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Digital, Internet & Technology

Broadcast Address Calculator

Find the directed broadcast address and last usable host of an IPv4 subnet, with the bitwise OR shown.

Your inputs

Results

Broadcast address

172.16.47.255

Last usable host
172.16.47.254
Wildcard mask
0.0.15.255

✓Exact calculation — rounded only for display

Notes for this result

  • Computed entirely in your browser; no address is sent anywhere.
Show calculation steps
  1. 10101100.00010000.00101101.11001000 (IP)
  2. | 00000000.00000000.00001111.11111111 (wildcard)
  3. = 10101100.00010000.00101111.11111111 (broadcast)

What this calculator does

The broadcast address is the IP with all host bits set to one.

Formula and method

Broadcast = IP OR wildcard (NOT mask)

Worked example

Calculated by this tool with its default inputs:

Inputs

  • IP address: 172.16.45.200
  • Subnet mask or /prefix: 255.255.240.0

Results

  • Broadcast address: 172.16.47.255
  • Last usable host: 172.16.47.254
  • Wildcard mask: 0.0.15.255

How to read the results

The last usable host is one below the broadcast address.

Assumptions and limitations

  • Calculated entirely in your browser — addresses and values are never sent to a server.
  • /31 and /32 have no broadcast address.

Questions

Is 255.255.255.255 a broadcast address?

It is the limited broadcast address for the local network.

Methodology and verification

Result type
Exact mathematical calculation (rounded only for display)
Formula version
1.0
Automated verification
3 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
Editorial review
Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.

Privacy

Everything you enter is calculated in this browser and is not sent to Numerith or anyone else. Inputs are added to a share link only if you choose to include them. Privacy policy