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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.

Network96.37.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
96.37.0.0
Broadcast address
96.37.255.255
First usable
96.37.0.1
Last usable
96.37.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
A (default /8)
As numbers
Hex 60250000 · Integer 1613037568 to 1613103103
Reverse DNS zone
37.96.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01100000.00100101..00000000.0000000096.37.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01100000.00100101..00000000.0000000096.37.0.0
Broadcast01100000.00100101..11111111.1111111196.37.255.255
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

96.37.0.0/16 makes 256 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
196.37.0.0/2496.37.0.1 to 96.37.0.25496.37.0.255254
296.37.1.0/2496.37.1.1 to 96.37.1.25496.37.1.255254
396.37.2.0/2496.37.2.1 to 96.37.2.25496.37.2.255254
496.37.3.0/2496.37.3.1 to 96.37.3.25496.37.3.255254
596.37.4.0/2496.37.4.1 to 96.37.4.25496.37.4.255254
696.37.5.0/2496.37.5.1 to 96.37.5.25496.37.5.255254
796.37.6.0/2496.37.6.1 to 96.37.6.25496.37.6.255254
896.37.7.0/2496.37.7.1 to 96.37.7.25496.37.7.255254
996.37.8.0/2496.37.8.1 to 96.37.8.25496.37.8.255254
1096.37.9.0/2496.37.9.1 to 96.37.9.25496.37.9.255254
1196.37.10.0/2496.37.10.1 to 96.37.10.25496.37.10.255254
1296.37.11.0/2496.37.11.1 to 96.37.11.25496.37.11.255254
1396.37.12.0/2496.37.12.1 to 96.37.12.25496.37.12.255254
1496.37.13.0/2496.37.13.1 to 96.37.13.25496.37.13.255254
1596.37.14.0/2496.37.14.1 to 96.37.14.25496.37.14.255254
1696.37.15.0/2496.37.15.1 to 96.37.15.25496.37.15.255254
1796.37.16.0/2496.37.16.1 to 96.37.16.25496.37.16.255254
1896.37.17.0/2496.37.17.1 to 96.37.17.25496.37.17.255254
1996.37.18.0/2496.37.18.1 to 96.37.18.25496.37.18.255254
2096.37.19.0/2496.37.19.1 to 96.37.19.25496.37.19.255254
2196.37.20.0/2496.37.20.1 to 96.37.20.25496.37.20.255254
2296.37.21.0/2496.37.21.1 to 96.37.21.25496.37.21.255254
2396.37.22.0/2496.37.22.1 to 96.37.22.25496.37.22.255254
2496.37.23.0/2496.37.23.1 to 96.37.23.25496.37.23.255254
2596.37.24.0/2496.37.24.1 to 96.37.24.25496.37.24.255254
2696.37.25.0/2496.37.25.1 to 96.37.25.25496.37.25.255254
2796.37.26.0/2496.37.26.1 to 96.37.26.25496.37.26.255254
2896.37.27.0/2496.37.27.1 to 96.37.27.25496.37.27.255254
2996.37.28.0/2496.37.28.1 to 96.37.28.25496.37.28.255254
3096.37.29.0/2496.37.29.1 to 96.37.29.25496.37.29.255254
3196.37.30.0/2496.37.30.1 to 96.37.30.25496.37.30.255254
3296.37.31.0/2496.37.31.1 to 96.37.31.25496.37.31.255254
3396.37.32.0/2496.37.32.1 to 96.37.32.25496.37.32.255254
3496.37.33.0/2496.37.33.1 to 96.37.33.25496.37.33.255254
