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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.

Network74.76.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
74.76.0.0
Broadcast address
74.76.127.255
First usable
74.76.0.1
Last usable
74.76.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
A (default /8)
As numbers
Hex 4A4C0000 · Integer 1246494720 to 1246527487
Reverse DNS zones
0.76.74.in-addr.arpa
1.76.74.in-addr.arpa
2.76.74.in-addr.arpa
3.76.74.in-addr.arpa
4.76.74.in-addr.arpa
5.76.74.in-addr.arpa
6.76.74.in-addr.arpa
7.76.74.in-addr.arpa
8.76.74.in-addr.arpa
9.76.74.in-addr.arpa
10.76.74.in-addr.arpa
11.76.74.in-addr.arpa
12.76.74.in-addr.arpa
13.76.74.in-addr.arpa
14.76.74.in-addr.arpa
15.76.74.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001010.01001100.00000000.0000000074.76.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network01001010.01001100.00000000.0000000074.76.0.0
Broadcast01001010.01001100.01111111.1111111174.76.127.255
Split into smaller subnets/25
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

74.76.0.0/17 makes 256 subnets of /25.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
174.76.0.0/2574.76.0.1 to 74.76.0.12674.76.0.127126
274.76.0.128/2574.76.0.129 to 74.76.0.25474.76.0.255126
374.76.1.0/2574.76.1.1 to 74.76.1.12674.76.1.127126
474.76.1.128/2574.76.1.129 to 74.76.1.25474.76.1.255126
574.76.2.0/2574.76.2.1 to 74.76.2.12674.76.2.127126
674.76.2.128/2574.76.2.129 to 74.76.2.25474.76.2.255126
774.76.3.0/2574.76.3.1 to 74.76.3.12674.76.3.127126
874.76.3.128/2574.76.3.129 to 74.76.3.25474.76.3.255126
974.76.4.0/2574.76.4.1 to 74.76.4.12674.76.4.127126
1074.76.4.128/2574.76.4.129 to 74.76.4.25474.76.4.255126
1174.76.5.0/2574.76.5.1 to 74.76.5.12674.76.5.127126
1274.76.5.128/2574.76.5.129 to 74.76.5.25474.76.5.255126
1374.76.6.0/2574.76.6.1 to 74.76.6.12674.76.6.127126
1474.76.6.128/2574.76.6.129 to 74.76.6.25474.76.6.255126
1574.76.7.0/2574.76.7.1 to 74.76.7.12674.76.7.127126
1674.76.7.128/2574.76.7.129 to 74.76.7.25474.76.7.255126
1774.76.8.0/2574.76.8.1 to 74.76.8.12674.76.8.127126
1874.76.8.128/2574.76.8.129 to 74.76.8.25474.76.8.255126
1974.76.9.0/2574.76.9.1 to 74.76.9.12674.76.9.127126
2074.76.9.128/2574.76.9.129 to 74.76.9.25474.76.9.255126
2174.76.10.0/2574.76.10.1 to 74.76.10.12674.76.10.127126
2274.76.10.128/2574.76.10.129 to 74.76.10.25474.76.10.255126
2374.76.11.0/2574.76.11.1 to 74.76.11.12674.76.11.127126
2474.76.11.128/2574.76.11.129 to 74.76.11.25474.76.11.255126
2574.76.12.0/2574.76.12.1 to 74.76.12.12674.76.12.127126
2674.76.12.128/2574.76.12.129 to 74.76.12.25474.76.12.255126
2774.76.13.0/2574.76.13.1 to 74.76.13.12674.76.13.127126
2874.76.13.128/2574.76.13.129 to 74.76.13.25474.76.13.255126
2974.76.14.0/2574.76.14.1 to 74.76.14.12674.76.14.127126
