Where does the period go when using parentheses?

Where should the period go when using parentheses? For example:

In sentence one, I use this example (which has a parenthesis at the end.)

Should the period be inside, or outside of the parentheses? What about if the entire sentence is a parenthetical (as below)?

(Where does the terminal punctuation go here?)

Is there a hard and fast rule?

Solution 1:

The best rule of thumb for punctuating in and around parenthetical remarks is that the sentence should be valid if you remove the parentheses and everything inside them.

Here I have an example (with a parenthetical remark).

Here is the same example (with the same remark, even.)

Removing the entire parenthetical remark from the first sentence still leaves me with a valid structure, while removing it from the second leaves me lacking any terminal punctuation; thus the first is correct.

References:

• The Punctuation Guide
• Study.com
• Grammar Girl

Solution 2:

If only part of the sentence is parenthetical, then you put the final punctuation outside of the parenthesis:

I enjoy breakfast (sometimes).

If the entire sentence is parenthetical, then you put the punctuation inside the parenthesis.

I enjoy breakfast. (I enjoy lunch more.)