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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.

Network22.128.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
22.128.0.0
Broadcast address
22.159.255.255
First usable
22.128.0.1
Last usable
22.159.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Public public
Old class
A (default /8)
As numbers
Hex 16800000 · Integer 377487360 to 379584511
Reverse DNS zones
128.22.in-addr.arpa
129.22.in-addr.arpa
130.22.in-addr.arpa
131.22.in-addr.arpa
132.22.in-addr.arpa
133.22.in-addr.arpa
134.22.in-addr.arpa
135.22.in-addr.arpa
136.22.in-addr.arpa
137.22.in-addr.arpa
138.22.in-addr.arpa
139.22.in-addr.arpa
140.22.in-addr.arpa
141.22.in-addr.arpa
142.22.in-addr.arpa
143.22.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00010110.10000000.00000000.0000000022.128.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network00010110.10000000.00000000.0000000022.128.0.0
Broadcast00010110.10011111.11111111.1111111122.159.255.255
Split into smaller subnets/20
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

22.128.0.0/11 makes 512 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
122.128.0.0/2022.128.0.1 to 22.128.15.25422.128.15.2554,094
222.128.16.0/2022.128.16.1 to 22.128.31.25422.128.31.2554,094
322.128.32.0/2022.128.32.1 to 22.128.47.25422.128.47.2554,094
422.128.48.0/2022.128.48.1 to 22.128.63.25422.128.63.2554,094
522.128.64.0/2022.128.64.1 to 22.128.79.25422.128.79.2554,094
622.128.80.0/2022.128.80.1 to 22.128.95.25422.128.95.2554,094
722.128.96.0/2022.128.96.1 to 22.128.111.25422.128.111.2554,094
822.128.112.0/2022.128.112.1 to 22.128.127.25422.128.127.2554,094
922.128.128.0/2022.128.128.1 to 22.128.143.25422.128.143.2554,094
1022.128.144.0/2022.128.144.1 to 22.128.159.25422.128.159.2554,094
1122.128.160.0/2022.128.160.1 to 22.128.175.25422.128.175.2554,094
1222.128.176.0/2022.128.176.1 to 22.128.191.25422.128.191.2554,094
1322.128.192.0/2022.128.192.1 to 22.128.207.25422.128.207.2554,094
1422.128.208.0/2022.128.208.1 to 22.128.223.25422.128.223.2554,094
1522.128.224.0/2022.128.224.1 to 22.128.239.25422.128.239.2554,094
1622.128.240.0/2022.128.240.1 to 22.128.255.25422.128.255.2554,094
1722.129.0.0/2022.129.0.1 to 22.129.15.25422.129.15.2554,094
1822.129.16.0/2022.129.16.1 to 22.129.31.25422.129.31.2554,094
1922.129.32.0/2022.129.32.1 to 22.129.47.25422.129.47.2554,094
2022.129.48.0/2022.129.48.1 to 22.129.63.25422.129.63.2554,094
2122.129.64.0/2022.129.64.1 to 22.129.79.25422.129.79.2554,094
2222.129.80.0/2022.129.80.1 to 22.129.95.25422.129.95.2554,094
2322.129.96.0/2022.129.96.1 to 22.129.111.25422.129.111.2554,094
2422.129.112.0/2022.129.112.1 to 22.129.127.25422.129.127.2554,094
2522.129.128.0/2022.129.128.1 to 22.129.143.25422.129.143.2554,094
2622.129.144.0/2022.129.144.1 to 22.129.159.25422.129.159.2554,094
2722.129.160.0/2022.129.160.1 to 22.129.175.25422.129.175.2554,094
2822.129.176.0/2022.129.176.1 to 22.129.191.25422.129.191.2554,094
2922.129.192.0/2022.129.192.1 to 22.129.207.25422.129.207.2554,094
