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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.

Network74.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
74.0.0.0
Broadcast address
74.127.255.255
First usable
74.0.0.1
Last usable
74.127.255.254
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 4A000000 · Integer 1241513984 to 1249902591
Reverse DNS zones
0.74.in-addr.arpa
1.74.in-addr.arpa
2.74.in-addr.arpa
3.74.in-addr.arpa
4.74.in-addr.arpa
5.74.in-addr.arpa
6.74.in-addr.arpa
7.74.in-addr.arpa
8.74.in-addr.arpa
9.74.in-addr.arpa
10.74.in-addr.arpa
11.74.in-addr.arpa
12.74.in-addr.arpa
13.74.in-addr.arpa
14.74.in-addr.arpa
15.74.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
Address01001010.00000000.00000000.0000000074.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01001010.00000000.00000000.0000000074.0.0.0
Broadcast01001010.01111111.11111111.1111111174.127.255.255
Split into smaller subnets/19
/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)

74.0.0.0/9 makes 1,024 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
174.0.0.0/1974.0.0.1 to 74.0.31.25474.0.31.2558,190
274.0.32.0/1974.0.32.1 to 74.0.63.25474.0.63.2558,190
374.0.64.0/1974.0.64.1 to 74.0.95.25474.0.95.2558,190
474.0.96.0/1974.0.96.1 to 74.0.127.25474.0.127.2558,190
574.0.128.0/1974.0.128.1 to 74.0.159.25474.0.159.2558,190
674.0.160.0/1974.0.160.1 to 74.0.191.25474.0.191.2558,190
774.0.192.0/1974.0.192.1 to 74.0.223.25474.0.223.2558,190
874.0.224.0/1974.0.224.1 to 74.0.255.25474.0.255.2558,190
974.1.0.0/1974.1.0.1 to 74.1.31.25474.1.31.2558,190
1074.1.32.0/1974.1.32.1 to 74.1.63.25474.1.63.2558,190
1174.1.64.0/1974.1.64.1 to 74.1.95.25474.1.95.2558,190
1274.1.96.0/1974.1.96.1 to 74.1.127.25474.1.127.2558,190
1374.1.128.0/1974.1.128.1 to 74.1.159.25474.1.159.2558,190
1474.1.160.0/1974.1.160.1 to 74.1.191.25474.1.191.2558,190
1574.1.192.0/1974.1.192.1 to 74.1.223.25474.1.223.2558,190
1674.1.224.0/1974.1.224.1 to 74.1.255.25474.1.255.2558,190
1774.2.0.0/1974.2.0.1 to 74.2.31.25474.2.31.2558,190
1874.2.32.0/1974.2.32.1 to 74.2.63.25474.2.63.2558,190
1974.2.64.0/1974.2.64.1 to 74.2.95.25474.2.95.2558,190
2074.2.96.0/1974.2.96.1 to 74.2.127.25474.2.127.2558,190
2174.2.128.0/1974.2.128.1 to 74.2.159.25474.2.159.2558,190
2274.2.160.0/1974.2.160.1 to 74.2.191.25474.2.191.2558,190
2374.2.192.0/1974.2.192.1 to 74.2.223.25474.2.223.2558,190
2474.2.224.0/1974.2.224.1 to 74.2.255.25474.2.255.2558,190
2574.3.0.0/1974.3.0.1 to 74.3.31.25474.3.31.2558,190
2674.3.32.0/1974.3.32.1 to 74.3.63.25474.3.63.2558,190
2774.3.64.0/1974.3.64.1 to 74.3.95.25474.3.95.2558,190
2874.3.96.0/1974.3.96.1 to 74.3.127.25474.3.127.2558,190
2974.3.128.0/1974.3.128.1 to 74.3.159.25474.3.159.2558,190
3074.3.160.0/1974.3.160.1 to 74.3.191.25474.3.191.2558,190
