How many grains of sand are there in the world?
Approximately 7,500,000,000,000,000,000, or seven quintillion five quadrillion grains of sand
Mathematicians at the University of Hawaii tried to guess the number by calculating the grains of sand in all the beaches of the earth. According to their formula on this page, the number of grains of sand will be the volume of sand divided by the volume per grain. However, since the parameters only specified the length of beaches around the world, the number of grains of sand in the world’s deserts and underneath the earth’s crater is probably excluded.