Drops to mL Converter
Convert drops (gtt) to milliliters using the drop factor of your dropper or IV set. Pick 20 gtt/mL for a standard pharmacy dropper, or 10, 15, or 60 gtt/mL for IV tubing, and enter the number of drops.
Example: with Number of drops (gtt) 60 · Drop factor 20 gtt/mL — standard metric / pharmacy dropper → Volume: 3.00 mL.
- In teaspoons0.61 tsp
- How it convertsAt 20 drops per mL, 60 drops = 3.00 mL
Computed by the calculator below using its default values. Change any input to see your own numbers.
mL = drops ÷ drop factor. A drop is not a fixed volume, so the drop factor of the specific device is what makes the number meaningful.
Why a drop is not a fixed amount
A drop only has a volume once you know what is dispensing it. Surface tension, fluid viscosity, and the diameter of the tip all change drop size, so the same liquid drips larger from a wide nozzle than a narrow one. To make drops meaningful, devices are rated by a drop factor — how many drops equal one milliliter.
The old pharmacy convention treats 20 drops as 1 mL, which is where the 0.05 mL 'official drop' comes from. IV tubing is labeled explicitly: macrodrip sets run 10, 15, or 20 gtt/mL, while microdrip (pediatric) sets deliver a fine 60 gtt/mL. Read the number off the package rather than assuming.
How it’s calculated
Volume in mL = number of drops ÷ drop factor (gtt/mL). Teaspoons use 1 US tsp = 4.92892 mL. Selectable factors are 20 (standard metric/pharmacy), 15 and 10 (IV macrodrip), and 60 (IV microdrip).
Drop size varies with the dropper, fluid, and technique, so any drops-to-volume conversion is approximate. For medication dosing, follow the device markings and the label, not a generic factor.
Common drop factors
| Device | Drop factor | 1 mL equals |
|---|---|---|
| Standard pharmacy dropper | 20 gtt/mL | 20 drops |
| IV macrodrip set | 10–15 gtt/mL | 10–15 drops |
| IV macrodrip set | 20 gtt/mL | 20 drops |
| IV microdrip (pediatric) | 60 gtt/mL | 60 drops |
Source: standard pharmaceutical drop convention and typical IV administration-set labeling.
Common mistakes
- Assuming every dropper is 20 gtt/mL — IV and specialty droppers differ, so read the label.
- Using drops to dose medication precisely; drop size drifts with viscosity and angle.
- Confusing a macrodrip set (10–20 gtt/mL) with a microdrip set (60 gtt/mL) when computing volume.
- Rounding drops to a whole mL when the fraction matters for small doses.
Frequently asked questions
How do I convert drops to milliliters?
Divide the number of drops by the drop factor. With a standard 20 gtt/mL dropper, 60 drops is 60 ÷ 20 = 3 mL. A 60 gtt/mL microdrip set turns the same 60 drops into 1 mL.
How many drops are in 1 mL?
It depends on the device. The classic pharmacy convention is 20 drops per mL, but IV sets range from 10 to 60 drops per mL. Always use the drop factor printed on your dropper or tubing.
Is a drop always 0.05 mL?
Only by convention. The 0.05 mL figure comes from the 20-drops-per-mL standard, but real drop size changes with the fluid and the tip, so it is an approximation.
Can I use this to dose my medicine?
Use it to understand the math, not to measure a dose. For medication, follow the syringe or dropper markings and the label, and ask a pharmacist if the units are unclear.