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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.

Network74.58.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
74.58.0.0
Broadcast address
74.59.255.255
First usable
74.58.0.1
Last usable
74.59.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 4A3A0000 · Integer 1245315072 to 1245446143
Reverse DNS zones
58.74.in-addr.arpa
59.74.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001010.00111010.00000000.0000000074.58.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01001010.00111010.00000000.0000000074.58.0.0
Broadcast01001010.00111011.11111111.1111111174.59.255.255
Split into smaller subnets/23
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

74.58.0.0/15 makes 256 subnets of /23.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
174.58.0.0/2374.58.0.1 to 74.58.1.25474.58.1.255510
274.58.2.0/2374.58.2.1 to 74.58.3.25474.58.3.255510
374.58.4.0/2374.58.4.1 to 74.58.5.25474.58.5.255510
474.58.6.0/2374.58.6.1 to 74.58.7.25474.58.7.255510
574.58.8.0/2374.58.8.1 to 74.58.9.25474.58.9.255510
674.58.10.0/2374.58.10.1 to 74.58.11.25474.58.11.255510
774.58.12.0/2374.58.12.1 to 74.58.13.25474.58.13.255510
874.58.14.0/2374.58.14.1 to 74.58.15.25474.58.15.255510
974.58.16.0/2374.58.16.1 to 74.58.17.25474.58.17.255510
1074.58.18.0/2374.58.18.1 to 74.58.19.25474.58.19.255510
1174.58.20.0/2374.58.20.1 to 74.58.21.25474.58.21.255510
1274.58.22.0/2374.58.22.1 to 74.58.23.25474.58.23.255510
1374.58.24.0/2374.58.24.1 to 74.58.25.25474.58.25.255510
1474.58.26.0/2374.58.26.1 to 74.58.27.25474.58.27.255510
1574.58.28.0/2374.58.28.1 to 74.58.29.25474.58.29.255510
1674.58.30.0/2374.58.30.1 to 74.58.31.25474.58.31.255510
1774.58.32.0/2374.58.32.1 to 74.58.33.25474.58.33.255510
1874.58.34.0/2374.58.34.1 to 74.58.35.25474.58.35.255510
1974.58.36.0/2374.58.36.1 to 74.58.37.25474.58.37.255510
2074.58.38.0/2374.58.38.1 to 74.58.39.25474.58.39.255510
2174.58.40.0/2374.58.40.1 to 74.58.41.25474.58.41.255510
2274.58.42.0/2374.58.42.1 to 74.58.43.25474.58.43.255510
2374.58.44.0/2374.58.44.1 to 74.58.45.25474.58.45.255510
2474.58.46.0/2374.58.46.1 to 74.58.47.25474.58.47.255510
2574.58.48.0/2374.58.48.1 to 74.58.49.25474.58.49.255510
2674.58.50.0/2374.58.50.1 to 74.58.51.25474.58.51.255510
2774.58.52.0/2374.58.52.1 to 74.58.53.25474.58.53.255510
2874.58.54.0/2374.58.54.1 to 74.58.55.25474.58.55.255510
2974.58.56.0/2374.58.56.1 to 74.58.57.25474.58.57.255510
3074.58.58.0/2374.58.58.1 to 74.58.59.25474.58.59.255510
3174.58.60.0/2374.58.60.1 to 74.58.61.25474.58.61.255510
3274.58.62.0/2374.58.62.1 to 74.58.63.25474.58.63.255510
3374.58.64.0/2374.58.64.1 to 74.58.65.25474.58.65.255510
