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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.

Network34.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
34.0.0.0
Broadcast address
35.255.255.255
First usable
34.0.0.1
Last usable
35.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
A (default /8)
As numbers
Hex 22000000 · Integer 570425344 to 603979775
Reverse DNS zones
34.in-addr.arpa
35.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00100010.00000000.00000000.0000000034.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network00100010.00000000.00000000.0000000034.0.0.0
Broadcast00100011.11111111.11111111.1111111135.255.255.255
Split into smaller subnets/19
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

34.0.0.0/7 makes 4,096 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
134.0.0.0/1934.0.0.1 to 34.0.31.25434.0.31.2558,190
234.0.32.0/1934.0.32.1 to 34.0.63.25434.0.63.2558,190
334.0.64.0/1934.0.64.1 to 34.0.95.25434.0.95.2558,190
434.0.96.0/1934.0.96.1 to 34.0.127.25434.0.127.2558,190
534.0.128.0/1934.0.128.1 to 34.0.159.25434.0.159.2558,190
634.0.160.0/1934.0.160.1 to 34.0.191.25434.0.191.2558,190
734.0.192.0/1934.0.192.1 to 34.0.223.25434.0.223.2558,190
834.0.224.0/1934.0.224.1 to 34.0.255.25434.0.255.2558,190
934.1.0.0/1934.1.0.1 to 34.1.31.25434.1.31.2558,190
1034.1.32.0/1934.1.32.1 to 34.1.63.25434.1.63.2558,190
1134.1.64.0/1934.1.64.1 to 34.1.95.25434.1.95.2558,190
1234.1.96.0/1934.1.96.1 to 34.1.127.25434.1.127.2558,190
1334.1.128.0/1934.1.128.1 to 34.1.159.25434.1.159.2558,190
1434.1.160.0/1934.1.160.1 to 34.1.191.25434.1.191.2558,190
1534.1.192.0/1934.1.192.1 to 34.1.223.25434.1.223.2558,190
1634.1.224.0/1934.1.224.1 to 34.1.255.25434.1.255.2558,190
1734.2.0.0/1934.2.0.1 to 34.2.31.25434.2.31.2558,190
1834.2.32.0/1934.2.32.1 to 34.2.63.25434.2.63.2558,190
1934.2.64.0/1934.2.64.1 to 34.2.95.25434.2.95.2558,190
2034.2.96.0/1934.2.96.1 to 34.2.127.25434.2.127.2558,190
2134.2.128.0/1934.2.128.1 to 34.2.159.25434.2.159.2558,190
2234.2.160.0/1934.2.160.1 to 34.2.191.25434.2.191.2558,190
2334.2.192.0/1934.2.192.1 to 34.2.223.25434.2.223.2558,190
2434.2.224.0/1934.2.224.1 to 34.2.255.25434.2.255.2558,190
2534.3.0.0/1934.3.0.1 to 34.3.31.25434.3.31.2558,190
2634.3.32.0/1934.3.32.1 to 34.3.63.25434.3.63.2558,190
2734.3.64.0/1934.3.64.1 to 34.3.95.25434.3.95.2558,190
2834.3.96.0/1934.3.96.1 to 34.3.127.25434.3.127.2558,190
2934.3.128.0/1934.3.128.1 to 34.3.159.25434.3.159.2558,190
3034.3.160.0/1934.3.160.1 to 34.3.191.25434.3.191.2558,190
3134.3.192.0/1934.3.192.1 to 34.3.223.25434.3.223.2558,190
3234.3.224.0/1934.3.224.1 to 34.3.255.25434.3.255.2558,190
3334.4.0.0/1934.4.0.1 to 34.4.31.25434.4.31.2558,190
