What the numbers mean
Just 25 millilitres in a one-litre world.
Imagine a one-litre bottle holding Earth's entire water supply. About 25 millilitres would be fresh. Most of even that small amount is frozen or underground.
Read the sourcesShrink the planet into a bottle
The US Geological Survey puts freshwater at about 2.5% of Earth's water. In our one-litre bottle, roughly 975 millilitres would be salty and 25 would be fresh. This compares how much water there is by volume. The blue area on a world map tells us how much surface it covers. [1]
Now open the smaller reserve
Of the freshwater itself, roughly 69% is in glaciers, ice caps and permanent snow, and about 30% is underground. Rivers hold only a tiny fraction. Notice what the percentages refer to: 30% of freshwater is much less than 30% of all water. Always check what counts as the whole. [1]
A full reservoir is only part of the story
The World Health Organization counts drinking water as safely managed when it is at home, available when needed and free from contamination. Having freshwater nearby does not guarantee that. Pipes, treatment and reliable supply determine what reaches a home. A planetary water total cannot tell us whether someone's tap will work tomorrow. [2]