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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/18
/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 2,048 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
134.0.0.0/1834.0.0.1 to 34.0.63.25434.0.63.25516,382
234.0.64.0/1834.0.64.1 to 34.0.127.25434.0.127.25516,382
334.0.128.0/1834.0.128.1 to 34.0.191.25434.0.191.25516,382
434.0.192.0/1834.0.192.1 to 34.0.255.25434.0.255.25516,382
534.1.0.0/1834.1.0.1 to 34.1.63.25434.1.63.25516,382
634.1.64.0/1834.1.64.1 to 34.1.127.25434.1.127.25516,382
734.1.128.0/1834.1.128.1 to 34.1.191.25434.1.191.25516,382
834.1.192.0/1834.1.192.1 to 34.1.255.25434.1.255.25516,382
934.2.0.0/1834.2.0.1 to 34.2.63.25434.2.63.25516,382
1034.2.64.0/1834.2.64.1 to 34.2.127.25434.2.127.25516,382
1134.2.128.0/1834.2.128.1 to 34.2.191.25434.2.191.25516,382
1234.2.192.0/1834.2.192.1 to 34.2.255.25434.2.255.25516,382
1334.3.0.0/1834.3.0.1 to 34.3.63.25434.3.63.25516,382
1434.3.64.0/1834.3.64.1 to 34.3.127.25434.3.127.25516,382
1534.3.128.0/1834.3.128.1 to 34.3.191.25434.3.191.25516,382
1634.3.192.0/1834.3.192.1 to 34.3.255.25434.3.255.25516,382
1734.4.0.0/1834.4.0.1 to 34.4.63.25434.4.63.25516,382
1834.4.64.0/1834.4.64.1 to 34.4.127.25434.4.127.25516,382
1934.4.128.0/1834.4.128.1 to 34.4.191.25434.4.191.25516,382
2034.4.192.0/1834.4.192.1 to 34.4.255.25434.4.255.25516,382
2134.5.0.0/1834.5.0.1 to 34.5.63.25434.5.63.25516,382
2234.5.64.0/1834.5.64.1 to 34.5.127.25434.5.127.25516,382
2334.5.128.0/1834.5.128.1 to 34.5.191.25434.5.191.25516,382
2434.5.192.0/1834.5.192.1 to 34.5.255.25434.5.255.25516,382
2534.6.0.0/1834.6.0.1 to 34.6.63.25434.6.63.25516,382
2634.6.64.0/1834.6.64.1 to 34.6.127.25434.6.127.25516,382
2734.6.128.0/1834.6.128.1 to 34.6.191.25434.6.191.25516,382
2834.6.192.0/1834.6.192.1 to 34.6.255.25434.6.255.25516,382
2934.7.0.0/1834.7.0.1 to 34.7.63.25434.7.63.25516,382
3034.7.64.0/1834.7.64.1 to 34.7.127.25434.7.127.25516,382
3134.7.128.0/1834.7.128.1 to 34.7.191.25434.7.191.25516,382
3234.7.192.0/1834.7.192.1 to 34.7.255.25434.7.255.25516,382
3334.8.0.0/1834.8.0.1 to 34.8.63.25434.8.63.25516,382
3434.8.64.0/1834.8.64.1 to 34.8.127.25434.8.127.25516,382
3534.8.128.0/1834.8.128.1 to 34.8.191.25434.8.191.25516,382
3634.8.192.0/1834.8.192.1 to 34.8.255.25434.8.255.25516,382
3734.9.0.0/1834.9.0.1 to 34.9.63.25434.9.63.25516,382
3834.9.64.0/1834.9.64.1 to 34.9.127.25434.9.127.25516,382
3934.9.128.0/1834.9.128.1 to 34.9.191.25434.9.191.25516,382
4034.9.192.0/1834.9.192.1 to 34.9.255.25434.9.255.25516,382
4134.10.0.0/1834.10.0.1 to 34.10.63.25434.10.63.25516,382
4234.10.64.0/1834.10.64.1 to 34.10.127.25434.10.127.25516,382
4334.10.128.0/1834.10.128.1 to 34.10.191.25434.10.191.25516,382
