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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.

Network34.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
34.0.0.0
Broadcast address
34.127.255.255
First usable
34.0.0.1
Last usable
34.127.255.254
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 22000000 · Integer 570425344 to 578813951
Reverse DNS zones
0.34.in-addr.arpa
1.34.in-addr.arpa
2.34.in-addr.arpa
3.34.in-addr.arpa
4.34.in-addr.arpa
5.34.in-addr.arpa
6.34.in-addr.arpa
7.34.in-addr.arpa
8.34.in-addr.arpa
9.34.in-addr.arpa
10.34.in-addr.arpa
11.34.in-addr.arpa
12.34.in-addr.arpa
13.34.in-addr.arpa
14.34.in-addr.arpa
15.34.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
Address00100010.00000000.00000000.0000000034.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network00100010.00000000.00000000.0000000034.0.0.0
Broadcast00100010.01111111.11111111.1111111134.127.255.255
Split into smaller subnets/20
/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)

34.0.0.0/9 makes 2,048 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
134.0.0.0/2034.0.0.1 to 34.0.15.25434.0.15.2554,094
234.0.16.0/2034.0.16.1 to 34.0.31.25434.0.31.2554,094
334.0.32.0/2034.0.32.1 to 34.0.47.25434.0.47.2554,094
434.0.48.0/2034.0.48.1 to 34.0.63.25434.0.63.2554,094
534.0.64.0/2034.0.64.1 to 34.0.79.25434.0.79.2554,094
634.0.80.0/2034.0.80.1 to 34.0.95.25434.0.95.2554,094
734.0.96.0/2034.0.96.1 to 34.0.111.25434.0.111.2554,094
834.0.112.0/2034.0.112.1 to 34.0.127.25434.0.127.2554,094
934.0.128.0/2034.0.128.1 to 34.0.143.25434.0.143.2554,094
1034.0.144.0/2034.0.144.1 to 34.0.159.25434.0.159.2554,094
1134.0.160.0/2034.0.160.1 to 34.0.175.25434.0.175.2554,094
1234.0.176.0/2034.0.176.1 to 34.0.191.25434.0.191.2554,094
1334.0.192.0/2034.0.192.1 to 34.0.207.25434.0.207.2554,094
1434.0.208.0/2034.0.208.1 to 34.0.223.25434.0.223.2554,094
1534.0.224.0/2034.0.224.1 to 34.0.239.25434.0.239.2554,094
1634.0.240.0/2034.0.240.1 to 34.0.255.25434.0.255.2554,094
1734.1.0.0/2034.1.0.1 to 34.1.15.25434.1.15.2554,094
1834.1.16.0/2034.1.16.1 to 34.1.31.25434.1.31.2554,094
1934.1.32.0/2034.1.32.1 to 34.1.47.25434.1.47.2554,094
2034.1.48.0/2034.1.48.1 to 34.1.63.25434.1.63.2554,094
2134.1.64.0/2034.1.64.1 to 34.1.79.25434.1.79.2554,094
2234.1.80.0/2034.1.80.1 to 34.1.95.25434.1.95.2554,094
2334.1.96.0/2034.1.96.1 to 34.1.111.25434.1.111.2554,094
2434.1.112.0/2034.1.112.1 to 34.1.127.25434.1.127.2554,094
2534.1.128.0/2034.1.128.1 to 34.1.143.25434.1.143.2554,094
2634.1.144.0/2034.1.144.1 to 34.1.159.25434.1.159.2554,094
2734.1.160.0/2034.1.160.1 to 34.1.175.25434.1.175.2554,094
2834.1.176.0/2034.1.176.1 to 34.1.191.25434.1.191.2554,094
2934.1.192.0/2034.1.192.1 to 34.1.207.25434.1.207.2554,094