3434.4.32.0/1934.4.32.1 to 34.4.63.25434.4.63.2558,190
3534.4.64.0/1934.4.64.1 to 34.4.95.25434.4.95.2558,190
3634.4.96.0/1934.4.96.1 to 34.4.127.25434.4.127.2558,190
3734.4.128.0/1934.4.128.1 to 34.4.159.25434.4.159.2558,190
3834.4.160.0/1934.4.160.1 to 34.4.191.25434.4.191.2558,190
3934.4.192.0/1934.4.192.1 to 34.4.223.25434.4.223.2558,190
4034.4.224.0/1934.4.224.1 to 34.4.255.25434.4.255.2558,190
4134.5.0.0/1934.5.0.1 to 34.5.31.25434.5.31.2558,190
4234.5.32.0/1934.5.32.1 to 34.5.63.25434.5.63.2558,190
4334.5.64.0/1934.5.64.1 to 34.5.95.25434.5.95.2558,190
4434.5.96.0/1934.5.96.1 to 34.5.127.25434.5.127.2558,190
4534.5.128.0/1934.5.128.1 to 34.5.159.25434.5.159.2558,190
4634.5.160.0/1934.5.160.1 to 34.5.191.25434.5.191.2558,190
4734.5.192.0/1934.5.192.1 to 34.5.223.25434.5.223.2558,190
4834.5.224.0/1934.5.224.1 to 34.5.255.25434.5.255.2558,190
4934.6.0.0/1934.6.0.1 to 34.6.31.25434.6.31.2558,190
5034.6.32.0/1934.6.32.1 to 34.6.63.25434.6.63.2558,190
5134.6.64.0/1934.6.64.1 to 34.6.95.25434.6.95.2558,190
5234.6.96.0/1934.6.96.1 to 34.6.127.25434.6.127.2558,190
5334.6.128.0/1934.6.128.1 to 34.6.159.25434.6.159.2558,190
5434.6.160.0/1934.6.160.1 to 34.6.191.25434.6.191.2558,190
5534.6.192.0/1934.6.192.1 to 34.6.223.25434.6.223.2558,190
5634.6.224.0/1934.6.224.1 to 34.6.255.25434.6.255.2558,190
5734.7.0.0/1934.7.0.1 to 34.7.31.25434.7.31.2558,190
5834.7.32.0/1934.7.32.1 to 34.7.63.25434.7.63.2558,190
5934.7.64.0/1934.7.64.1 to 34.7.95.25434.7.95.2558,190
6034.7.96.0/1934.7.96.1 to 34.7.127.25434.7.127.2558,190
6134.7.128.0/1934.7.128.1 to 34.7.159.25434.7.159.2558,190
6234.7.160.0/1934.7.160.1 to 34.7.191.25434.7.191.2558,190
6334.7.192.0/1934.7.192.1 to 34.7.223.25434.7.223.2558,190
6434.7.224.0/1934.7.224.1 to 34.7.255.25434.7.255.2558,190
6534.8.0.0/1934.8.0.1 to 34.8.31.25434.8.31.2558,190
6634.8.32.0/1934.8.32.1 to 34.8.63.25434.8.63.2558,190
6734.8.64.0/1934.8.64.1 to 34.8.95.25434.8.95.2558,190
6834.8.96.0/1934.8.96.1 to 34.8.127.25434.8.127.2558,190
6934.8.128.0/1934.8.128.1 to 34.8.159.25434.8.159.2558,190
7034.8.160.0/1934.8.160.1 to 34.8.191.25434.8.191.2558,190
7134.8.192.0/1934.8.192.1 to 34.8.223.25434.8.223.2558,190
7234.8.224.0/1934.8.224.1 to 34.8.255.25434.8.255.2558,190
7334.9.0.0/1934.9.0.1 to 34.9.31.25434.9.31.2558,190
7434.9.32.0/1934.9.32.1 to 34.9.63.25434.9.63.2558,190
7534.9.64.0/1934.9.64.1 to 34.9.95.25434.9.95.2558,190
7634.9.96.0/1934.9.96.1 to 34.9.127.25434.9.127.2558,190
7734.9.128.0/1934.9.128.1 to 34.9.159.25434.9.159.2558,190
7834.9.160.0/1934.9.160.1 to 34.9.191.25434.9.191.2558,190
7934.9.192.0/1934.9.192.1 to 34.9.223.25434.9.223.2558,190
8034.9.224.0/1934.9.224.1 to 34.9.255.25434.9.255.2558,190
8134.10.0.0/1934.10.0.1 to 34.10.31.25434.10.31.2558,190