3596.37.34.0/2496.37.34.1 to 96.37.34.25496.37.34.255254
3696.37.35.0/2496.37.35.1 to 96.37.35.25496.37.35.255254
3796.37.36.0/2496.37.36.1 to 96.37.36.25496.37.36.255254
3896.37.37.0/2496.37.37.1 to 96.37.37.25496.37.37.255254
3996.37.38.0/2496.37.38.1 to 96.37.38.25496.37.38.255254
4096.37.39.0/2496.37.39.1 to 96.37.39.25496.37.39.255254
4196.37.40.0/2496.37.40.1 to 96.37.40.25496.37.40.255254
4296.37.41.0/2496.37.41.1 to 96.37.41.25496.37.41.255254
4396.37.42.0/2496.37.42.1 to 96.37.42.25496.37.42.255254
4496.37.43.0/2496.37.43.1 to 96.37.43.25496.37.43.255254
4596.37.44.0/2496.37.44.1 to 96.37.44.25496.37.44.255254
4696.37.45.0/2496.37.45.1 to 96.37.45.25496.37.45.255254
4796.37.46.0/2496.37.46.1 to 96.37.46.25496.37.46.255254
4896.37.47.0/2496.37.47.1 to 96.37.47.25496.37.47.255254
4996.37.48.0/2496.37.48.1 to 96.37.48.25496.37.48.255254
5096.37.49.0/2496.37.49.1 to 96.37.49.25496.37.49.255254
5196.37.50.0/2496.37.50.1 to 96.37.50.25496.37.50.255254
5296.37.51.0/2496.37.51.1 to 96.37.51.25496.37.51.255254
5396.37.52.0/2496.37.52.1 to 96.37.52.25496.37.52.255254
5496.37.53.0/2496.37.53.1 to 96.37.53.25496.37.53.255254
5596.37.54.0/2496.37.54.1 to 96.37.54.25496.37.54.255254
5696.37.55.0/2496.37.55.1 to 96.37.55.25496.37.55.255254
5796.37.56.0/2496.37.56.1 to 96.37.56.25496.37.56.255254
5896.37.57.0/2496.37.57.1 to 96.37.57.25496.37.57.255254
5996.37.58.0/2496.37.58.1 to 96.37.58.25496.37.58.255254
6096.37.59.0/2496.37.59.1 to 96.37.59.25496.37.59.255254
6196.37.60.0/2496.37.60.1 to 96.37.60.25496.37.60.255254
6296.37.61.0/2496.37.61.1 to 96.37.61.25496.37.61.255254
6396.37.62.0/2496.37.62.1 to 96.37.62.25496.37.62.255254
6496.37.63.0/2496.37.63.1 to 96.37.63.25496.37.63.255254
6596.37.64.0/2496.37.64.1 to 96.37.64.25496.37.64.255254
6696.37.65.0/2496.37.65.1 to 96.37.65.25496.37.65.255254
6796.37.66.0/2496.37.66.1 to 96.37.66.25496.37.66.255254
6896.37.67.0/2496.37.67.1 to 96.37.67.25496.37.67.255254
6996.37.68.0/2496.37.68.1 to 96.37.68.25496.37.68.255254
7096.37.69.0/2496.37.69.1 to 96.37.69.25496.37.69.255254
7196.37.70.0/2496.37.70.1 to 96.37.70.25496.37.70.255254
7296.37.71.0/2496.37.71.1 to 96.37.71.25496.37.71.255254
7396.37.72.0/2496.37.72.1 to 96.37.72.25496.37.72.255254
7496.37.73.0/2496.37.73.1 to 96.37.73.25496.37.73.255254
7596.37.74.0/2496.37.74.1 to 96.37.74.25496.37.74.255254
7696.37.75.0/2496.37.75.1 to 96.37.75.25496.37.75.255254
7796.37.76.0/2496.37.76.1 to 96.37.76.25496.37.76.255254
7896.37.77.0/2496.37.77.1 to 96.37.77.25496.37.77.255254
7996.37.78.0/2496.37.78.1 to 96.37.78.25496.37.78.255254
8096.37.79.0/2496.37.79.1 to 96.37.79.25496.37.79.255254
8196.37.80.0/2496.37.80.1 to 96.37.80.25496.37.80.255254
