Business 101 question

[Jerseydave]

Let me start by stating I did not go to school for business, nor do I have a business degree.

With that said, what is the typical rule when it comes to assessing a value of a business?

For instance, is the value of a business based on weekly gross sales or weekly net profit?
At what percentage of that figure?

I've been told in my business (wholesale meat making a very small margin compared to anything retail) the value is figured at 16X the weekly gross sales.
(example, a business that has $10K gross sales per week is valued at $160K.)
Make any sense?