8234.10.32.0/1934.10.32.1 to 34.10.63.25434.10.63.2558,190
8334.10.64.0/1934.10.64.1 to 34.10.95.25434.10.95.2558,190
8434.10.96.0/1934.10.96.1 to 34.10.127.25434.10.127.2558,190
8534.10.128.0/1934.10.128.1 to 34.10.159.25434.10.159.2558,190
8634.10.160.0/1934.10.160.1 to 34.10.191.25434.10.191.2558,190
8734.10.192.0/1934.10.192.1 to 34.10.223.25434.10.223.2558,190
8834.10.224.0/1934.10.224.1 to 34.10.255.25434.10.255.2558,190
8934.11.0.0/1934.11.0.1 to 34.11.31.25434.11.31.2558,190
9034.11.32.0/1934.11.32.1 to 34.11.63.25434.11.63.2558,190
9134.11.64.0/1934.11.64.1 to 34.11.95.25434.11.95.2558,190
9234.11.96.0/1934.11.96.1 to 34.11.127.25434.11.127.2558,190
9334.11.128.0/1934.11.128.1 to 34.11.159.25434.11.159.2558,190
9434.11.160.0/1934.11.160.1 to 34.11.191.25434.11.191.2558,190
9534.11.192.0/1934.11.192.1 to 34.11.223.25434.11.223.2558,190
9634.11.224.0/1934.11.224.1 to 34.11.255.25434.11.255.2558,190
9734.12.0.0/1934.12.0.1 to 34.12.31.25434.12.31.2558,190
9834.12.32.0/1934.12.32.1 to 34.12.63.25434.12.63.2558,190
9934.12.64.0/1934.12.64.1 to 34.12.95.25434.12.95.2558,190
10034.12.96.0/1934.12.96.1 to 34.12.127.25434.12.127.2558,190
10134.12.128.0/1934.12.128.1 to 34.12.159.25434.12.159.2558,190
10234.12.160.0/1934.12.160.1 to 34.12.191.25434.12.191.2558,190
10334.12.192.0/1934.12.192.1 to 34.12.223.25434.12.223.2558,190
10434.12.224.0/1934.12.224.1 to 34.12.255.25434.12.255.2558,190
10534.13.0.0/1934.13.0.1 to 34.13.31.25434.13.31.2558,190
10634.13.32.0/1934.13.32.1 to 34.13.63.25434.13.63.2558,190
10734.13.64.0/1934.13.64.1 to 34.13.95.25434.13.95.2558,190
10834.13.96.0/1934.13.96.1 to 34.13.127.25434.13.127.2558,190
10934.13.128.0/1934.13.128.1 to 34.13.159.25434.13.159.2558,190
11034.13.160.0/1934.13.160.1 to 34.13.191.25434.13.191.2558,190
11134.13.192.0/1934.13.192.1 to 34.13.223.25434.13.223.2558,190
11234.13.224.0/1934.13.224.1 to 34.13.255.25434.13.255.2558,190
11334.14.0.0/1934.14.0.1 to 34.14.31.25434.14.31.2558,190
11434.14.32.0/1934.14.32.1 to 34.14.63.25434.14.63.2558,190
11534.14.64.0/1934.14.64.1 to 34.14.95.25434.14.95.2558,190
11634.14.96.0/1934.14.96.1 to 34.14.127.25434.14.127.2558,190
11734.14.128.0/1934.14.128.1 to 34.14.159.25434.14.159.2558,190
11834.14.160.0/1934.14.160.1 to 34.14.191.25434.14.191.2558,190
11934.14.192.0/1934.14.192.1 to 34.14.223.25434.14.223.2558,190
12034.14.224.0/1934.14.224.1 to 34.14.255.25434.14.255.2558,190
12134.15.0.0/1934.15.0.1 to 34.15.31.25434.15.31.2558,190
12234.15.32.0/1934.15.32.1 to 34.15.63.25434.15.63.2558,190
12334.15.64.0/1934.15.64.1 to 34.15.95.25434.15.95.2558,190
12434.15.96.0/1934.15.96.1 to 34.15.127.25434.15.127.2558,190
12534.15.128.0/1934.15.128.1 to 34.15.159.25434.15.159.2558,190
