So how much water exists on and above our watery planet? The earth’s sur­face is about 70 per­cent cov­ered with water, and the oceans hold about 96 per­cent of it. Water exists in the air as water vapor, in rivers and lakes, in ice­caps and glac­i­ers, in the ground as soil mois­ture and aquifers, and even in plant and ani­mals. All of that water would fit into sphere with a diam­e­ter of about 860 miles.