A pre-money valuation is a term widely used in private equity or venture capital industries, referring to the valuation of a company or asset prior to an investment or financing. If an investment adds cash to a company, the company will have different valuations before and after the investment. The pre-money valuation refers to the company's valuation before the investment.
External investors, such as venture capitalists and angel investors will use a pre-money valuation to determine how much equity to demand in return for their cash injection to an entrepreneur and his or her startup company. This is calculated on a fully diluted basis.
Usually, a company receives many rounds of financing (conventionally named Round A, Round B, Round C, etc.) rather than a big lump sum in order to decrease the risk for investors and to motivate entrepreneurs. Pre- and post-money valuation concepts apply to each round.
Read more about Pre-money Valuation: Basic Formulae, Round A, Round B, Upround and Downround