Download of IPv4Calc 1.2 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. The application belongs to Internet & Network Tools. This free Mac application is a product of AB Software.
From the developer:
IPv4Calc is a simple application for network operators and students that allow you to expand a given IP address and subnet mask to its relevant values, such as address class, address type, number of host, major network, broadcast address, and wildcard mask.
You may want to check out more software for Mac, such as FileMaker Server, IPNetSentryX or Radmind Assistant, which might be similar to IPv4Calc.