Astronomers estimate that there are approximately 200 billion trillion stars in the observable universe. This number is derived by estimating the number of stars in our Milky Way galaxy-about 100 billion stars-and multiplying it by the estimated number of galaxies in the universe, which is around 2 trillion galaxies. Multiplying these gives roughly 200 billion trillion stars, or 200 sextillion stars in total
. To put it in perspective, the Milky Way alone contains about 100 billion stars, and the universe contains roughly 2 trillion galaxies, each with varying numbers of stars. The total number is so vast that it is often compared to the number of grains of sand on all the beaches on Earth or the number of cups of water in all the Earth's oceans
. In scientific notation, this estimate ranges from about 102210^{22}1022 to 102410^{24}1024 stars in the observable universe, reflecting uncertainties in galaxy counts and star formation rates
. Thus, while the exact number is difficult to determine, the best current estimate is on the order of 200 billion trillion stars in the observable universe.
