For IPv4, a network may also be characterized by its **subnet mask** or **netmask**, which is the [bitmask](https://en.wikipedia.org/wiki/Bitmask "Bitmask") that, when applied by a [bitwise AND](https://en.wikipedia.org/wiki/Bitwise_AND "Bitwise AND") operation to any IP address in the network, yields the routing prefix. ||Addresses|Hosts|Netmask|Amount of a Class C| |---|---|---|---|---| |/30|4|2|255.255.255.252|1/64| |/29|8|6|255.255.255.248|1/32| |/28|16|14|255.255.255.240|1/16| |/27|32|30|255.255.255.224|1/8| |/26|64|62|255.255.255.192|1/4| |/25|128|126|255.255.255.128|1/2| |/24|256|254|255.255.255.0|1| |/23|512|510|255.255.254.0|2| |/22|1024|1022|255.255.252.0|4| |/21|2048|2046|255.255.248.0|8| |/20|4096|4094|255.255.240.0|16| |/19|8192|8190|255.255.224.0|32| |/18|16384|16382|255.255.192.0|64| |/17|32768|32766|255.255.128.0|128| |/16|65536|65534|255.255.0.0|256| [IP Subnet Calculator](https://www.calculator.net/ip-subnet-calculator.html)