The reviews and opinions below are posted by SnapFiles visitors. They do not necessarily reflect our opinion, and they are solely based upon the experience of individual users.
I use LanCalculator pretty frequently at work. The interface and information given (mask, inverted wildcard mask, IP ranges, etc) are all available in the normal dotted decimal format but also in binary, decimal and hex.
It's by far the best subnet calculator I've found. (But soon I'll need IPv6 and that's the one thing it's missing.)