How to use this tool
Enter an IPv4 address with its prefix, such as 192.168.1.42/24.
Read network, broadcast and host range together. /31 and /32 use their stated special conventions; usable does not mean public or routable.
Network = floor(address / block size) × block size; block size = 2^(32−prefix)
Worked example
192.168.1.0/24 · network
Fixed example using the settings below. Monetary examples use USD; dates and times use their stated reference values. This example stays unchanged when you edit your calculation.
Example inputs
- IPv4 address / prefix: 192.168.1.42/24
Method illustration: 192.168.1.42/24 has network 192.168.1.0 and broadcast 192.168.1.255.
Assumptions and limits
- IPv4 only. /31 is interpreted as a point-to-point subnet with two usable addresses (RFC 3021); /32 is one host route.
- Usable does not imply a globally routable/public address. Reserved and private ranges retain their special meanings.
Method reference: RFC 3021 point-to-point /31 networks
Check or report a result
Check the units, selected calculation and assumptions first. Compare the fixed example above with your inputs to identify what changed.
Report a calculation issue with the page address, hypothetical inputs, result displayed and result expected. Do not include passwords, bank details or other private information.