IP Addressing for CIDR Networks

Network Size Considerations

The following table shows the address space associated with each address block prefix assignable using Classless Inter-Domain Routing (CIDR).

# of IP Addresses Address Block Prefix
32 /27
64 /26
128 /25
256 /24
512 /23
1024 /22
2048 /21
4096 /20
8192 /19
16,384 /18
32,768 /17
65,536 /16
131,072 /15
262,144 /14
524,288 /13

Note that for each address block prefix, the number of addresses shown includes the network and broadcast addresses.

CIDR Network Calculator

Calculate the network parameters for a CIDR address.

Input your query:  
Valid input for the calculator includes:
address block prefix /19
subnet mask 255.255.255.192
subnet mask (hex) 0xffffffc0
wildcard bits 0.0.0.31
IP address/address block prefix 192.168.10.56/26
IP address/subnet mask 192.168.0.13/255.255.255.0
IP address/subnet mask (hex) 192.168.0.13/0xffffff00
IP address/wildcard bits 192.168.0.169/0.0.0.127

Omitting an IP address in the input will return:

  1. address block prefix
  2. subnet mask
  3. subnet mask (hex)
  4. wildcard bits
  5. number of usable IP addresses

cluding an IP address in the input will return the above values plus:

  1. network address
  2. broadcast address
  3. first usable IP address
  4. last usable IP address