12634.15.160.0/1934.15.160.1 to 34.15.191.25434.15.191.2558,190
12734.15.192.0/1934.15.192.1 to 34.15.223.25434.15.223.2558,190
12834.15.224.0/1934.15.224.1 to 34.15.255.25434.15.255.2558,190
12934.16.0.0/1934.16.0.1 to 34.16.31.25434.16.31.2558,190
13034.16.32.0/1934.16.32.1 to 34.16.63.25434.16.63.2558,190
13134.16.64.0/1934.16.64.1 to 34.16.95.25434.16.95.2558,190
13234.16.96.0/1934.16.96.1 to 34.16.127.25434.16.127.2558,190
13334.16.128.0/1934.16.128.1 to 34.16.159.25434.16.159.2558,190
13434.16.160.0/1934.16.160.1 to 34.16.191.25434.16.191.2558,190
13534.16.192.0/1934.16.192.1 to 34.16.223.25434.16.223.2558,190
13634.16.224.0/1934.16.224.1 to 34.16.255.25434.16.255.2558,190
13734.17.0.0/1934.17.0.1 to 34.17.31.25434.17.31.2558,190
13834.17.32.0/1934.17.32.1 to 34.17.63.25434.17.63.2558,190
13934.17.64.0/1934.17.64.1 to 34.17.95.25434.17.95.2558,190
14034.17.96.0/1934.17.96.1 to 34.17.127.25434.17.127.2558,190
14134.17.128.0/1934.17.128.1 to 34.17.159.25434.17.159.2558,190
14234.17.160.0/1934.17.160.1 to 34.17.191.25434.17.191.2558,190
14334.17.192.0/1934.17.192.1 to 34.17.223.25434.17.223.2558,190
14434.17.224.0/1934.17.224.1 to 34.17.255.25434.17.255.2558,190
14534.18.0.0/1934.18.0.1 to 34.18.31.25434.18.31.2558,190
14634.18.32.0/1934.18.32.1 to 34.18.63.25434.18.63.2558,190
14734.18.64.0/1934.18.64.1 to 34.18.95.25434.18.95.2558,190
14834.18.96.0/1934.18.96.1 to 34.18.127.25434.18.127.2558,190
14934.18.128.0/1934.18.128.1 to 34.18.159.25434.18.159.2558,190
15034.18.160.0/1934.18.160.1 to 34.18.191.25434.18.191.2558,190
15134.18.192.0/1934.18.192.1 to 34.18.223.25434.18.223.2558,190
15234.18.224.0/1934.18.224.1 to 34.18.255.25434.18.255.2558,190
15334.19.0.0/1934.19.0.1 to 34.19.31.25434.19.31.2558,190
15434.19.32.0/1934.19.32.1 to 34.19.63.25434.19.63.2558,190
15534.19.64.0/1934.19.64.1 to 34.19.95.25434.19.95.2558,190
15634.19.96.0/1934.19.96.1 to 34.19.127.25434.19.127.2558,190
15734.19.128.0/1934.19.128.1 to 34.19.159.25434.19.159.2558,190
15834.19.160.0/1934.19.160.1 to 34.19.191.25434.19.191.2558,190
15934.19.192.0/1934.19.192.1 to 34.19.223.25434.19.223.2558,190
16034.19.224.0/1934.19.224.1 to 34.19.255.25434.19.255.2558,190
16134.20.0.0/1934.20.0.1 to 34.20.31.25434.20.31.2558,190
16234.20.32.0/1934.20.32.1 to 34.20.63.25434.20.63.2558,190
16334.20.64.0/1934.20.64.1 to 34.20.95.25434.20.95.2558,190
16434.20.96.0/1934.20.96.1 to 34.20.127.25434.20.127.2558,190
16534.20.128.0/1934.20.128.1 to 34.20.159.25434.20.159.2558,190
16634.20.160.0/1934.20.160.1 to 34.20.191.25434.20.191.2558,190
16734.20.192.0/1934.20.192.1 to 34.20.223.25434.20.223.2558,190
16834.20.224.0/1934.20.224.1 to 34.20.255.25434.20.255.2558,190
16934.21.0.0/1934.21.0.1 to 34.21.31.25434.21.31.2558,190
