How to use the IP Subnet & CIDR Calculator
- Enter an IP address with a prefix, e.g. 192.168.1.130/26.
- Read the network, broadcast, host range and masks.
- Optionally split the network into smaller subnets.
What does this tool do?
CIDR notation like /24 says how many leading bits identify the network. A /24 has 256 addresses, 254 of them usable for hosts once the network and broadcast addresses are reserved.
The calculator also shows the subnet and wildcard masks, binary form, address class and whether the address is private, public, loopback or link-local.
Why use it?
- Accepts CIDR or a dotted mask.
- Subnet splitting.
- Private/public detection.
Privacy
The calculation happens instantly in your browser. The numbers you enter are not sent to our servers or saved. There's no account to create and nothing to install.
Frequently asked questions
Why are /31 and /32 different?
A /32 is a single host and a /31 is a point-to-point link (RFC 3021); neither reserves network and broadcast addresses.
Last reviewed by the M2Toolkit team.