Used LanCalculator for Windows?
Developer’s Description
By LanTricks
LanCalculator - makes possible not only to easily calculate the subnet addresses range and subnet masks but also broadcast address, net address, net prefix and net mask inversion which is used in the access control lists (ACL) of Cisco network equipment. One key press is enough to calculate all parameters after net address and mask were entered.
To complete the picture additional display is given in binary, decimal and hexadecimal notation. Version 1.0.2.29 may include unspecified updates, enhancements, or bug fixes.
Explore More

CyD Network Utilities
Free
EMCO Remote Desktop Starter
Trial version
EMCO Remote Desktop Professional
Trial version
Mr.Who
Free
ReaSoft Network Firewall
Trial versionCommCorder
Trial version
Network Inventory Software
Trial version
Alchemy Network Monitor
Trial version
JimIP Switcher
Free
NT Meter
Trial version
HTTP Test Tool
Free
JiJi AD Bulk Manager
Trial version