17034.21.32.0/1934.21.32.1 to 34.21.63.25434.21.63.2558,190
17134.21.64.0/1934.21.64.1 to 34.21.95.25434.21.95.2558,190
17234.21.96.0/1934.21.96.1 to 34.21.127.25434.21.127.2558,190
17334.21.128.0/1934.21.128.1 to 34.21.159.25434.21.159.2558,190
17434.21.160.0/1934.21.160.1 to 34.21.191.25434.21.191.2558,190
17534.21.192.0/1934.21.192.1 to 34.21.223.25434.21.223.2558,190
17634.21.224.0/1934.21.224.1 to 34.21.255.25434.21.255.2558,190
17734.22.0.0/1934.22.0.1 to 34.22.31.25434.22.31.2558,190
17834.22.32.0/1934.22.32.1 to 34.22.63.25434.22.63.2558,190
17934.22.64.0/1934.22.64.1 to 34.22.95.25434.22.95.2558,190
18034.22.96.0/1934.22.96.1 to 34.22.127.25434.22.127.2558,190
18134.22.128.0/1934.22.128.1 to 34.22.159.25434.22.159.2558,190
18234.22.160.0/1934.22.160.1 to 34.22.191.25434.22.191.2558,190
18334.22.192.0/1934.22.192.1 to 34.22.223.25434.22.223.2558,190
18434.22.224.0/1934.22.224.1 to 34.22.255.25434.22.255.2558,190
18534.23.0.0/1934.23.0.1 to 34.23.31.25434.23.31.2558,190
18634.23.32.0/1934.23.32.1 to 34.23.63.25434.23.63.2558,190
18734.23.64.0/1934.23.64.1 to 34.23.95.25434.23.95.2558,190
18834.23.96.0/1934.23.96.1 to 34.23.127.25434.23.127.2558,190
18934.23.128.0/1934.23.128.1 to 34.23.159.25434.23.159.2558,190
19034.23.160.0/1934.23.160.1 to 34.23.191.25434.23.191.2558,190
19134.23.192.0/1934.23.192.1 to 34.23.223.25434.23.223.2558,190
19234.23.224.0/1934.23.224.1 to 34.23.255.25434.23.255.2558,190
19334.24.0.0/1934.24.0.1 to 34.24.31.25434.24.31.2558,190
19434.24.32.0/1934.24.32.1 to 34.24.63.25434.24.63.2558,190
19534.24.64.0/1934.24.64.1 to 34.24.95.25434.24.95.2558,190
19634.24.96.0/1934.24.96.1 to 34.24.127.25434.24.127.2558,190
19734.24.128.0/1934.24.128.1 to 34.24.159.25434.24.159.2558,190
19834.24.160.0/1934.24.160.1 to 34.24.191.25434.24.191.2558,190
19934.24.192.0/1934.24.192.1 to 34.24.223.25434.24.223.2558,190
20034.24.224.0/1934.24.224.1 to 34.24.255.25434.24.255.2558,190
20134.25.0.0/1934.25.0.1 to 34.25.31.25434.25.31.2558,190
20234.25.32.0/1934.25.32.1 to 34.25.63.25434.25.63.2558,190
20334.25.64.0/1934.25.64.1 to 34.25.95.25434.25.95.2558,190
20434.25.96.0/1934.25.96.1 to 34.25.127.25434.25.127.2558,190
20534.25.128.0/1934.25.128.1 to 34.25.159.25434.25.159.2558,190
20634.25.160.0/1934.25.160.1 to 34.25.191.25434.25.191.2558,190
20734.25.192.0/1934.25.192.1 to 34.25.223.25434.25.223.2558,190
20834.25.224.0/1934.25.224.1 to 34.25.255.25434.25.255.2558,190
20934.26.0.0/1934.26.0.1 to 34.26.31.25434.26.31.2558,190
21034.26.32.0/1934.26.32.1 to 34.26.63.25434.26.63.2558,190
21134.26.64.0/1934.26.64.1 to 34.26.95.25434.26.95.2558,190
21234.26.96.0/1934.26.96.1 to 34.26.127.25434.26.127.2558,190
21334.26.128.0/1934.26.128.1 to 34.26.159.25434.26.159.2558,190