3174.3.192.0/1974.3.192.1 to 74.3.223.25474.3.223.2558,190
3274.3.224.0/1974.3.224.1 to 74.3.255.25474.3.255.2558,190
3374.4.0.0/1974.4.0.1 to 74.4.31.25474.4.31.2558,190
3474.4.32.0/1974.4.32.1 to 74.4.63.25474.4.63.2558,190
3574.4.64.0/1974.4.64.1 to 74.4.95.25474.4.95.2558,190
3674.4.96.0/1974.4.96.1 to 74.4.127.25474.4.127.2558,190
3774.4.128.0/1974.4.128.1 to 74.4.159.25474.4.159.2558,190
3874.4.160.0/1974.4.160.1 to 74.4.191.25474.4.191.2558,190
3974.4.192.0/1974.4.192.1 to 74.4.223.25474.4.223.2558,190
4074.4.224.0/1974.4.224.1 to 74.4.255.25474.4.255.2558,190
4174.5.0.0/1974.5.0.1 to 74.5.31.25474.5.31.2558,190
4274.5.32.0/1974.5.32.1 to 74.5.63.25474.5.63.2558,190
4374.5.64.0/1974.5.64.1 to 74.5.95.25474.5.95.2558,190
4474.5.96.0/1974.5.96.1 to 74.5.127.25474.5.127.2558,190
4574.5.128.0/1974.5.128.1 to 74.5.159.25474.5.159.2558,190
4674.5.160.0/1974.5.160.1 to 74.5.191.25474.5.191.2558,190
4774.5.192.0/1974.5.192.1 to 74.5.223.25474.5.223.2558,190
4874.5.224.0/1974.5.224.1 to 74.5.255.25474.5.255.2558,190
4974.6.0.0/1974.6.0.1 to 74.6.31.25474.6.31.2558,190
5074.6.32.0/1974.6.32.1 to 74.6.63.25474.6.63.2558,190
5174.6.64.0/1974.6.64.1 to 74.6.95.25474.6.95.2558,190
5274.6.96.0/1974.6.96.1 to 74.6.127.25474.6.127.2558,190
5374.6.128.0/1974.6.128.1 to 74.6.159.25474.6.159.2558,190
5474.6.160.0/1974.6.160.1 to 74.6.191.25474.6.191.2558,190
5574.6.192.0/1974.6.192.1 to 74.6.223.25474.6.223.2558,190
5674.6.224.0/1974.6.224.1 to 74.6.255.25474.6.255.2558,190
5774.7.0.0/1974.7.0.1 to 74.7.31.25474.7.31.2558,190
5874.7.32.0/1974.7.32.1 to 74.7.63.25474.7.63.2558,190
5974.7.64.0/1974.7.64.1 to 74.7.95.25474.7.95.2558,190
6074.7.96.0/1974.7.96.1 to 74.7.127.25474.7.127.2558,190
6174.7.128.0/1974.7.128.1 to 74.7.159.25474.7.159.2558,190
6274.7.160.0/1974.7.160.1 to 74.7.191.25474.7.191.2558,190
6374.7.192.0/1974.7.192.1 to 74.7.223.25474.7.223.2558,190
6474.7.224.0/1974.7.224.1 to 74.7.255.25474.7.255.2558,190
6574.8.0.0/1974.8.0.1 to 74.8.31.25474.8.31.2558,190
6674.8.32.0/1974.8.32.1 to 74.8.63.25474.8.63.2558,190
6774.8.64.0/1974.8.64.1 to 74.8.95.25474.8.95.2558,190
6874.8.96.0/1974.8.96.1 to 74.8.127.25474.8.127.2558,190
6974.8.128.0/1974.8.128.1 to 74.8.159.25474.8.159.2558,190
7074.8.160.0/1974.8.160.1 to 74.8.191.25474.8.191.2558,190
7174.8.192.0/1974.8.192.1 to 74.8.223.25474.8.223.2558,190
7274.8.224.0/1974.8.224.1 to 74.8.255.25474.8.255.2558,190
7374.9.0.0/1974.9.0.1 to 74.9.31.25474.9.31.2558,190
7474.9.32.0/1974.9.32.1 to 74.9.63.25474.9.63.2558,190
7574.9.64.0/1974.9.64.1 to 74.9.95.25474.9.95.2558,190
7674.9.96.0/1974.9.96.1 to 74.9.127.25474.9.127.2558,190
7774.9.128.0/1974.9.128.1 to 74.9.159.25474.9.159.2558,190
7874.9.160.0/1974.9.160.1 to 74.9.191.25474.9.191.2558,190