3034.1.208.0/2034.1.208.1 to 34.1.223.25434.1.223.2554,094
3134.1.224.0/2034.1.224.1 to 34.1.239.25434.1.239.2554,094
3234.1.240.0/2034.1.240.1 to 34.1.255.25434.1.255.2554,094
3334.2.0.0/2034.2.0.1 to 34.2.15.25434.2.15.2554,094
3434.2.16.0/2034.2.16.1 to 34.2.31.25434.2.31.2554,094
3534.2.32.0/2034.2.32.1 to 34.2.47.25434.2.47.2554,094
3634.2.48.0/2034.2.48.1 to 34.2.63.25434.2.63.2554,094
3734.2.64.0/2034.2.64.1 to 34.2.79.25434.2.79.2554,094
3834.2.80.0/2034.2.80.1 to 34.2.95.25434.2.95.2554,094
3934.2.96.0/2034.2.96.1 to 34.2.111.25434.2.111.2554,094
4034.2.112.0/2034.2.112.1 to 34.2.127.25434.2.127.2554,094
4134.2.128.0/2034.2.128.1 to 34.2.143.25434.2.143.2554,094
4234.2.144.0/2034.2.144.1 to 34.2.159.25434.2.159.2554,094
4334.2.160.0/2034.2.160.1 to 34.2.175.25434.2.175.2554,094
4434.2.176.0/2034.2.176.1 to 34.2.191.25434.2.191.2554,094
4534.2.192.0/2034.2.192.1 to 34.2.207.25434.2.207.2554,094
4634.2.208.0/2034.2.208.1 to 34.2.223.25434.2.223.2554,094
4734.2.224.0/2034.2.224.1 to 34.2.239.25434.2.239.2554,094
4834.2.240.0/2034.2.240.1 to 34.2.255.25434.2.255.2554,094
4934.3.0.0/2034.3.0.1 to 34.3.15.25434.3.15.2554,094
5034.3.16.0/2034.3.16.1 to 34.3.31.25434.3.31.2554,094
5134.3.32.0/2034.3.32.1 to 34.3.47.25434.3.47.2554,094
5234.3.48.0/2034.3.48.1 to 34.3.63.25434.3.63.2554,094
5334.3.64.0/2034.3.64.1 to 34.3.79.25434.3.79.2554,094
5434.3.80.0/2034.3.80.1 to 34.3.95.25434.3.95.2554,094
5534.3.96.0/2034.3.96.1 to 34.3.111.25434.3.111.2554,094
5634.3.112.0/2034.3.112.1 to 34.3.127.25434.3.127.2554,094
5734.3.128.0/2034.3.128.1 to 34.3.143.25434.3.143.2554,094
5834.3.144.0/2034.3.144.1 to 34.3.159.25434.3.159.2554,094
5934.3.160.0/2034.3.160.1 to 34.3.175.25434.3.175.2554,094
6034.3.176.0/2034.3.176.1 to 34.3.191.25434.3.191.2554,094
6134.3.192.0/2034.3.192.1 to 34.3.207.25434.3.207.2554,094
6234.3.208.0/2034.3.208.1 to 34.3.223.25434.3.223.2554,094
6334.3.224.0/2034.3.224.1 to 34.3.239.25434.3.239.2554,094
6434.3.240.0/2034.3.240.1 to 34.3.255.25434.3.255.2554,094
6534.4.0.0/2034.4.0.1 to 34.4.15.25434.4.15.2554,094
6634.4.16.0/2034.4.16.1 to 34.4.31.25434.4.31.2554,094
6734.4.32.0/2034.4.32.1 to 34.4.47.25434.4.47.2554,094
6834.4.48.0/2034.4.48.1 to 34.4.63.25434.4.63.2554,094
6934.4.64.0/2034.4.64.1 to 34.4.79.25434.4.79.2554,094
7034.4.80.0/2034.4.80.1 to 34.4.95.25434.4.95.2554,094
7134.4.96.0/2034.4.96.1 to 34.4.111.25434.4.111.2554,094
7234.4.112.0/2034.4.112.1 to 34.4.127.25434.4.127.2554,094
7334.4.128.0/2034.4.128.1 to 34.4.143.25434.4.143.2554,094
7434.4.144.0/2034.4.144.1 to 34.4.159.25434.4.159.2554,094
7534.4.160.0/2034.4.160.1 to 34.4.175.25434.4.175.2554,094
7634.4.176.0/2034.4.176.1 to 34.4.191.25434.4.191.2554,094
