Drops per mL Converter
Convert a prescription in mL into drops — for eye drops, oral solutions, and IV drip sets.
Frequently asked questions
It's the United States Pharmacopeia (USP) standard for an 'official' dropper, used for oral solutions and ophthalmic preparations under standardized conditions. Real-world droppers vary slightly (15-25 drops/mL depending on liquid viscosity, angle, and dropper bore), but 20 is the conventional reference.
IV sets are designed for different flow rates. Micro-drip sets (60 gtt/mL) deliver tiny drops for fine-grained pediatric or low-volume infusions. Macro-drip sets (10, 15, or 20 gtt/mL) deliver larger drops for high-volume adult fluid therapy. The drop factor is printed on every IV set wrapper — always check before calculating.
Yes — thick liquids (glycerine, suspensions) produce fewer, larger drops than water. The USP 20 gtt/mL standard is calibrated for an aqueous solution of typical viscosity. For very thick formulations, the actual count can drop to 15-17 per mL. For practical pharmacy use, the standard factor is close enough.
For drops per minute, you also need the infusion time. Use the IV Drip Rate Calculator — it takes mL, time, and drop factor and returns drops/min directly. This converter just goes from mL ↔ drops without time.
Half-drops aren't physically deliverable from a standard dropper. The tool shows both the exact decimal (for math verification) and the rounded whole-drop count (for practical dosing). When the half-drop is close to 0.5, count it as +1 drop to avoid under-dosing.
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