When exactly will we run out of IPv4 addresses? Since there only are around 4 billion IPv4 addresses available, the WILL run out at some point. This site provides a countdown timer that gives us a clue about when the regional registries (that means the authorities responsible for handling IP addresses for a given region) will run out of available IP addresses in the v4 range. So it's not all that far away after all, at least according to some estimates.