7734.4.192.0/2034.4.192.1 to 34.4.207.25434.4.207.2554,094
7834.4.208.0/2034.4.208.1 to 34.4.223.25434.4.223.2554,094
7934.4.224.0/2034.4.224.1 to 34.4.239.25434.4.239.2554,094
8034.4.240.0/2034.4.240.1 to 34.4.255.25434.4.255.2554,094
8134.5.0.0/2034.5.0.1 to 34.5.15.25434.5.15.2554,094
8234.5.16.0/2034.5.16.1 to 34.5.31.25434.5.31.2554,094
8334.5.32.0/2034.5.32.1 to 34.5.47.25434.5.47.2554,094
8434.5.48.0/2034.5.48.1 to 34.5.63.25434.5.63.2554,094
8534.5.64.0/2034.5.64.1 to 34.5.79.25434.5.79.2554,094
8634.5.80.0/2034.5.80.1 to 34.5.95.25434.5.95.2554,094
8734.5.96.0/2034.5.96.1 to 34.5.111.25434.5.111.2554,094
8834.5.112.0/2034.5.112.1 to 34.5.127.25434.5.127.2554,094
8934.5.128.0/2034.5.128.1 to 34.5.143.25434.5.143.2554,094
9034.5.144.0/2034.5.144.1 to 34.5.159.25434.5.159.2554,094
9134.5.160.0/2034.5.160.1 to 34.5.175.25434.5.175.2554,094
9234.5.176.0/2034.5.176.1 to 34.5.191.25434.5.191.2554,094
9334.5.192.0/2034.5.192.1 to 34.5.207.25434.5.207.2554,094
9434.5.208.0/2034.5.208.1 to 34.5.223.25434.5.223.2554,094
9534.5.224.0/2034.5.224.1 to 34.5.239.25434.5.239.2554,094
9634.5.240.0/2034.5.240.1 to 34.5.255.25434.5.255.2554,094
9734.6.0.0/2034.6.0.1 to 34.6.15.25434.6.15.2554,094
9834.6.16.0/2034.6.16.1 to 34.6.31.25434.6.31.2554,094
9934.6.32.0/2034.6.32.1 to 34.6.47.25434.6.47.2554,094
10034.6.48.0/2034.6.48.1 to 34.6.63.25434.6.63.2554,094
10134.6.64.0/2034.6.64.1 to 34.6.79.25434.6.79.2554,094
10234.6.80.0/2034.6.80.1 to 34.6.95.25434.6.95.2554,094
10334.6.96.0/2034.6.96.1 to 34.6.111.25434.6.111.2554,094
10434.6.112.0/2034.6.112.1 to 34.6.127.25434.6.127.2554,094
10534.6.128.0/2034.6.128.1 to 34.6.143.25434.6.143.2554,094
10634.6.144.0/2034.6.144.1 to 34.6.159.25434.6.159.2554,094
10734.6.160.0/2034.6.160.1 to 34.6.175.25434.6.175.2554,094
10834.6.176.0/2034.6.176.1 to 34.6.191.25434.6.191.2554,094
10934.6.192.0/2034.6.192.1 to 34.6.207.25434.6.207.2554,094
11034.6.208.0/2034.6.208.1 to 34.6.223.25434.6.223.2554,094
11134.6.224.0/2034.6.224.1 to 34.6.239.25434.6.239.2554,094
11234.6.240.0/2034.6.240.1 to 34.6.255.25434.6.255.2554,094
11334.7.0.0/2034.7.0.1 to 34.7.15.25434.7.15.2554,094
11434.7.16.0/2034.7.16.1 to 34.7.31.25434.7.31.2554,094
11534.7.32.0/2034.7.32.1 to 34.7.47.25434.7.47.2554,094
11634.7.48.0/2034.7.48.1 to 34.7.63.25434.7.63.2554,094
11734.7.64.0/2034.7.64.1 to 34.7.79.25434.7.79.2554,094
11834.7.80.0/2034.7.80.1 to 34.7.95.25434.7.95.2554,094
11934.7.96.0/2034.7.96.1 to 34.7.111.25434.7.111.2554,094
12034.7.112.0/2034.7.112.1 to 34.7.127.25434.7.127.2554,094
12134.7.128.0/2034.7.128.1 to 34.7.143.25434.7.143.2554,094
12234.7.144.0/2034.7.144.1 to 34.7.159.25434.7.159.2554,094
12334.7.160.0/2034.7.160.1 to 34.7.175.25434.7.175.2554,094
12434.7.176.0/2034.7.176.1 to 34.7.191.25434.7.191.2554,094
