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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.

Network96.4.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
96.4.0.0
Broadcast address
96.5.255.255
First usable
96.4.0.1
Last usable
96.5.255.254
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 60040000 · Integer 1610874880 to 1611005951
Reverse DNS zones
4.96.in-addr.arpa
5.96.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
Address01100000.00000100.00000000.0000000096.4.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01100000.00000100.00000000.0000000096.4.0.0
Broadcast01100000.00000101.11111111.1111111196.5.255.255
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)

96.4.0.0/15 makes 256 subnets of /23.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
196.4.0.0/2396.4.0.1 to 96.4.1.25496.4.1.255510
296.4.2.0/2396.4.2.1 to 96.4.3.25496.4.3.255510
396.4.4.0/2396.4.4.1 to 96.4.5.25496.4.5.255510
496.4.6.0/2396.4.6.1 to 96.4.7.25496.4.7.255510
596.4.8.0/2396.4.8.1 to 96.4.9.25496.4.9.255510
696.4.10.0/2396.4.10.1 to 96.4.11.25496.4.11.255510
796.4.12.0/2396.4.12.1 to 96.4.13.25496.4.13.255510
896.4.14.0/2396.4.14.1 to 96.4.15.25496.4.15.255510
996.4.16.0/2396.4.16.1 to 96.4.17.25496.4.17.255510
1096.4.18.0/2396.4.18.1 to 96.4.19.25496.4.19.255510
1196.4.20.0/2396.4.20.1 to 96.4.21.25496.4.21.255510
1296.4.22.0/2396.4.22.1 to 96.4.23.25496.4.23.255510
1396.4.24.0/2396.4.24.1 to 96.4.25.25496.4.25.255510
1496.4.26.0/2396.4.26.1 to 96.4.27.25496.4.27.255510
1596.4.28.0/2396.4.28.1 to 96.4.29.25496.4.29.255510
1696.4.30.0/2396.4.30.1 to 96.4.31.25496.4.31.255510
1796.4.32.0/2396.4.32.1 to 96.4.33.25496.4.33.255510
1896.4.34.0/2396.4.34.1 to 96.4.35.25496.4.35.255510
1996.4.36.0/2396.4.36.1 to 96.4.37.25496.4.37.255510
2096.4.38.0/2396.4.38.1 to 96.4.39.25496.4.39.255510
2196.4.40.0/2396.4.40.1 to 96.4.41.25496.4.41.255510
2296.4.42.0/2396.4.42.1 to 96.4.43.25496.4.43.255510
2396.4.44.0/2396.4.44.1 to 96.4.45.25496.4.45.255510
2496.4.46.0/2396.4.46.1 to 96.4.47.25496.4.47.255510
2596.4.48.0/2396.4.48.1 to 96.4.49.25496.4.49.255510
2696.4.50.0/2396.4.50.1 to 96.4.51.25496.4.51.255510
2796.4.52.0/2396.4.52.1 to 96.4.53.25496.4.53.255510
2896.4.54.0/2396.4.54.1 to 96.4.55.25496.4.55.255510
2996.4.56.0/2396.4.56.1 to 96.4.57.25496.4.57.255510
3096.4.58.0/2396.4.58.1 to 96.4.59.25496.4.59.255510
3196.4.60.0/2396.4.60.1 to 96.4.61.25496.4.61.255510
3296.4.62.0/2396.4.62.1 to 96.4.63.25496.4.63.255510
3396.4.64.0/2396.4.64.1 to 96.4.65.25496.4.65.255510