3022.129.208.0/2022.129.208.1 to 22.129.223.25422.129.223.2554,094
3122.129.224.0/2022.129.224.1 to 22.129.239.25422.129.239.2554,094
3222.129.240.0/2022.129.240.1 to 22.129.255.25422.129.255.2554,094
3322.130.0.0/2022.130.0.1 to 22.130.15.25422.130.15.2554,094
3422.130.16.0/2022.130.16.1 to 22.130.31.25422.130.31.2554,094
3522.130.32.0/2022.130.32.1 to 22.130.47.25422.130.47.2554,094
3622.130.48.0/2022.130.48.1 to 22.130.63.25422.130.63.2554,094
3722.130.64.0/2022.130.64.1 to 22.130.79.25422.130.79.2554,094
3822.130.80.0/2022.130.80.1 to 22.130.95.25422.130.95.2554,094
3922.130.96.0/2022.130.96.1 to 22.130.111.25422.130.111.2554,094
4022.130.112.0/2022.130.112.1 to 22.130.127.25422.130.127.2554,094
4122.130.128.0/2022.130.128.1 to 22.130.143.25422.130.143.2554,094
4222.130.144.0/2022.130.144.1 to 22.130.159.25422.130.159.2554,094
4322.130.160.0/2022.130.160.1 to 22.130.175.25422.130.175.2554,094
4422.130.176.0/2022.130.176.1 to 22.130.191.25422.130.191.2554,094
4522.130.192.0/2022.130.192.1 to 22.130.207.25422.130.207.2554,094
4622.130.208.0/2022.130.208.1 to 22.130.223.25422.130.223.2554,094
4722.130.224.0/2022.130.224.1 to 22.130.239.25422.130.239.2554,094
4822.130.240.0/2022.130.240.1 to 22.130.255.25422.130.255.2554,094
4922.131.0.0/2022.131.0.1 to 22.131.15.25422.131.15.2554,094
5022.131.16.0/2022.131.16.1 to 22.131.31.25422.131.31.2554,094
5122.131.32.0/2022.131.32.1 to 22.131.47.25422.131.47.2554,094
5222.131.48.0/2022.131.48.1 to 22.131.63.25422.131.63.2554,094
5322.131.64.0/2022.131.64.1 to 22.131.79.25422.131.79.2554,094
5422.131.80.0/2022.131.80.1 to 22.131.95.25422.131.95.2554,094
5522.131.96.0/2022.131.96.1 to 22.131.111.25422.131.111.2554,094
5622.131.112.0/2022.131.112.1 to 22.131.127.25422.131.127.2554,094
5722.131.128.0/2022.131.128.1 to 22.131.143.25422.131.143.2554,094
5822.131.144.0/2022.131.144.1 to 22.131.159.25422.131.159.2554,094
5922.131.160.0/2022.131.160.1 to 22.131.175.25422.131.175.2554,094
6022.131.176.0/2022.131.176.1 to 22.131.191.25422.131.191.2554,094
6122.131.192.0/2022.131.192.1 to 22.131.207.25422.131.207.2554,094
6222.131.208.0/2022.131.208.1 to 22.131.223.25422.131.223.2554,094
6322.131.224.0/2022.131.224.1 to 22.131.239.25422.131.239.2554,094
6422.131.240.0/2022.131.240.1 to 22.131.255.25422.131.255.2554,094
6522.132.0.0/2022.132.0.1 to 22.132.15.25422.132.15.2554,094
6622.132.16.0/2022.132.16.1 to 22.132.31.25422.132.31.2554,094
6722.132.32.0/2022.132.32.1 to 22.132.47.25422.132.47.2554,094
6822.132.48.0/2022.132.48.1 to 22.132.63.25422.132.63.2554,094
6922.132.64.0/2022.132.64.1 to 22.132.79.25422.132.79.2554,094
7022.132.80.0/2022.132.80.1 to 22.132.95.25422.132.95.2554,094
7122.132.96.0/2022.132.96.1 to 22.132.111.25422.132.111.2554,094
7222.132.112.0/2022.132.112.1 to 22.132.127.25422.132.127.2554,094
7322.132.128.0/2022.132.128.1 to 22.132.143.25422.132.143.2554,094
7422.132.144.0/2022.132.144.1 to 22.132.159.25422.132.159.2554,094
7522.132.160.0/2022.132.160.1 to 22.132.175.25422.132.175.2554,094
