I often need to work with IP addresses and IP subnets. Somehow humans are not very good at binary arithmetic, so converting from to /18 does take some time. Calculating how many hosts could fit in there and what the address-range is, is an even bigger challange.

Luckily there exists a nice tool called the subnet calculator, which does all of these calculations in an instant. The Internet offers lots of these; some are Win32 applications while others run online; Some require to input each octet individually, others are more liberal.

After some hours of search, I didn’t find a subnetcalc that fits my needs. I’m sure it exists somewhere in the 427000 hits, I just didn’t find it. Instead, I wrote my own one.

It’s a web-based calculator that runs entirely on HTML and JavaScript. This makes it usable online as well as offline (by simply saving the HTML-page). It currently supports IPv4 and some IPv6 addresses.

One Comment

  1. Niobos says:

    Update: IPv6 support is official and documented