12534.7.192.0/2034.7.192.1 to 34.7.207.25434.7.207.2554,094
12634.7.208.0/2034.7.208.1 to 34.7.223.25434.7.223.2554,094
12734.7.224.0/2034.7.224.1 to 34.7.239.25434.7.239.2554,094
12834.7.240.0/2034.7.240.1 to 34.7.255.25434.7.255.2554,094
12934.8.0.0/2034.8.0.1 to 34.8.15.25434.8.15.2554,094
13034.8.16.0/2034.8.16.1 to 34.8.31.25434.8.31.2554,094
13134.8.32.0/2034.8.32.1 to 34.8.47.25434.8.47.2554,094
13234.8.48.0/2034.8.48.1 to 34.8.63.25434.8.63.2554,094
13334.8.64.0/2034.8.64.1 to 34.8.79.25434.8.79.2554,094
13434.8.80.0/2034.8.80.1 to 34.8.95.25434.8.95.2554,094
13534.8.96.0/2034.8.96.1 to 34.8.111.25434.8.111.2554,094
13634.8.112.0/2034.8.112.1 to 34.8.127.25434.8.127.2554,094
13734.8.128.0/2034.8.128.1 to 34.8.143.25434.8.143.2554,094
13834.8.144.0/2034.8.144.1 to 34.8.159.25434.8.159.2554,094
13934.8.160.0/2034.8.160.1 to 34.8.175.25434.8.175.2554,094
14034.8.176.0/2034.8.176.1 to 34.8.191.25434.8.191.2554,094
14134.8.192.0/2034.8.192.1 to 34.8.207.25434.8.207.2554,094
14234.8.208.0/2034.8.208.1 to 34.8.223.25434.8.223.2554,094
14334.8.224.0/2034.8.224.1 to 34.8.239.25434.8.239.2554,094
14434.8.240.0/2034.8.240.1 to 34.8.255.25434.8.255.2554,094
14534.9.0.0/2034.9.0.1 to 34.9.15.25434.9.15.2554,094
14634.9.16.0/2034.9.16.1 to 34.9.31.25434.9.31.2554,094
14734.9.32.0/2034.9.32.1 to 34.9.47.25434.9.47.2554,094
14834.9.48.0/2034.9.48.1 to 34.9.63.25434.9.63.2554,094
14934.9.64.0/2034.9.64.1 to 34.9.79.25434.9.79.2554,094
15034.9.80.0/2034.9.80.1 to 34.9.95.25434.9.95.2554,094
15134.9.96.0/2034.9.96.1 to 34.9.111.25434.9.111.2554,094
15234.9.112.0/2034.9.112.1 to 34.9.127.25434.9.127.2554,094
15334.9.128.0/2034.9.128.1 to 34.9.143.25434.9.143.2554,094
15434.9.144.0/2034.9.144.1 to 34.9.159.25434.9.159.2554,094
15534.9.160.0/2034.9.160.1 to 34.9.175.25434.9.175.2554,094
15634.9.176.0/2034.9.176.1 to 34.9.191.25434.9.191.2554,094
15734.9.192.0/2034.9.192.1 to 34.9.207.25434.9.207.2554,094
15834.9.208.0/2034.9.208.1 to 34.9.223.25434.9.223.2554,094
15934.9.224.0/2034.9.224.1 to 34.9.239.25434.9.239.2554,094
16034.9.240.0/2034.9.240.1 to 34.9.255.25434.9.255.2554,094
16134.10.0.0/2034.10.0.1 to 34.10.15.25434.10.15.2554,094
16234.10.16.0/2034.10.16.1 to 34.10.31.25434.10.31.2554,094
16334.10.32.0/2034.10.32.1 to 34.10.47.25434.10.47.2554,094
16434.10.48.0/2034.10.48.1 to 34.10.63.25434.10.63.2554,094
16534.10.64.0/2034.10.64.1 to 34.10.79.25434.10.79.2554,094
16634.10.80.0/2034.10.80.1 to 34.10.95.25434.10.95.2554,094
16734.10.96.0/2034.10.96.1 to 34.10.111.25434.10.111.2554,094
16834.10.112.0/2034.10.112.1 to 34.10.127.25434.10.127.2554,094
16934.10.128.0/2034.10.128.1 to 34.10.143.25434.10.143.2554,094
17034.10.144.0/2034.10.144.1 to 34.10.159.25434.10.159.2554,094