3074.76.14.128/2574.76.14.129 to 74.76.14.25474.76.14.255126
3174.76.15.0/2574.76.15.1 to 74.76.15.12674.76.15.127126
3274.76.15.128/2574.76.15.129 to 74.76.15.25474.76.15.255126
3374.76.16.0/2574.76.16.1 to 74.76.16.12674.76.16.127126
3474.76.16.128/2574.76.16.129 to 74.76.16.25474.76.16.255126
3574.76.17.0/2574.76.17.1 to 74.76.17.12674.76.17.127126
3674.76.17.128/2574.76.17.129 to 74.76.17.25474.76.17.255126
3774.76.18.0/2574.76.18.1 to 74.76.18.12674.76.18.127126
3874.76.18.128/2574.76.18.129 to 74.76.18.25474.76.18.255126
3974.76.19.0/2574.76.19.1 to 74.76.19.12674.76.19.127126
4074.76.19.128/2574.76.19.129 to 74.76.19.25474.76.19.255126
4174.76.20.0/2574.76.20.1 to 74.76.20.12674.76.20.127126
4274.76.20.128/2574.76.20.129 to 74.76.20.25474.76.20.255126
4374.76.21.0/2574.76.21.1 to 74.76.21.12674.76.21.127126
4474.76.21.128/2574.76.21.129 to 74.76.21.25474.76.21.255126
4574.76.22.0/2574.76.22.1 to 74.76.22.12674.76.22.127126
4674.76.22.128/2574.76.22.129 to 74.76.22.25474.76.22.255126
4774.76.23.0/2574.76.23.1 to 74.76.23.12674.76.23.127126
4874.76.23.128/2574.76.23.129 to 74.76.23.25474.76.23.255126
4974.76.24.0/2574.76.24.1 to 74.76.24.12674.76.24.127126
5074.76.24.128/2574.76.24.129 to 74.76.24.25474.76.24.255126
5174.76.25.0/2574.76.25.1 to 74.76.25.12674.76.25.127126
5274.76.25.128/2574.76.25.129 to 74.76.25.25474.76.25.255126
5374.76.26.0/2574.76.26.1 to 74.76.26.12674.76.26.127126
5474.76.26.128/2574.76.26.129 to 74.76.26.25474.76.26.255126
5574.76.27.0/2574.76.27.1 to 74.76.27.12674.76.27.127126
5674.76.27.128/2574.76.27.129 to 74.76.27.25474.76.27.255126
5774.76.28.0/2574.76.28.1 to 74.76.28.12674.76.28.127126
5874.76.28.128/2574.76.28.129 to 74.76.28.25474.76.28.255126
5974.76.29.0/2574.76.29.1 to 74.76.29.12674.76.29.127126
6074.76.29.128/2574.76.29.129 to 74.76.29.25474.76.29.255126
6174.76.30.0/2574.76.30.1 to 74.76.30.12674.76.30.127126
6274.76.30.128/2574.76.30.129 to 74.76.30.25474.76.30.255126
6374.76.31.0/2574.76.31.1 to 74.76.31.12674.76.31.127126
6474.76.31.128/2574.76.31.129 to 74.76.31.25474.76.31.255126
6574.76.32.0/2574.76.32.1 to 74.76.32.12674.76.32.127126
6674.76.32.128/2574.76.32.129 to 74.76.32.25474.76.32.255126
6774.76.33.0/2574.76.33.1 to 74.76.33.12674.76.33.127126
6874.76.33.128/2574.76.33.129 to 74.76.33.25474.76.33.255126
6974.76.34.0/2574.76.34.1 to 74.76.34.12674.76.34.127126
7074.76.34.128/2574.76.34.129 to 74.76.34.25474.76.34.255126
7174.76.35.0/2574.76.35.1 to 74.76.35.12674.76.35.127126
7274.76.35.128/2574.76.35.129 to 74.76.35.25474.76.35.255126
7374.76.36.0/2574.76.36.1 to 74.76.36.12674.76.36.127126
7474.76.36.128/2574.76.36.129 to 74.76.36.25474.76.36.255126
7574.76.37.0/2574.76.37.1 to 74.76.37.12674.76.37.127126
7674.76.37.128/2574.76.37.129 to 74.76.37.25474.76.37.255126
