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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network86.128.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
86.128.0.0
Broadcast address
86.255.255.255
First usable
86.128.0.1
Last usable
86.255.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
A (default /8)
As numbers
Hex 56800000 · Integer 1451229184 to 1459617791
Reverse DNS zones
128.86.in-addr.arpa
129.86.in-addr.arpa
130.86.in-addr.arpa
131.86.in-addr.arpa
132.86.in-addr.arpa
133.86.in-addr.arpa
134.86.in-addr.arpa
135.86.in-addr.arpa
136.86.in-addr.arpa
137.86.in-addr.arpa
138.86.in-addr.arpa
139.86.in-addr.arpa
140.86.in-addr.arpa
141.86.in-addr.arpa
142.86.in-addr.arpa
143.86.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010110.10000000.00000000.0000000086.128.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01010110.10000000.00000000.0000000086.128.0.0
Broadcast01010110.11111111.11111111.1111111186.255.255.255
Split into smaller subnets/18
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

86.128.0.0/9 makes 512 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
186.128.0.0/1886.128.0.1 to 86.128.63.25486.128.63.25516,382
286.128.64.0/1886.128.64.1 to 86.128.127.25486.128.127.25516,382
386.128.128.0/1886.128.128.1 to 86.128.191.25486.128.191.25516,382
486.128.192.0/1886.128.192.1 to 86.128.255.25486.128.255.25516,382
586.129.0.0/1886.129.0.1 to 86.129.63.25486.129.63.25516,382
686.129.64.0/1886.129.64.1 to 86.129.127.25486.129.127.25516,382
786.129.128.0/1886.129.128.1 to 86.129.191.25486.129.191.25516,382
886.129.192.0/1886.129.192.1 to 86.129.255.25486.129.255.25516,382
986.130.0.0/1886.130.0.1 to 86.130.63.25486.130.63.25516,382
1086.130.64.0/1886.130.64.1 to 86.130.127.25486.130.127.25516,382
1186.130.128.0/1886.130.128.1 to 86.130.191.25486.130.191.25516,382
1286.130.192.0/1886.130.192.1 to 86.130.255.25486.130.255.25516,382
1386.131.0.0/1886.131.0.1 to 86.131.63.25486.131.63.25516,382
1486.131.64.0/1886.131.64.1 to 86.131.127.25486.131.127.25516,382
1586.131.128.0/1886.131.128.1 to 86.131.191.25486.131.191.25516,382
1686.131.192.0/1886.131.192.1 to 86.131.255.25486.131.255.25516,382
1786.132.0.0/1886.132.0.1 to 86.132.63.25486.132.63.25516,382
1886.132.64.0/1886.132.64.1 to 86.132.127.25486.132.127.25516,382
1986.132.128.0/1886.132.128.1 to 86.132.191.25486.132.191.25516,382
2086.132.192.0/1886.132.192.1 to 86.132.255.25486.132.255.25516,382
2186.133.0.0/1886.133.0.1 to 86.133.63.25486.133.63.25516,382
2286.133.64.0/1886.133.64.1 to 86.133.127.25486.133.127.25516,382
2386.133.128.0/1886.133.128.1 to 86.133.191.25486.133.191.25516,382
2486.133.192.0/1886.133.192.1 to 86.133.255.25486.133.255.25516,382
2586.134.0.0/1886.134.0.1 to 86.134.63.25486.134.63.25516,382
2686.134.64.0/1886.134.64.1 to 86.134.127.25486.134.127.25516,382
2786.134.128.0/1886.134.128.1 to 86.134.191.25486.134.191.25516,382
2886.134.192.0/1886.134.192.1 to 86.134.255.25486.134.255.25516,382
2986.135.0.0/1886.135.0.1 to 86.135.63.25486.135.63.25516,382