7974.9.192.0/1974.9.192.1 to 74.9.223.25474.9.223.2558,190
8074.9.224.0/1974.9.224.1 to 74.9.255.25474.9.255.2558,190
8174.10.0.0/1974.10.0.1 to 74.10.31.25474.10.31.2558,190
8274.10.32.0/1974.10.32.1 to 74.10.63.25474.10.63.2558,190
8374.10.64.0/1974.10.64.1 to 74.10.95.25474.10.95.2558,190
8474.10.96.0/1974.10.96.1 to 74.10.127.25474.10.127.2558,190
8574.10.128.0/1974.10.128.1 to 74.10.159.25474.10.159.2558,190
8674.10.160.0/1974.10.160.1 to 74.10.191.25474.10.191.2558,190
8774.10.192.0/1974.10.192.1 to 74.10.223.25474.10.223.2558,190
8874.10.224.0/1974.10.224.1 to 74.10.255.25474.10.255.2558,190
8974.11.0.0/1974.11.0.1 to 74.11.31.25474.11.31.2558,190
9074.11.32.0/1974.11.32.1 to 74.11.63.25474.11.63.2558,190
9174.11.64.0/1974.11.64.1 to 74.11.95.25474.11.95.2558,190
9274.11.96.0/1974.11.96.1 to 74.11.127.25474.11.127.2558,190
9374.11.128.0/1974.11.128.1 to 74.11.159.25474.11.159.2558,190
9474.11.160.0/1974.11.160.1 to 74.11.191.25474.11.191.2558,190
9574.11.192.0/1974.11.192.1 to 74.11.223.25474.11.223.2558,190
9674.11.224.0/1974.11.224.1 to 74.11.255.25474.11.255.2558,190
9774.12.0.0/1974.12.0.1 to 74.12.31.25474.12.31.2558,190
9874.12.32.0/1974.12.32.1 to 74.12.63.25474.12.63.2558,190
9974.12.64.0/1974.12.64.1 to 74.12.95.25474.12.95.2558,190
10074.12.96.0/1974.12.96.1 to 74.12.127.25474.12.127.2558,190
10174.12.128.0/1974.12.128.1 to 74.12.159.25474.12.159.2558,190
10274.12.160.0/1974.12.160.1 to 74.12.191.25474.12.191.2558,190
10374.12.192.0/1974.12.192.1 to 74.12.223.25474.12.223.2558,190
10474.12.224.0/1974.12.224.1 to 74.12.255.25474.12.255.2558,190
10574.13.0.0/1974.13.0.1 to 74.13.31.25474.13.31.2558,190
10674.13.32.0/1974.13.32.1 to 74.13.63.25474.13.63.2558,190
10774.13.64.0/1974.13.64.1 to 74.13.95.25474.13.95.2558,190
10874.13.96.0/1974.13.96.1 to 74.13.127.25474.13.127.2558,190
10974.13.128.0/1974.13.128.1 to 74.13.159.25474.13.159.2558,190
11074.13.160.0/1974.13.160.1 to 74.13.191.25474.13.191.2558,190
11174.13.192.0/1974.13.192.1 to 74.13.223.25474.13.223.2558,190
11274.13.224.0/1974.13.224.1 to 74.13.255.25474.13.255.2558,190
11374.14.0.0/1974.14.0.1 to 74.14.31.25474.14.31.2558,190
11474.14.32.0/1974.14.32.1 to 74.14.63.25474.14.63.2558,190
11574.14.64.0/1974.14.64.1 to 74.14.95.25474.14.95.2558,190
11674.14.96.0/1974.14.96.1 to 74.14.127.25474.14.127.2558,190
11774.14.128.0/1974.14.128.1 to 74.14.159.25474.14.159.2558,190
11874.14.160.0/1974.14.160.1 to 74.14.191.25474.14.191.2558,190
11974.14.192.0/1974.14.192.1 to 74.14.223.25474.14.223.2558,190
12074.14.224.0/1974.14.224.1 to 74.14.255.25474.14.255.2558,190
12174.15.0.0/1974.15.0.1 to 74.15.31.25474.15.31.2558,190
12274.15.32.0/1974.15.32.1 to 74.15.63.25474.15.63.2558,190
12374.15.64.0/1974.15.64.1 to 74.15.95.25474.15.95.2558,190
