Typically, what percentage of the company is sold during each round of funding

You should think about is in terms of 3 variables:

1. How much money will your company have to raise before you ultimately exit (sell your shares)?

2. When do you anticipate raising rounds of financing? How much money will the company have to raise from these rounds and what inflection points will you try to link these financings to?

3. How much of your company will you be willing to sell to complete each of these financings. Alternatively, you might ask yourself; how much of the company you think you should still own when you cross the finish line?

Naturally, there are a wide range of precedents so it is hard to derive a formula for this. Ultimately the stronger the performance of you and your company, the less capital you raise and the better you time your financings; the greater the stake you will retain in your company.

John, I'm not sure, but it could sound as if you have the problem understood backwards. Capital investment is an additive process, you print new shares to the new investors.

There are no typical percentages. There could be some typical percentage ranges, but IMHO it is misleading to think in those terms -- it is better to think in terms of pre- and post-money valuation.

Pre-money valuation is really the important part. It depends on lots of things, typically:

• Gut feeling of how formidable the entrepreneurs are, what the size of the potential market is, how solid barriers to entry the company will be able to erect.
• Proven tracktion (proven end user demand), exisiting sales.
• Reduction of technology risk (going from Powerpoint slides to working prototype to working at scale).
• What other companies at a similar stage have been valued at lately.

Here is a classic e-book which kind of outlines typical business angel thinking on early stage valuations.

Particularly at later stages of financing (when a company is mature, generating significant revenues, and maybe on a clear 1-2 year path to an IPO), the structure of a security can help you manage dilution from a share issuance. Complex structures can allow investors to pay a higher nominal price (i.e. own a small %) in order to trade for: (i) managing the risk of returning less than their invested capital (ii) more predictability in returning a minimum amount of cash. Some rights/preferences that can achieve these goals include: liquidation preferences, dividends & redemption rights.

Although Zippy's framework is helpful, it can be ineffecient, or worse, dangerous if you (mis)interpret his rational as calculating the minimum amount of capital to raise. Reasonably overcapitalizing a business can help you extend your lead in tough times when your competition is capital constrained, help you sleep better at night while you experiment (and fail) with your startup, and avoid being in a very weak negotiating position if/when you reach out for more funds.