8296.37.81.0/2496.37.81.1 to 96.37.81.25496.37.81.255254
8396.37.82.0/2496.37.82.1 to 96.37.82.25496.37.82.255254
8496.37.83.0/2496.37.83.1 to 96.37.83.25496.37.83.255254
8596.37.84.0/2496.37.84.1 to 96.37.84.25496.37.84.255254
8696.37.85.0/2496.37.85.1 to 96.37.85.25496.37.85.255254
8796.37.86.0/2496.37.86.1 to 96.37.86.25496.37.86.255254
8896.37.87.0/2496.37.87.1 to 96.37.87.25496.37.87.255254
8996.37.88.0/2496.37.88.1 to 96.37.88.25496.37.88.255254
9096.37.89.0/2496.37.89.1 to 96.37.89.25496.37.89.255254
9196.37.90.0/2496.37.90.1 to 96.37.90.25496.37.90.255254
9296.37.91.0/2496.37.91.1 to 96.37.91.25496.37.91.255254
9396.37.92.0/2496.37.92.1 to 96.37.92.25496.37.92.255254
9496.37.93.0/2496.37.93.1 to 96.37.93.25496.37.93.255254
9596.37.94.0/2496.37.94.1 to 96.37.94.25496.37.94.255254
9696.37.95.0/2496.37.95.1 to 96.37.95.25496.37.95.255254
9796.37.96.0/2496.37.96.1 to 96.37.96.25496.37.96.255254
9896.37.97.0/2496.37.97.1 to 96.37.97.25496.37.97.255254
9996.37.98.0/2496.37.98.1 to 96.37.98.25496.37.98.255254
10096.37.99.0/2496.37.99.1 to 96.37.99.25496.37.99.255254
10196.37.100.0/2496.37.100.1 to 96.37.100.25496.37.100.255254
10296.37.101.0/2496.37.101.1 to 96.37.101.25496.37.101.255254
10396.37.102.0/2496.37.102.1 to 96.37.102.25496.37.102.255254
10496.37.103.0/2496.37.103.1 to 96.37.103.25496.37.103.255254
10596.37.104.0/2496.37.104.1 to 96.37.104.25496.37.104.255254
10696.37.105.0/2496.37.105.1 to 96.37.105.25496.37.105.255254
10796.37.106.0/2496.37.106.1 to 96.37.106.25496.37.106.255254
10896.37.107.0/2496.37.107.1 to 96.37.107.25496.37.107.255254
10996.37.108.0/2496.37.108.1 to 96.37.108.25496.37.108.255254
11096.37.109.0/2496.37.109.1 to 96.37.109.25496.37.109.255254
11196.37.110.0/2496.37.110.1 to 96.37.110.25496.37.110.255254
11296.37.111.0/2496.37.111.1 to 96.37.111.25496.37.111.255254
11396.37.112.0/2496.37.112.1 to 96.37.112.25496.37.112.255254
11496.37.113.0/2496.37.113.1 to 96.37.113.25496.37.113.255254
11596.37.114.0/2496.37.114.1 to 96.37.114.25496.37.114.255254
11696.37.115.0/2496.37.115.1 to 96.37.115.25496.37.115.255254
11796.37.116.0/2496.37.116.1 to 96.37.116.25496.37.116.255254
11896.37.117.0/2496.37.117.1 to 96.37.117.25496.37.117.255254
11996.37.118.0/2496.37.118.1 to 96.37.118.25496.37.118.255254
12096.37.119.0/2496.37.119.1 to 96.37.119.25496.37.119.255254
12196.37.120.0/2496.37.120.1 to 96.37.120.25496.37.120.255254
12296.37.121.0/2496.37.121.1 to 96.37.121.25496.37.121.255254
12396.37.122.0/2496.37.122.1 to 96.37.122.25496.37.122.255254
12496.37.123.0/2496.37.123.1 to 96.37.123.25496.37.123.255254
12596.37.124.0/2496.37.124.1 to 96.37.124.25496.37.124.255254
12696.37.125.0/2496.37.125.1 to 96.37.125.25496.37.125.255254
