There are two commonly known forms of perfumery: oil-based (in dropper bottle) and alcohol-based (in sprayer bottle / atomizer). Between the two, oil-based perfume diffuses slower than its spray counterpart, making it better for use in a hotter weather, while the sprayer is better for cooler weather.

With winter coming, you may want to convert oil-based perfume into a carry-on atomizer bottle. There is an easy way to do this precisely without having to use measuring tools.

First, fill in an empty carry-on atomizer bottle with tap water until it’s full. Then, put on the spray cap and spray all the water out like crazy. Count how many spray it takes to empty the bottle. The number of sprays is the number of drops of perfume you fill into the bottle. For example, if it takes 40 sprays to empty, then you’ll want to pour in 40 drops of perfume into the bottle. Then fill it with alcohol buffer until it’s full.

This simple conversion means every one drop of oil-based product is equivalent to one spray. Pretty easy, right?