17134.10.160.0/2034.10.160.1 to 34.10.175.25434.10.175.2554,094
17234.10.176.0/2034.10.176.1 to 34.10.191.25434.10.191.2554,094
17334.10.192.0/2034.10.192.1 to 34.10.207.25434.10.207.2554,094
17434.10.208.0/2034.10.208.1 to 34.10.223.25434.10.223.2554,094
17534.10.224.0/2034.10.224.1 to 34.10.239.25434.10.239.2554,094
17634.10.240.0/2034.10.240.1 to 34.10.255.25434.10.255.2554,094
17734.11.0.0/2034.11.0.1 to 34.11.15.25434.11.15.2554,094
17834.11.16.0/2034.11.16.1 to 34.11.31.25434.11.31.2554,094
17934.11.32.0/2034.11.32.1 to 34.11.47.25434.11.47.2554,094
18034.11.48.0/2034.11.48.1 to 34.11.63.25434.11.63.2554,094
18134.11.64.0/2034.11.64.1 to 34.11.79.25434.11.79.2554,094
18234.11.80.0/2034.11.80.1 to 34.11.95.25434.11.95.2554,094
18334.11.96.0/2034.11.96.1 to 34.11.111.25434.11.111.2554,094
18434.11.112.0/2034.11.112.1 to 34.11.127.25434.11.127.2554,094
18534.11.128.0/2034.11.128.1 to 34.11.143.25434.11.143.2554,094
18634.11.144.0/2034.11.144.1 to 34.11.159.25434.11.159.2554,094
18734.11.160.0/2034.11.160.1 to 34.11.175.25434.11.175.2554,094
18834.11.176.0/2034.11.176.1 to 34.11.191.25434.11.191.2554,094
18934.11.192.0/2034.11.192.1 to 34.11.207.25434.11.207.2554,094
19034.11.208.0/2034.11.208.1 to 34.11.223.25434.11.223.2554,094
19134.11.224.0/2034.11.224.1 to 34.11.239.25434.11.239.2554,094
19234.11.240.0/2034.11.240.1 to 34.11.255.25434.11.255.2554,094
19334.12.0.0/2034.12.0.1 to 34.12.15.25434.12.15.2554,094
19434.12.16.0/2034.12.16.1 to 34.12.31.25434.12.31.2554,094
19534.12.32.0/2034.12.32.1 to 34.12.47.25434.12.47.2554,094
19634.12.48.0/2034.12.48.1 to 34.12.63.25434.12.63.2554,094
19734.12.64.0/2034.12.64.1 to 34.12.79.25434.12.79.2554,094
19834.12.80.0/2034.12.80.1 to 34.12.95.25434.12.95.2554,094
19934.12.96.0/2034.12.96.1 to 34.12.111.25434.12.111.2554,094
20034.12.112.0/2034.12.112.1 to 34.12.127.25434.12.127.2554,094
20134.12.128.0/2034.12.128.1 to 34.12.143.25434.12.143.2554,094
20234.12.144.0/2034.12.144.1 to 34.12.159.25434.12.159.2554,094
20334.12.160.0/2034.12.160.1 to 34.12.175.25434.12.175.2554,094
20434.12.176.0/2034.12.176.1 to 34.12.191.25434.12.191.2554,094
20534.12.192.0/2034.12.192.1 to 34.12.207.25434.12.207.2554,094
20634.12.208.0/2034.12.208.1 to 34.12.223.25434.12.223.2554,094
20734.12.224.0/2034.12.224.1 to 34.12.239.25434.12.239.2554,094
20834.12.240.0/2034.12.240.1 to 34.12.255.25434.12.255.2554,094
20934.13.0.0/2034.13.0.1 to 34.13.15.25434.13.15.2554,094
21034.13.16.0/2034.13.16.1 to 34.13.31.25434.13.31.2554,094
21134.13.32.0/2034.13.32.1 to 34.13.47.25434.13.47.2554,094
21234.13.48.0/2034.13.48.1 to 34.13.63.25434.13.63.2554,094
21334.13.64.0/2034.13.64.1 to 34.13.79.25434.13.79.2554,094
