There are more molecules in a glass of water than there are glasses of water in the ocean.

(If you doubt this, consider Avogadro’s number: 6.02 x 10^23. This means that for every 18 grams of water, there are 602 billion billion molecules. A liter of water weighs 1,000 grams, meaning that a 1 liter bottle of water contains 3.31 x 10^25 molecules.

The volume of the Earth’s oceans is about 1.4 x 10^9 cubic kilometers. That works out to 1.4 x 10^21 liters, meaning that there are more than 2,000 times as many molecules in a glass of water than there are glasses of water in the ocean..)

Hope I got all of the math correct.