CIDR Subnet Calculator
Decode IPv4 CIDR into network, broadcast, mask, and host range.
Network
192.168.1.0
Broadcast
192.168.1.255
Subnet mask
255.255.255.0
Wildcard mask
0.0.0.255
First host
192.168.1.1
Last host
192.168.1.254
Total addresses
256
Usable hosts
254
Network and broadcast addresses are not assignable to hosts in /24 and smaller. /31 (point-to-point) and /32 (single host) are special: every address is usable.
About
Paste a CIDR block like 10.0.0.0/16 and get the network address, broadcast address, subnet mask, wildcard mask, first and last usable host, and total host count. Built for network engineers who don't want to do the bit math by hand.
How to use
- Paste a CIDR like 192.168.1.0/24.
- Read the network details and host range.
FAQ
Why are usable hosts 2 fewer than total addresses?+
Network and broadcast addresses are reserved on /24 and smaller. Subtracting them gives the count of addresses you can actually assign.
What about /31 and /32?+
Both addresses are usable on /31 (point-to-point links) per RFC 3021, and /32 represents a single host. The tool handles both correctly.