4434.10.192.0/1834.10.192.1 to 34.10.255.25434.10.255.25516,382
4534.11.0.0/1834.11.0.1 to 34.11.63.25434.11.63.25516,382
4634.11.64.0/1834.11.64.1 to 34.11.127.25434.11.127.25516,382
4734.11.128.0/1834.11.128.1 to 34.11.191.25434.11.191.25516,382
4834.11.192.0/1834.11.192.1 to 34.11.255.25434.11.255.25516,382
4934.12.0.0/1834.12.0.1 to 34.12.63.25434.12.63.25516,382
5034.12.64.0/1834.12.64.1 to 34.12.127.25434.12.127.25516,382
5134.12.128.0/1834.12.128.1 to 34.12.191.25434.12.191.25516,382
5234.12.192.0/1834.12.192.1 to 34.12.255.25434.12.255.25516,382
5334.13.0.0/1834.13.0.1 to 34.13.63.25434.13.63.25516,382
5434.13.64.0/1834.13.64.1 to 34.13.127.25434.13.127.25516,382
5534.13.128.0/1834.13.128.1 to 34.13.191.25434.13.191.25516,382
5634.13.192.0/1834.13.192.1 to 34.13.255.25434.13.255.25516,382
5734.14.0.0/1834.14.0.1 to 34.14.63.25434.14.63.25516,382
5834.14.64.0/1834.14.64.1 to 34.14.127.25434.14.127.25516,382
5934.14.128.0/1834.14.128.1 to 34.14.191.25434.14.191.25516,382
6034.14.192.0/1834.14.192.1 to 34.14.255.25434.14.255.25516,382
6134.15.0.0/1834.15.0.1 to 34.15.63.25434.15.63.25516,382
6234.15.64.0/1834.15.64.1 to 34.15.127.25434.15.127.25516,382
6334.15.128.0/1834.15.128.1 to 34.15.191.25434.15.191.25516,382
6434.15.192.0/1834.15.192.1 to 34.15.255.25434.15.255.25516,382
6534.16.0.0/1834.16.0.1 to 34.16.63.25434.16.63.25516,382
6634.16.64.0/1834.16.64.1 to 34.16.127.25434.16.127.25516,382
6734.16.128.0/1834.16.128.1 to 34.16.191.25434.16.191.25516,382
6834.16.192.0/1834.16.192.1 to 34.16.255.25434.16.255.25516,382
6934.17.0.0/1834.17.0.1 to 34.17.63.25434.17.63.25516,382
7034.17.64.0/1834.17.64.1 to 34.17.127.25434.17.127.25516,382
7134.17.128.0/1834.17.128.1 to 34.17.191.25434.17.191.25516,382
7234.17.192.0/1834.17.192.1 to 34.17.255.25434.17.255.25516,382
7334.18.0.0/1834.18.0.1 to 34.18.63.25434.18.63.25516,382
7434.18.64.0/1834.18.64.1 to 34.18.127.25434.18.127.25516,382
7534.18.128.0/1834.18.128.1 to 34.18.191.25434.18.191.25516,382
7634.18.192.0/1834.18.192.1 to 34.18.255.25434.18.255.25516,382
7734.19.0.0/1834.19.0.1 to 34.19.63.25434.19.63.25516,382
7834.19.64.0/1834.19.64.1 to 34.19.127.25434.19.127.25516,382
7934.19.128.0/1834.19.128.1 to 34.19.191.25434.19.191.25516,382
8034.19.192.0/1834.19.192.1 to 34.19.255.25434.19.255.25516,382
8134.20.0.0/1834.20.0.1 to 34.20.63.25434.20.63.25516,382
8234.20.64.0/1834.20.64.1 to 34.20.127.25434.20.127.25516,382
8334.20.128.0/1834.20.128.1 to 34.20.191.25434.20.191.25516,382
8434.20.192.0/1834.20.192.1 to 34.20.255.25434.20.255.25516,382
8534.21.0.0/1834.21.0.1 to 34.21.63.25434.21.63.25516,382
8634.21.64.0/1834.21.64.1 to 34.21.127.25434.21.127.25516,382
