IPv4 Subnet Calculator

Convert IPv4 CIDR notation.

Network breakout

Classless Inter-Domain Routing (CIDR)

CIDR is a system used for allocating IP addresses and routing IP packets. In short, IP addresses are considered to have two parts: the network address and the host identifier. These parts are represented by the bits in the IP address, and is commonly represented with CIDR notation.

CIDR notation

Standard syntax for writing IP addresses with a routing prefix. It consists of an IP address, a slash, then a number of bits to measure the routing prefix. The bits are applied to the address from left to right. is an example of CIDR notation.

Subnet mask

Bit mask that can be used to define the network portion of an IP address.

Wildcard masks

Bit masks used in computer networking. While uses may vary, a common scenario is to specify a range of hosts for access control lists (ACLs). These masks are the inverse of a subnet mask.