the time in minutes: 1000 gtt ÷ 20 min = 50 gtt/min
- Units cancel: mL × (gtt/mL) leaves gtt; dividing by minutes gives gtt/min.
Example result: 50 gtt/min. You cannot count part of a drop — round to the nearest whole drop.
Common mistake to avoid: Use the drop factor supplied in the problem and time in minutes. A rate in mL/hr is not a rate in drops per minute.
Dosage formulas · Unit conversion reference
Problem
50 mL is to infuse over 60 minutes using tubing with a drop factor of 10 gtt/mL. What is the drip rate?
You cannot count part of a drop — round to the nearest whole drop.
These are practice problems for exam preparation. Every number in them is generated by CARE for teaching purposes — nothing here is a real order and nothing here is a clinical dosing tool. Do not use this page to work out a dose for a real patient: use your facility's policy, the actual order, and an independent double-check where your policy requires one.
Medication calculations also appear inside real exam practice, mixed with everything else and scored the same way. Try a free quiz drawn from the actual question bank.
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