8734.21.128.0/1834.21.128.1 to 34.21.191.25434.21.191.25516,382
8834.21.192.0/1834.21.192.1 to 34.21.255.25434.21.255.25516,382
8934.22.0.0/1834.22.0.1 to 34.22.63.25434.22.63.25516,382
9034.22.64.0/1834.22.64.1 to 34.22.127.25434.22.127.25516,382
9134.22.128.0/1834.22.128.1 to 34.22.191.25434.22.191.25516,382
9234.22.192.0/1834.22.192.1 to 34.22.255.25434.22.255.25516,382
9334.23.0.0/1834.23.0.1 to 34.23.63.25434.23.63.25516,382
9434.23.64.0/1834.23.64.1 to 34.23.127.25434.23.127.25516,382
9534.23.128.0/1834.23.128.1 to 34.23.191.25434.23.191.25516,382
9634.23.192.0/1834.23.192.1 to 34.23.255.25434.23.255.25516,382
9734.24.0.0/1834.24.0.1 to 34.24.63.25434.24.63.25516,382
9834.24.64.0/1834.24.64.1 to 34.24.127.25434.24.127.25516,382
9934.24.128.0/1834.24.128.1 to 34.24.191.25434.24.191.25516,382
10034.24.192.0/1834.24.192.1 to 34.24.255.25434.24.255.25516,382
10134.25.0.0/1834.25.0.1 to 34.25.63.25434.25.63.25516,382
10234.25.64.0/1834.25.64.1 to 34.25.127.25434.25.127.25516,382
10334.25.128.0/1834.25.128.1 to 34.25.191.25434.25.191.25516,382
10434.25.192.0/1834.25.192.1 to 34.25.255.25434.25.255.25516,382
10534.26.0.0/1834.26.0.1 to 34.26.63.25434.26.63.25516,382
10634.26.64.0/1834.26.64.1 to 34.26.127.25434.26.127.25516,382
10734.26.128.0/1834.26.128.1 to 34.26.191.25434.26.191.25516,382
10834.26.192.0/1834.26.192.1 to 34.26.255.25434.26.255.25516,382
10934.27.0.0/1834.27.0.1 to 34.27.63.25434.27.63.25516,382
11034.27.64.0/1834.27.64.1 to 34.27.127.25434.27.127.25516,382
11134.27.128.0/1834.27.128.1 to 34.27.191.25434.27.191.25516,382
11234.27.192.0/1834.27.192.1 to 34.27.255.25434.27.255.25516,382
11334.28.0.0/1834.28.0.1 to 34.28.63.25434.28.63.25516,382
11434.28.64.0/1834.28.64.1 to 34.28.127.25434.28.127.25516,382
11534.28.128.0/1834.28.128.1 to 34.28.191.25434.28.191.25516,382
11634.28.192.0/1834.28.192.1 to 34.28.255.25434.28.255.25516,382
11734.29.0.0/1834.29.0.1 to 34.29.63.25434.29.63.25516,382
11834.29.64.0/1834.29.64.1 to 34.29.127.25434.29.127.25516,382
11934.29.128.0/1834.29.128.1 to 34.29.191.25434.29.191.25516,382
12034.29.192.0/1834.29.192.1 to 34.29.255.25434.29.255.25516,382
12134.30.0.0/1834.30.0.1 to 34.30.63.25434.30.63.25516,382
12234.30.64.0/1834.30.64.1 to 34.30.127.25434.30.127.25516,382
12334.30.128.0/1834.30.128.1 to 34.30.191.25434.30.191.25516,382
12434.30.192.0/1834.30.192.1 to 34.30.255.25434.30.255.25516,382
12534.31.0.0/1834.31.0.1 to 34.31.63.25434.31.63.25516,382
12634.31.64.0/1834.31.64.1 to 34.31.127.25434.31.127.25516,382
12734.31.128.0/1834.31.128.1 to 34.31.191.25434.31.191.25516,382
12834.31.192.0/1834.31.192.1 to 34.31.255.25434.31.255.25516,382
12934.32.0.0/1834.32.0.1 to 34.32.63.25434.32.63.25516,382
