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IPv4 Subnet Calculator

Developer Utilities

Calculate the network, broadcast, mask, wildcard and usable host range for any IPv4 CIDR block.

How to use

Calculate a subnet

Enter an address with a prefix such as 192.168.1.0/24. The tool computes every key value for that block.

  1. Enter an IPv4 address or CIDR block.
  2. Read the network and broadcast addresses.
  3. Copy the JSON result for scripting.

Usable hosts

For prefixes from /1 to /30 the first and last addresses are reserved, so usable hosts equal the total minus two. /31 and /32 are treated as point-to-point and single-host ranges.

Frequently asked questions

What is a wildcard mask?

A wildcard mask is the bitwise inverse of the subnet mask. It is commonly used in access control lists.

How do I know if an address is private?

The tool flags 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16 as private networks.

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