📡 Broadcast Address Calculator
Enter any IPv4 address and subnet mask to instantly calculate the broadcast address, network address, usable host range, and full subnet details.
| CIDR | Subnet Mask | Total IPs | Usable Hosts | Broadcast Octet | Common Use |
|---|---|---|---|---|---|
| /8 | 255.0.0.0 | 16,777,216 | 16,777,214 | x.255.255.255 | Class A Enterprise |
| /16 | 255.255.0.0 | 65,536 | 65,534 | x.x.255.255 | Class B / Large LAN |
| /20 | 255.255.240.0 | 4,096 | 4,094 | x.x.x+15.255 | Campus / Large VLAN |
| /22 | 255.255.252.0 | 1,024 | 1,022 | x.x.x+3.255 | Cluster / Large Dept |
| /23 | 255.255.254.0 | 512 | 510 | x.x.x+1.255 | Medium Dept VLAN |
| /24 | 255.255.255.0 | 256 | 254 | x.x.x.255 | Standard Home / LAN |
| /25 | 255.255.255.128 | 128 | 126 | x.x.x.127 / .255 | Split /24 VLAN |
| /26 | 255.255.255.192 | 64 | 62 | x.x.x.63/127/191/255 | Small VLAN |
| /27 | 255.255.255.224 | 32 | 30 | varies | IoT / DMZ |
| /28 | 255.255.255.240 | 16 | 14 | varies | IoT / Server Cluster |
| /29 | 255.255.255.248 | 8 | 6 | varies | Server Segment |
| /30 | 255.255.255.252 | 4 | 2 | varies | Point-to-Point |
| /31 | 255.255.255.254 | 2 | 2* | N/A (RFC 3021) | P2P (no broadcast) |
| /32 | 255.255.255.255 | 1 | 1 | Host Itself | Loopback / Host Route |
| Range | Default Mask | CIDR | Total Hosts | Class | Typical Use |
|---|---|---|---|---|---|
| 10.0.0.0 — 10.255.255.255 | 255.0.0.0 | /8 | 16,777,216 | A | Enterprise / Data Centers |
| 172.16.0.0 — 172.31.255.255 | 255.255.0.0 | /12 | 1,048,576 | B | Corporate WANs |
| 192.168.0.0 — 192.168.255.255 | 255.255.255.0 | /16 | 65,536 | C | Home / SOHO Networks |
| 127.0.0.0 — 127.255.255.255 | 255.0.0.0 | /8 | N/A | Loopback | Local Host Testing |
| 169.254.0.0 — 169.254.255.255 | 255.255.0.0 | /16 | 65,024 | Link-Local | APIPA (no DHCP) |
| Use Case | Recommended CIDR | Usable Hosts | Notes |
|---|---|---|---|
| Home Network | /24 | 254 | Standard for most routers |
| Home Lab | /23 or /22 | 510 / 1,022 | Room for VMs and devices |
| Guest WiFi | /25 or /26 | 126 / 62 | Isolate guest traffic |
| IoT VLAN | /27 or /28 | 30 / 14 | Limit attack surface |
| Server Segment | /28 or /29 | 14 / 6 | Static assignment |
| Point-to-Point Link | /30 | 2 | Router-to-router WAN |
| Management VLAN | /28 or /27 | 14 / 30 | Switches, APs, UPSes |
| Proxmox Cluster | /22 or /23 | 1,022 / 510 | Nodes + VMs + storage |
| VoIP VLAN | /25 | 126 | QoS priority segment |
| Backup Network | /29 | 6 | Isolated backup traffic |
The broadcast address is found by performing a bitwise OR of the IP address with the inverted (bitwise NOT) subnet mask. In simpler terms: take the network address and set all host bits to 1. For a /24 network like 192.168.1.0, the broadcast is always 192.168.1.255. For a /28 at 192.168.1.16, the broadcast is 192.168.1.31.
Every subnet loses 2 addresses for infrastructure: the network address (all host bits = 0, the first IP) and the broadcast address (all host bits = 1, the last IP). So a /28 with 16 total IPs provides only 14 usable host addresses. Exception: /31 subnets (RFC 3021) used for point-to-point links have no broadcast and use both IPs for hosts.
The broadcast address is a special IP address that helps send a message to every device in a local net or subnet. When one sends a packet to this address, it grabs attention of all hosts tied to the net, rather than one single machine. In short words it answers when you lack a precise target, then the information goes to all.
IPv4 addresses have 32 bits, that split into four octets. Each of those octets stores 8 bits and can express a value between 0 and 255. To get the broadcast address, one sets all host bits in the IP address to binary 1.
What is a broadcast address in a network
Like this, for net 192.168.1.0/24, it becomes 192.168.1.255, because the last bits of the final octet change to 11111111, whcih matches 255.
In a net range, the first address shows the net address, while the final always points to the broadcast address. Between them everything can serve as addresses for hosts. One does not assign the net or the broadcast address to real devices.
For instance, in a /28 net, 192.168.0.15 could work as a broadcast address, but knot in a /24 net. Everything depends on the subnet size.
Another separate broadcast address is 255.255.255.255. It belongs to the limited net, that means the local net. One uses it for things like DHCP, where clients send messages to find a server in the net.
Still these sends cannot be routed. Routers separate broadcast domains. If 255.255.255.255 could be routed, the amount of traffic could grow so much that it would cause serious troublesthrough the whole internet.
A broadcast address differs from a multicast address. Multicast targets a certain group of devices, instead of every single unit. Many IoT devices, like Google Home and Chromecast, use multicast to find all others in the net.
To find the net and broadcast addresses, one does a logical AND operation between the IP address and subnet mask. The net address results from filling all host bits with zeros, while the broadcast address comes from flipping those bits to ones. In a /30 subnet, there are only four addresses; one for the net, two useful for hosts and one broadcast address.
Pinging the broadcast address is not always bad in small amounts, but it does not scale well. It cannot spread past one single subnet or VLAN. Wake-on-LAN shows practical use, where one sometimes sends packets to an address like 192.168.1.255 to wake a sleeping machine in the network.
