how many drops in milliliter?

Wikipedia is definitely accurate here. I remember all this stuff from those boring physics and engineering classes in college...

I find it amusing that two high priests of water drops proclaim different numbers. I have a few theories that could account for that.

1. The size of a water drop varies over time. If this reaches the scientific community, I predict it will blow Einstein's theories out of the water. According to my theory, 65 million years ago, water drops weighed 10 pounds, and it was rain drops that killed the dinosaurs.

2. One high priest was using American drops and the other was using metric drops.

3. Neither one actually counted the drops. They calculated the number of drops theoretically, as part of their college thesis.

I have more than a passing interest in the subject because I use eye drops to prevent glaucoma damage. I took a more unorthodox, and possibly heretical approach. I actually counted the drops. When squoze out of a 5 ml polypropylene bottle that originally contained eye drops, I got 26 drops of room temperature tap water per gram of water.

I think I can safely assume that 1 ml of my tap water weighs very close to 1 gram. As a second check on the quantity of water, 5 grams of water fills the bottle to the same height as an unopened bottle of eye drops. The label of this prescription bottle says it contains 5 ml. I also feel comfortable thinking my jeweler's scale is accurate within 2 %, as it tells me my U.S. nickel weighs 5.0 grams.

So there you have it folks. I guess I should mention that apparently the size of water drops does vary depending on the size of the opening in the bottle, and the material the bottle is made out of.

Hi all....I was mixing some juniper oil in propylene glycol yesterday and needed to know how many drops of that mixture were in 1 mL....firstly I filled my dropper to the 1 mL mark with room temp water and counted the drops which equaled 20 drops exactly....then I took a duplicate dropper and did the same thing but with the juniper/PG solution....this was 40 drops exactly....the specific gravity made quite a difference.

[Mrs X]

Originally Posted by Unregistered

Hi all....I was mixing some juniper oil in propylene glycol yesterday and needed to know how many drops of that mixture were in 1 mL....firstly I filled my dropper to the 1 mL mark with room temp water and counted the drops which equaled 20 drops exactly....then I took a duplicate dropper and did the same thing but with the juniper/PG solution....this was 40 drops exactly....the specific gravity made quite a difference.

Excellent experiment. - From memory it is surface tension that controls the size of the drops. Surface tension even in water changes with temperature.

how many drops per aqueous solution and per oily solution

Originally Posted by Unregistered

How many drops are in one milliliter?

depends on the viscosity of the liquid.

It's 20 drops per mL. I work in a pharmacy and that's the standardized conversion for any prescription or OTC medication (i.e. eye drops, ear drops, formularies, etc.) Or in other words, 1 drop = 0.05 mL

Originally Posted by Unregistered

How many drops are in one milliliter?

Please provide answer

Depends on how big your drops are. They tend to be between 15 and 25drops

So, pushing aside all these 'standards'.

How many drops are in a milliliter, at STP (not stone temple pilots), of pure distilled water given it's specific viscosity/surface tension?