How much should I spend on vacation? Assume I make $100,000 a year, save 1/3 of it, and have no debts.?

Do you invest? saving is not enough. you should be investing as well. Having said that. The scenario you describe in your question is similar to my situation.

The question here is not how much, but why do you want to spend $_____(fill the blank)? will you feel comfortable spending $_____ on a single vacation?

You see this is the thing. it is not about the amount you could be spending on a vacation, it is about how fulfilling and meaningful the vacation will be for you.

No-one here can answer that question. There is no right or wrong answer, given you have no debts.

Spend what you want - if holidays / travel are important to you, then go on a couple of decent trips abroad each year. That is what I do - I have no debts, and my enjoyment is a couple of foreign holidays a year.

If what you want to do and have time to do costs $8000, that's what you should spend. If it costs $200, then that's what you should spend.

Why would there be some kind of rule or guideline for how much you should spend on vacation? Spend whatever you want, assuming you don't go into heavy debt and that you are being smart about saving and investing.

There is no law about it. You may spend what amount you wish.

If you make $100k you should be putting at least $15k per year into your retirement mutual funds.