7622.132.176.0/2022.132.176.1 to 22.132.191.25422.132.191.2554,094
7722.132.192.0/2022.132.192.1 to 22.132.207.25422.132.207.2554,094
7822.132.208.0/2022.132.208.1 to 22.132.223.25422.132.223.2554,094
7922.132.224.0/2022.132.224.1 to 22.132.239.25422.132.239.2554,094
8022.132.240.0/2022.132.240.1 to 22.132.255.25422.132.255.2554,094
8122.133.0.0/2022.133.0.1 to 22.133.15.25422.133.15.2554,094
8222.133.16.0/2022.133.16.1 to 22.133.31.25422.133.31.2554,094
8322.133.32.0/2022.133.32.1 to 22.133.47.25422.133.47.2554,094
8422.133.48.0/2022.133.48.1 to 22.133.63.25422.133.63.2554,094
8522.133.64.0/2022.133.64.1 to 22.133.79.25422.133.79.2554,094
8622.133.80.0/2022.133.80.1 to 22.133.95.25422.133.95.2554,094
8722.133.96.0/2022.133.96.1 to 22.133.111.25422.133.111.2554,094
8822.133.112.0/2022.133.112.1 to 22.133.127.25422.133.127.2554,094
8922.133.128.0/2022.133.128.1 to 22.133.143.25422.133.143.2554,094
9022.133.144.0/2022.133.144.1 to 22.133.159.25422.133.159.2554,094
9122.133.160.0/2022.133.160.1 to 22.133.175.25422.133.175.2554,094
9222.133.176.0/2022.133.176.1 to 22.133.191.25422.133.191.2554,094
9322.133.192.0/2022.133.192.1 to 22.133.207.25422.133.207.2554,094
9422.133.208.0/2022.133.208.1 to 22.133.223.25422.133.223.2554,094
9522.133.224.0/2022.133.224.1 to 22.133.239.25422.133.239.2554,094
9622.133.240.0/2022.133.240.1 to 22.133.255.25422.133.255.2554,094
9722.134.0.0/2022.134.0.1 to 22.134.15.25422.134.15.2554,094
9822.134.16.0/2022.134.16.1 to 22.134.31.25422.134.31.2554,094
9922.134.32.0/2022.134.32.1 to 22.134.47.25422.134.47.2554,094
10022.134.48.0/2022.134.48.1 to 22.134.63.25422.134.63.2554,094
10122.134.64.0/2022.134.64.1 to 22.134.79.25422.134.79.2554,094
10222.134.80.0/2022.134.80.1 to 22.134.95.25422.134.95.2554,094
10322.134.96.0/2022.134.96.1 to 22.134.111.25422.134.111.2554,094
10422.134.112.0/2022.134.112.1 to 22.134.127.25422.134.127.2554,094
10522.134.128.0/2022.134.128.1 to 22.134.143.25422.134.143.2554,094
10622.134.144.0/2022.134.144.1 to 22.134.159.25422.134.159.2554,094
10722.134.160.0/2022.134.160.1 to 22.134.175.25422.134.175.2554,094
10822.134.176.0/2022.134.176.1 to 22.134.191.25422.134.191.2554,094
10922.134.192.0/2022.134.192.1 to 22.134.207.25422.134.207.2554,094
11022.134.208.0/2022.134.208.1 to 22.134.223.25422.134.223.2554,094
11122.134.224.0/2022.134.224.1 to 22.134.239.25422.134.239.2554,094
11222.134.240.0/2022.134.240.1 to 22.134.255.25422.134.255.2554,094
11322.135.0.0/2022.135.0.1 to 22.135.15.25422.135.15.2554,094
11422.135.16.0/2022.135.16.1 to 22.135.31.25422.135.31.2554,094
11522.135.32.0/2022.135.32.1 to 22.135.47.25422.135.47.2554,094
11622.135.48.0/2022.135.48.1 to 22.135.63.25422.135.63.2554,094
11722.135.64.0/2022.135.64.1 to 22.135.79.25422.135.79.2554,094
11822.135.80.0/2022.135.80.1 to 22.135.95.25422.135.95.2554,094
11922.135.96.0/2022.135.96.1 to 22.135.111.25422.135.111.2554,094
12022.135.112.0/2022.135.112.1 to 22.135.127.25422.135.127.2554,094
12122.135.128.0/2022.135.128.1 to 22.135.143.25422.135.143.2554,094
