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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.

Network74.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
74.0.0.0
Broadcast address
74.63.255.255
First usable
74.0.0.1
Last usable
74.63.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 4A000000 · Integer 1241513984 to 1245708287
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 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001010.00000000.00000000.0000000074.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network01001010.00000000.00000000.0000000074.0.0.0
Broadcast01001010.00111111.11111111.1111111174.63.255.255
Split into smaller subnets/18
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

74.0.0.0/10 makes 256 subnets of /18.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
174.0.0.0/1874.0.0.1 to 74.0.63.25474.0.63.25516,382
274.0.64.0/1874.0.64.1 to 74.0.127.25474.0.127.25516,382
374.0.128.0/1874.0.128.1 to 74.0.191.25474.0.191.25516,382
474.0.192.0/1874.0.192.1 to 74.0.255.25474.0.255.25516,382
574.1.0.0/1874.1.0.1 to 74.1.63.25474.1.63.25516,382
674.1.64.0/1874.1.64.1 to 74.1.127.25474.1.127.25516,382
774.1.128.0/1874.1.128.1 to 74.1.191.25474.1.191.25516,382
874.1.192.0/1874.1.192.1 to 74.1.255.25474.1.255.25516,382
974.2.0.0/1874.2.0.1 to 74.2.63.25474.2.63.25516,382
1074.2.64.0/1874.2.64.1 to 74.2.127.25474.2.127.25516,382
1174.2.128.0/1874.2.128.1 to 74.2.191.25474.2.191.25516,382
1274.2.192.0/1874.2.192.1 to 74.2.255.25474.2.255.25516,382
1374.3.0.0/1874.3.0.1 to 74.3.63.25474.3.63.25516,382
1474.3.64.0/1874.3.64.1 to 74.3.127.25474.3.127.25516,382
1574.3.128.0/1874.3.128.1 to 74.3.191.25474.3.191.25516,382
1674.3.192.0/1874.3.192.1 to 74.3.255.25474.3.255.25516,382
1774.4.0.0/1874.4.0.1 to 74.4.63.25474.4.63.25516,382
1874.4.64.0/1874.4.64.1 to 74.4.127.25474.4.127.25516,382
1974.4.128.0/1874.4.128.1 to 74.4.191.25474.4.191.25516,382
2074.4.192.0/1874.4.192.1 to 74.4.255.25474.4.255.25516,382
2174.5.0.0/1874.5.0.1 to 74.5.63.25474.5.63.25516,382
2274.5.64.0/1874.5.64.1 to 74.5.127.25474.5.127.25516,382
2374.5.128.0/1874.5.128.1 to 74.5.191.25474.5.191.25516,382
2474.5.192.0/1874.5.192.1 to 74.5.255.25474.5.255.25516,382
2574.6.0.0/1874.6.0.1 to 74.6.63.25474.6.63.25516,382
2674.6.64.0/1874.6.64.1 to 74.6.127.25474.6.127.25516,382
2774.6.128.0/1874.6.128.1 to 74.6.191.25474.6.191.25516,382
2874.6.192.0/1874.6.192.1 to 74.6.255.25474.6.255.25516,382
2974.7.0.0/1874.7.0.1 to 74.7.63.25474.7.63.25516,382
3074.7.64.0/1874.7.64.1 to 74.7.127.25474.7.127.25516,382
3174.7.128.0/1874.7.128.1 to 74.7.191.25474.7.191.25516,382
3274.7.192.0/1874.7.192.1 to 74.7.255.25474.7.255.25516,382
3374.8.0.0/1874.8.0.1 to 74.8.63.25474.8.63.25516,382
3474.8.64.0/1874.8.64.1 to 74.8.127.25474.8.127.25516,382