7774.76.38.0/2574.76.38.1 to 74.76.38.12674.76.38.127126
7874.76.38.128/2574.76.38.129 to 74.76.38.25474.76.38.255126
7974.76.39.0/2574.76.39.1 to 74.76.39.12674.76.39.127126
8074.76.39.128/2574.76.39.129 to 74.76.39.25474.76.39.255126
8174.76.40.0/2574.76.40.1 to 74.76.40.12674.76.40.127126
8274.76.40.128/2574.76.40.129 to 74.76.40.25474.76.40.255126
8374.76.41.0/2574.76.41.1 to 74.76.41.12674.76.41.127126
8474.76.41.128/2574.76.41.129 to 74.76.41.25474.76.41.255126
8574.76.42.0/2574.76.42.1 to 74.76.42.12674.76.42.127126
8674.76.42.128/2574.76.42.129 to 74.76.42.25474.76.42.255126
8774.76.43.0/2574.76.43.1 to 74.76.43.12674.76.43.127126
8874.76.43.128/2574.76.43.129 to 74.76.43.25474.76.43.255126
8974.76.44.0/2574.76.44.1 to 74.76.44.12674.76.44.127126
9074.76.44.128/2574.76.44.129 to 74.76.44.25474.76.44.255126
9174.76.45.0/2574.76.45.1 to 74.76.45.12674.76.45.127126
9274.76.45.128/2574.76.45.129 to 74.76.45.25474.76.45.255126
9374.76.46.0/2574.76.46.1 to 74.76.46.12674.76.46.127126
9474.76.46.128/2574.76.46.129 to 74.76.46.25474.76.46.255126
9574.76.47.0/2574.76.47.1 to 74.76.47.12674.76.47.127126
9674.76.47.128/2574.76.47.129 to 74.76.47.25474.76.47.255126
9774.76.48.0/2574.76.48.1 to 74.76.48.12674.76.48.127126
9874.76.48.128/2574.76.48.129 to 74.76.48.25474.76.48.255126
9974.76.49.0/2574.76.49.1 to 74.76.49.12674.76.49.127126
10074.76.49.128/2574.76.49.129 to 74.76.49.25474.76.49.255126
10174.76.50.0/2574.76.50.1 to 74.76.50.12674.76.50.127126
10274.76.50.128/2574.76.50.129 to 74.76.50.25474.76.50.255126
10374.76.51.0/2574.76.51.1 to 74.76.51.12674.76.51.127126
10474.76.51.128/2574.76.51.129 to 74.76.51.25474.76.51.255126
10574.76.52.0/2574.76.52.1 to 74.76.52.12674.76.52.127126
10674.76.52.128/2574.76.52.129 to 74.76.52.25474.76.52.255126
10774.76.53.0/2574.76.53.1 to 74.76.53.12674.76.53.127126
10874.76.53.128/2574.76.53.129 to 74.76.53.25474.76.53.255126
10974.76.54.0/2574.76.54.1 to 74.76.54.12674.76.54.127126
11074.76.54.128/2574.76.54.129 to 74.76.54.25474.76.54.255126
11174.76.55.0/2574.76.55.1 to 74.76.55.12674.76.55.127126
11274.76.55.128/2574.76.55.129 to 74.76.55.25474.76.55.255126
11374.76.56.0/2574.76.56.1 to 74.76.56.12674.76.56.127126
11474.76.56.128/2574.76.56.129 to 74.76.56.25474.76.56.255126
11574.76.57.0/2574.76.57.1 to 74.76.57.12674.76.57.127126
11674.76.57.128/2574.76.57.129 to 74.76.57.25474.76.57.255126
11774.76.58.0/2574.76.58.1 to 74.76.58.12674.76.58.127126
11874.76.58.128/2574.76.58.129 to 74.76.58.25474.76.58.255126
11974.76.59.0/2574.76.59.1 to 74.76.59.12674.76.59.127126
12074.76.59.128/2574.76.59.129 to 74.76.59.25474.76.59.255126
12174.76.60.0/2574.76.60.1 to 74.76.60.12674.76.60.127126
12274.76.60.128/2574.76.60.129 to 74.76.60.25474.76.60.255126