3474.58.66.0/2374.58.66.1 to 74.58.67.25474.58.67.255510
3574.58.68.0/2374.58.68.1 to 74.58.69.25474.58.69.255510
3674.58.70.0/2374.58.70.1 to 74.58.71.25474.58.71.255510
3774.58.72.0/2374.58.72.1 to 74.58.73.25474.58.73.255510
3874.58.74.0/2374.58.74.1 to 74.58.75.25474.58.75.255510
3974.58.76.0/2374.58.76.1 to 74.58.77.25474.58.77.255510
4074.58.78.0/2374.58.78.1 to 74.58.79.25474.58.79.255510
4174.58.80.0/2374.58.80.1 to 74.58.81.25474.58.81.255510
4274.58.82.0/2374.58.82.1 to 74.58.83.25474.58.83.255510
4374.58.84.0/2374.58.84.1 to 74.58.85.25474.58.85.255510
4474.58.86.0/2374.58.86.1 to 74.58.87.25474.58.87.255510
4574.58.88.0/2374.58.88.1 to 74.58.89.25474.58.89.255510
4674.58.90.0/2374.58.90.1 to 74.58.91.25474.58.91.255510
4774.58.92.0/2374.58.92.1 to 74.58.93.25474.58.93.255510
4874.58.94.0/2374.58.94.1 to 74.58.95.25474.58.95.255510
4974.58.96.0/2374.58.96.1 to 74.58.97.25474.58.97.255510
5074.58.98.0/2374.58.98.1 to 74.58.99.25474.58.99.255510
5174.58.100.0/2374.58.100.1 to 74.58.101.25474.58.101.255510
5274.58.102.0/2374.58.102.1 to 74.58.103.25474.58.103.255510
5374.58.104.0/2374.58.104.1 to 74.58.105.25474.58.105.255510
5474.58.106.0/2374.58.106.1 to 74.58.107.25474.58.107.255510
5574.58.108.0/2374.58.108.1 to 74.58.109.25474.58.109.255510
5674.58.110.0/2374.58.110.1 to 74.58.111.25474.58.111.255510
5774.58.112.0/2374.58.112.1 to 74.58.113.25474.58.113.255510
5874.58.114.0/2374.58.114.1 to 74.58.115.25474.58.115.255510
5974.58.116.0/2374.58.116.1 to 74.58.117.25474.58.117.255510
6074.58.118.0/2374.58.118.1 to 74.58.119.25474.58.119.255510
6174.58.120.0/2374.58.120.1 to 74.58.121.25474.58.121.255510
6274.58.122.0/2374.58.122.1 to 74.58.123.25474.58.123.255510
6374.58.124.0/2374.58.124.1 to 74.58.125.25474.58.125.255510
6474.58.126.0/2374.58.126.1 to 74.58.127.25474.58.127.255510
6574.58.128.0/2374.58.128.1 to 74.58.129.25474.58.129.255510
6674.58.130.0/2374.58.130.1 to 74.58.131.25474.58.131.255510
6774.58.132.0/2374.58.132.1 to 74.58.133.25474.58.133.255510
6874.58.134.0/2374.58.134.1 to 74.58.135.25474.58.135.255510
6974.58.136.0/2374.58.136.1 to 74.58.137.25474.58.137.255510
7074.58.138.0/2374.58.138.1 to 74.58.139.25474.58.139.255510
7174.58.140.0/2374.58.140.1 to 74.58.141.25474.58.141.255510
7274.58.142.0/2374.58.142.1 to 74.58.143.25474.58.143.255510
7374.58.144.0/2374.58.144.1 to 74.58.145.25474.58.145.255510
7474.58.146.0/2374.58.146.1 to 74.58.147.25474.58.147.255510
7574.58.148.0/2374.58.148.1 to 74.58.149.25474.58.149.255510
7674.58.150.0/2374.58.150.1 to 74.58.151.25474.58.151.255510
7774.58.152.0/2374.58.152.1 to 74.58.153.25474.58.153.255510
7874.58.154.0/2374.58.154.1 to 74.58.155.25474.58.155.255510
7974.58.156.0/2374.58.156.1 to 74.58.157.25474.58.157.255510