3574.8.128.0/1874.8.128.1 to 74.8.191.25474.8.191.25516,382
3674.8.192.0/1874.8.192.1 to 74.8.255.25474.8.255.25516,382
3774.9.0.0/1874.9.0.1 to 74.9.63.25474.9.63.25516,382
3874.9.64.0/1874.9.64.1 to 74.9.127.25474.9.127.25516,382
3974.9.128.0/1874.9.128.1 to 74.9.191.25474.9.191.25516,382
4074.9.192.0/1874.9.192.1 to 74.9.255.25474.9.255.25516,382
4174.10.0.0/1874.10.0.1 to 74.10.63.25474.10.63.25516,382
4274.10.64.0/1874.10.64.1 to 74.10.127.25474.10.127.25516,382
4374.10.128.0/1874.10.128.1 to 74.10.191.25474.10.191.25516,382
4474.10.192.0/1874.10.192.1 to 74.10.255.25474.10.255.25516,382
4574.11.0.0/1874.11.0.1 to 74.11.63.25474.11.63.25516,382
4674.11.64.0/1874.11.64.1 to 74.11.127.25474.11.127.25516,382
4774.11.128.0/1874.11.128.1 to 74.11.191.25474.11.191.25516,382
4874.11.192.0/1874.11.192.1 to 74.11.255.25474.11.255.25516,382
4974.12.0.0/1874.12.0.1 to 74.12.63.25474.12.63.25516,382
5074.12.64.0/1874.12.64.1 to 74.12.127.25474.12.127.25516,382
5174.12.128.0/1874.12.128.1 to 74.12.191.25474.12.191.25516,382
5274.12.192.0/1874.12.192.1 to 74.12.255.25474.12.255.25516,382
5374.13.0.0/1874.13.0.1 to 74.13.63.25474.13.63.25516,382
5474.13.64.0/1874.13.64.1 to 74.13.127.25474.13.127.25516,382
5574.13.128.0/1874.13.128.1 to 74.13.191.25474.13.191.25516,382
5674.13.192.0/1874.13.192.1 to 74.13.255.25474.13.255.25516,382
5774.14.0.0/1874.14.0.1 to 74.14.63.25474.14.63.25516,382
5874.14.64.0/1874.14.64.1 to 74.14.127.25474.14.127.25516,382
5974.14.128.0/1874.14.128.1 to 74.14.191.25474.14.191.25516,382
6074.14.192.0/1874.14.192.1 to 74.14.255.25474.14.255.25516,382
6174.15.0.0/1874.15.0.1 to 74.15.63.25474.15.63.25516,382
6274.15.64.0/1874.15.64.1 to 74.15.127.25474.15.127.25516,382
6374.15.128.0/1874.15.128.1 to 74.15.191.25474.15.191.25516,382
6474.15.192.0/1874.15.192.1 to 74.15.255.25474.15.255.25516,382
6574.16.0.0/1874.16.0.1 to 74.16.63.25474.16.63.25516,382
6674.16.64.0/1874.16.64.1 to 74.16.127.25474.16.127.25516,382
6774.16.128.0/1874.16.128.1 to 74.16.191.25474.16.191.25516,382
6874.16.192.0/1874.16.192.1 to 74.16.255.25474.16.255.25516,382
6974.17.0.0/1874.17.0.1 to 74.17.63.25474.17.63.25516,382
7074.17.64.0/1874.17.64.1 to 74.17.127.25474.17.127.25516,382
7174.17.128.0/1874.17.128.1 to 74.17.191.25474.17.191.25516,382
7274.17.192.0/1874.17.192.1 to 74.17.255.25474.17.255.25516,382
7374.18.0.0/1874.18.0.1 to 74.18.63.25474.18.63.25516,382
7474.18.64.0/1874.18.64.1 to 74.18.127.25474.18.127.25516,382
7574.18.128.0/1874.18.128.1 to 74.18.191.25474.18.191.25516,382
7674.18.192.0/1874.18.192.1 to 74.18.255.25474.18.255.25516,382
7774.19.0.0/1874.19.0.1 to 74.19.63.25474.19.63.25516,382
7874.19.64.0/1874.19.64.1 to 74.19.127.25474.19.127.25516,382
7974.19.128.0/1874.19.128.1 to 74.19.191.25474.19.191.25516,382
