Netmask Subnet Calculator
Use our Netmask subnet calculator below to show information about the subnet you enter.
In addition to a CIDR notation, the prefix can also be specified as a network mask which has the same quad-dotted decimal representation an IP address does. For example 255.255.255.0 is the network mask for 192.168.0.1/24.
When using the CIDR notation, the prefix size represents the number of most significant bits. For example, the binary representation for a prefix size of 24 is 11111111.11111111.11111111.00000000, or 255.255.255.0 in quad-dotted decimal notation.
The network mask is also called subnet mask if it designates a subnet within a larger hierarchy network.
Get started below with your own netmask calculation. Enter in a IP address and then select the network mask. Our netmask subnet calculator will handle the rest and show you all relevant information about the subnet.