12222.135.144.0/2022.135.144.1 to 22.135.159.25422.135.159.2554,094
12322.135.160.0/2022.135.160.1 to 22.135.175.25422.135.175.2554,094
12422.135.176.0/2022.135.176.1 to 22.135.191.25422.135.191.2554,094
12522.135.192.0/2022.135.192.1 to 22.135.207.25422.135.207.2554,094
12622.135.208.0/2022.135.208.1 to 22.135.223.25422.135.223.2554,094
12722.135.224.0/2022.135.224.1 to 22.135.239.25422.135.239.2554,094
12822.135.240.0/2022.135.240.1 to 22.135.255.25422.135.255.2554,094
12922.136.0.0/2022.136.0.1 to 22.136.15.25422.136.15.2554,094
13022.136.16.0/2022.136.16.1 to 22.136.31.25422.136.31.2554,094
13122.136.32.0/2022.136.32.1 to 22.136.47.25422.136.47.2554,094
13222.136.48.0/2022.136.48.1 to 22.136.63.25422.136.63.2554,094
13322.136.64.0/2022.136.64.1 to 22.136.79.25422.136.79.2554,094
13422.136.80.0/2022.136.80.1 to 22.136.95.25422.136.95.2554,094
13522.136.96.0/2022.136.96.1 to 22.136.111.25422.136.111.2554,094
13622.136.112.0/2022.136.112.1 to 22.136.127.25422.136.127.2554,094
13722.136.128.0/2022.136.128.1 to 22.136.143.25422.136.143.2554,094
13822.136.144.0/2022.136.144.1 to 22.136.159.25422.136.159.2554,094
13922.136.160.0/2022.136.160.1 to 22.136.175.25422.136.175.2554,094
14022.136.176.0/2022.136.176.1 to 22.136.191.25422.136.191.2554,094
14122.136.192.0/2022.136.192.1 to 22.136.207.25422.136.207.2554,094
14222.136.208.0/2022.136.208.1 to 22.136.223.25422.136.223.2554,094
14322.136.224.0/2022.136.224.1 to 22.136.239.25422.136.239.2554,094
14422.136.240.0/2022.136.240.1 to 22.136.255.25422.136.255.2554,094
14522.137.0.0/2022.137.0.1 to 22.137.15.25422.137.15.2554,094
14622.137.16.0/2022.137.16.1 to 22.137.31.25422.137.31.2554,094
14722.137.32.0/2022.137.32.1 to 22.137.47.25422.137.47.2554,094
14822.137.48.0/2022.137.48.1 to 22.137.63.25422.137.63.2554,094
14922.137.64.0/2022.137.64.1 to 22.137.79.25422.137.79.2554,094
15022.137.80.0/2022.137.80.1 to 22.137.95.25422.137.95.2554,094
15122.137.96.0/2022.137.96.1 to 22.137.111.25422.137.111.2554,094
15222.137.112.0/2022.137.112.1 to 22.137.127.25422.137.127.2554,094
15322.137.128.0/2022.137.128.1 to 22.137.143.25422.137.143.2554,094
15422.137.144.0/2022.137.144.1 to 22.137.159.25422.137.159.2554,094
15522.137.160.0/2022.137.160.1 to 22.137.175.25422.137.175.2554,094
15622.137.176.0/2022.137.176.1 to 22.137.191.25422.137.191.2554,094
15722.137.192.0/2022.137.192.1 to 22.137.207.25422.137.207.2554,094
15822.137.208.0/2022.137.208.1 to 22.137.223.25422.137.223.2554,094
15922.137.224.0/2022.137.224.1 to 22.137.239.25422.137.239.2554,094
16022.137.240.0/2022.137.240.1 to 22.137.255.25422.137.255.2554,094
16122.138.0.0/2022.138.0.1 to 22.138.15.25422.138.15.2554,094
16222.138.16.0/2022.138.16.1 to 22.138.31.25422.138.31.2554,094
16322.138.32.0/2022.138.32.1 to 22.138.47.25422.138.47.2554,094
16422.138.48.0/2022.138.48.1 to 22.138.63.25422.138.63.2554,094
16522.138.64.0/2022.138.64.1 to 22.138.79.25422.138.79.2554,094
16622.138.80.0/2022.138.80.1 to 22.138.95.25422.138.95.2554,094
