Yes.
:)
Calculate it in such a way that is consistent and makes sense for you. Everyone's scenario is different. We're not your benchmark, your savings is.
Exactly this. I can tell you exactly how *I* do it if you want.* And I think it makes sense. But I've also heard other folks explain different mechanisms that have a consistent and logical argument to them. Do it the same. Save as much as you can. Use the percentage as a score of "now" vs "some other time" and not a score of "mine" vs "yours".
*How I calculate:
percent = ((income - expenses) / income ) * 100
income is gross income. And ALL of it. (stock dividends are income, too.)
expenses is ALL expenses (and tax is an expense)
401k contributions come out of income... but are not an expense (hence, part of savings)
employer matches are income
I also exclude a few things... for instance I have income categories like Rebates or gifted money or ... well, various things I don't count on repeating on a regular basis. Using them as a basis for savings calculation would skew it. I'd rather be conservative.