You may not have thought much about your competition or outsourcing some of your work, but things like that will impact your ability to make a profit. And you will find this especially so in the beginning phases of your business. Even you are just opening a lemonade stand in the front yard, you will still need to know what Susie is selling her lemonade for on the next street over!
But your fixed expenses don't do this. They remain the same no matter what sales does. That's why it's call fixed. These are expenses like rent, taxes, utilities, phone, salaries, insurance, etc. A lot of business owners never consider this. They just lump all their expenses together. But you could never make an accurate plan if you combine all your expenses together. If you project your sales higher and want to know what your expenses will be, you have to separate your fixed and variable. So, thinking about this principle, let me ask you a question. If your sales grew 10% and nothing else changed, would your profit margin be higher, the same, or less? Profit margin is % of profit against sales