3086.135.64.0/1886.135.64.1 to 86.135.127.25486.135.127.25516,382
3186.135.128.0/1886.135.128.1 to 86.135.191.25486.135.191.25516,382
3286.135.192.0/1886.135.192.1 to 86.135.255.25486.135.255.25516,382
3386.136.0.0/1886.136.0.1 to 86.136.63.25486.136.63.25516,382
3486.136.64.0/1886.136.64.1 to 86.136.127.25486.136.127.25516,382
3586.136.128.0/1886.136.128.1 to 86.136.191.25486.136.191.25516,382
3686.136.192.0/1886.136.192.1 to 86.136.255.25486.136.255.25516,382
3786.137.0.0/1886.137.0.1 to 86.137.63.25486.137.63.25516,382
3886.137.64.0/1886.137.64.1 to 86.137.127.25486.137.127.25516,382
3986.137.128.0/1886.137.128.1 to 86.137.191.25486.137.191.25516,382
4086.137.192.0/1886.137.192.1 to 86.137.255.25486.137.255.25516,382
4186.138.0.0/1886.138.0.1 to 86.138.63.25486.138.63.25516,382
4286.138.64.0/1886.138.64.1 to 86.138.127.25486.138.127.25516,382
4386.138.128.0/1886.138.128.1 to 86.138.191.25486.138.191.25516,382
4486.138.192.0/1886.138.192.1 to 86.138.255.25486.138.255.25516,382
4586.139.0.0/1886.139.0.1 to 86.139.63.25486.139.63.25516,382
4686.139.64.0/1886.139.64.1 to 86.139.127.25486.139.127.25516,382
4786.139.128.0/1886.139.128.1 to 86.139.191.25486.139.191.25516,382
4886.139.192.0/1886.139.192.1 to 86.139.255.25486.139.255.25516,382
4986.140.0.0/1886.140.0.1 to 86.140.63.25486.140.63.25516,382
5086.140.64.0/1886.140.64.1 to 86.140.127.25486.140.127.25516,382
5186.140.128.0/1886.140.128.1 to 86.140.191.25486.140.191.25516,382
5286.140.192.0/1886.140.192.1 to 86.140.255.25486.140.255.25516,382
5386.141.0.0/1886.141.0.1 to 86.141.63.25486.141.63.25516,382
5486.141.64.0/1886.141.64.1 to 86.141.127.25486.141.127.25516,382
5586.141.128.0/1886.141.128.1 to 86.141.191.25486.141.191.25516,382
5686.141.192.0/1886.141.192.1 to 86.141.255.25486.141.255.25516,382
5786.142.0.0/1886.142.0.1 to 86.142.63.25486.142.63.25516,382
5886.142.64.0/1886.142.64.1 to 86.142.127.25486.142.127.25516,382
5986.142.128.0/1886.142.128.1 to 86.142.191.25486.142.191.25516,382
6086.142.192.0/1886.142.192.1 to 86.142.255.25486.142.255.25516,382
6186.143.0.0/1886.143.0.1 to 86.143.63.25486.143.63.25516,382
6286.143.64.0/1886.143.64.1 to 86.143.127.25486.143.127.25516,382
6386.143.128.0/1886.143.128.1 to 86.143.191.25486.143.191.25516,382
6486.143.192.0/1886.143.192.1 to 86.143.255.25486.143.255.25516,382
6586.144.0.0/1886.144.0.1 to 86.144.63.25486.144.63.25516,382
6686.144.64.0/1886.144.64.1 to 86.144.127.25486.144.127.25516,382
6786.144.128.0/1886.144.128.1 to 86.144.191.25486.144.191.25516,382
6886.144.192.0/1886.144.192.1 to 86.144.255.25486.144.255.25516,382
6986.145.0.0/1886.145.0.1 to 86.145.63.25486.145.63.25516,382
7086.145.64.0/1886.145.64.1 to 86.145.127.25486.145.127.25516,382
7186.145.128.0/1886.145.128.1 to 86.145.191.25486.145.191.25516,382
7286.145.192.0/1886.145.192.1 to 86.145.255.25486.145.255.25516,382
7386.146.0.0/1886.146.0.1 to 86.146.63.25486.146.63.25516,382
7486.146.64.0/1886.146.64.1 to 86.146.127.25486.146.127.25516,382
7586.146.128.0/1886.146.128.1 to 86.146.191.25486.146.191.25516,382
