IP Subnet Calculator
Calculate IPv4 subnets from a CIDR: network, broadcast, usable range, mask, wildcard.
About this tool
Calculate an IPv4 subnet from a CIDR notation or address plus mask. Get the network address, broadcast, first and last usable hosts, total number of addresses, subnet mask, wildcard mask and binary breakdown. Useful for network planning, VLAN sizing and firewall rules. Runs locally in your browser.
What does CIDR /24 actually mean?
CIDR is the count of bits in the network portion of the address. /24 means the first 24 bits identify the network, leaving 8 bits (256 addresses) for hosts. The bigger the number, the smaller the subnet.
What is the difference between network, broadcast and usable hosts?
The network address is the first address of the block, the broadcast is the last. Usable host addresses sit in between (network + 1 to broadcast - 1). A /30 has 4 addresses but only 2 are usable.