You're right about the variables. ;) Boiling it down to something like "You should get life insurance for eight to ten times your annual income" is a bit like "An engagement ring should cost two months' salary." It's a tidy marketing pitch.

Life insurance provides protection in case something bad happens and you die. How much protection you want to buy is up to you. You already have a good idea what your policies will cover now if you were to die: your mortgage plus $100k.

Whether that's "enough" for you and your family is something you and your family have to answer, and that involves a detailed look at your current finances as well as getting predictions of your future expenses down on paper.

Then, should you need more, you decide what kind of insurance is appropriate. Term is usually cheaper but does not accumulate cash value; whole life, universal, etc. are usually more expensive, but accumulate cash value. (Very broad strokes there.)

The last thought I have is that the more insurance you have, the less of your monthly income is available to invest, pay down debt, save, etc. It costs more to hedge more.