8074.58.158.0/2374.58.158.1 to 74.58.159.25474.58.159.255510
8174.58.160.0/2374.58.160.1 to 74.58.161.25474.58.161.255510
8274.58.162.0/2374.58.162.1 to 74.58.163.25474.58.163.255510
8374.58.164.0/2374.58.164.1 to 74.58.165.25474.58.165.255510
8474.58.166.0/2374.58.166.1 to 74.58.167.25474.58.167.255510
8574.58.168.0/2374.58.168.1 to 74.58.169.25474.58.169.255510
8674.58.170.0/2374.58.170.1 to 74.58.171.25474.58.171.255510
8774.58.172.0/2374.58.172.1 to 74.58.173.25474.58.173.255510
8874.58.174.0/2374.58.174.1 to 74.58.175.25474.58.175.255510
8974.58.176.0/2374.58.176.1 to 74.58.177.25474.58.177.255510
9074.58.178.0/2374.58.178.1 to 74.58.179.25474.58.179.255510
9174.58.180.0/2374.58.180.1 to 74.58.181.25474.58.181.255510
9274.58.182.0/2374.58.182.1 to 74.58.183.25474.58.183.255510
9374.58.184.0/2374.58.184.1 to 74.58.185.25474.58.185.255510
9474.58.186.0/2374.58.186.1 to 74.58.187.25474.58.187.255510
9574.58.188.0/2374.58.188.1 to 74.58.189.25474.58.189.255510
9674.58.190.0/2374.58.190.1 to 74.58.191.25474.58.191.255510
9774.58.192.0/2374.58.192.1 to 74.58.193.25474.58.193.255510
9874.58.194.0/2374.58.194.1 to 74.58.195.25474.58.195.255510
9974.58.196.0/2374.58.196.1 to 74.58.197.25474.58.197.255510
10074.58.198.0/2374.58.198.1 to 74.58.199.25474.58.199.255510
10174.58.200.0/2374.58.200.1 to 74.58.201.25474.58.201.255510
10274.58.202.0/2374.58.202.1 to 74.58.203.25474.58.203.255510
10374.58.204.0/2374.58.204.1 to 74.58.205.25474.58.205.255510
10474.58.206.0/2374.58.206.1 to 74.58.207.25474.58.207.255510
10574.58.208.0/2374.58.208.1 to 74.58.209.25474.58.209.255510
10674.58.210.0/2374.58.210.1 to 74.58.211.25474.58.211.255510
10774.58.212.0/2374.58.212.1 to 74.58.213.25474.58.213.255510
10874.58.214.0/2374.58.214.1 to 74.58.215.25474.58.215.255510
10974.58.216.0/2374.58.216.1 to 74.58.217.25474.58.217.255510
11074.58.218.0/2374.58.218.1 to 74.58.219.25474.58.219.255510
11174.58.220.0/2374.58.220.1 to 74.58.221.25474.58.221.255510
11274.58.222.0/2374.58.222.1 to 74.58.223.25474.58.223.255510
11374.58.224.0/2374.58.224.1 to 74.58.225.25474.58.225.255510
11474.58.226.0/2374.58.226.1 to 74.58.227.25474.58.227.255510
11574.58.228.0/2374.58.228.1 to 74.58.229.25474.58.229.255510
11674.58.230.0/2374.58.230.1 to 74.58.231.25474.58.231.255510
11774.58.232.0/2374.58.232.1 to 74.58.233.25474.58.233.255510
11874.58.234.0/2374.58.234.1 to 74.58.235.25474.58.235.255510
11974.58.236.0/2374.58.236.1 to 74.58.237.25474.58.237.255510
12074.58.238.0/2374.58.238.1 to 74.58.239.25474.58.239.255510
12174.58.240.0/2374.58.240.1 to 74.58.241.25474.58.241.255510
12274.58.242.0/2374.58.242.1 to 74.58.243.25474.58.243.255510
12374.58.244.0/2374.58.244.1 to 74.58.245.25474.58.245.255510
