If you develop a good Profit & Loss Statement for your existing business for the current year or for the first year of your proposed business, you can use this data to actually project how much sales you would need to yield the income you want and the profit margin you want. You can plan ahead as far as you want. Sound impossible? It's actually pretty simple and can be pretty accurate plan.
A plan should include but is not limited to the following: 1. A statement of your business purpose 2. A description of your company 3. The goals of your company 4. The structure of the company (sole_proprietorship, partnership or corporation) 5. The product or service that you are selling 6. A market analysis of your product or service 7. Resources spent (time and money) 8. A financial plan to include financial statements 9. Information about the managing principals in the company 10. How you plan to manage and operate the company