So here is how you would do it: Projected sales = fixed exp (足ꯠ) divided by 1_ƖǑ% + 27ǔ% + 12ǔ% + 25% (your new profit margin) = 造같 (new sales) You can do this for as many years out as you want. Obviously this is based on your first year's fixed expenses remaining constant and no consideration of depreciation, inflation, or taxes. But most likely you would need to increase your fixed expenses because you're going to probably have more rent, utilities, or such as your business grows. So, you would simple put in your new fixed expense number in place of the existing one for each of the years you would be planning for. So, you see if you decided you wanted a 35% profit margin at year 5 then you could see how much sales it would take to give you that. Now it's also important to know how many more customers you would need as well so you should always look at that unless you have another way of growing your sales other than with new customers.
Another consideration. Should the business plan be a document that is focused on selling an idea for a product or service? For many years I worked in a company that did not want anything in a business plan that could be construed as showing a bias towards or against a project. The mantra was to only present facts in the business plan. The Operations Research Department was there to review the analysis as being unbiased. To handle the "what if" scenarios or sensitivity analysis we prepared a supplemental analysis documents which were mostly financial oriented. Personally, I like a factual approach and use the presentation of the final document to point out the conservative aspects of the content.