July 21 (Reuters) - Paycor HCM Inc's shares rose more than 20% in their Nasdaq debut on Wednesday, giving the human capital management company backed by private equity firm Apax Partners a valuation of $4.8 billion.

The stock opened at $28 per share, above the IPO price of $23 each.

Paycor on Tuesday raised $425.5 million through the sale of 18.5 million shares in an initial public offering, where the stock was priced above an earlier targeted range of $18 to $21.

The Cincinnati, Ohio-based company joins a clutch of firms this week looking to cash in on a fertile capital market flush with funds and witnessing unprecedented levels of activity.

UK-based Apax acquired Paycor in 2018, and will hold the majority of its outstanding common stock after the offering.

Founded in 1990, Paycor offers solutions for managing human resources, payroll, talent and workforce, targeting businesses with a headcount between 10 and 1,000. It had over 44,000 clients as of March 31 this year.

Goldman Sachs and J.P. Morgan are the lead underwriters for the offering. (Reporting by Sohini Podder; Editing by Ramakrishnan M.)