A business plan's length is a topic of some debate. Some venture capitalists insist that the number of pages is of utmost importance while other investors say page counts are meaningless. They all agree, however, that a business plan should describe a business concept eloquently and concisely and pay close attention to how the entrepreneur will execute his or her concept. Another ray of hope: there are some basic, industry-standard formatting guidelines that can aid entrepreneurs in their quest for financing.
Venture capitalists and loan officers view literally thousands of business plans and spend only a few minutes at a time looking at certain areas of a plan. The textual portion of the plan (not including financial charts and tables or the financial appendix) should typically be about 15 to 30 pages in length. If your business concept is complicated (or your products and services really need a few pages of description), a longer plan is acceptable. Although you don't want to short change your concept, plans longer than 100 pages (excluding appendices) are rarely taken seriously.
A major key for business plan length is readability. Using elaborate fonts and small font sizes is another practice that is universally frowned upon. Spacing text in an effective manner helps a tired investor get to the germane points of your business plan. It's also important to include charts that are necessary to illustrate your funding; the business plan should never include anything extraneous or "filler." The appendix is not generally counted as part of the plan proper, and it should be no longer than the business plan. The appendix usually contains tables with month-by-month breakdown of sales, personnel, cash flow, etc.
Your business plan should also be very portable. It should never be too large to give someone fits while trying to bind the document, nor should it be thin enough to blow away in the wind on your way to that all-important business meeting. Of course, the most important aspect of a business plan is a compelling idea; the right length will help set your business relationship with an investor on the right footing.