IP Subnet Calculator

Calculate network address, broadcast, host range, and mask from CIDR.

Quick answer: Free IPv4 Subnet Calculator online. Calculate network addresses, broadcast ranges, and subnet masks from any CIDR notation instantly.

Network address192.168.1.0/24
Subnet mask255.255.255.0
Broadcast address192.168.1.255
Usable host range192.168.1.1 – 192.168.1.254
Total addresses256
Usable hosts254
Wildcard mask0.0.0.255

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Calculate the network address, broadcast address, usable host range, subnet mask, and total addresses for any IPv4 network from an IP and CIDR prefix.

How it works

  1. Input the base IPv4 address into the tool.
  2. Enter the CIDR prefix (e.g., 24).
  3. Instantly view the calculated subnet mask, broadcast IP, and usable host range.

Frequently asked questions

What does a /24 actually mean?

The /24 is CIDR notation indicating the first 24 bits are dedicated to the network, leaving 8 bits for hosts. This translates to the classic 255.255.255.0 subnet mask.

Why are two addresses always unusable in a range?

The absolute first IP defines the network identifier, and the final IP is reserved for mass broadcasting. Neither can be assigned to a specific computer.

What is a wildcard mask?

It is the exact mathematical inverse of the subnet mask, heavily utilized in Cisco Access Control Lists (ACLs).

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