The "rule of thumb" for changing total teeth count is add or subtract 1/2 of the tooth difference. For example, going from a 46T to a 50T chainring you should add 4/2=2 half-links. If the difference is an odd number go to the next even number since you can't add 1/2 of a link. The reason for adding only 1/2 of the difference is that the chain only wraps around 1/2 of the chainring or cog.

Before anyone says anything, yes, there are 1/2-links available but they are unusual and not commonly used.