13034.32.64.0/1834.32.64.1 to 34.32.127.25434.32.127.25516,382
13134.32.128.0/1834.32.128.1 to 34.32.191.25434.32.191.25516,382
13234.32.192.0/1834.32.192.1 to 34.32.255.25434.32.255.25516,382
13334.33.0.0/1834.33.0.1 to 34.33.63.25434.33.63.25516,382
13434.33.64.0/1834.33.64.1 to 34.33.127.25434.33.127.25516,382
13534.33.128.0/1834.33.128.1 to 34.33.191.25434.33.191.25516,382
13634.33.192.0/1834.33.192.1 to 34.33.255.25434.33.255.25516,382
13734.34.0.0/1834.34.0.1 to 34.34.63.25434.34.63.25516,382
13834.34.64.0/1834.34.64.1 to 34.34.127.25434.34.127.25516,382
13934.34.128.0/1834.34.128.1 to 34.34.191.25434.34.191.25516,382
14034.34.192.0/1834.34.192.1 to 34.34.255.25434.34.255.25516,382
14134.35.0.0/1834.35.0.1 to 34.35.63.25434.35.63.25516,382
14234.35.64.0/1834.35.64.1 to 34.35.127.25434.35.127.25516,382
14334.35.128.0/1834.35.128.1 to 34.35.191.25434.35.191.25516,382
14434.35.192.0/1834.35.192.1 to 34.35.255.25434.35.255.25516,382
14534.36.0.0/1834.36.0.1 to 34.36.63.25434.36.63.25516,382
14634.36.64.0/1834.36.64.1 to 34.36.127.25434.36.127.25516,382
14734.36.128.0/1834.36.128.1 to 34.36.191.25434.36.191.25516,382
14834.36.192.0/1834.36.192.1 to 34.36.255.25434.36.255.25516,382
14934.37.0.0/1834.37.0.1 to 34.37.63.25434.37.63.25516,382
15034.37.64.0/1834.37.64.1 to 34.37.127.25434.37.127.25516,382
15134.37.128.0/1834.37.128.1 to 34.37.191.25434.37.191.25516,382
15234.37.192.0/1834.37.192.1 to 34.37.255.25434.37.255.25516,382
15334.38.0.0/1834.38.0.1 to 34.38.63.25434.38.63.25516,382
15434.38.64.0/1834.38.64.1 to 34.38.127.25434.38.127.25516,382
15534.38.128.0/1834.38.128.1 to 34.38.191.25434.38.191.25516,382
15634.38.192.0/1834.38.192.1 to 34.38.255.25434.38.255.25516,382
15734.39.0.0/1834.39.0.1 to 34.39.63.25434.39.63.25516,382
15834.39.64.0/1834.39.64.1 to 34.39.127.25434.39.127.25516,382
15934.39.128.0/1834.39.128.1 to 34.39.191.25434.39.191.25516,382
16034.39.192.0/1834.39.192.1 to 34.39.255.25434.39.255.25516,382
16134.40.0.0/1834.40.0.1 to 34.40.63.25434.40.63.25516,382
16234.40.64.0/1834.40.64.1 to 34.40.127.25434.40.127.25516,382
16334.40.128.0/1834.40.128.1 to 34.40.191.25434.40.191.25516,382
16434.40.192.0/1834.40.192.1 to 34.40.255.25434.40.255.25516,382
16534.41.0.0/1834.41.0.1 to 34.41.63.25434.41.63.25516,382
16634.41.64.0/1834.41.64.1 to 34.41.127.25434.41.127.25516,382
16734.41.128.0/1834.41.128.1 to 34.41.191.25434.41.191.25516,382
16834.41.192.0/1834.41.192.1 to 34.41.255.25434.41.255.25516,382
16934.42.0.0/1834.42.0.1 to 34.42.63.25434.42.63.25516,382
17034.42.64.0/1834.42.64.1 to 34.42.127.25434.42.127.25516,382
17134.42.128.0/1834.42.128.1 to 34.42.191.25434.42.191.25516,382
