How much is Google Inc. (search) really worth? The online search engine leader appears poised to weigh in with its opinion, helping bring clarity to a question that has been puzzling Silicon Valley and Wall Street since the company filed its IPO plans 2 1/2 months ago.

Industry analysts expect Google to provide a self-appraisal when the Mountain View-based company updates the prospectus for its initial public offering with its second quarter results. Google's second quarter ended June 30, meaning the update could come as early as this week.

Based on the numbers filed so far, industry experts have pegged Google's market value at between $20 billion and $30 billion — an extraordinary figure for a company that hasn't even celebrated its sixth birthday yet.

The estimates are likely to become more precise once Google sets a price range, said Kathleen Smith, an IPO analyst for Renaissance Capital in Greenwich, Conn. "That's when the analysis will really begin because we will finally have something to work with," she said.

Google officials didn't immediately respond to a request for comment Monday. Companies pursuing IPOs generally are forbidden to make public comments about the process or their finances.

Setting a price range for an IPO is a seminal step taken by all companies preparing to sell their stock for the first time. After a company sets a price range, its executives and investment bankers typically meet with analysts and institutional investors for several weeks before finally selling the shares.

Barring complications, Google's IPO could be completed next month, although industry observers say it wouldn't be surprising if the company decided to wait until after Labor Day.

Google hinted at what the company might be worth last month in a filing that valued employee stock options. In that assessment, the company estimated its stock was worth $88.13 per share as of March 31, a price that assigned Google a market value of about $23 billion.

Analysts expect Google to split its stock before going public so its shares aren't so expensive. Executing a stock split wouldn't affect Google's market value because the technique also increases the number of shares outstanding in proportion to the reduction in per-share price.

Google's IPO price could still change even after the company establishes a target. The company hopes to determine the final price in an auction that will be open to all qualified investors who set up an account at one of 30 participating brokerages.

The second-quarter results also will influence the company's market value, said American Technology Research analyst Mark Mahaney, who estimated Google's market value at $30 billion in April. He may reconsider that figure, depending on how much the second quarter deviates from the rapid growth that propelled Google during the first quarter.

The company earned $64 million on revenue of $390 million during the three months ended in March, more than doubling a profit of $25.8 million on revenue of $179 million at the same time last year.