16722.138.96.0/2022.138.96.1 to 22.138.111.25422.138.111.2554,094
16822.138.112.0/2022.138.112.1 to 22.138.127.25422.138.127.2554,094
16922.138.128.0/2022.138.128.1 to 22.138.143.25422.138.143.2554,094
17022.138.144.0/2022.138.144.1 to 22.138.159.25422.138.159.2554,094
17122.138.160.0/2022.138.160.1 to 22.138.175.25422.138.175.2554,094
17222.138.176.0/2022.138.176.1 to 22.138.191.25422.138.191.2554,094
17322.138.192.0/2022.138.192.1 to 22.138.207.25422.138.207.2554,094
17422.138.208.0/2022.138.208.1 to 22.138.223.25422.138.223.2554,094
17522.138.224.0/2022.138.224.1 to 22.138.239.25422.138.239.2554,094
17622.138.240.0/2022.138.240.1 to 22.138.255.25422.138.255.2554,094
17722.139.0.0/2022.139.0.1 to 22.139.15.25422.139.15.2554,094
17822.139.16.0/2022.139.16.1 to 22.139.31.25422.139.31.2554,094
17922.139.32.0/2022.139.32.1 to 22.139.47.25422.139.47.2554,094
18022.139.48.0/2022.139.48.1 to 22.139.63.25422.139.63.2554,094
18122.139.64.0/2022.139.64.1 to 22.139.79.25422.139.79.2554,094
18222.139.80.0/2022.139.80.1 to 22.139.95.25422.139.95.2554,094
18322.139.96.0/2022.139.96.1 to 22.139.111.25422.139.111.2554,094
18422.139.112.0/2022.139.112.1 to 22.139.127.25422.139.127.2554,094
18522.139.128.0/2022.139.128.1 to 22.139.143.25422.139.143.2554,094
18622.139.144.0/2022.139.144.1 to 22.139.159.25422.139.159.2554,094
18722.139.160.0/2022.139.160.1 to 22.139.175.25422.139.175.2554,094
18822.139.176.0/2022.139.176.1 to 22.139.191.25422.139.191.2554,094
18922.139.192.0/2022.139.192.1 to 22.139.207.25422.139.207.2554,094
19022.139.208.0/2022.139.208.1 to 22.139.223.25422.139.223.2554,094
19122.139.224.0/2022.139.224.1 to 22.139.239.25422.139.239.2554,094
19222.139.240.0/2022.139.240.1 to 22.139.255.25422.139.255.2554,094
19322.140.0.0/2022.140.0.1 to 22.140.15.25422.140.15.2554,094
19422.140.16.0/2022.140.16.1 to 22.140.31.25422.140.31.2554,094
19522.140.32.0/2022.140.32.1 to 22.140.47.25422.140.47.2554,094
19622.140.48.0/2022.140.48.1 to 22.140.63.25422.140.63.2554,094
19722.140.64.0/2022.140.64.1 to 22.140.79.25422.140.79.2554,094
19822.140.80.0/2022.140.80.1 to 22.140.95.25422.140.95.2554,094
19922.140.96.0/2022.140.96.1 to 22.140.111.25422.140.111.2554,094
20022.140.112.0/2022.140.112.1 to 22.140.127.25422.140.127.2554,094
20122.140.128.0/2022.140.128.1 to 22.140.143.25422.140.143.2554,094
20222.140.144.0/2022.140.144.1 to 22.140.159.25422.140.159.2554,094
20322.140.160.0/2022.140.160.1 to 22.140.175.25422.140.175.2554,094
20422.140.176.0/2022.140.176.1 to 22.140.191.25422.140.191.2554,094
20522.140.192.0/2022.140.192.1 to 22.140.207.25422.140.207.2554,094
20622.140.208.0/2022.140.208.1 to 22.140.223.25422.140.223.2554,094
20722.140.224.0/2022.140.224.1 to 22.140.239.25422.140.239.2554,094
20822.140.240.0/2022.140.240.1 to 22.140.255.25422.140.255.2554,094
20922.141.0.0/2022.141.0.1 to 22.141.15.25422.141.15.2554,094
21022.141.16.0/2022.141.16.1 to 22.141.31.25422.141.31.2554,094
21122.141.32.0/2022.141.32.1 to 22.141.47.25422.141.47.2554,094
21222.141.48.0/2022.141.48.1 to 22.141.63.25422.141.63.2554,094