17234.42.192.0/1834.42.192.1 to 34.42.255.25434.42.255.25516,382
17334.43.0.0/1834.43.0.1 to 34.43.63.25434.43.63.25516,382
17434.43.64.0/1834.43.64.1 to 34.43.127.25434.43.127.25516,382
17534.43.128.0/1834.43.128.1 to 34.43.191.25434.43.191.25516,382
17634.43.192.0/1834.43.192.1 to 34.43.255.25434.43.255.25516,382
17734.44.0.0/1834.44.0.1 to 34.44.63.25434.44.63.25516,382
17834.44.64.0/1834.44.64.1 to 34.44.127.25434.44.127.25516,382
17934.44.128.0/1834.44.128.1 to 34.44.191.25434.44.191.25516,382
18034.44.192.0/1834.44.192.1 to 34.44.255.25434.44.255.25516,382
18134.45.0.0/1834.45.0.1 to 34.45.63.25434.45.63.25516,382
18234.45.64.0/1834.45.64.1 to 34.45.127.25434.45.127.25516,382
18334.45.128.0/1834.45.128.1 to 34.45.191.25434.45.191.25516,382
18434.45.192.0/1834.45.192.1 to 34.45.255.25434.45.255.25516,382
18534.46.0.0/1834.46.0.1 to 34.46.63.25434.46.63.25516,382
18634.46.64.0/1834.46.64.1 to 34.46.127.25434.46.127.25516,382
18734.46.128.0/1834.46.128.1 to 34.46.191.25434.46.191.25516,382
18834.46.192.0/1834.46.192.1 to 34.46.255.25434.46.255.25516,382
18934.47.0.0/1834.47.0.1 to 34.47.63.25434.47.63.25516,382
19034.47.64.0/1834.47.64.1 to 34.47.127.25434.47.127.25516,382
19134.47.128.0/1834.47.128.1 to 34.47.191.25434.47.191.25516,382
19234.47.192.0/1834.47.192.1 to 34.47.255.25434.47.255.25516,382
19334.48.0.0/1834.48.0.1 to 34.48.63.25434.48.63.25516,382
19434.48.64.0/1834.48.64.1 to 34.48.127.25434.48.127.25516,382
19534.48.128.0/1834.48.128.1 to 34.48.191.25434.48.191.25516,382
19634.48.192.0/1834.48.192.1 to 34.48.255.25434.48.255.25516,382
19734.49.0.0/1834.49.0.1 to 34.49.63.25434.49.63.25516,382
19834.49.64.0/1834.49.64.1 to 34.49.127.25434.49.127.25516,382
19934.49.128.0/1834.49.128.1 to 34.49.191.25434.49.191.25516,382
20034.49.192.0/1834.49.192.1 to 34.49.255.25434.49.255.25516,382
20134.50.0.0/1834.50.0.1 to 34.50.63.25434.50.63.25516,382
20234.50.64.0/1834.50.64.1 to 34.50.127.25434.50.127.25516,382
20334.50.128.0/1834.50.128.1 to 34.50.191.25434.50.191.25516,382
20434.50.192.0/1834.50.192.1 to 34.50.255.25434.50.255.25516,382
20534.51.0.0/1834.51.0.1 to 34.51.63.25434.51.63.25516,382
20634.51.64.0/1834.51.64.1 to 34.51.127.25434.51.127.25516,382
20734.51.128.0/1834.51.128.1 to 34.51.191.25434.51.191.25516,382
20834.51.192.0/1834.51.192.1 to 34.51.255.25434.51.255.25516,382
20934.52.0.0/1834.52.0.1 to 34.52.63.25434.52.63.25516,382
21034.52.64.0/1834.52.64.1 to 34.52.127.25434.52.127.25516,382
21134.52.128.0/1834.52.128.1 to 34.52.191.25434.52.191.25516,382
21234.52.192.0/1834.52.192.1 to 34.52.255.25434.52.255.25516,382
21334.53.0.0/1834.53.0.1 to 34.53.63.25434.53.63.25516,382
21434.53.64.0/1834.53.64.1 to 34.53.127.25434.53.127.25516,382
