Petaliter to Drop

The drop (medical/pharmacological) is an approximate unit of volume equal to about 0.05 milliliters, or 50 microliters.

1 drop ≈ 0.05 mL = 50 µL ≈ 1/20 mL. Approximately 20 drops = 1 mL (for water-like liquids).

To mL: multiply by 0.05 (approximate). To µL: multiply by 50. 20 drops ≈ 1 mL for aqueous solutions.

Eye drop medication, ear drops, essential oil use, flavoring extracts in cooking, and IV drip rate measurement.

The size of a drop varies significantly: water drops from a glass dropper (~50 µL) differ from rain drops (~50,000–100,000 µL) by a factor of 1,000.

Assuming all drops are the same size — oily liquids produce larger drops than water. Always check the dropper calibration.

20 drops ≈ 1 mL for water-based solutions. In IV therapy, standard drip sets deliver 10, 15, or 20 drops/mL depending on the design.