Broadcast Address Calculator
Find the broadcast address (last IP) of any IPv4 subnet. Enter an IP and CIDR (e.g. 192.168.1.10/24) and see the broadcast and network addresses instantly. Runs in your browser.
Get the Broadcast Address
Enter any IPv4 address and CIDR (e.g. 192.168.1.10/24), then click Get broadcast.
Result
| Subnet mask | 255.255.255.0 |
|---|---|
| Network address | 192.168.1.0 |
| Broadcast address | 192.168.1.255 |
What Is a Broadcast Address?
In IPv4, every subnet has two reserved addresses: the network address (first) and the broadcast address (last). The broadcast address has all host bits set to 1. When a host sends a packet to the broadcast address, the packet is delivered to every host in that subnet. It is used for discovery (e.g. DHCP, ARP) and legacy protocols. No host should be assigned the broadcast address; it is not a usable host IP.
To compute it: take the network address and set all host bits to 1. For 192.168.1.0/24, the network is 192.168.1.0 and the broadcast is 192.168.1.255. Our subnet calculator does this for any IP and CIDR. The network address calculator explains the first address; the IP range calculator covers the full range from first to last.
How to Calculate Broadcast Address
Given an IP and prefix length (e.g. 10.0.0.5/22), determine the network address (IP AND subnet mask), then set all host bits to 1 to get the broadcast. This tool accepts the IP and CIDR and displays the broadcast address with no math required. For wildcard masks (inverse of subnet mask) used in ACLs, see the wildcard mask calculator. For the number of hosts in the block, use the IP block size calculator.
Broadcast in Practice
Configuring routers, firewalls, or DHCP servers often requires knowing the broadcast address. Some tools and scripts expect the range in start–end or CIDR form. Our IP range generator lists every IP in a range including the broadcast. For geolocation of an IP in your range, use IP lookup; for connectivity tests use ping test or traceroute.
FAQs
What is a broadcast address?
The broadcast address is the last address in a subnet. It is used to send a packet to all hosts in that subnet at once. Host bits are all 1s.
How do I find the broadcast address?
Use our subnet calculator: enter the IP and CIDR. It shows the broadcast address. Alternatively, set all host bits of the subnet to 1.
Is the broadcast address usable for a host?
No. The network address (first) and broadcast address (last) are reserved. Only addresses in between are assignable to hosts.
Does IPv6 have broadcast?
IPv6 does not use broadcast. It uses multicast. Our IPv6 subnet calculator shows the subnet range for IPv6.