Subnet Calculator
Work out network address, broadcast, usable host range and mask from any IPv4 address and prefix length.
Any address inside the network you are working on.
Netmask 255.255.255.0
How the host count is worked out
Total addresses is 2 ^ (32 - prefix). Usable hosts subtracts the
network and broadcast addresses, so it is that total minus two.
Two prefixes are special. A /31 has no broadcast address and
carries two usable addresses on point-to-point links (RFC 3021), and a
/32 is a single host route. Both are reported as such rather than
as a negative host count.