8074.19.192.0/1874.19.192.1 to 74.19.255.25474.19.255.25516,382
8174.20.0.0/1874.20.0.1 to 74.20.63.25474.20.63.25516,382
8274.20.64.0/1874.20.64.1 to 74.20.127.25474.20.127.25516,382
8374.20.128.0/1874.20.128.1 to 74.20.191.25474.20.191.25516,382
8474.20.192.0/1874.20.192.1 to 74.20.255.25474.20.255.25516,382
8574.21.0.0/1874.21.0.1 to 74.21.63.25474.21.63.25516,382
8674.21.64.0/1874.21.64.1 to 74.21.127.25474.21.127.25516,382
8774.21.128.0/1874.21.128.1 to 74.21.191.25474.21.191.25516,382
8874.21.192.0/1874.21.192.1 to 74.21.255.25474.21.255.25516,382
8974.22.0.0/1874.22.0.1 to 74.22.63.25474.22.63.25516,382
9074.22.64.0/1874.22.64.1 to 74.22.127.25474.22.127.25516,382
9174.22.128.0/1874.22.128.1 to 74.22.191.25474.22.191.25516,382
9274.22.192.0/1874.22.192.1 to 74.22.255.25474.22.255.25516,382
9374.23.0.0/1874.23.0.1 to 74.23.63.25474.23.63.25516,382
9474.23.64.0/1874.23.64.1 to 74.23.127.25474.23.127.25516,382
9574.23.128.0/1874.23.128.1 to 74.23.191.25474.23.191.25516,382
9674.23.192.0/1874.23.192.1 to 74.23.255.25474.23.255.25516,382
9774.24.0.0/1874.24.0.1 to 74.24.63.25474.24.63.25516,382
9874.24.64.0/1874.24.64.1 to 74.24.127.25474.24.127.25516,382
9974.24.128.0/1874.24.128.1 to 74.24.191.25474.24.191.25516,382
10074.24.192.0/1874.24.192.1 to 74.24.255.25474.24.255.25516,382
10174.25.0.0/1874.25.0.1 to 74.25.63.25474.25.63.25516,382
10274.25.64.0/1874.25.64.1 to 74.25.127.25474.25.127.25516,382
10374.25.128.0/1874.25.128.1 to 74.25.191.25474.25.191.25516,382
10474.25.192.0/1874.25.192.1 to 74.25.255.25474.25.255.25516,382
10574.26.0.0/1874.26.0.1 to 74.26.63.25474.26.63.25516,382
10674.26.64.0/1874.26.64.1 to 74.26.127.25474.26.127.25516,382
10774.26.128.0/1874.26.128.1 to 74.26.191.25474.26.191.25516,382
10874.26.192.0/1874.26.192.1 to 74.26.255.25474.26.255.25516,382
10974.27.0.0/1874.27.0.1 to 74.27.63.25474.27.63.25516,382
11074.27.64.0/1874.27.64.1 to 74.27.127.25474.27.127.25516,382
11174.27.128.0/1874.27.128.1 to 74.27.191.25474.27.191.25516,382
11274.27.192.0/1874.27.192.1 to 74.27.255.25474.27.255.25516,382
11374.28.0.0/1874.28.0.1 to 74.28.63.25474.28.63.25516,382
11474.28.64.0/1874.28.64.1 to 74.28.127.25474.28.127.25516,382
11574.28.128.0/1874.28.128.1 to 74.28.191.25474.28.191.25516,382
11674.28.192.0/1874.28.192.1 to 74.28.255.25474.28.255.25516,382
11774.29.0.0/1874.29.0.1 to 74.29.63.25474.29.63.25516,382
11874.29.64.0/1874.29.64.1 to 74.29.127.25474.29.127.25516,382
11974.29.128.0/1874.29.128.1 to 74.29.191.25474.29.191.25516,382
12074.29.192.0/1874.29.192.1 to 74.29.255.25474.29.255.25516,382
12174.30.0.0/1874.30.0.1 to 74.30.63.25474.30.63.25516,382
12274.30.64.0/1874.30.64.1 to 74.30.127.25474.30.127.25516,382
12374.30.128.0/1874.30.128.1 to 74.30.191.25474.30.191.25516,382
12474.30.192.0/1874.30.192.1 to 74.30.255.25474.30.255.25516,382