12474.58.246.0/2374.58.246.1 to 74.58.247.25474.58.247.255510
12574.58.248.0/2374.58.248.1 to 74.58.249.25474.58.249.255510
12674.58.250.0/2374.58.250.1 to 74.58.251.25474.58.251.255510
12774.58.252.0/2374.58.252.1 to 74.58.253.25474.58.253.255510
12874.58.254.0/2374.58.254.1 to 74.58.255.25474.58.255.255510
12974.59.0.0/2374.59.0.1 to 74.59.1.25474.59.1.255510
13074.59.2.0/2374.59.2.1 to 74.59.3.25474.59.3.255510
13174.59.4.0/2374.59.4.1 to 74.59.5.25474.59.5.255510
13274.59.6.0/2374.59.6.1 to 74.59.7.25474.59.7.255510
13374.59.8.0/2374.59.8.1 to 74.59.9.25474.59.9.255510
13474.59.10.0/2374.59.10.1 to 74.59.11.25474.59.11.255510
13574.59.12.0/2374.59.12.1 to 74.59.13.25474.59.13.255510
13674.59.14.0/2374.59.14.1 to 74.59.15.25474.59.15.255510
13774.59.16.0/2374.59.16.1 to 74.59.17.25474.59.17.255510
13874.59.18.0/2374.59.18.1 to 74.59.19.25474.59.19.255510
13974.59.20.0/2374.59.20.1 to 74.59.21.25474.59.21.255510
14074.59.22.0/2374.59.22.1 to 74.59.23.25474.59.23.255510
14174.59.24.0/2374.59.24.1 to 74.59.25.25474.59.25.255510
14274.59.26.0/2374.59.26.1 to 74.59.27.25474.59.27.255510
14374.59.28.0/2374.59.28.1 to 74.59.29.25474.59.29.255510
14474.59.30.0/2374.59.30.1 to 74.59.31.25474.59.31.255510
14574.59.32.0/2374.59.32.1 to 74.59.33.25474.59.33.255510
14674.59.34.0/2374.59.34.1 to 74.59.35.25474.59.35.255510
14774.59.36.0/2374.59.36.1 to 74.59.37.25474.59.37.255510
14874.59.38.0/2374.59.38.1 to 74.59.39.25474.59.39.255510
14974.59.40.0/2374.59.40.1 to 74.59.41.25474.59.41.255510
15074.59.42.0/2374.59.42.1 to 74.59.43.25474.59.43.255510
15174.59.44.0/2374.59.44.1 to 74.59.45.25474.59.45.255510
15274.59.46.0/2374.59.46.1 to 74.59.47.25474.59.47.255510
15374.59.48.0/2374.59.48.1 to 74.59.49.25474.59.49.255510
15474.59.50.0/2374.59.50.1 to 74.59.51.25474.59.51.255510
15574.59.52.0/2374.59.52.1 to 74.59.53.25474.59.53.255510
15674.59.54.0/2374.59.54.1 to 74.59.55.25474.59.55.255510
15774.59.56.0/2374.59.56.1 to 74.59.57.25474.59.57.255510
15874.59.58.0/2374.59.58.1 to 74.59.59.25474.59.59.255510
15974.59.60.0/2374.59.60.1 to 74.59.61.25474.59.61.255510
16074.59.62.0/2374.59.62.1 to 74.59.63.25474.59.63.255510
16174.59.64.0/2374.59.64.1 to 74.59.65.25474.59.65.255510
16274.59.66.0/2374.59.66.1 to 74.59.67.25474.59.67.255510
16374.59.68.0/2374.59.68.1 to 74.59.69.25474.59.69.255510
16474.59.70.0/2374.59.70.1 to 74.59.71.25474.59.71.255510
16574.59.72.0/2374.59.72.1 to 74.59.73.25474.59.73.255510
16674.59.74.0/2374.59.74.1 to 74.59.75.25474.59.75.255510
16774.59.76.0/2374.59.76.1 to 74.59.77.25474.59.77.255510
16874.59.78.0/2374.59.78.1 to 74.59.79.25474.59.79.255510
16974.59.80.0/2374.59.80.1 to 74.59.81.25474.59.81.255510