3496.4.66.0/2396.4.66.1 to 96.4.67.25496.4.67.255510
3596.4.68.0/2396.4.68.1 to 96.4.69.25496.4.69.255510
3696.4.70.0/2396.4.70.1 to 96.4.71.25496.4.71.255510
3796.4.72.0/2396.4.72.1 to 96.4.73.25496.4.73.255510
3896.4.74.0/2396.4.74.1 to 96.4.75.25496.4.75.255510
3996.4.76.0/2396.4.76.1 to 96.4.77.25496.4.77.255510
4096.4.78.0/2396.4.78.1 to 96.4.79.25496.4.79.255510
4196.4.80.0/2396.4.80.1 to 96.4.81.25496.4.81.255510
4296.4.82.0/2396.4.82.1 to 96.4.83.25496.4.83.255510
4396.4.84.0/2396.4.84.1 to 96.4.85.25496.4.85.255510
4496.4.86.0/2396.4.86.1 to 96.4.87.25496.4.87.255510
4596.4.88.0/2396.4.88.1 to 96.4.89.25496.4.89.255510
4696.4.90.0/2396.4.90.1 to 96.4.91.25496.4.91.255510
4796.4.92.0/2396.4.92.1 to 96.4.93.25496.4.93.255510
4896.4.94.0/2396.4.94.1 to 96.4.95.25496.4.95.255510
4996.4.96.0/2396.4.96.1 to 96.4.97.25496.4.97.255510
5096.4.98.0/2396.4.98.1 to 96.4.99.25496.4.99.255510
5196.4.100.0/2396.4.100.1 to 96.4.101.25496.4.101.255510
5296.4.102.0/2396.4.102.1 to 96.4.103.25496.4.103.255510
5396.4.104.0/2396.4.104.1 to 96.4.105.25496.4.105.255510
5496.4.106.0/2396.4.106.1 to 96.4.107.25496.4.107.255510
5596.4.108.0/2396.4.108.1 to 96.4.109.25496.4.109.255510
5696.4.110.0/2396.4.110.1 to 96.4.111.25496.4.111.255510
5796.4.112.0/2396.4.112.1 to 96.4.113.25496.4.113.255510
5896.4.114.0/2396.4.114.1 to 96.4.115.25496.4.115.255510
5996.4.116.0/2396.4.116.1 to 96.4.117.25496.4.117.255510
6096.4.118.0/2396.4.118.1 to 96.4.119.25496.4.119.255510
6196.4.120.0/2396.4.120.1 to 96.4.121.25496.4.121.255510
6296.4.122.0/2396.4.122.1 to 96.4.123.25496.4.123.255510
6396.4.124.0/2396.4.124.1 to 96.4.125.25496.4.125.255510
6496.4.126.0/2396.4.126.1 to 96.4.127.25496.4.127.255510
6596.4.128.0/2396.4.128.1 to 96.4.129.25496.4.129.255510
6696.4.130.0/2396.4.130.1 to 96.4.131.25496.4.131.255510
6796.4.132.0/2396.4.132.1 to 96.4.133.25496.4.133.255510
6896.4.134.0/2396.4.134.1 to 96.4.135.25496.4.135.255510
6996.4.136.0/2396.4.136.1 to 96.4.137.25496.4.137.255510
7096.4.138.0/2396.4.138.1 to 96.4.139.25496.4.139.255510
7196.4.140.0/2396.4.140.1 to 96.4.141.25496.4.141.255510
7296.4.142.0/2396.4.142.1 to 96.4.143.25496.4.143.255510
7396.4.144.0/2396.4.144.1 to 96.4.145.25496.4.145.255510
7496.4.146.0/2396.4.146.1 to 96.4.147.25496.4.147.255510
7596.4.148.0/2396.4.148.1 to 96.4.149.25496.4.149.255510
7696.4.150.0/2396.4.150.1 to 96.4.151.25496.4.151.255510
7796.4.152.0/2396.4.152.1 to 96.4.153.25496.4.153.255510
7896.4.154.0/2396.4.154.1 to 96.4.155.25496.4.155.255510
7996.4.156.0/2396.4.156.1 to 96.4.157.25496.4.157.255510