12574.31.0.0/1874.31.0.1 to 74.31.63.25474.31.63.25516,382
12674.31.64.0/1874.31.64.1 to 74.31.127.25474.31.127.25516,382
12774.31.128.0/1874.31.128.1 to 74.31.191.25474.31.191.25516,382
12874.31.192.0/1874.31.192.1 to 74.31.255.25474.31.255.25516,382
12974.32.0.0/1874.32.0.1 to 74.32.63.25474.32.63.25516,382
13074.32.64.0/1874.32.64.1 to 74.32.127.25474.32.127.25516,382
13174.32.128.0/1874.32.128.1 to 74.32.191.25474.32.191.25516,382
13274.32.192.0/1874.32.192.1 to 74.32.255.25474.32.255.25516,382
13374.33.0.0/1874.33.0.1 to 74.33.63.25474.33.63.25516,382
13474.33.64.0/1874.33.64.1 to 74.33.127.25474.33.127.25516,382
13574.33.128.0/1874.33.128.1 to 74.33.191.25474.33.191.25516,382
13674.33.192.0/1874.33.192.1 to 74.33.255.25474.33.255.25516,382
13774.34.0.0/1874.34.0.1 to 74.34.63.25474.34.63.25516,382
13874.34.64.0/1874.34.64.1 to 74.34.127.25474.34.127.25516,382
13974.34.128.0/1874.34.128.1 to 74.34.191.25474.34.191.25516,382
14074.34.192.0/1874.34.192.1 to 74.34.255.25474.34.255.25516,382
14174.35.0.0/1874.35.0.1 to 74.35.63.25474.35.63.25516,382
14274.35.64.0/1874.35.64.1 to 74.35.127.25474.35.127.25516,382
14374.35.128.0/1874.35.128.1 to 74.35.191.25474.35.191.25516,382
14474.35.192.0/1874.35.192.1 to 74.35.255.25474.35.255.25516,382
14574.36.0.0/1874.36.0.1 to 74.36.63.25474.36.63.25516,382
14674.36.64.0/1874.36.64.1 to 74.36.127.25474.36.127.25516,382
14774.36.128.0/1874.36.128.1 to 74.36.191.25474.36.191.25516,382
14874.36.192.0/1874.36.192.1 to 74.36.255.25474.36.255.25516,382
14974.37.0.0/1874.37.0.1 to 74.37.63.25474.37.63.25516,382
15074.37.64.0/1874.37.64.1 to 74.37.127.25474.37.127.25516,382
15174.37.128.0/1874.37.128.1 to 74.37.191.25474.37.191.25516,382
15274.37.192.0/1874.37.192.1 to 74.37.255.25474.37.255.25516,382
15374.38.0.0/1874.38.0.1 to 74.38.63.25474.38.63.25516,382
15474.38.64.0/1874.38.64.1 to 74.38.127.25474.38.127.25516,382
15574.38.128.0/1874.38.128.1 to 74.38.191.25474.38.191.25516,382
15674.38.192.0/1874.38.192.1 to 74.38.255.25474.38.255.25516,382
15774.39.0.0/1874.39.0.1 to 74.39.63.25474.39.63.25516,382
15874.39.64.0/1874.39.64.1 to 74.39.127.25474.39.127.25516,382
15974.39.128.0/1874.39.128.1 to 74.39.191.25474.39.191.25516,382
16074.39.192.0/1874.39.192.1 to 74.39.255.25474.39.255.25516,382
16174.40.0.0/1874.40.0.1 to 74.40.63.25474.40.63.25516,382
16274.40.64.0/1874.40.64.1 to 74.40.127.25474.40.127.25516,382
16374.40.128.0/1874.40.128.1 to 74.40.191.25474.40.191.25516,382
16474.40.192.0/1874.40.192.1 to 74.40.255.25474.40.255.25516,382
16574.41.0.0/1874.41.0.1 to 74.41.63.25474.41.63.25516,382
16674.41.64.0/1874.41.64.1 to 74.41.127.25474.41.127.25516,382
16774.41.128.0/1874.41.128.1 to 74.41.191.25474.41.191.25516,382
16874.41.192.0/1874.41.192.1 to 74.41.255.25474.41.255.25516,382
