Work out a network's address, broadcast, usable hosts and IP range from any IP and CIDR.
A /24 network has 256 addresses. Common home networks are /24; larger networks use smaller prefixes like /16.
Usable hosts exclude the network and broadcast addresses, except on /31 point-to-point links (2 usable, no broadcast) and /32 single hosts (1 address, no range).
network address
How to use this tool
Type any IPv4 address in the network, for example 192.168.1.10.
Type 24 for a /24 network, 16 for a /16, and so on.
The network address starts the range and the broadcast address ends it.
First and last usable addresses exclude network and broadcast (with /31 and /32 exceptions).
Formula & worked example
192.168.1.10/24: mask 255.255.255.0, network 192.168.1.0, broadcast 192.168.1.255, 256 addresses, 254 usable, range 192.168.1.1 – 192.168.1.254.
Limitations — read this before you rely on it
This covers IPv4 only, not IPv6, and it does not validate whether an address block is public, private or reserved — check allocation rules before assigning addresses.
Frequently asked questions
It splits an IP and CIDR prefix into network address, broadcast address, mask and usable host range.
A 24-bit network prefix, leaving 8 host bits: 256 addresses, 254 usable. The mask is 255.255.255.0.
254 usable hosts, plus the network and broadcast addresses making 256 total.
The last address in the subnet, used to send to every host on that network at once.
/31 is a point-to-point link with 2 usable addresses and no broadcast; /32 is a single host.