17074.59.82.0/2374.59.82.1 to 74.59.83.25474.59.83.255510
17174.59.84.0/2374.59.84.1 to 74.59.85.25474.59.85.255510
17274.59.86.0/2374.59.86.1 to 74.59.87.25474.59.87.255510
17374.59.88.0/2374.59.88.1 to 74.59.89.25474.59.89.255510
17474.59.90.0/2374.59.90.1 to 74.59.91.25474.59.91.255510
17574.59.92.0/2374.59.92.1 to 74.59.93.25474.59.93.255510
17674.59.94.0/2374.59.94.1 to 74.59.95.25474.59.95.255510
17774.59.96.0/2374.59.96.1 to 74.59.97.25474.59.97.255510
17874.59.98.0/2374.59.98.1 to 74.59.99.25474.59.99.255510
17974.59.100.0/2374.59.100.1 to 74.59.101.25474.59.101.255510
18074.59.102.0/2374.59.102.1 to 74.59.103.25474.59.103.255510
18174.59.104.0/2374.59.104.1 to 74.59.105.25474.59.105.255510
18274.59.106.0/2374.59.106.1 to 74.59.107.25474.59.107.255510
18374.59.108.0/2374.59.108.1 to 74.59.109.25474.59.109.255510
18474.59.110.0/2374.59.110.1 to 74.59.111.25474.59.111.255510
18574.59.112.0/2374.59.112.1 to 74.59.113.25474.59.113.255510
18674.59.114.0/2374.59.114.1 to 74.59.115.25474.59.115.255510
18774.59.116.0/2374.59.116.1 to 74.59.117.25474.59.117.255510
18874.59.118.0/2374.59.118.1 to 74.59.119.25474.59.119.255510
18974.59.120.0/2374.59.120.1 to 74.59.121.25474.59.121.255510
19074.59.122.0/2374.59.122.1 to 74.59.123.25474.59.123.255510
19174.59.124.0/2374.59.124.1 to 74.59.125.25474.59.125.255510
19274.59.126.0/2374.59.126.1 to 74.59.127.25474.59.127.255510
19374.59.128.0/2374.59.128.1 to 74.59.129.25474.59.129.255510
19474.59.130.0/2374.59.130.1 to 74.59.131.25474.59.131.255510
19574.59.132.0/2374.59.132.1 to 74.59.133.25474.59.133.255510
19674.59.134.0/2374.59.134.1 to 74.59.135.25474.59.135.255510
19774.59.136.0/2374.59.136.1 to 74.59.137.25474.59.137.255510
19874.59.138.0/2374.59.138.1 to 74.59.139.25474.59.139.255510
19974.59.140.0/2374.59.140.1 to 74.59.141.25474.59.141.255510
20074.59.142.0/2374.59.142.1 to 74.59.143.25474.59.143.255510
20174.59.144.0/2374.59.144.1 to 74.59.145.25474.59.145.255510
20274.59.146.0/2374.59.146.1 to 74.59.147.25474.59.147.255510
20374.59.148.0/2374.59.148.1 to 74.59.149.25474.59.149.255510
20474.59.150.0/2374.59.150.1 to 74.59.151.25474.59.151.255510
20574.59.152.0/2374.59.152.1 to 74.59.153.25474.59.153.255510
20674.59.154.0/2374.59.154.1 to 74.59.155.25474.59.155.255510
20774.59.156.0/2374.59.156.1 to 74.59.157.25474.59.157.255510
20874.59.158.0/2374.59.158.1 to 74.59.159.25474.59.159.255510
20974.59.160.0/2374.59.160.1 to 74.59.161.25474.59.161.255510
21074.59.162.0/2374.59.162.1 to 74.59.163.25474.59.163.255510
21174.59.164.0/2374.59.164.1 to 74.59.165.25474.59.165.255510
21274.59.166.0/2374.59.166.1 to 74.59.167.25474.59.167.255510
21374.59.168.0/2374.59.168.1 to 74.59.169.25474.59.169.255510