7686.146.192.0/1886.146.192.1 to 86.146.255.25486.146.255.25516,382
7786.147.0.0/1886.147.0.1 to 86.147.63.25486.147.63.25516,382
7886.147.64.0/1886.147.64.1 to 86.147.127.25486.147.127.25516,382
7986.147.128.0/1886.147.128.1 to 86.147.191.25486.147.191.25516,382
8086.147.192.0/1886.147.192.1 to 86.147.255.25486.147.255.25516,382
8186.148.0.0/1886.148.0.1 to 86.148.63.25486.148.63.25516,382
8286.148.64.0/1886.148.64.1 to 86.148.127.25486.148.127.25516,382
8386.148.128.0/1886.148.128.1 to 86.148.191.25486.148.191.25516,382
8486.148.192.0/1886.148.192.1 to 86.148.255.25486.148.255.25516,382
8586.149.0.0/1886.149.0.1 to 86.149.63.25486.149.63.25516,382
8686.149.64.0/1886.149.64.1 to 86.149.127.25486.149.127.25516,382
8786.149.128.0/1886.149.128.1 to 86.149.191.25486.149.191.25516,382
8886.149.192.0/1886.149.192.1 to 86.149.255.25486.149.255.25516,382
8986.150.0.0/1886.150.0.1 to 86.150.63.25486.150.63.25516,382
9086.150.64.0/1886.150.64.1 to 86.150.127.25486.150.127.25516,382
9186.150.128.0/1886.150.128.1 to 86.150.191.25486.150.191.25516,382
9286.150.192.0/1886.150.192.1 to 86.150.255.25486.150.255.25516,382
9386.151.0.0/1886.151.0.1 to 86.151.63.25486.151.63.25516,382
9486.151.64.0/1886.151.64.1 to 86.151.127.25486.151.127.25516,382
9586.151.128.0/1886.151.128.1 to 86.151.191.25486.151.191.25516,382
9686.151.192.0/1886.151.192.1 to 86.151.255.25486.151.255.25516,382
9786.152.0.0/1886.152.0.1 to 86.152.63.25486.152.63.25516,382
9886.152.64.0/1886.152.64.1 to 86.152.127.25486.152.127.25516,382
9986.152.128.0/1886.152.128.1 to 86.152.191.25486.152.191.25516,382
10086.152.192.0/1886.152.192.1 to 86.152.255.25486.152.255.25516,382
10186.153.0.0/1886.153.0.1 to 86.153.63.25486.153.63.25516,382
10286.153.64.0/1886.153.64.1 to 86.153.127.25486.153.127.25516,382
10386.153.128.0/1886.153.128.1 to 86.153.191.25486.153.191.25516,382
10486.153.192.0/1886.153.192.1 to 86.153.255.25486.153.255.25516,382
10586.154.0.0/1886.154.0.1 to 86.154.63.25486.154.63.25516,382
10686.154.64.0/1886.154.64.1 to 86.154.127.25486.154.127.25516,382
10786.154.128.0/1886.154.128.1 to 86.154.191.25486.154.191.25516,382
10886.154.192.0/1886.154.192.1 to 86.154.255.25486.154.255.25516,382
10986.155.0.0/1886.155.0.1 to 86.155.63.25486.155.63.25516,382
11086.155.64.0/1886.155.64.1 to 86.155.127.25486.155.127.25516,382
11186.155.128.0/1886.155.128.1 to 86.155.191.25486.155.191.25516,382
11286.155.192.0/1886.155.192.1 to 86.155.255.25486.155.255.25516,382
11386.156.0.0/1886.156.0.1 to 86.156.63.25486.156.63.25516,382
11486.156.64.0/1886.156.64.1 to 86.156.127.25486.156.127.25516,382
11586.156.128.0/1886.156.128.1 to 86.156.191.25486.156.191.25516,382
11686.156.192.0/1886.156.192.1 to 86.156.255.25486.156.255.25516,382
11786.157.0.0/1886.157.0.1 to 86.157.63.25486.157.63.25516,382
11886.157.64.0/1886.157.64.1 to 86.157.127.25486.157.127.25516,382
11986.157.128.0/1886.157.128.1 to 86.157.191.25486.157.191.25516,382
12086.157.192.0/1886.157.192.1 to 86.157.255.25486.157.255.25516,382
12186.158.0.0/1886.158.0.1 to 86.158.63.25486.158.63.25516,382