8096.4.158.0/2396.4.158.1 to 96.4.159.25496.4.159.255510
8196.4.160.0/2396.4.160.1 to 96.4.161.25496.4.161.255510
8296.4.162.0/2396.4.162.1 to 96.4.163.25496.4.163.255510
8396.4.164.0/2396.4.164.1 to 96.4.165.25496.4.165.255510
8496.4.166.0/2396.4.166.1 to 96.4.167.25496.4.167.255510
8596.4.168.0/2396.4.168.1 to 96.4.169.25496.4.169.255510
8696.4.170.0/2396.4.170.1 to 96.4.171.25496.4.171.255510
8796.4.172.0/2396.4.172.1 to 96.4.173.25496.4.173.255510
8896.4.174.0/2396.4.174.1 to 96.4.175.25496.4.175.255510
8996.4.176.0/2396.4.176.1 to 96.4.177.25496.4.177.255510
9096.4.178.0/2396.4.178.1 to 96.4.179.25496.4.179.255510
9196.4.180.0/2396.4.180.1 to 96.4.181.25496.4.181.255510
9296.4.182.0/2396.4.182.1 to 96.4.183.25496.4.183.255510
9396.4.184.0/2396.4.184.1 to 96.4.185.25496.4.185.255510
9496.4.186.0/2396.4.186.1 to 96.4.187.25496.4.187.255510
9596.4.188.0/2396.4.188.1 to 96.4.189.25496.4.189.255510
9696.4.190.0/2396.4.190.1 to 96.4.191.25496.4.191.255510
9796.4.192.0/2396.4.192.1 to 96.4.193.25496.4.193.255510
9896.4.194.0/2396.4.194.1 to 96.4.195.25496.4.195.255510
9996.4.196.0/2396.4.196.1 to 96.4.197.25496.4.197.255510
10096.4.198.0/2396.4.198.1 to 96.4.199.25496.4.199.255510
10196.4.200.0/2396.4.200.1 to 96.4.201.25496.4.201.255510
10296.4.202.0/2396.4.202.1 to 96.4.203.25496.4.203.255510
10396.4.204.0/2396.4.204.1 to 96.4.205.25496.4.205.255510
10496.4.206.0/2396.4.206.1 to 96.4.207.25496.4.207.255510
10596.4.208.0/2396.4.208.1 to 96.4.209.25496.4.209.255510
10696.4.210.0/2396.4.210.1 to 96.4.211.25496.4.211.255510
10796.4.212.0/2396.4.212.1 to 96.4.213.25496.4.213.255510
10896.4.214.0/2396.4.214.1 to 96.4.215.25496.4.215.255510
10996.4.216.0/2396.4.216.1 to 96.4.217.25496.4.217.255510
11096.4.218.0/2396.4.218.1 to 96.4.219.25496.4.219.255510
11196.4.220.0/2396.4.220.1 to 96.4.221.25496.4.221.255510
11296.4.222.0/2396.4.222.1 to 96.4.223.25496.4.223.255510
11396.4.224.0/2396.4.224.1 to 96.4.225.25496.4.225.255510
11496.4.226.0/2396.4.226.1 to 96.4.227.25496.4.227.255510
11596.4.228.0/2396.4.228.1 to 96.4.229.25496.4.229.255510
11696.4.230.0/2396.4.230.1 to 96.4.231.25496.4.231.255510
11796.4.232.0/2396.4.232.1 to 96.4.233.25496.4.233.255510
11896.4.234.0/2396.4.234.1 to 96.4.235.25496.4.235.255510
11996.4.236.0/2396.4.236.1 to 96.4.237.25496.4.237.255510
12096.4.238.0/2396.4.238.1 to 96.4.239.25496.4.239.255510
12196.4.240.0/2396.4.240.1 to 96.4.241.25496.4.241.255510
12296.4.242.0/2396.4.242.1 to 96.4.243.25496.4.243.255510