21434.26.160.0/1934.26.160.1 to 34.26.191.25434.26.191.2558,190
21534.26.192.0/1934.26.192.1 to 34.26.223.25434.26.223.2558,190
21634.26.224.0/1934.26.224.1 to 34.26.255.25434.26.255.2558,190
21734.27.0.0/1934.27.0.1 to 34.27.31.25434.27.31.2558,190
21834.27.32.0/1934.27.32.1 to 34.27.63.25434.27.63.2558,190
21934.27.64.0/1934.27.64.1 to 34.27.95.25434.27.95.2558,190
22034.27.96.0/1934.27.96.1 to 34.27.127.25434.27.127.2558,190
22134.27.128.0/1934.27.128.1 to 34.27.159.25434.27.159.2558,190
22234.27.160.0/1934.27.160.1 to 34.27.191.25434.27.191.2558,190
22334.27.192.0/1934.27.192.1 to 34.27.223.25434.27.223.2558,190
22434.27.224.0/1934.27.224.1 to 34.27.255.25434.27.255.2558,190
22534.28.0.0/1934.28.0.1 to 34.28.31.25434.28.31.2558,190
22634.28.32.0/1934.28.32.1 to 34.28.63.25434.28.63.2558,190
22734.28.64.0/1934.28.64.1 to 34.28.95.25434.28.95.2558,190
22834.28.96.0/1934.28.96.1 to 34.28.127.25434.28.127.2558,190
22934.28.128.0/1934.28.128.1 to 34.28.159.25434.28.159.2558,190
23034.28.160.0/1934.28.160.1 to 34.28.191.25434.28.191.2558,190
23134.28.192.0/1934.28.192.1 to 34.28.223.25434.28.223.2558,190
23234.28.224.0/1934.28.224.1 to 34.28.255.25434.28.255.2558,190
23334.29.0.0/1934.29.0.1 to 34.29.31.25434.29.31.2558,190
23434.29.32.0/1934.29.32.1 to 34.29.63.25434.29.63.2558,190
23534.29.64.0/1934.29.64.1 to 34.29.95.25434.29.95.2558,190
23634.29.96.0/1934.29.96.1 to 34.29.127.25434.29.127.2558,190
23734.29.128.0/1934.29.128.1 to 34.29.159.25434.29.159.2558,190
23834.29.160.0/1934.29.160.1 to 34.29.191.25434.29.191.2558,190
23934.29.192.0/1934.29.192.1 to 34.29.223.25434.29.223.2558,190
24034.29.224.0/1934.29.224.1 to 34.29.255.25434.29.255.2558,190
24134.30.0.0/1934.30.0.1 to 34.30.31.25434.30.31.2558,190
24234.30.32.0/1934.30.32.1 to 34.30.63.25434.30.63.2558,190
24334.30.64.0/1934.30.64.1 to 34.30.95.25434.30.95.2558,190
24434.30.96.0/1934.30.96.1 to 34.30.127.25434.30.127.2558,190
24534.30.128.0/1934.30.128.1 to 34.30.159.25434.30.159.2558,190
24634.30.160.0/1934.30.160.1 to 34.30.191.25434.30.191.2558,190
24734.30.192.0/1934.30.192.1 to 34.30.223.25434.30.223.2558,190
24834.30.224.0/1934.30.224.1 to 34.30.255.25434.30.255.2558,190
24934.31.0.0/1934.31.0.1 to 34.31.31.25434.31.31.2558,190
25034.31.32.0/1934.31.32.1 to 34.31.63.25434.31.63.2558,190
25134.31.64.0/1934.31.64.1 to 34.31.95.25434.31.95.2558,190
25234.31.96.0/1934.31.96.1 to 34.31.127.25434.31.127.2558,190
25334.31.128.0/1934.31.128.1 to 34.31.159.25434.31.159.2558,190
25434.31.160.0/1934.31.160.1 to 34.31.191.25434.31.191.2558,190
25534.31.192.0/1934.31.192.1 to 34.31.223.25434.31.223.2558,190
25634.31.224.0/1934.31.224.1 to 34.31.255.25434.31.255.2558,190

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.