12374.76.61.0/2574.76.61.1 to 74.76.61.12674.76.61.127126
12474.76.61.128/2574.76.61.129 to 74.76.61.25474.76.61.255126
12574.76.62.0/2574.76.62.1 to 74.76.62.12674.76.62.127126
12674.76.62.128/2574.76.62.129 to 74.76.62.25474.76.62.255126
12774.76.63.0/2574.76.63.1 to 74.76.63.12674.76.63.127126
12874.76.63.128/2574.76.63.129 to 74.76.63.25474.76.63.255126
12974.76.64.0/2574.76.64.1 to 74.76.64.12674.76.64.127126
13074.76.64.128/2574.76.64.129 to 74.76.64.25474.76.64.255126
13174.76.65.0/2574.76.65.1 to 74.76.65.12674.76.65.127126
13274.76.65.128/2574.76.65.129 to 74.76.65.25474.76.65.255126
13374.76.66.0/2574.76.66.1 to 74.76.66.12674.76.66.127126
13474.76.66.128/2574.76.66.129 to 74.76.66.25474.76.66.255126
13574.76.67.0/2574.76.67.1 to 74.76.67.12674.76.67.127126
13674.76.67.128/2574.76.67.129 to 74.76.67.25474.76.67.255126
13774.76.68.0/2574.76.68.1 to 74.76.68.12674.76.68.127126
13874.76.68.128/2574.76.68.129 to 74.76.68.25474.76.68.255126
13974.76.69.0/2574.76.69.1 to 74.76.69.12674.76.69.127126
14074.76.69.128/2574.76.69.129 to 74.76.69.25474.76.69.255126
14174.76.70.0/2574.76.70.1 to 74.76.70.12674.76.70.127126
14274.76.70.128/2574.76.70.129 to 74.76.70.25474.76.70.255126
14374.76.71.0/2574.76.71.1 to 74.76.71.12674.76.71.127126
14474.76.71.128/2574.76.71.129 to 74.76.71.25474.76.71.255126
14574.76.72.0/2574.76.72.1 to 74.76.72.12674.76.72.127126
14674.76.72.128/2574.76.72.129 to 74.76.72.25474.76.72.255126
14774.76.73.0/2574.76.73.1 to 74.76.73.12674.76.73.127126
14874.76.73.128/2574.76.73.129 to 74.76.73.25474.76.73.255126
14974.76.74.0/2574.76.74.1 to 74.76.74.12674.76.74.127126
15074.76.74.128/2574.76.74.129 to 74.76.74.25474.76.74.255126
15174.76.75.0/2574.76.75.1 to 74.76.75.12674.76.75.127126
15274.76.75.128/2574.76.75.129 to 74.76.75.25474.76.75.255126
15374.76.76.0/2574.76.76.1 to 74.76.76.12674.76.76.127126
15474.76.76.128/2574.76.76.129 to 74.76.76.25474.76.76.255126
15574.76.77.0/2574.76.77.1 to 74.76.77.12674.76.77.127126
15674.76.77.128/2574.76.77.129 to 74.76.77.25474.76.77.255126
15774.76.78.0/2574.76.78.1 to 74.76.78.12674.76.78.127126
15874.76.78.128/2574.76.78.129 to 74.76.78.25474.76.78.255126
15974.76.79.0/2574.76.79.1 to 74.76.79.12674.76.79.127126
16074.76.79.128/2574.76.79.129 to 74.76.79.25474.76.79.255126
16174.76.80.0/2574.76.80.1 to 74.76.80.12674.76.80.127126
16274.76.80.128/2574.76.80.129 to 74.76.80.25474.76.80.255126
16374.76.81.0/2574.76.81.1 to 74.76.81.12674.76.81.127126
16474.76.81.128/2574.76.81.129 to 74.76.81.25474.76.81.255126
16574.76.82.0/2574.76.82.1 to 74.76.82.12674.76.82.127126
16674.76.82.128/2574.76.82.129 to 74.76.82.25474.76.82.255126
16774.76.83.0/2574.76.83.1 to 74.76.83.12674.76.83.127126
16874.76.83.128/2574.76.83.129 to 74.76.83.25474.76.83.255126
