As kids, we've been taught that 70% of the Earth is covered with water, and that is A LOT. A lot indeed, but only in terms of area coverage... For if water is compared to the overall mass, things are quite different.
If you look at the image above (source), the small blue sphere on top-left corner of our dry Earth is the relative amounts of Earth's water in comparison to the size of the Earth! It is indeed THAT small!
In numbers, our Earth has a volume of 332,500,000 mi3 (1,386,000,000 km3) and a diameter of 169.5 miles (272.8 kilometers). If we gather ALL the water on earth, oceans, lakes, underwater reservoirs, rivers, icebergs, glaciers, soil moisture, water vapor in the air, and even the water that living organisms and pants have, then we would build a sphere with volume 22,339 mi3 (93,113 km3) and diameter 34.9 miles (56.2 kilometers).