CIDR Calculator
Split an IPv4 CIDR into network, broadcast, netmask, wildcard, and usable host range. Paste 10.0.0.0/8 or 192.168.1.20/24. The math stays in the browser. There is no IP lookup.
Runs in your browser. Nothing is uploaded.
- Network
- 192.168.1.0/24
- Broadcast
- 192.168.1.255
- Netmask
- 255.255.255.0
- Wildcard
- 0.0.0.255
- First host
- 192.168.1.1
- Last host
- 192.168.1.254
- Addresses
- 256
- Usable hosts
- 254
- Host range
- 192.168.1.1 - 192.168.1.254
About this tool
Split an IPv4 CIDR such as 192.168.1.10/24 into the network address, broadcast, netmask, wildcard mask, and usable host range. Prefixes /31 and /32 follow the point-to-point and single-host cases, so every address in the block counts as a host.
How to use: type an address and a prefix from 0 to 32. Copy the summary from the sticky bar. A host address is masked down to the network, so 192.168.1.10/24 and 192.168.1.0/24 describe the same block.
Example: 10.0.0.0/8 is network 10.0.0.0, netmask 255.0.0.0, and broadcast 10.255.255.255. 172.16.5.4/32 is a single host. 10.1.1.0/31 has two usable addresses.
The arithmetic stays in the tab. This does not look up your public IP, geolocate an address, or upload the CIDR. Related: the IPv4 converter for dotted, integer, hex, and binary forms of one address.
FAQ
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