12474.15.96.0/1974.15.96.1 to 74.15.127.25474.15.127.2558,190
12574.15.128.0/1974.15.128.1 to 74.15.159.25474.15.159.2558,190
12674.15.160.0/1974.15.160.1 to 74.15.191.25474.15.191.2558,190
12774.15.192.0/1974.15.192.1 to 74.15.223.25474.15.223.2558,190
12874.15.224.0/1974.15.224.1 to 74.15.255.25474.15.255.2558,190
12974.16.0.0/1974.16.0.1 to 74.16.31.25474.16.31.2558,190
13074.16.32.0/1974.16.32.1 to 74.16.63.25474.16.63.2558,190
13174.16.64.0/1974.16.64.1 to 74.16.95.25474.16.95.2558,190
13274.16.96.0/1974.16.96.1 to 74.16.127.25474.16.127.2558,190
13374.16.128.0/1974.16.128.1 to 74.16.159.25474.16.159.2558,190
13474.16.160.0/1974.16.160.1 to 74.16.191.25474.16.191.2558,190
13574.16.192.0/1974.16.192.1 to 74.16.223.25474.16.223.2558,190
13674.16.224.0/1974.16.224.1 to 74.16.255.25474.16.255.2558,190
13774.17.0.0/1974.17.0.1 to 74.17.31.25474.17.31.2558,190
13874.17.32.0/1974.17.32.1 to 74.17.63.25474.17.63.2558,190
13974.17.64.0/1974.17.64.1 to 74.17.95.25474.17.95.2558,190
14074.17.96.0/1974.17.96.1 to 74.17.127.25474.17.127.2558,190
14174.17.128.0/1974.17.128.1 to 74.17.159.25474.17.159.2558,190
14274.17.160.0/1974.17.160.1 to 74.17.191.25474.17.191.2558,190
14374.17.192.0/1974.17.192.1 to 74.17.223.25474.17.223.2558,190
14474.17.224.0/1974.17.224.1 to 74.17.255.25474.17.255.2558,190
14574.18.0.0/1974.18.0.1 to 74.18.31.25474.18.31.2558,190
14674.18.32.0/1974.18.32.1 to 74.18.63.25474.18.63.2558,190
14774.18.64.0/1974.18.64.1 to 74.18.95.25474.18.95.2558,190
14874.18.96.0/1974.18.96.1 to 74.18.127.25474.18.127.2558,190
14974.18.128.0/1974.18.128.1 to 74.18.159.25474.18.159.2558,190
15074.18.160.0/1974.18.160.1 to 74.18.191.25474.18.191.2558,190
15174.18.192.0/1974.18.192.1 to 74.18.223.25474.18.223.2558,190
15274.18.224.0/1974.18.224.1 to 74.18.255.25474.18.255.2558,190
15374.19.0.0/1974.19.0.1 to 74.19.31.25474.19.31.2558,190
15474.19.32.0/1974.19.32.1 to 74.19.63.25474.19.63.2558,190
15574.19.64.0/1974.19.64.1 to 74.19.95.25474.19.95.2558,190
15674.19.96.0/1974.19.96.1 to 74.19.127.25474.19.127.2558,190
15774.19.128.0/1974.19.128.1 to 74.19.159.25474.19.159.2558,190
15874.19.160.0/1974.19.160.1 to 74.19.191.25474.19.191.2558,190
15974.19.192.0/1974.19.192.1 to 74.19.223.25474.19.223.2558,190
16074.19.224.0/1974.19.224.1 to 74.19.255.25474.19.255.2558,190
16174.20.0.0/1974.20.0.1 to 74.20.31.25474.20.31.2558,190
16274.20.32.0/1974.20.32.1 to 74.20.63.25474.20.63.2558,190
16374.20.64.0/1974.20.64.1 to 74.20.95.25474.20.95.2558,190
16474.20.96.0/1974.20.96.1 to 74.20.127.25474.20.127.2558,190
16574.20.128.0/1974.20.128.1 to 74.20.159.25474.20.159.2558,190
16674.20.160.0/1974.20.160.1 to 74.20.191.25474.20.191.2558,190
16774.20.192.0/1974.20.192.1 to 74.20.223.25474.20.223.2558,190
16874.20.224.0/1974.20.224.1 to 74.20.255.25474.20.255.2558,190
