Calculate IP addresses, subnet masks, CIDR prefixes, and network information online
The IP/Subnet Calculator is an online network address calculation tool. Enter an IPv4 address and CIDR prefix to quickly calculate the network address, broadcast address, subnet mask, wildcard mask, first usable IP, last usable IP, total addresses and usable hosts. It also supports quick conversion between subnet masks and CIDR prefixes, making it useful for network configuration, server deployment, LAN planning and development troubleshooting.
After entering an IPv4 address and CIDR prefix, the tool automatically calculates the complete network information based on the network and host portions of the address.
The network address identifies the network to which an IP address belongs. It is calculated by performing a bitwise AND operation between the IP address and subnet mask, with all host bits set to 0.
The broadcast address is used to send broadcast traffic to all hosts within a subnet. For a standard IPv4 subnet, the broadcast address is usually the last address in the network range.
The subnet mask separates the network portion from the host portion of an IPv4 address. For example, the CIDR prefix /24 corresponds to the subnet mask 255.255.255.0.
A wildcard mask, also called an inverse mask, is the bitwise inverse of a subnet mask. It is commonly used in ACLs, routing policies and network device configurations.
For a standard IPv4 subnet, the tool can calculate the first usable IP and last usable IP to quickly determine the address range available for hosts.
CIDR stands for Classless Inter-Domain Routing. It represents the network prefix length after an IP address, such as 192.168.1.0/24. The /24 prefix means that the first 24 bits belong to the network portion and the remaining 8 bits belong to the host portion.
The number of addresses in an IPv4 subnet is determined by the number of host bits. For an IPv4 network with a CIDR prefix of /n, the total number of addresses is normally 2^(32-n).
In a standard subnet, the network address and broadcast address are normally not assigned to hosts, so the number of usable hosts is generally the total number of addresses minus 2. For example, a /24 network contains 256 addresses, of which 254 are normally available for hosts.
Enter a standard IPv4 subnet mask such as 255.255.255.0 and the tool calculates its corresponding CIDR prefix length, which is /24.
Enter a CIDR prefix such as /24 and the tool quickly calculates the corresponding subnet mask, which is 255.255.255.0.
192.168.1.0/24 contains 256 IPv4 addresses, ranging from 192.168.1.0 to 192.168.1.255. The network address is 192.168.1.0, the broadcast address is 192.168.1.255, and the standard usable host range is 192.168.1.1 to 192.168.1.254.
The IPv4 CIDR prefix /24 corresponds to the subnet mask 255.255.255.0. It contains 256 addresses, with 254 normally usable host addresses.
The network address identifies the subnet itself, with all host bits set to 0. The broadcast address represents all hosts in the subnet, with all host bits set to 1. Neither is normally used as a standard host address.
A wildcard mask is the bitwise inverse of a subnet mask. For example, the wildcard mask for 255.255.255.0 is 0.0.0.255. It is commonly used in network device ACLs and access control rules.
An IPv4 address consists of 32 binary bits. The CIDR prefix specifies how many bits belong to the network portion, while the remaining bits belong to the host portion. The network address is calculated by performing a bitwise AND operation between the IP address and subnet mask. The broadcast address is obtained by setting all host bits of the network address to 1.
Comments 0