16974.42.0.0/1874.42.0.1 to 74.42.63.25474.42.63.25516,382
17074.42.64.0/1874.42.64.1 to 74.42.127.25474.42.127.25516,382
17174.42.128.0/1874.42.128.1 to 74.42.191.25474.42.191.25516,382
17274.42.192.0/1874.42.192.1 to 74.42.255.25474.42.255.25516,382
17374.43.0.0/1874.43.0.1 to 74.43.63.25474.43.63.25516,382
17474.43.64.0/1874.43.64.1 to 74.43.127.25474.43.127.25516,382
17574.43.128.0/1874.43.128.1 to 74.43.191.25474.43.191.25516,382
17674.43.192.0/1874.43.192.1 to 74.43.255.25474.43.255.25516,382
17774.44.0.0/1874.44.0.1 to 74.44.63.25474.44.63.25516,382
17874.44.64.0/1874.44.64.1 to 74.44.127.25474.44.127.25516,382
17974.44.128.0/1874.44.128.1 to 74.44.191.25474.44.191.25516,382
18074.44.192.0/1874.44.192.1 to 74.44.255.25474.44.255.25516,382
18174.45.0.0/1874.45.0.1 to 74.45.63.25474.45.63.25516,382
18274.45.64.0/1874.45.64.1 to 74.45.127.25474.45.127.25516,382
18374.45.128.0/1874.45.128.1 to 74.45.191.25474.45.191.25516,382
18474.45.192.0/1874.45.192.1 to 74.45.255.25474.45.255.25516,382
18574.46.0.0/1874.46.0.1 to 74.46.63.25474.46.63.25516,382
18674.46.64.0/1874.46.64.1 to 74.46.127.25474.46.127.25516,382
18774.46.128.0/1874.46.128.1 to 74.46.191.25474.46.191.25516,382
18874.46.192.0/1874.46.192.1 to 74.46.255.25474.46.255.25516,382
18974.47.0.0/1874.47.0.1 to 74.47.63.25474.47.63.25516,382
19074.47.64.0/1874.47.64.1 to 74.47.127.25474.47.127.25516,382
19174.47.128.0/1874.47.128.1 to 74.47.191.25474.47.191.25516,382
19274.47.192.0/1874.47.192.1 to 74.47.255.25474.47.255.25516,382
19374.48.0.0/1874.48.0.1 to 74.48.63.25474.48.63.25516,382
19474.48.64.0/1874.48.64.1 to 74.48.127.25474.48.127.25516,382
19574.48.128.0/1874.48.128.1 to 74.48.191.25474.48.191.25516,382
19674.48.192.0/1874.48.192.1 to 74.48.255.25474.48.255.25516,382
19774.49.0.0/1874.49.0.1 to 74.49.63.25474.49.63.25516,382
19874.49.64.0/1874.49.64.1 to 74.49.127.25474.49.127.25516,382
19974.49.128.0/1874.49.128.1 to 74.49.191.25474.49.191.25516,382
20074.49.192.0/1874.49.192.1 to 74.49.255.25474.49.255.25516,382
20174.50.0.0/1874.50.0.1 to 74.50.63.25474.50.63.25516,382
20274.50.64.0/1874.50.64.1 to 74.50.127.25474.50.127.25516,382
20374.50.128.0/1874.50.128.1 to 74.50.191.25474.50.191.25516,382
20474.50.192.0/1874.50.192.1 to 74.50.255.25474.50.255.25516,382
20574.51.0.0/1874.51.0.1 to 74.51.63.25474.51.63.25516,382
20674.51.64.0/1874.51.64.1 to 74.51.127.25474.51.127.25516,382
20774.51.128.0/1874.51.128.1 to 74.51.191.25474.51.191.25516,382
20874.51.192.0/1874.51.192.1 to 74.51.255.25474.51.255.25516,382
20974.52.0.0/1874.52.0.1 to 74.52.63.25474.52.63.25516,382
21074.52.64.0/1874.52.64.1 to 74.52.127.25474.52.127.25516,382
21174.52.128.0/1874.52.128.1 to 74.52.191.25474.52.191.25516,382
21274.52.192.0/1874.52.192.1 to 74.52.255.25474.52.255.25516,382
21374.53.0.0/1874.53.0.1 to 74.53.63.25474.53.63.25516,382
