CIDR (Classless Inter-Domain Routing) is a method for allocating IP addresses and routing Internet Protocol packets. This calculator helps you determine subnet information based on an IP address and CIDR notation.

How to use: Enter an IP address and select a CIDR mask (1-32). The calculator will display the corresponding subnet mask, wildcard mask, network address, and usable IP range.

Key terms:

CIDR Mask Bits: The number of bits in the subnet mask (e.g., /24 = 24 bits)
Subnet Mask: Defines which portion of an IP address is the network vs host
Wildcard Mask: Inverse of subnet mask, used in ACLs and routing
Network Address: The first address in the subnet (network identifier)
Broadcast Address: The last address in the subnet for broadcasting

IP Address	CIDR Mask Bits
Subnet Mask	Wildcard Mask
Maximum Subnets	Maximum Addresses
IPv4 Network Address	CIDR Route Address
Subnet Address Range

Networking

CIDR Calculator

IP Address

CIDR Mask Bits

Subnet Mask

Wildcard Mask

Maximum Subnets

Maximum Addresses

IPv4 Network Address

CIDR Route Address

Subnet Address Range

About CIDR Calculator