Why do you need to know these percentages? As your sales increases or decreases, your material cost, labor cost, and variable expenses will track accordingly. They will track very close to the same % as your current business. As an example, let's say your current sales is averaging 贄ꯠ per month and your material cost is averaging ฤꯠ per month. That's 20% of your sales (ฤꯠ ÷ 贄ꯠ = 20%). So, what would your material cost be if your sales were averaging 赨ꯠ per month? It would still be 20% but it would be 20% of 赨ꯠ or ุꯠ. So with these percentages, you can project your material, labor and variable expenses. See how it works?
Did you ever stop and think what a unique position you're in as a business owner? I don't know of any other way you can have as much control over your success than owning a business. When you work for someone else, you are totally at their mercy as to what your future may be like. It doesn't matter whether it is a private business you work for or a large corporation. Your future is in their hands. The only thing that might qualify other than owning a business would be to inherit or win a lot of money that would give you everything you want in life. So, why make a business plan the normal way when you could first make one that could give you what you want in life? Have you ever thought about doing a plan like that? Would you know how? Would you have the time to do it?