12796.37.126.0/2496.37.126.1 to 96.37.126.25496.37.126.255254
12896.37.127.0/2496.37.127.1 to 96.37.127.25496.37.127.255254
12996.37.128.0/2496.37.128.1 to 96.37.128.25496.37.128.255254
13096.37.129.0/2496.37.129.1 to 96.37.129.25496.37.129.255254
13196.37.130.0/2496.37.130.1 to 96.37.130.25496.37.130.255254
13296.37.131.0/2496.37.131.1 to 96.37.131.25496.37.131.255254
13396.37.132.0/2496.37.132.1 to 96.37.132.25496.37.132.255254
13496.37.133.0/2496.37.133.1 to 96.37.133.25496.37.133.255254
13596.37.134.0/2496.37.134.1 to 96.37.134.25496.37.134.255254
13696.37.135.0/2496.37.135.1 to 96.37.135.25496.37.135.255254
13796.37.136.0/2496.37.136.1 to 96.37.136.25496.37.136.255254
13896.37.137.0/2496.37.137.1 to 96.37.137.25496.37.137.255254
13996.37.138.0/2496.37.138.1 to 96.37.138.25496.37.138.255254
14096.37.139.0/2496.37.139.1 to 96.37.139.25496.37.139.255254
14196.37.140.0/2496.37.140.1 to 96.37.140.25496.37.140.255254
14296.37.141.0/2496.37.141.1 to 96.37.141.25496.37.141.255254
14396.37.142.0/2496.37.142.1 to 96.37.142.25496.37.142.255254
14496.37.143.0/2496.37.143.1 to 96.37.143.25496.37.143.255254
14596.37.144.0/2496.37.144.1 to 96.37.144.25496.37.144.255254
14696.37.145.0/2496.37.145.1 to 96.37.145.25496.37.145.255254
14796.37.146.0/2496.37.146.1 to 96.37.146.25496.37.146.255254
14896.37.147.0/2496.37.147.1 to 96.37.147.25496.37.147.255254
14996.37.148.0/2496.37.148.1 to 96.37.148.25496.37.148.255254
15096.37.149.0/2496.37.149.1 to 96.37.149.25496.37.149.255254
15196.37.150.0/2496.37.150.1 to 96.37.150.25496.37.150.255254
15296.37.151.0/2496.37.151.1 to 96.37.151.25496.37.151.255254
15396.37.152.0/2496.37.152.1 to 96.37.152.25496.37.152.255254
15496.37.153.0/2496.37.153.1 to 96.37.153.25496.37.153.255254
15596.37.154.0/2496.37.154.1 to 96.37.154.25496.37.154.255254
15696.37.155.0/2496.37.155.1 to 96.37.155.25496.37.155.255254
15796.37.156.0/2496.37.156.1 to 96.37.156.25496.37.156.255254
15896.37.157.0/2496.37.157.1 to 96.37.157.25496.37.157.255254
15996.37.158.0/2496.37.158.1 to 96.37.158.25496.37.158.255254
16096.37.159.0/2496.37.159.1 to 96.37.159.25496.37.159.255254
16196.37.160.0/2496.37.160.1 to 96.37.160.25496.37.160.255254
16296.37.161.0/2496.37.161.1 to 96.37.161.25496.37.161.255254
16396.37.162.0/2496.37.162.1 to 96.37.162.25496.37.162.255254
16496.37.163.0/2496.37.163.1 to 96.37.163.25496.37.163.255254
16596.37.164.0/2496.37.164.1 to 96.37.164.25496.37.164.255254
16696.37.165.0/2496.37.165.1 to 96.37.165.25496.37.165.255254
16796.37.166.0/2496.37.166.1 to 96.37.166.25496.37.166.255254
16896.37.167.0/2496.37.167.1 to 96.37.167.25496.37.167.255254
16996.37.168.0/2496.37.168.1 to 96.37.168.25496.37.168.255254
17096.37.169.0/2496.37.169.1 to 96.37.169.25496.37.169.255254