21434.13.80.0/2034.13.80.1 to 34.13.95.25434.13.95.2554,094
21534.13.96.0/2034.13.96.1 to 34.13.111.25434.13.111.2554,094
21634.13.112.0/2034.13.112.1 to 34.13.127.25434.13.127.2554,094
21734.13.128.0/2034.13.128.1 to 34.13.143.25434.13.143.2554,094
21834.13.144.0/2034.13.144.1 to 34.13.159.25434.13.159.2554,094
21934.13.160.0/2034.13.160.1 to 34.13.175.25434.13.175.2554,094
22034.13.176.0/2034.13.176.1 to 34.13.191.25434.13.191.2554,094
22134.13.192.0/2034.13.192.1 to 34.13.207.25434.13.207.2554,094
22234.13.208.0/2034.13.208.1 to 34.13.223.25434.13.223.2554,094
22334.13.224.0/2034.13.224.1 to 34.13.239.25434.13.239.2554,094
22434.13.240.0/2034.13.240.1 to 34.13.255.25434.13.255.2554,094
22534.14.0.0/2034.14.0.1 to 34.14.15.25434.14.15.2554,094
22634.14.16.0/2034.14.16.1 to 34.14.31.25434.14.31.2554,094
22734.14.32.0/2034.14.32.1 to 34.14.47.25434.14.47.2554,094
22834.14.48.0/2034.14.48.1 to 34.14.63.25434.14.63.2554,094
22934.14.64.0/2034.14.64.1 to 34.14.79.25434.14.79.2554,094
23034.14.80.0/2034.14.80.1 to 34.14.95.25434.14.95.2554,094
23134.14.96.0/2034.14.96.1 to 34.14.111.25434.14.111.2554,094
23234.14.112.0/2034.14.112.1 to 34.14.127.25434.14.127.2554,094
23334.14.128.0/2034.14.128.1 to 34.14.143.25434.14.143.2554,094
23434.14.144.0/2034.14.144.1 to 34.14.159.25434.14.159.2554,094
23534.14.160.0/2034.14.160.1 to 34.14.175.25434.14.175.2554,094
23634.14.176.0/2034.14.176.1 to 34.14.191.25434.14.191.2554,094
23734.14.192.0/2034.14.192.1 to 34.14.207.25434.14.207.2554,094
23834.14.208.0/2034.14.208.1 to 34.14.223.25434.14.223.2554,094
23934.14.224.0/2034.14.224.1 to 34.14.239.25434.14.239.2554,094
24034.14.240.0/2034.14.240.1 to 34.14.255.25434.14.255.2554,094
24134.15.0.0/2034.15.0.1 to 34.15.15.25434.15.15.2554,094
24234.15.16.0/2034.15.16.1 to 34.15.31.25434.15.31.2554,094
24334.15.32.0/2034.15.32.1 to 34.15.47.25434.15.47.2554,094
24434.15.48.0/2034.15.48.1 to 34.15.63.25434.15.63.2554,094
24534.15.64.0/2034.15.64.1 to 34.15.79.25434.15.79.2554,094
24634.15.80.0/2034.15.80.1 to 34.15.95.25434.15.95.2554,094
24734.15.96.0/2034.15.96.1 to 34.15.111.25434.15.111.2554,094
24834.15.112.0/2034.15.112.1 to 34.15.127.25434.15.127.2554,094
24934.15.128.0/2034.15.128.1 to 34.15.143.25434.15.143.2554,094
25034.15.144.0/2034.15.144.1 to 34.15.159.25434.15.159.2554,094
25134.15.160.0/2034.15.160.1 to 34.15.175.25434.15.175.2554,094
25234.15.176.0/2034.15.176.1 to 34.15.191.25434.15.191.2554,094
25334.15.192.0/2034.15.192.1 to 34.15.207.25434.15.207.2554,094
25434.15.208.0/2034.15.208.1 to 34.15.223.25434.15.223.2554,094
25534.15.224.0/2034.15.224.1 to 34.15.239.25434.15.239.2554,094
25634.15.240.0/2034.15.240.1 to 34.15.255.25434.15.255.2554,094

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.