12396.4.244.0/2396.4.244.1 to 96.4.245.25496.4.245.255510
12496.4.246.0/2396.4.246.1 to 96.4.247.25496.4.247.255510
12596.4.248.0/2396.4.248.1 to 96.4.249.25496.4.249.255510
12696.4.250.0/2396.4.250.1 to 96.4.251.25496.4.251.255510
12796.4.252.0/2396.4.252.1 to 96.4.253.25496.4.253.255510
12896.4.254.0/2396.4.254.1 to 96.4.255.25496.4.255.255510
12996.5.0.0/2396.5.0.1 to 96.5.1.25496.5.1.255510
13096.5.2.0/2396.5.2.1 to 96.5.3.25496.5.3.255510
13196.5.4.0/2396.5.4.1 to 96.5.5.25496.5.5.255510
13296.5.6.0/2396.5.6.1 to 96.5.7.25496.5.7.255510
13396.5.8.0/2396.5.8.1 to 96.5.9.25496.5.9.255510
13496.5.10.0/2396.5.10.1 to 96.5.11.25496.5.11.255510
13596.5.12.0/2396.5.12.1 to 96.5.13.25496.5.13.255510
13696.5.14.0/2396.5.14.1 to 96.5.15.25496.5.15.255510
13796.5.16.0/2396.5.16.1 to 96.5.17.25496.5.17.255510
13896.5.18.0/2396.5.18.1 to 96.5.19.25496.5.19.255510
13996.5.20.0/2396.5.20.1 to 96.5.21.25496.5.21.255510
14096.5.22.0/2396.5.22.1 to 96.5.23.25496.5.23.255510
14196.5.24.0/2396.5.24.1 to 96.5.25.25496.5.25.255510
14296.5.26.0/2396.5.26.1 to 96.5.27.25496.5.27.255510
14396.5.28.0/2396.5.28.1 to 96.5.29.25496.5.29.255510
14496.5.30.0/2396.5.30.1 to 96.5.31.25496.5.31.255510
14596.5.32.0/2396.5.32.1 to 96.5.33.25496.5.33.255510
14696.5.34.0/2396.5.34.1 to 96.5.35.25496.5.35.255510
14796.5.36.0/2396.5.36.1 to 96.5.37.25496.5.37.255510
14896.5.38.0/2396.5.38.1 to 96.5.39.25496.5.39.255510
14996.5.40.0/2396.5.40.1 to 96.5.41.25496.5.41.255510
15096.5.42.0/2396.5.42.1 to 96.5.43.25496.5.43.255510
15196.5.44.0/2396.5.44.1 to 96.5.45.25496.5.45.255510
15296.5.46.0/2396.5.46.1 to 96.5.47.25496.5.47.255510
15396.5.48.0/2396.5.48.1 to 96.5.49.25496.5.49.255510
15496.5.50.0/2396.5.50.1 to 96.5.51.25496.5.51.255510
15596.5.52.0/2396.5.52.1 to 96.5.53.25496.5.53.255510
15696.5.54.0/2396.5.54.1 to 96.5.55.25496.5.55.255510
15796.5.56.0/2396.5.56.1 to 96.5.57.25496.5.57.255510
15896.5.58.0/2396.5.58.1 to 96.5.59.25496.5.59.255510
15996.5.60.0/2396.5.60.1 to 96.5.61.25496.5.61.255510
16096.5.62.0/2396.5.62.1 to 96.5.63.25496.5.63.255510
16196.5.64.0/2396.5.64.1 to 96.5.65.25496.5.65.255510
16296.5.66.0/2396.5.66.1 to 96.5.67.25496.5.67.255510
16396.5.68.0/2396.5.68.1 to 96.5.69.25496.5.69.255510
16496.5.70.0/2396.5.70.1 to 96.5.71.25496.5.71.255510
16596.5.72.0/2396.5.72.1 to 96.5.73.25496.5.73.255510
16696.5.74.0/2396.5.74.1 to 96.5.75.25496.5.75.255510
16796.5.76.0/2396.5.76.1 to 96.5.77.25496.5.77.255510
16896.5.78.0/2396.5.78.1 to 96.5.79.25496.5.79.255510
16996.5.80.0/2396.5.80.1 to 96.5.81.25496.5.81.255510