17196.37.170.0/2496.37.170.1 to 96.37.170.25496.37.170.255254
17296.37.171.0/2496.37.171.1 to 96.37.171.25496.37.171.255254
17396.37.172.0/2496.37.172.1 to 96.37.172.25496.37.172.255254
17496.37.173.0/2496.37.173.1 to 96.37.173.25496.37.173.255254
17596.37.174.0/2496.37.174.1 to 96.37.174.25496.37.174.255254
17696.37.175.0/2496.37.175.1 to 96.37.175.25496.37.175.255254
17796.37.176.0/2496.37.176.1 to 96.37.176.25496.37.176.255254
17896.37.177.0/2496.37.177.1 to 96.37.177.25496.37.177.255254
17996.37.178.0/2496.37.178.1 to 96.37.178.25496.37.178.255254
18096.37.179.0/2496.37.179.1 to 96.37.179.25496.37.179.255254
18196.37.180.0/2496.37.180.1 to 96.37.180.25496.37.180.255254
18296.37.181.0/2496.37.181.1 to 96.37.181.25496.37.181.255254
18396.37.182.0/2496.37.182.1 to 96.37.182.25496.37.182.255254
18496.37.183.0/2496.37.183.1 to 96.37.183.25496.37.183.255254
18596.37.184.0/2496.37.184.1 to 96.37.184.25496.37.184.255254
18696.37.185.0/2496.37.185.1 to 96.37.185.25496.37.185.255254
18796.37.186.0/2496.37.186.1 to 96.37.186.25496.37.186.255254
18896.37.187.0/2496.37.187.1 to 96.37.187.25496.37.187.255254
18996.37.188.0/2496.37.188.1 to 96.37.188.25496.37.188.255254
19096.37.189.0/2496.37.189.1 to 96.37.189.25496.37.189.255254
19196.37.190.0/2496.37.190.1 to 96.37.190.25496.37.190.255254
19296.37.191.0/2496.37.191.1 to 96.37.191.25496.37.191.255254
19396.37.192.0/2496.37.192.1 to 96.37.192.25496.37.192.255254
19496.37.193.0/2496.37.193.1 to 96.37.193.25496.37.193.255254
19596.37.194.0/2496.37.194.1 to 96.37.194.25496.37.194.255254
19696.37.195.0/2496.37.195.1 to 96.37.195.25496.37.195.255254
19796.37.196.0/2496.37.196.1 to 96.37.196.25496.37.196.255254
19896.37.197.0/2496.37.197.1 to 96.37.197.25496.37.197.255254
19996.37.198.0/2496.37.198.1 to 96.37.198.25496.37.198.255254
20096.37.199.0/2496.37.199.1 to 96.37.199.25496.37.199.255254
20196.37.200.0/2496.37.200.1 to 96.37.200.25496.37.200.255254
20296.37.201.0/2496.37.201.1 to 96.37.201.25496.37.201.255254
20396.37.202.0/2496.37.202.1 to 96.37.202.25496.37.202.255254
20496.37.203.0/2496.37.203.1 to 96.37.203.25496.37.203.255254
20596.37.204.0/2496.37.204.1 to 96.37.204.25496.37.204.255254
20696.37.205.0/2496.37.205.1 to 96.37.205.25496.37.205.255254
20796.37.206.0/2496.37.206.1 to 96.37.206.25496.37.206.255254
20896.37.207.0/2496.37.207.1 to 96.37.207.25496.37.207.255254
20996.37.208.0/2496.37.208.1 to 96.37.208.25496.37.208.255254
21096.37.209.0/2496.37.209.1 to 96.37.209.25496.37.209.255254
21196.37.210.0/2496.37.210.1 to 96.37.210.25496.37.210.255254
21296.37.211.0/2496.37.211.1 to 96.37.211.25496.37.211.255254
21396.37.212.0/2496.37.212.1 to 96.37.212.25496.37.212.255254