12286.158.64.0/1886.158.64.1 to 86.158.127.25486.158.127.25516,382
12386.158.128.0/1886.158.128.1 to 86.158.191.25486.158.191.25516,382
12486.158.192.0/1886.158.192.1 to 86.158.255.25486.158.255.25516,382
12586.159.0.0/1886.159.0.1 to 86.159.63.25486.159.63.25516,382
12686.159.64.0/1886.159.64.1 to 86.159.127.25486.159.127.25516,382
12786.159.128.0/1886.159.128.1 to 86.159.191.25486.159.191.25516,382
12886.159.192.0/1886.159.192.1 to 86.159.255.25486.159.255.25516,382
12986.160.0.0/1886.160.0.1 to 86.160.63.25486.160.63.25516,382
13086.160.64.0/1886.160.64.1 to 86.160.127.25486.160.127.25516,382
13186.160.128.0/1886.160.128.1 to 86.160.191.25486.160.191.25516,382
13286.160.192.0/1886.160.192.1 to 86.160.255.25486.160.255.25516,382
13386.161.0.0/1886.161.0.1 to 86.161.63.25486.161.63.25516,382
13486.161.64.0/1886.161.64.1 to 86.161.127.25486.161.127.25516,382
13586.161.128.0/1886.161.128.1 to 86.161.191.25486.161.191.25516,382
13686.161.192.0/1886.161.192.1 to 86.161.255.25486.161.255.25516,382
13786.162.0.0/1886.162.0.1 to 86.162.63.25486.162.63.25516,382
13886.162.64.0/1886.162.64.1 to 86.162.127.25486.162.127.25516,382
13986.162.128.0/1886.162.128.1 to 86.162.191.25486.162.191.25516,382
14086.162.192.0/1886.162.192.1 to 86.162.255.25486.162.255.25516,382
14186.163.0.0/1886.163.0.1 to 86.163.63.25486.163.63.25516,382
14286.163.64.0/1886.163.64.1 to 86.163.127.25486.163.127.25516,382
14386.163.128.0/1886.163.128.1 to 86.163.191.25486.163.191.25516,382
14486.163.192.0/1886.163.192.1 to 86.163.255.25486.163.255.25516,382
14586.164.0.0/1886.164.0.1 to 86.164.63.25486.164.63.25516,382
14686.164.64.0/1886.164.64.1 to 86.164.127.25486.164.127.25516,382
14786.164.128.0/1886.164.128.1 to 86.164.191.25486.164.191.25516,382
14886.164.192.0/1886.164.192.1 to 86.164.255.25486.164.255.25516,382
14986.165.0.0/1886.165.0.1 to 86.165.63.25486.165.63.25516,382
15086.165.64.0/1886.165.64.1 to 86.165.127.25486.165.127.25516,382
15186.165.128.0/1886.165.128.1 to 86.165.191.25486.165.191.25516,382
15286.165.192.0/1886.165.192.1 to 86.165.255.25486.165.255.25516,382
15386.166.0.0/1886.166.0.1 to 86.166.63.25486.166.63.25516,382
15486.166.64.0/1886.166.64.1 to 86.166.127.25486.166.127.25516,382
15586.166.128.0/1886.166.128.1 to 86.166.191.25486.166.191.25516,382
15686.166.192.0/1886.166.192.1 to 86.166.255.25486.166.255.25516,382
15786.167.0.0/1886.167.0.1 to 86.167.63.25486.167.63.25516,382
15886.167.64.0/1886.167.64.1 to 86.167.127.25486.167.127.25516,382
15986.167.128.0/1886.167.128.1 to 86.167.191.25486.167.191.25516,382
16086.167.192.0/1886.167.192.1 to 86.167.255.25486.167.255.25516,382
16186.168.0.0/1886.168.0.1 to 86.168.63.25486.168.63.25516,382
16286.168.64.0/1886.168.64.1 to 86.168.127.25486.168.127.25516,382
16386.168.128.0/1886.168.128.1 to 86.168.191.25486.168.191.25516,382
16486.168.192.0/1886.168.192.1 to 86.168.255.25486.168.255.25516,382
16586.169.0.0/1886.169.0.1 to 86.169.63.25486.169.63.25516,382
16686.169.64.0/1886.169.64.1 to 86.169.127.25486.169.127.25516,382
