[exitb]

By far most of the water is in the oceans, which have an average depth of 3688m. 2% of the water is currently frozen, so one can easily estimate how much would the sea level raise, had it all melt.

EDIT: Corrected km to meters, as comment below points out.

[ditn]

For those reading this with incredulity I believe the above commenter made a typo - the average depth is 3688m, or 12,100ft.