17096.5.82.0/2396.5.82.1 to 96.5.83.25496.5.83.255510
17196.5.84.0/2396.5.84.1 to 96.5.85.25496.5.85.255510
17296.5.86.0/2396.5.86.1 to 96.5.87.25496.5.87.255510
17396.5.88.0/2396.5.88.1 to 96.5.89.25496.5.89.255510
17496.5.90.0/2396.5.90.1 to 96.5.91.25496.5.91.255510
17596.5.92.0/2396.5.92.1 to 96.5.93.25496.5.93.255510
17696.5.94.0/2396.5.94.1 to 96.5.95.25496.5.95.255510
17796.5.96.0/2396.5.96.1 to 96.5.97.25496.5.97.255510
17896.5.98.0/2396.5.98.1 to 96.5.99.25496.5.99.255510
17996.5.100.0/2396.5.100.1 to 96.5.101.25496.5.101.255510
18096.5.102.0/2396.5.102.1 to 96.5.103.25496.5.103.255510
18196.5.104.0/2396.5.104.1 to 96.5.105.25496.5.105.255510
18296.5.106.0/2396.5.106.1 to 96.5.107.25496.5.107.255510
18396.5.108.0/2396.5.108.1 to 96.5.109.25496.5.109.255510
18496.5.110.0/2396.5.110.1 to 96.5.111.25496.5.111.255510
18596.5.112.0/2396.5.112.1 to 96.5.113.25496.5.113.255510
18696.5.114.0/2396.5.114.1 to 96.5.115.25496.5.115.255510
18796.5.116.0/2396.5.116.1 to 96.5.117.25496.5.117.255510
18896.5.118.0/2396.5.118.1 to 96.5.119.25496.5.119.255510
18996.5.120.0/2396.5.120.1 to 96.5.121.25496.5.121.255510
19096.5.122.0/2396.5.122.1 to 96.5.123.25496.5.123.255510
19196.5.124.0/2396.5.124.1 to 96.5.125.25496.5.125.255510
19296.5.126.0/2396.5.126.1 to 96.5.127.25496.5.127.255510
19396.5.128.0/2396.5.128.1 to 96.5.129.25496.5.129.255510
19496.5.130.0/2396.5.130.1 to 96.5.131.25496.5.131.255510
19596.5.132.0/2396.5.132.1 to 96.5.133.25496.5.133.255510
19696.5.134.0/2396.5.134.1 to 96.5.135.25496.5.135.255510
19796.5.136.0/2396.5.136.1 to 96.5.137.25496.5.137.255510
19896.5.138.0/2396.5.138.1 to 96.5.139.25496.5.139.255510
19996.5.140.0/2396.5.140.1 to 96.5.141.25496.5.141.255510
20096.5.142.0/2396.5.142.1 to 96.5.143.25496.5.143.255510
20196.5.144.0/2396.5.144.1 to 96.5.145.25496.5.145.255510
20296.5.146.0/2396.5.146.1 to 96.5.147.25496.5.147.255510
20396.5.148.0/2396.5.148.1 to 96.5.149.25496.5.149.255510
20496.5.150.0/2396.5.150.1 to 96.5.151.25496.5.151.255510
20596.5.152.0/2396.5.152.1 to 96.5.153.25496.5.153.255510
20696.5.154.0/2396.5.154.1 to 96.5.155.25496.5.155.255510
20796.5.156.0/2396.5.156.1 to 96.5.157.25496.5.157.255510
20896.5.158.0/2396.5.158.1 to 96.5.159.25496.5.159.255510
20996.5.160.0/2396.5.160.1 to 96.5.161.25496.5.161.255510
21096.5.162.0/2396.5.162.1 to 96.5.163.25496.5.163.255510
21196.5.164.0/2396.5.164.1 to 96.5.165.25496.5.165.255510
21296.5.166.0/2396.5.166.1 to 96.5.167.25496.5.167.255510
21396.5.168.0/2396.5.168.1 to 96.5.169.25496.5.169.255510