16974.76.84.0/2574.76.84.1 to 74.76.84.12674.76.84.127126
17074.76.84.128/2574.76.84.129 to 74.76.84.25474.76.84.255126
17174.76.85.0/2574.76.85.1 to 74.76.85.12674.76.85.127126
17274.76.85.128/2574.76.85.129 to 74.76.85.25474.76.85.255126
17374.76.86.0/2574.76.86.1 to 74.76.86.12674.76.86.127126
17474.76.86.128/2574.76.86.129 to 74.76.86.25474.76.86.255126
17574.76.87.0/2574.76.87.1 to 74.76.87.12674.76.87.127126
17674.76.87.128/2574.76.87.129 to 74.76.87.25474.76.87.255126
17774.76.88.0/2574.76.88.1 to 74.76.88.12674.76.88.127126
17874.76.88.128/2574.76.88.129 to 74.76.88.25474.76.88.255126
17974.76.89.0/2574.76.89.1 to 74.76.89.12674.76.89.127126
18074.76.89.128/2574.76.89.129 to 74.76.89.25474.76.89.255126
18174.76.90.0/2574.76.90.1 to 74.76.90.12674.76.90.127126
18274.76.90.128/2574.76.90.129 to 74.76.90.25474.76.90.255126
18374.76.91.0/2574.76.91.1 to 74.76.91.12674.76.91.127126
18474.76.91.128/2574.76.91.129 to 74.76.91.25474.76.91.255126
18574.76.92.0/2574.76.92.1 to 74.76.92.12674.76.92.127126
18674.76.92.128/2574.76.92.129 to 74.76.92.25474.76.92.255126
18774.76.93.0/2574.76.93.1 to 74.76.93.12674.76.93.127126
18874.76.93.128/2574.76.93.129 to 74.76.93.25474.76.93.255126
18974.76.94.0/2574.76.94.1 to 74.76.94.12674.76.94.127126
19074.76.94.128/2574.76.94.129 to 74.76.94.25474.76.94.255126
19174.76.95.0/2574.76.95.1 to 74.76.95.12674.76.95.127126
19274.76.95.128/2574.76.95.129 to 74.76.95.25474.76.95.255126
19374.76.96.0/2574.76.96.1 to 74.76.96.12674.76.96.127126
19474.76.96.128/2574.76.96.129 to 74.76.96.25474.76.96.255126
19574.76.97.0/2574.76.97.1 to 74.76.97.12674.76.97.127126
19674.76.97.128/2574.76.97.129 to 74.76.97.25474.76.97.255126
19774.76.98.0/2574.76.98.1 to 74.76.98.12674.76.98.127126
19874.76.98.128/2574.76.98.129 to 74.76.98.25474.76.98.255126
19974.76.99.0/2574.76.99.1 to 74.76.99.12674.76.99.127126
20074.76.99.128/2574.76.99.129 to 74.76.99.25474.76.99.255126
20174.76.100.0/2574.76.100.1 to 74.76.100.12674.76.100.127126
20274.76.100.128/2574.76.100.129 to 74.76.100.25474.76.100.255126
20374.76.101.0/2574.76.101.1 to 74.76.101.12674.76.101.127126
20474.76.101.128/2574.76.101.129 to 74.76.101.25474.76.101.255126
20574.76.102.0/2574.76.102.1 to 74.76.102.12674.76.102.127126
20674.76.102.128/2574.76.102.129 to 74.76.102.25474.76.102.255126
20774.76.103.0/2574.76.103.1 to 74.76.103.12674.76.103.127126
20874.76.103.128/2574.76.103.129 to 74.76.103.25474.76.103.255126
20974.76.104.0/2574.76.104.1 to 74.76.104.12674.76.104.127126
21074.76.104.128/2574.76.104.129 to 74.76.104.25474.76.104.255126
21174.76.105.0/2574.76.105.1 to 74.76.105.12674.76.105.127126
21274.76.105.128/2574.76.105.129 to 74.76.105.25474.76.105.255126
21374.76.106.0/2574.76.106.1 to 74.76.106.12674.76.106.127126
21474.76.106.128/2574.76.106.129 to 74.76.106.25474.76.106.255126