16974.21.0.0/1974.21.0.1 to 74.21.31.25474.21.31.2558,190
17074.21.32.0/1974.21.32.1 to 74.21.63.25474.21.63.2558,190
17174.21.64.0/1974.21.64.1 to 74.21.95.25474.21.95.2558,190
17274.21.96.0/1974.21.96.1 to 74.21.127.25474.21.127.2558,190
17374.21.128.0/1974.21.128.1 to 74.21.159.25474.21.159.2558,190
17474.21.160.0/1974.21.160.1 to 74.21.191.25474.21.191.2558,190
17574.21.192.0/1974.21.192.1 to 74.21.223.25474.21.223.2558,190
17674.21.224.0/1974.21.224.1 to 74.21.255.25474.21.255.2558,190
17774.22.0.0/1974.22.0.1 to 74.22.31.25474.22.31.2558,190
17874.22.32.0/1974.22.32.1 to 74.22.63.25474.22.63.2558,190
17974.22.64.0/1974.22.64.1 to 74.22.95.25474.22.95.2558,190
18074.22.96.0/1974.22.96.1 to 74.22.127.25474.22.127.2558,190
18174.22.128.0/1974.22.128.1 to 74.22.159.25474.22.159.2558,190
18274.22.160.0/1974.22.160.1 to 74.22.191.25474.22.191.2558,190
18374.22.192.0/1974.22.192.1 to 74.22.223.25474.22.223.2558,190
18474.22.224.0/1974.22.224.1 to 74.22.255.25474.22.255.2558,190
18574.23.0.0/1974.23.0.1 to 74.23.31.25474.23.31.2558,190
18674.23.32.0/1974.23.32.1 to 74.23.63.25474.23.63.2558,190
18774.23.64.0/1974.23.64.1 to 74.23.95.25474.23.95.2558,190
18874.23.96.0/1974.23.96.1 to 74.23.127.25474.23.127.2558,190
18974.23.128.0/1974.23.128.1 to 74.23.159.25474.23.159.2558,190
19074.23.160.0/1974.23.160.1 to 74.23.191.25474.23.191.2558,190
19174.23.192.0/1974.23.192.1 to 74.23.223.25474.23.223.2558,190
19274.23.224.0/1974.23.224.1 to 74.23.255.25474.23.255.2558,190
19374.24.0.0/1974.24.0.1 to 74.24.31.25474.24.31.2558,190
19474.24.32.0/1974.24.32.1 to 74.24.63.25474.24.63.2558,190
19574.24.64.0/1974.24.64.1 to 74.24.95.25474.24.95.2558,190
19674.24.96.0/1974.24.96.1 to 74.24.127.25474.24.127.2558,190
19774.24.128.0/1974.24.128.1 to 74.24.159.25474.24.159.2558,190
19874.24.160.0/1974.24.160.1 to 74.24.191.25474.24.191.2558,190
19974.24.192.0/1974.24.192.1 to 74.24.223.25474.24.223.2558,190
20074.24.224.0/1974.24.224.1 to 74.24.255.25474.24.255.2558,190
20174.25.0.0/1974.25.0.1 to 74.25.31.25474.25.31.2558,190
20274.25.32.0/1974.25.32.1 to 74.25.63.25474.25.63.2558,190
20374.25.64.0/1974.25.64.1 to 74.25.95.25474.25.95.2558,190
20474.25.96.0/1974.25.96.1 to 74.25.127.25474.25.127.2558,190
20574.25.128.0/1974.25.128.1 to 74.25.159.25474.25.159.2558,190
20674.25.160.0/1974.25.160.1 to 74.25.191.25474.25.191.2558,190
20774.25.192.0/1974.25.192.1 to 74.25.223.25474.25.223.2558,190
20874.25.224.0/1974.25.224.1 to 74.25.255.25474.25.255.2558,190
20974.26.0.0/1974.26.0.1 to 74.26.31.25474.26.31.2558,190
21074.26.32.0/1974.26.32.1 to 74.26.63.25474.26.63.2558,190
21174.26.64.0/1974.26.64.1 to 74.26.95.25474.26.95.2558,190
21274.26.96.0/1974.26.96.1 to 74.26.127.25474.26.127.2558,190
