CIDR Calculator

Calculate IP address ranges and subnets from a CIDR block.

CIDR Notation (e.g., 192.168.1.0/24)

Network Address

192.168.1.0

Broadcast Address

192.168.1.255

Subnet Mask

255.255.255.0

Wildcard Mask

0.0.0.255

First Usable IP

192.168.1.1

Last Usable IP

192.168.1.254

Total IP Addresses

256

Usable Hosts

254

IP Class

Class C

Prefix Length

/24

• CIDR (Classless Inter-Domain Routing) defines IP address ranges

• Format: IP/prefix where prefix is number of network bits (0-32)

• /24 = 256 IPs (254 usable), /16 = 65,536 IPs

• Smaller prefix = larger network (e.g., /8 is bigger than /24)

• Network address is first IP, broadcast is last IP

• Usable hosts = total - 2 (network and broadcast addresses)