Toolzy

IP Subnet Calculator

Calculate network address, broadcast, host range and masks from an IPv4 address and CIDR prefix.

Network address192.168.1.0
Broadcast address192.168.1.255
First usable host192.168.1.1
Last usable host192.168.1.254
Usable hosts254
Subnet mask255.255.255.0
Wildcard mask0.0.0.255

Enter an IPv4 address and a CIDR prefix to see the full subnet breakdown. Everything is computed in your browser.

How to use

  1. Type an IPv4 address such as 192.168.1.10.
  2. Set the CIDR prefix (for example 24).
  3. Read the network, broadcast, host range and masks.

Frequently asked questions

Why are usable hosts two less than the total?
The network and broadcast addresses are reserved, so a /24 has 256 addresses but 254 usable hosts. /31 and /32 are special cases.
What is a wildcard mask?
It is the bitwise inverse of the subnet mask, used mainly in ACLs on routers such as Cisco IOS.

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