Subnet Calculator

Enter CIDR notation (e.g. 192.168.0.0/24) to calculate the network address, broadcast, usable host range and count, and subnet mask. All calculations happen inside your browser.

Enter CIDR to see the result.

How to use

  1. Enter the CIDR notation (IP address/prefix).
  2. The network, broadcast, and host range are calculated automatically.
  3. You can also check the subnet mask and wildcard mask.

Frequently asked questions

What is CIDR notation?

CIDR appends a slash and a prefix length after the IP address. For example, 192.168.0.0/24 means the first 24 bits are the network portion.

How is the usable host count calculated?

It is generally 2 to the power of (32 − prefix) minus 2 for the network and broadcast addresses. /31 and /32 are exceptions, counted as 2 and 1 respectively.

Are the values I enter sent to a server?

No. All calculations happen only inside your browser, and the values you enter are never sent to or stored on any server.