Example, let's say if someone says, I have allocated one
/64 address. How can I convert that to a size in
/30? How many
/30 equals to one
How can I convert that to a size in /30?
This question does not actually make sense.
How many /30 equals to one /64?
Neither does this question make sense.
I assume you mean IPv6 because there is no such thing as an IPv4
Your last question could make sense if you reverse it to ask how many
/64 networks can be made from a
/30 prefix. The way to calculate that is to subtract 30 from 64 to get 34. The answer would be 2 to the power of the result.
64 - 30 = 34 2^34 = 17,179,869,184
That means you can derive 17,179,869,184
/64 networks from one
For IPv6, you will probably divide your
/30 prefix into
/48 (or shorter) prefixes to assign each site a
/48 prefix. That means that you can have 262,144 sites, each with 65,536 standard IPv6
The reason to use
/48 (or shorter) for each site is that is the longest prefix that the ISPs will advertise on the public Internet.