21374.26.128.0/1974.26.128.1 to 74.26.159.25474.26.159.2558,190
21474.26.160.0/1974.26.160.1 to 74.26.191.25474.26.191.2558,190
21574.26.192.0/1974.26.192.1 to 74.26.223.25474.26.223.2558,190
21674.26.224.0/1974.26.224.1 to 74.26.255.25474.26.255.2558,190
21774.27.0.0/1974.27.0.1 to 74.27.31.25474.27.31.2558,190
21874.27.32.0/1974.27.32.1 to 74.27.63.25474.27.63.2558,190
21974.27.64.0/1974.27.64.1 to 74.27.95.25474.27.95.2558,190
22074.27.96.0/1974.27.96.1 to 74.27.127.25474.27.127.2558,190
22174.27.128.0/1974.27.128.1 to 74.27.159.25474.27.159.2558,190
22274.27.160.0/1974.27.160.1 to 74.27.191.25474.27.191.2558,190
22374.27.192.0/1974.27.192.1 to 74.27.223.25474.27.223.2558,190
22474.27.224.0/1974.27.224.1 to 74.27.255.25474.27.255.2558,190
22574.28.0.0/1974.28.0.1 to 74.28.31.25474.28.31.2558,190
22674.28.32.0/1974.28.32.1 to 74.28.63.25474.28.63.2558,190
22774.28.64.0/1974.28.64.1 to 74.28.95.25474.28.95.2558,190
22874.28.96.0/1974.28.96.1 to 74.28.127.25474.28.127.2558,190
22974.28.128.0/1974.28.128.1 to 74.28.159.25474.28.159.2558,190
23074.28.160.0/1974.28.160.1 to 74.28.191.25474.28.191.2558,190
23174.28.192.0/1974.28.192.1 to 74.28.223.25474.28.223.2558,190
23274.28.224.0/1974.28.224.1 to 74.28.255.25474.28.255.2558,190
23374.29.0.0/1974.29.0.1 to 74.29.31.25474.29.31.2558,190
23474.29.32.0/1974.29.32.1 to 74.29.63.25474.29.63.2558,190
23574.29.64.0/1974.29.64.1 to 74.29.95.25474.29.95.2558,190
23674.29.96.0/1974.29.96.1 to 74.29.127.25474.29.127.2558,190
23774.29.128.0/1974.29.128.1 to 74.29.159.25474.29.159.2558,190
23874.29.160.0/1974.29.160.1 to 74.29.191.25474.29.191.2558,190
23974.29.192.0/1974.29.192.1 to 74.29.223.25474.29.223.2558,190
24074.29.224.0/1974.29.224.1 to 74.29.255.25474.29.255.2558,190
24174.30.0.0/1974.30.0.1 to 74.30.31.25474.30.31.2558,190
24274.30.32.0/1974.30.32.1 to 74.30.63.25474.30.63.2558,190
24374.30.64.0/1974.30.64.1 to 74.30.95.25474.30.95.2558,190
24474.30.96.0/1974.30.96.1 to 74.30.127.25474.30.127.2558,190
24574.30.128.0/1974.30.128.1 to 74.30.159.25474.30.159.2558,190
24674.30.160.0/1974.30.160.1 to 74.30.191.25474.30.191.2558,190
24774.30.192.0/1974.30.192.1 to 74.30.223.25474.30.223.2558,190
24874.30.224.0/1974.30.224.1 to 74.30.255.25474.30.255.2558,190
24974.31.0.0/1974.31.0.1 to 74.31.31.25474.31.31.2558,190
25074.31.32.0/1974.31.32.1 to 74.31.63.25474.31.63.2558,190
25174.31.64.0/1974.31.64.1 to 74.31.95.25474.31.95.2558,190
25274.31.96.0/1974.31.96.1 to 74.31.127.25474.31.127.2558,190
25374.31.128.0/1974.31.128.1 to 74.31.159.25474.31.159.2558,190
25474.31.160.0/1974.31.160.1 to 74.31.191.25474.31.191.2558,190
25574.31.192.0/1974.31.192.1 to 74.31.223.25474.31.223.2558,190
25674.31.224.0/1974.31.224.1 to 74.31.255.25474.31.255.2558,190

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.