21474.59.170.0/2374.59.170.1 to 74.59.171.25474.59.171.255510
21574.59.172.0/2374.59.172.1 to 74.59.173.25474.59.173.255510
21674.59.174.0/2374.59.174.1 to 74.59.175.25474.59.175.255510
21774.59.176.0/2374.59.176.1 to 74.59.177.25474.59.177.255510
21874.59.178.0/2374.59.178.1 to 74.59.179.25474.59.179.255510
21974.59.180.0/2374.59.180.1 to 74.59.181.25474.59.181.255510
22074.59.182.0/2374.59.182.1 to 74.59.183.25474.59.183.255510
22174.59.184.0/2374.59.184.1 to 74.59.185.25474.59.185.255510
22274.59.186.0/2374.59.186.1 to 74.59.187.25474.59.187.255510
22374.59.188.0/2374.59.188.1 to 74.59.189.25474.59.189.255510
22474.59.190.0/2374.59.190.1 to 74.59.191.25474.59.191.255510
22574.59.192.0/2374.59.192.1 to 74.59.193.25474.59.193.255510
22674.59.194.0/2374.59.194.1 to 74.59.195.25474.59.195.255510
22774.59.196.0/2374.59.196.1 to 74.59.197.25474.59.197.255510
22874.59.198.0/2374.59.198.1 to 74.59.199.25474.59.199.255510
22974.59.200.0/2374.59.200.1 to 74.59.201.25474.59.201.255510
23074.59.202.0/2374.59.202.1 to 74.59.203.25474.59.203.255510
23174.59.204.0/2374.59.204.1 to 74.59.205.25474.59.205.255510
23274.59.206.0/2374.59.206.1 to 74.59.207.25474.59.207.255510
23374.59.208.0/2374.59.208.1 to 74.59.209.25474.59.209.255510
23474.59.210.0/2374.59.210.1 to 74.59.211.25474.59.211.255510
23574.59.212.0/2374.59.212.1 to 74.59.213.25474.59.213.255510
23674.59.214.0/2374.59.214.1 to 74.59.215.25474.59.215.255510
23774.59.216.0/2374.59.216.1 to 74.59.217.25474.59.217.255510
23874.59.218.0/2374.59.218.1 to 74.59.219.25474.59.219.255510
23974.59.220.0/2374.59.220.1 to 74.59.221.25474.59.221.255510
24074.59.222.0/2374.59.222.1 to 74.59.223.25474.59.223.255510
24174.59.224.0/2374.59.224.1 to 74.59.225.25474.59.225.255510
24274.59.226.0/2374.59.226.1 to 74.59.227.25474.59.227.255510
24374.59.228.0/2374.59.228.1 to 74.59.229.25474.59.229.255510
24474.59.230.0/2374.59.230.1 to 74.59.231.25474.59.231.255510
24574.59.232.0/2374.59.232.1 to 74.59.233.25474.59.233.255510
24674.59.234.0/2374.59.234.1 to 74.59.235.25474.59.235.255510
24774.59.236.0/2374.59.236.1 to 74.59.237.25474.59.237.255510
24874.59.238.0/2374.59.238.1 to 74.59.239.25474.59.239.255510
24974.59.240.0/2374.59.240.1 to 74.59.241.25474.59.241.255510
25074.59.242.0/2374.59.242.1 to 74.59.243.25474.59.243.255510
25174.59.244.0/2374.59.244.1 to 74.59.245.25474.59.245.255510
25274.59.246.0/2374.59.246.1 to 74.59.247.25474.59.247.255510
25374.59.248.0/2374.59.248.1 to 74.59.249.25474.59.249.255510
25474.59.250.0/2374.59.250.1 to 74.59.251.25474.59.251.255510
25574.59.252.0/2374.59.252.1 to 74.59.253.25474.59.253.255510
25674.59.254.0/2374.59.254.1 to 74.59.255.25474.59.255.255510

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.