Enter an IP address with CIDR notation or subnet mask to calculate network details, host ranges and subnet breakdowns.
The Subnet & CIDR Calculator accepts any IPv4 address in CIDR notation (e.g. 192.168.1.0/24) or with a dotted subnet mask (e.g. 10.0.0.0/255.255.255.0) and calculates the network address, broadcast address, first and last usable host addresses, wildcard mask, total addresses, usable host count and network class. The binary visualiser shows which bits are network bits (blue) and which are host bits (green). The subnet breakdown table splits the network into smaller subnets at a prefix length of your choice, up to the first 256 subnets. All calculations run entirely in your browser.