Questions and answers — drops
How many drops are in a ml?
How the drop factor works, common values and how to calculate drops per minute.
Short answer: How many drops are in a ml depends on the giving set. Common drop factors are 20 drops/ml for a standard set, 15 for a blood set and 60 for a microdrip set. Read the drop factor on the packaging or in the question.
Drop factors
Always use the factor stated on the giving set or in the question.
| Type | Common drop factor |
|---|---|
| Standard infusion set | 20 drops/ml |
| Blood set | 15 drops/ml |
| Microdrip (e.g. children) | 60 drops/ml |
Good to know: These figures are common values. Your course or the manufacturer may state different ones, so follow the question.
Calculate drops per minute
Drops/min = (Volume × Drop factor) ÷ Time in minutes
Example: 1000 ml over 8 hours with 20 drops/ml. (1000 × 20) ÷ 480 = 41.7, so about 42 drops/min.
Use the drip rate calculator to work it out directly. Rate in ml/h: infusion rate.
Frequently asked questions
How many drops are in a ml?+
It depends on the giving set. 20 drops/ml is common for a standard set, 15 for a blood set and 60 for a microdrip set.
Where do I find the drop factor?+
On the giving set packaging or in the question.
How do I calculate drops per minute?+
(Volume × drop factor) ÷ time in minutes.
Practise drip rates in Dos
Dos is a practice app for drug calculations. It has practice tests of ten questions, a built-in calculator next to each question, and statistics per topic.