21496.5.170.0/2396.5.170.1 to 96.5.171.25496.5.171.255510
21596.5.172.0/2396.5.172.1 to 96.5.173.25496.5.173.255510
21696.5.174.0/2396.5.174.1 to 96.5.175.25496.5.175.255510
21796.5.176.0/2396.5.176.1 to 96.5.177.25496.5.177.255510
21896.5.178.0/2396.5.178.1 to 96.5.179.25496.5.179.255510
21996.5.180.0/2396.5.180.1 to 96.5.181.25496.5.181.255510
22096.5.182.0/2396.5.182.1 to 96.5.183.25496.5.183.255510
22196.5.184.0/2396.5.184.1 to 96.5.185.25496.5.185.255510
22296.5.186.0/2396.5.186.1 to 96.5.187.25496.5.187.255510
22396.5.188.0/2396.5.188.1 to 96.5.189.25496.5.189.255510
22496.5.190.0/2396.5.190.1 to 96.5.191.25496.5.191.255510
22596.5.192.0/2396.5.192.1 to 96.5.193.25496.5.193.255510
22696.5.194.0/2396.5.194.1 to 96.5.195.25496.5.195.255510
22796.5.196.0/2396.5.196.1 to 96.5.197.25496.5.197.255510
22896.5.198.0/2396.5.198.1 to 96.5.199.25496.5.199.255510
22996.5.200.0/2396.5.200.1 to 96.5.201.25496.5.201.255510
23096.5.202.0/2396.5.202.1 to 96.5.203.25496.5.203.255510
23196.5.204.0/2396.5.204.1 to 96.5.205.25496.5.205.255510
23296.5.206.0/2396.5.206.1 to 96.5.207.25496.5.207.255510
23396.5.208.0/2396.5.208.1 to 96.5.209.25496.5.209.255510
23496.5.210.0/2396.5.210.1 to 96.5.211.25496.5.211.255510
23596.5.212.0/2396.5.212.1 to 96.5.213.25496.5.213.255510
23696.5.214.0/2396.5.214.1 to 96.5.215.25496.5.215.255510
23796.5.216.0/2396.5.216.1 to 96.5.217.25496.5.217.255510
23896.5.218.0/2396.5.218.1 to 96.5.219.25496.5.219.255510
23996.5.220.0/2396.5.220.1 to 96.5.221.25496.5.221.255510
24096.5.222.0/2396.5.222.1 to 96.5.223.25496.5.223.255510
24196.5.224.0/2396.5.224.1 to 96.5.225.25496.5.225.255510
24296.5.226.0/2396.5.226.1 to 96.5.227.25496.5.227.255510
24396.5.228.0/2396.5.228.1 to 96.5.229.25496.5.229.255510
24496.5.230.0/2396.5.230.1 to 96.5.231.25496.5.231.255510
24596.5.232.0/2396.5.232.1 to 96.5.233.25496.5.233.255510
24696.5.234.0/2396.5.234.1 to 96.5.235.25496.5.235.255510
24796.5.236.0/2396.5.236.1 to 96.5.237.25496.5.237.255510
24896.5.238.0/2396.5.238.1 to 96.5.239.25496.5.239.255510
24996.5.240.0/2396.5.240.1 to 96.5.241.25496.5.241.255510
25096.5.242.0/2396.5.242.1 to 96.5.243.25496.5.243.255510
25196.5.244.0/2396.5.244.1 to 96.5.245.25496.5.245.255510
25296.5.246.0/2396.5.246.1 to 96.5.247.25496.5.247.255510
25396.5.248.0/2396.5.248.1 to 96.5.249.25496.5.249.255510
25496.5.250.0/2396.5.250.1 to 96.5.251.25496.5.251.255510
25596.5.252.0/2396.5.252.1 to 96.5.253.25496.5.253.255510
25696.5.254.0/2396.5.254.1 to 96.5.255.25496.5.255.255510

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.