Fitbit plans to sell nearly 30 million shares in its initial public offering at prices between 14 to $16 a share, according to its updated filing with the Securities & Exchange Commission. At the top end of that range, Fitbit's IPO would take in $477.6 million at a valuation of $3.28 billion.

At the midpoint of the price range, Fitbit would be valued at nearly $3.1 billion

Underwriters have the opportunity to sell another 4.5 million additional shares to service over-allotments.

Overall, Fitbit plans to sell about 22.4 million shares in the offering, while investors will sell almost 7.5 million shares in the offering.

Among the sellers, Foundry Group will sell nearly 2.9 million of its 52.7 million shares, and True Ventures plans to sell nearly 2 million of its 40.9 million shares. Co-founders James Park and Eric Friedman, who serve as CEO and chief technology officer respectively, will both sell almost 700,000 shares from their identical stakes of about 20 million shares.

The company revealed in May regulatory filings that it made a $131.8 million profit last year on revenue that nearly tripled to $745.4 million. Since 2007, Fitbit has sold roughly 20.5 million of its fitness-tracking devices with more than half sold last year.

Fitbit is expected to price its IPO and begin trading on June 17, according to Bloomberg News, and plans to list on the New York Stock Exchange under the symbol FIT.