The offering could occur as soon as next week.
The valuation, on a fully diluted basis, is about 20% below the $10-billion level the company achieved in its latest private funding round in 2014. They each plan to sell 2.3 million of their own shares, generating about $39 million.
The company is one of a class of well-funded, closely-watched technology companies that have achieved a private valuation of more than $1 billion. Adding in the value of restricted stock units lifts the company's valuation to around $8 billion.
San Francisco-based Dropbox is aiming to raise as much as $648 million in its U.S. IPO, marketing 36 million shares of Class A common stock for $16 to $18 apiece, according to the filing with the Securities and Exchange Commission.
Drew Houston, the founder and CEO of Dropbox, at the annual Allen & Company Sun Valley Conference in 2016 in Sun Valley, Idaho. That technique essentially allows Drobox to set a higher per-share price in its IPO without changing the economics of its previous owners or the company as a whole.
US Secretary of State, Rex Tillerson arrives Nigeria today
Secretary of State Rex Tillerson listens to a question during a news conference in Nairobi, Kenya, March 9, 2018. Shortly after his arrival, Tillerson also met with President Uhuru Kenyatta.
The San Francisco-based company reported $1.1 billion in revenue a year ago, with a net loss of $111 million. The proceeds include United States dollars 100 million from a concurrent private placement of shares at the same price as the IPO to Salesforce.
Dropbox claims more than 500 million users in more than 180 countries, but the less-good news is that only about 11 million are paying for the privilege. Its venture arm, Salesforce Ventures, invests in enterprise cloud companies and it will be purchasing some $100m of Dropbox stock.
Converting users into paying customers is the company's next challenge.
Dropbox shares will trade on the Nasdaq under the ticker symbol DBX.