21474.53.64.0/1874.53.64.1 to 74.53.127.25474.53.127.25516,382
21574.53.128.0/1874.53.128.1 to 74.53.191.25474.53.191.25516,382
21674.53.192.0/1874.53.192.1 to 74.53.255.25474.53.255.25516,382
21774.54.0.0/1874.54.0.1 to 74.54.63.25474.54.63.25516,382
21874.54.64.0/1874.54.64.1 to 74.54.127.25474.54.127.25516,382
21974.54.128.0/1874.54.128.1 to 74.54.191.25474.54.191.25516,382
22074.54.192.0/1874.54.192.1 to 74.54.255.25474.54.255.25516,382
22174.55.0.0/1874.55.0.1 to 74.55.63.25474.55.63.25516,382
22274.55.64.0/1874.55.64.1 to 74.55.127.25474.55.127.25516,382
22374.55.128.0/1874.55.128.1 to 74.55.191.25474.55.191.25516,382
22474.55.192.0/1874.55.192.1 to 74.55.255.25474.55.255.25516,382
22574.56.0.0/1874.56.0.1 to 74.56.63.25474.56.63.25516,382
22674.56.64.0/1874.56.64.1 to 74.56.127.25474.56.127.25516,382
22774.56.128.0/1874.56.128.1 to 74.56.191.25474.56.191.25516,382
22874.56.192.0/1874.56.192.1 to 74.56.255.25474.56.255.25516,382
22974.57.0.0/1874.57.0.1 to 74.57.63.25474.57.63.25516,382
23074.57.64.0/1874.57.64.1 to 74.57.127.25474.57.127.25516,382
23174.57.128.0/1874.57.128.1 to 74.57.191.25474.57.191.25516,382
23274.57.192.0/1874.57.192.1 to 74.57.255.25474.57.255.25516,382
23374.58.0.0/1874.58.0.1 to 74.58.63.25474.58.63.25516,382
23474.58.64.0/1874.58.64.1 to 74.58.127.25474.58.127.25516,382
23574.58.128.0/1874.58.128.1 to 74.58.191.25474.58.191.25516,382
23674.58.192.0/1874.58.192.1 to 74.58.255.25474.58.255.25516,382
23774.59.0.0/1874.59.0.1 to 74.59.63.25474.59.63.25516,382
23874.59.64.0/1874.59.64.1 to 74.59.127.25474.59.127.25516,382
23974.59.128.0/1874.59.128.1 to 74.59.191.25474.59.191.25516,382
24074.59.192.0/1874.59.192.1 to 74.59.255.25474.59.255.25516,382
24174.60.0.0/1874.60.0.1 to 74.60.63.25474.60.63.25516,382
24274.60.64.0/1874.60.64.1 to 74.60.127.25474.60.127.25516,382
24374.60.128.0/1874.60.128.1 to 74.60.191.25474.60.191.25516,382
24474.60.192.0/1874.60.192.1 to 74.60.255.25474.60.255.25516,382
24574.61.0.0/1874.61.0.1 to 74.61.63.25474.61.63.25516,382
24674.61.64.0/1874.61.64.1 to 74.61.127.25474.61.127.25516,382
24774.61.128.0/1874.61.128.1 to 74.61.191.25474.61.191.25516,382
24874.61.192.0/1874.61.192.1 to 74.61.255.25474.61.255.25516,382
24974.62.0.0/1874.62.0.1 to 74.62.63.25474.62.63.25516,382
25074.62.64.0/1874.62.64.1 to 74.62.127.25474.62.127.25516,382
25174.62.128.0/1874.62.128.1 to 74.62.191.25474.62.191.25516,382
25274.62.192.0/1874.62.192.1 to 74.62.255.25474.62.255.25516,382
25374.63.0.0/1874.63.0.1 to 74.63.63.25474.63.63.25516,382
25474.63.64.0/1874.63.64.1 to 74.63.127.25474.63.127.25516,382
25574.63.128.0/1874.63.128.1 to 74.63.191.25474.63.191.25516,382
25674.63.192.0/1874.63.192.1 to 74.63.255.25474.63.255.25516,382

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.