21322.141.64.0/2022.141.64.1 to 22.141.79.25422.141.79.2554,094
21422.141.80.0/2022.141.80.1 to 22.141.95.25422.141.95.2554,094
21522.141.96.0/2022.141.96.1 to 22.141.111.25422.141.111.2554,094
21622.141.112.0/2022.141.112.1 to 22.141.127.25422.141.127.2554,094
21722.141.128.0/2022.141.128.1 to 22.141.143.25422.141.143.2554,094
21822.141.144.0/2022.141.144.1 to 22.141.159.25422.141.159.2554,094
21922.141.160.0/2022.141.160.1 to 22.141.175.25422.141.175.2554,094
22022.141.176.0/2022.141.176.1 to 22.141.191.25422.141.191.2554,094
22122.141.192.0/2022.141.192.1 to 22.141.207.25422.141.207.2554,094
22222.141.208.0/2022.141.208.1 to 22.141.223.25422.141.223.2554,094
22322.141.224.0/2022.141.224.1 to 22.141.239.25422.141.239.2554,094
22422.141.240.0/2022.141.240.1 to 22.141.255.25422.141.255.2554,094
22522.142.0.0/2022.142.0.1 to 22.142.15.25422.142.15.2554,094
22622.142.16.0/2022.142.16.1 to 22.142.31.25422.142.31.2554,094
22722.142.32.0/2022.142.32.1 to 22.142.47.25422.142.47.2554,094
22822.142.48.0/2022.142.48.1 to 22.142.63.25422.142.63.2554,094
22922.142.64.0/2022.142.64.1 to 22.142.79.25422.142.79.2554,094
23022.142.80.0/2022.142.80.1 to 22.142.95.25422.142.95.2554,094
23122.142.96.0/2022.142.96.1 to 22.142.111.25422.142.111.2554,094
23222.142.112.0/2022.142.112.1 to 22.142.127.25422.142.127.2554,094
23322.142.128.0/2022.142.128.1 to 22.142.143.25422.142.143.2554,094
23422.142.144.0/2022.142.144.1 to 22.142.159.25422.142.159.2554,094
23522.142.160.0/2022.142.160.1 to 22.142.175.25422.142.175.2554,094
23622.142.176.0/2022.142.176.1 to 22.142.191.25422.142.191.2554,094
23722.142.192.0/2022.142.192.1 to 22.142.207.25422.142.207.2554,094
23822.142.208.0/2022.142.208.1 to 22.142.223.25422.142.223.2554,094
23922.142.224.0/2022.142.224.1 to 22.142.239.25422.142.239.2554,094
24022.142.240.0/2022.142.240.1 to 22.142.255.25422.142.255.2554,094
24122.143.0.0/2022.143.0.1 to 22.143.15.25422.143.15.2554,094
24222.143.16.0/2022.143.16.1 to 22.143.31.25422.143.31.2554,094
24322.143.32.0/2022.143.32.1 to 22.143.47.25422.143.47.2554,094
24422.143.48.0/2022.143.48.1 to 22.143.63.25422.143.63.2554,094
24522.143.64.0/2022.143.64.1 to 22.143.79.25422.143.79.2554,094
24622.143.80.0/2022.143.80.1 to 22.143.95.25422.143.95.2554,094
24722.143.96.0/2022.143.96.1 to 22.143.111.25422.143.111.2554,094
24822.143.112.0/2022.143.112.1 to 22.143.127.25422.143.127.2554,094
24922.143.128.0/2022.143.128.1 to 22.143.143.25422.143.143.2554,094
25022.143.144.0/2022.143.144.1 to 22.143.159.25422.143.159.2554,094
25122.143.160.0/2022.143.160.1 to 22.143.175.25422.143.175.2554,094
25222.143.176.0/2022.143.176.1 to 22.143.191.25422.143.191.2554,094
25322.143.192.0/2022.143.192.1 to 22.143.207.25422.143.207.2554,094
25422.143.208.0/2022.143.208.1 to 22.143.223.25422.143.223.2554,094
25522.143.224.0/2022.143.224.1 to 22.143.239.25422.143.239.2554,094
25622.143.240.0/2022.143.240.1 to 22.143.255.25422.143.255.2554,094

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.