21534.53.128.0/1834.53.128.1 to 34.53.191.25434.53.191.25516,382
21634.53.192.0/1834.53.192.1 to 34.53.255.25434.53.255.25516,382
21734.54.0.0/1834.54.0.1 to 34.54.63.25434.54.63.25516,382
21834.54.64.0/1834.54.64.1 to 34.54.127.25434.54.127.25516,382
21934.54.128.0/1834.54.128.1 to 34.54.191.25434.54.191.25516,382
22034.54.192.0/1834.54.192.1 to 34.54.255.25434.54.255.25516,382
22134.55.0.0/1834.55.0.1 to 34.55.63.25434.55.63.25516,382
22234.55.64.0/1834.55.64.1 to 34.55.127.25434.55.127.25516,382
22334.55.128.0/1834.55.128.1 to 34.55.191.25434.55.191.25516,382
22434.55.192.0/1834.55.192.1 to 34.55.255.25434.55.255.25516,382
22534.56.0.0/1834.56.0.1 to 34.56.63.25434.56.63.25516,382
22634.56.64.0/1834.56.64.1 to 34.56.127.25434.56.127.25516,382
22734.56.128.0/1834.56.128.1 to 34.56.191.25434.56.191.25516,382
22834.56.192.0/1834.56.192.1 to 34.56.255.25434.56.255.25516,382
22934.57.0.0/1834.57.0.1 to 34.57.63.25434.57.63.25516,382
23034.57.64.0/1834.57.64.1 to 34.57.127.25434.57.127.25516,382
23134.57.128.0/1834.57.128.1 to 34.57.191.25434.57.191.25516,382
23234.57.192.0/1834.57.192.1 to 34.57.255.25434.57.255.25516,382
23334.58.0.0/1834.58.0.1 to 34.58.63.25434.58.63.25516,382
23434.58.64.0/1834.58.64.1 to 34.58.127.25434.58.127.25516,382
23534.58.128.0/1834.58.128.1 to 34.58.191.25434.58.191.25516,382
23634.58.192.0/1834.58.192.1 to 34.58.255.25434.58.255.25516,382
23734.59.0.0/1834.59.0.1 to 34.59.63.25434.59.63.25516,382
23834.59.64.0/1834.59.64.1 to 34.59.127.25434.59.127.25516,382
23934.59.128.0/1834.59.128.1 to 34.59.191.25434.59.191.25516,382
24034.59.192.0/1834.59.192.1 to 34.59.255.25434.59.255.25516,382
24134.60.0.0/1834.60.0.1 to 34.60.63.25434.60.63.25516,382
24234.60.64.0/1834.60.64.1 to 34.60.127.25434.60.127.25516,382
24334.60.128.0/1834.60.128.1 to 34.60.191.25434.60.191.25516,382
24434.60.192.0/1834.60.192.1 to 34.60.255.25434.60.255.25516,382
24534.61.0.0/1834.61.0.1 to 34.61.63.25434.61.63.25516,382
24634.61.64.0/1834.61.64.1 to 34.61.127.25434.61.127.25516,382
24734.61.128.0/1834.61.128.1 to 34.61.191.25434.61.191.25516,382
24834.61.192.0/1834.61.192.1 to 34.61.255.25434.61.255.25516,382
24934.62.0.0/1834.62.0.1 to 34.62.63.25434.62.63.25516,382
25034.62.64.0/1834.62.64.1 to 34.62.127.25434.62.127.25516,382
25134.62.128.0/1834.62.128.1 to 34.62.191.25434.62.191.25516,382
25234.62.192.0/1834.62.192.1 to 34.62.255.25434.62.255.25516,382
25334.63.0.0/1834.63.0.1 to 34.63.63.25434.63.63.25516,382
25434.63.64.0/1834.63.64.1 to 34.63.127.25434.63.127.25516,382
25534.63.128.0/1834.63.128.1 to 34.63.191.25434.63.191.25516,382
25634.63.192.0/1834.63.192.1 to 34.63.255.25434.63.255.25516,382

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.