21496.37.213.0/2496.37.213.1 to 96.37.213.25496.37.213.255254
21596.37.214.0/2496.37.214.1 to 96.37.214.25496.37.214.255254
21696.37.215.0/2496.37.215.1 to 96.37.215.25496.37.215.255254
21796.37.216.0/2496.37.216.1 to 96.37.216.25496.37.216.255254
21896.37.217.0/2496.37.217.1 to 96.37.217.25496.37.217.255254
21996.37.218.0/2496.37.218.1 to 96.37.218.25496.37.218.255254
22096.37.219.0/2496.37.219.1 to 96.37.219.25496.37.219.255254
22196.37.220.0/2496.37.220.1 to 96.37.220.25496.37.220.255254
22296.37.221.0/2496.37.221.1 to 96.37.221.25496.37.221.255254
22396.37.222.0/2496.37.222.1 to 96.37.222.25496.37.222.255254
22496.37.223.0/2496.37.223.1 to 96.37.223.25496.37.223.255254
22596.37.224.0/2496.37.224.1 to 96.37.224.25496.37.224.255254
22696.37.225.0/2496.37.225.1 to 96.37.225.25496.37.225.255254
22796.37.226.0/2496.37.226.1 to 96.37.226.25496.37.226.255254
22896.37.227.0/2496.37.227.1 to 96.37.227.25496.37.227.255254
22996.37.228.0/2496.37.228.1 to 96.37.228.25496.37.228.255254
23096.37.229.0/2496.37.229.1 to 96.37.229.25496.37.229.255254
23196.37.230.0/2496.37.230.1 to 96.37.230.25496.37.230.255254
23296.37.231.0/2496.37.231.1 to 96.37.231.25496.37.231.255254
23396.37.232.0/2496.37.232.1 to 96.37.232.25496.37.232.255254
23496.37.233.0/2496.37.233.1 to 96.37.233.25496.37.233.255254
23596.37.234.0/2496.37.234.1 to 96.37.234.25496.37.234.255254
23696.37.235.0/2496.37.235.1 to 96.37.235.25496.37.235.255254
23796.37.236.0/2496.37.236.1 to 96.37.236.25496.37.236.255254
23896.37.237.0/2496.37.237.1 to 96.37.237.25496.37.237.255254
23996.37.238.0/2496.37.238.1 to 96.37.238.25496.37.238.255254
24096.37.239.0/2496.37.239.1 to 96.37.239.25496.37.239.255254
24196.37.240.0/2496.37.240.1 to 96.37.240.25496.37.240.255254
24296.37.241.0/2496.37.241.1 to 96.37.241.25496.37.241.255254
24396.37.242.0/2496.37.242.1 to 96.37.242.25496.37.242.255254
24496.37.243.0/2496.37.243.1 to 96.37.243.25496.37.243.255254
24596.37.244.0/2496.37.244.1 to 96.37.244.25496.37.244.255254
24696.37.245.0/2496.37.245.1 to 96.37.245.25496.37.245.255254
24796.37.246.0/2496.37.246.1 to 96.37.246.25496.37.246.255254
24896.37.247.0/2496.37.247.1 to 96.37.247.25496.37.247.255254
24996.37.248.0/2496.37.248.1 to 96.37.248.25496.37.248.255254
25096.37.249.0/2496.37.249.1 to 96.37.249.25496.37.249.255254
25196.37.250.0/2496.37.250.1 to 96.37.250.25496.37.250.255254
25296.37.251.0/2496.37.251.1 to 96.37.251.25496.37.251.255254
25396.37.252.0/2496.37.252.1 to 96.37.252.25496.37.252.255254
25496.37.253.0/2496.37.253.1 to 96.37.253.25496.37.253.255254
25596.37.254.0/2496.37.254.1 to 96.37.254.25496.37.254.255254
25696.37.255.0/2496.37.255.1 to 96.37.255.25496.37.255.255254

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.