16786.169.128.0/1886.169.128.1 to 86.169.191.25486.169.191.25516,382
16886.169.192.0/1886.169.192.1 to 86.169.255.25486.169.255.25516,382
16986.170.0.0/1886.170.0.1 to 86.170.63.25486.170.63.25516,382
17086.170.64.0/1886.170.64.1 to 86.170.127.25486.170.127.25516,382
17186.170.128.0/1886.170.128.1 to 86.170.191.25486.170.191.25516,382
17286.170.192.0/1886.170.192.1 to 86.170.255.25486.170.255.25516,382
17386.171.0.0/1886.171.0.1 to 86.171.63.25486.171.63.25516,382
17486.171.64.0/1886.171.64.1 to 86.171.127.25486.171.127.25516,382
17586.171.128.0/1886.171.128.1 to 86.171.191.25486.171.191.25516,382
17686.171.192.0/1886.171.192.1 to 86.171.255.25486.171.255.25516,382
17786.172.0.0/1886.172.0.1 to 86.172.63.25486.172.63.25516,382
17886.172.64.0/1886.172.64.1 to 86.172.127.25486.172.127.25516,382
17986.172.128.0/1886.172.128.1 to 86.172.191.25486.172.191.25516,382
18086.172.192.0/1886.172.192.1 to 86.172.255.25486.172.255.25516,382
18186.173.0.0/1886.173.0.1 to 86.173.63.25486.173.63.25516,382
18286.173.64.0/1886.173.64.1 to 86.173.127.25486.173.127.25516,382
18386.173.128.0/1886.173.128.1 to 86.173.191.25486.173.191.25516,382
18486.173.192.0/1886.173.192.1 to 86.173.255.25486.173.255.25516,382
18586.174.0.0/1886.174.0.1 to 86.174.63.25486.174.63.25516,382
18686.174.64.0/1886.174.64.1 to 86.174.127.25486.174.127.25516,382
18786.174.128.0/1886.174.128.1 to 86.174.191.25486.174.191.25516,382
18886.174.192.0/1886.174.192.1 to 86.174.255.25486.174.255.25516,382
18986.175.0.0/1886.175.0.1 to 86.175.63.25486.175.63.25516,382
19086.175.64.0/1886.175.64.1 to 86.175.127.25486.175.127.25516,382
19186.175.128.0/1886.175.128.1 to 86.175.191.25486.175.191.25516,382
19286.175.192.0/1886.175.192.1 to 86.175.255.25486.175.255.25516,382
19386.176.0.0/1886.176.0.1 to 86.176.63.25486.176.63.25516,382
19486.176.64.0/1886.176.64.1 to 86.176.127.25486.176.127.25516,382
19586.176.128.0/1886.176.128.1 to 86.176.191.25486.176.191.25516,382
19686.176.192.0/1886.176.192.1 to 86.176.255.25486.176.255.25516,382
19786.177.0.0/1886.177.0.1 to 86.177.63.25486.177.63.25516,382
19886.177.64.0/1886.177.64.1 to 86.177.127.25486.177.127.25516,382
19986.177.128.0/1886.177.128.1 to 86.177.191.25486.177.191.25516,382
20086.177.192.0/1886.177.192.1 to 86.177.255.25486.177.255.25516,382
20186.178.0.0/1886.178.0.1 to 86.178.63.25486.178.63.25516,382
20286.178.64.0/1886.178.64.1 to 86.178.127.25486.178.127.25516,382
20386.178.128.0/1886.178.128.1 to 86.178.191.25486.178.191.25516,382
20486.178.192.0/1886.178.192.1 to 86.178.255.25486.178.255.25516,382
20586.179.0.0/1886.179.0.1 to 86.179.63.25486.179.63.25516,382
20686.179.64.0/1886.179.64.1 to 86.179.127.25486.179.127.25516,382
20786.179.128.0/1886.179.128.1 to 86.179.191.25486.179.191.25516,382
20886.179.192.0/1886.179.192.1 to 86.179.255.25486.179.255.25516,382
20986.180.0.0/1886.180.0.1 to 86.180.63.25486.180.63.25516,382
21086.180.64.0/1886.180.64.1 to 86.180.127.25486.180.127.25516,382
21186.180.128.0/1886.180.128.1 to 86.180.191.25486.180.191.25516,382