21574.76.107.0/2574.76.107.1 to 74.76.107.12674.76.107.127126
21674.76.107.128/2574.76.107.129 to 74.76.107.25474.76.107.255126
21774.76.108.0/2574.76.108.1 to 74.76.108.12674.76.108.127126
21874.76.108.128/2574.76.108.129 to 74.76.108.25474.76.108.255126
21974.76.109.0/2574.76.109.1 to 74.76.109.12674.76.109.127126
22074.76.109.128/2574.76.109.129 to 74.76.109.25474.76.109.255126
22174.76.110.0/2574.76.110.1 to 74.76.110.12674.76.110.127126
22274.76.110.128/2574.76.110.129 to 74.76.110.25474.76.110.255126
22374.76.111.0/2574.76.111.1 to 74.76.111.12674.76.111.127126
22474.76.111.128/2574.76.111.129 to 74.76.111.25474.76.111.255126
22574.76.112.0/2574.76.112.1 to 74.76.112.12674.76.112.127126
22674.76.112.128/2574.76.112.129 to 74.76.112.25474.76.112.255126
22774.76.113.0/2574.76.113.1 to 74.76.113.12674.76.113.127126
22874.76.113.128/2574.76.113.129 to 74.76.113.25474.76.113.255126
22974.76.114.0/2574.76.114.1 to 74.76.114.12674.76.114.127126
23074.76.114.128/2574.76.114.129 to 74.76.114.25474.76.114.255126
23174.76.115.0/2574.76.115.1 to 74.76.115.12674.76.115.127126
23274.76.115.128/2574.76.115.129 to 74.76.115.25474.76.115.255126
23374.76.116.0/2574.76.116.1 to 74.76.116.12674.76.116.127126
23474.76.116.128/2574.76.116.129 to 74.76.116.25474.76.116.255126
23574.76.117.0/2574.76.117.1 to 74.76.117.12674.76.117.127126
23674.76.117.128/2574.76.117.129 to 74.76.117.25474.76.117.255126
23774.76.118.0/2574.76.118.1 to 74.76.118.12674.76.118.127126
23874.76.118.128/2574.76.118.129 to 74.76.118.25474.76.118.255126
23974.76.119.0/2574.76.119.1 to 74.76.119.12674.76.119.127126
24074.76.119.128/2574.76.119.129 to 74.76.119.25474.76.119.255126
24174.76.120.0/2574.76.120.1 to 74.76.120.12674.76.120.127126
24274.76.120.128/2574.76.120.129 to 74.76.120.25474.76.120.255126
24374.76.121.0/2574.76.121.1 to 74.76.121.12674.76.121.127126
24474.76.121.128/2574.76.121.129 to 74.76.121.25474.76.121.255126
24574.76.122.0/2574.76.122.1 to 74.76.122.12674.76.122.127126
24674.76.122.128/2574.76.122.129 to 74.76.122.25474.76.122.255126
24774.76.123.0/2574.76.123.1 to 74.76.123.12674.76.123.127126
24874.76.123.128/2574.76.123.129 to 74.76.123.25474.76.123.255126
24974.76.124.0/2574.76.124.1 to 74.76.124.12674.76.124.127126
25074.76.124.128/2574.76.124.129 to 74.76.124.25474.76.124.255126
25174.76.125.0/2574.76.125.1 to 74.76.125.12674.76.125.127126
25274.76.125.128/2574.76.125.129 to 74.76.125.25474.76.125.255126
25374.76.126.0/2574.76.126.1 to 74.76.126.12674.76.126.127126
25474.76.126.128/2574.76.126.129 to 74.76.126.25474.76.126.255126
25574.76.127.0/2574.76.127.1 to 74.76.127.12674.76.127.127126
25674.76.127.128/2574.76.127.129 to 74.76.127.25474.76.127.255126

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.