21286.180.192.0/1886.180.192.1 to 86.180.255.25486.180.255.25516,382
21386.181.0.0/1886.181.0.1 to 86.181.63.25486.181.63.25516,382
21486.181.64.0/1886.181.64.1 to 86.181.127.25486.181.127.25516,382
21586.181.128.0/1886.181.128.1 to 86.181.191.25486.181.191.25516,382
21686.181.192.0/1886.181.192.1 to 86.181.255.25486.181.255.25516,382
21786.182.0.0/1886.182.0.1 to 86.182.63.25486.182.63.25516,382
21886.182.64.0/1886.182.64.1 to 86.182.127.25486.182.127.25516,382
21986.182.128.0/1886.182.128.1 to 86.182.191.25486.182.191.25516,382
22086.182.192.0/1886.182.192.1 to 86.182.255.25486.182.255.25516,382
22186.183.0.0/1886.183.0.1 to 86.183.63.25486.183.63.25516,382
22286.183.64.0/1886.183.64.1 to 86.183.127.25486.183.127.25516,382
22386.183.128.0/1886.183.128.1 to 86.183.191.25486.183.191.25516,382
22486.183.192.0/1886.183.192.1 to 86.183.255.25486.183.255.25516,382
22586.184.0.0/1886.184.0.1 to 86.184.63.25486.184.63.25516,382
22686.184.64.0/1886.184.64.1 to 86.184.127.25486.184.127.25516,382
22786.184.128.0/1886.184.128.1 to 86.184.191.25486.184.191.25516,382
22886.184.192.0/1886.184.192.1 to 86.184.255.25486.184.255.25516,382
22986.185.0.0/1886.185.0.1 to 86.185.63.25486.185.63.25516,382
23086.185.64.0/1886.185.64.1 to 86.185.127.25486.185.127.25516,382
23186.185.128.0/1886.185.128.1 to 86.185.191.25486.185.191.25516,382
23286.185.192.0/1886.185.192.1 to 86.185.255.25486.185.255.25516,382
23386.186.0.0/1886.186.0.1 to 86.186.63.25486.186.63.25516,382
23486.186.64.0/1886.186.64.1 to 86.186.127.25486.186.127.25516,382
23586.186.128.0/1886.186.128.1 to 86.186.191.25486.186.191.25516,382
23686.186.192.0/1886.186.192.1 to 86.186.255.25486.186.255.25516,382
23786.187.0.0/1886.187.0.1 to 86.187.63.25486.187.63.25516,382
23886.187.64.0/1886.187.64.1 to 86.187.127.25486.187.127.25516,382
23986.187.128.0/1886.187.128.1 to 86.187.191.25486.187.191.25516,382
24086.187.192.0/1886.187.192.1 to 86.187.255.25486.187.255.25516,382
24186.188.0.0/1886.188.0.1 to 86.188.63.25486.188.63.25516,382
24286.188.64.0/1886.188.64.1 to 86.188.127.25486.188.127.25516,382
24386.188.128.0/1886.188.128.1 to 86.188.191.25486.188.191.25516,382
24486.188.192.0/1886.188.192.1 to 86.188.255.25486.188.255.25516,382
24586.189.0.0/1886.189.0.1 to 86.189.63.25486.189.63.25516,382
24686.189.64.0/1886.189.64.1 to 86.189.127.25486.189.127.25516,382
24786.189.128.0/1886.189.128.1 to 86.189.191.25486.189.191.25516,382
24886.189.192.0/1886.189.192.1 to 86.189.255.25486.189.255.25516,382
24986.190.0.0/1886.190.0.1 to 86.190.63.25486.190.63.25516,382
25086.190.64.0/1886.190.64.1 to 86.190.127.25486.190.127.25516,382
25186.190.128.0/1886.190.128.1 to 86.190.191.25486.190.191.25516,382
25286.190.192.0/1886.190.192.1 to 86.190.255.25486.190.255.25516,382
25386.191.0.0/1886.191.0.1 to 86.191.63.25486.191.63.25516,382
25486.191.64.0/1886.191.64.1 to 86.191.127.25486.191.127.25516,382
25586.191.128.0/1886.191.128.1 to 86.191.191.25486.191.191.25516,382
25686.191.192.0/1886.191.192.1 to 86.191.255.25486.191.255.25516,382

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.