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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.

Network68.112.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
68.112.0.0
Broadcast address
68.127.255.255
First usable
68.112.0.1
Last usable
68.127.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Public public
Old class
A (default /8)
As numbers
Hex 44700000 · Integer 1148190720 to 1149239295
Reverse DNS zones
112.68.in-addr.arpa
113.68.in-addr.arpa
114.68.in-addr.arpa
115.68.in-addr.arpa
116.68.in-addr.arpa
117.68.in-addr.arpa
118.68.in-addr.arpa
119.68.in-addr.arpa
120.68.in-addr.arpa
121.68.in-addr.arpa
122.68.in-addr.arpa
123.68.in-addr.arpa
124.68.in-addr.arpa
125.68.in-addr.arpa
126.68.in-addr.arpa
127.68.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01000100.01110000.00000000.0000000068.112.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network01000100.01110000.00000000.0000000068.112.0.0
Broadcast01000100.01111111.11111111.1111111168.127.255.255
Split into smaller subnets/23
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

68.112.0.0/12 makes 2,048 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
168.112.0.0/2368.112.0.1 to 68.112.1.25468.112.1.255510
268.112.2.0/2368.112.2.1 to 68.112.3.25468.112.3.255510
368.112.4.0/2368.112.4.1 to 68.112.5.25468.112.5.255510
468.112.6.0/2368.112.6.1 to 68.112.7.25468.112.7.255510
568.112.8.0/2368.112.8.1 to 68.112.9.25468.112.9.255510
668.112.10.0/2368.112.10.1 to 68.112.11.25468.112.11.255510
768.112.12.0/2368.112.12.1 to 68.112.13.25468.112.13.255510
868.112.14.0/2368.112.14.1 to 68.112.15.25468.112.15.255510
968.112.16.0/2368.112.16.1 to 68.112.17.25468.112.17.255510
1068.112.18.0/2368.112.18.1 to 68.112.19.25468.112.19.255510
1168.112.20.0/2368.112.20.1 to 68.112.21.25468.112.21.255510
1268.112.22.0/2368.112.22.1 to 68.112.23.25468.112.23.255510
1368.112.24.0/2368.112.24.1 to 68.112.25.25468.112.25.255510
1468.112.26.0/2368.112.26.1 to 68.112.27.25468.112.27.255510
1568.112.28.0/2368.112.28.1 to 68.112.29.25468.112.29.255510
1668.112.30.0/2368.112.30.1 to 68.112.31.25468.112.31.255510
1768.112.32.0/2368.112.32.1 to 68.112.33.25468.112.33.255510
1868.112.34.0/2368.112.34.1 to 68.112.35.25468.112.35.255510
1968.112.36.0/2368.112.36.1 to 68.112.37.25468.112.37.255510
2068.112.38.0/2368.112.38.1 to 68.112.39.25468.112.39.255510
2168.112.40.0/2368.112.40.1 to 68.112.41.25468.112.41.255510
2268.112.42.0/2368.112.42.1 to 68.112.43.25468.112.43.255510
2368.112.44.0/2368.112.44.1 to 68.112.45.25468.112.45.255510
2468.112.46.0/2368.112.46.1 to 68.112.47.25468.112.47.255510
2568.112.48.0/2368.112.48.1 to 68.112.49.25468.112.49.255510
2668.112.50.0/2368.112.50.1 to 68.112.51.25468.112.51.255510
2768.112.52.0/2368.112.52.1 to 68.112.53.25468.112.53.255510
2868.112.54.0/2368.112.54.1 to 68.112.55.25468.112.55.255510
2968.112.56.0/2368.112.56.1 to 68.112.57.25468.112.57.255510
3068.112.58.0/2368.112.58.1 to 68.112.59.25468.112.59.255510
3168.112.60.0/2368.112.60.1 to 68.112.61.25468.112.61.255510
3268.112.62.0/2368.112.62.1 to 68.112.63.25468.112.63.255510
3368.112.64.0/2368.112.64.1 to 68.112.65.25468.112.65.255510
3468.112.66.0/2368.112.66.1 to 68.112.67.25468.112.67.255510
3568.112.68.0/2368.112.68.1 to 68.112.69.25468.112.69.255510
3668.112.70.0/2368.112.70.1 to 68.112.71.25468.112.71.255510
3768.112.72.0/2368.112.72.1 to 68.112.73.25468.112.73.255510
3868.112.74.0/2368.112.74.1 to 68.112.75.25468.112.75.255510
3968.112.76.0/2368.112.76.1 to 68.112.77.25468.112.77.255510
4068.112.78.0/2368.112.78.1 to 68.112.79.25468.112.79.255510
4168.112.80.0/2368.112.80.1 to 68.112.81.25468.112.81.255510
4268.112.82.0/2368.112.82.1 to 68.112.83.25468.112.83.255510
4368.112.84.0/2368.112.84.1 to 68.112.85.25468.112.85.255510
4468.112.86.0/2368.112.86.1 to 68.112.87.25468.112.87.255510
4568.112.88.0/2368.112.88.1 to 68.112.89.25468.112.89.255510
4668.112.90.0/2368.112.90.1 to 68.112.91.25468.112.91.255510
4768.112.92.0/2368.112.92.1 to 68.112.93.25468.112.93.255510
4868.112.94.0/2368.112.94.1 to 68.112.95.25468.112.95.255510
4968.112.96.0/2368.112.96.1 to 68.112.97.25468.112.97.255510
5068.112.98.0/2368.112.98.1 to 68.112.99.25468.112.99.255510
5168.112.100.0/2368.112.100.1 to 68.112.101.25468.112.101.255510
5268.112.102.0/2368.112.102.1 to 68.112.103.25468.112.103.255510
5368.112.104.0/2368.112.104.1 to 68.112.105.25468.112.105.255510
5468.112.106.0/2368.112.106.1 to 68.112.107.25468.112.107.255510
5568.112.108.0/2368.112.108.1 to 68.112.109.25468.112.109.255510
5668.112.110.0/2368.112.110.1 to 68.112.111.25468.112.111.255510
5768.112.112.0/2368.112.112.1 to 68.112.113.25468.112.113.255510
5868.112.114.0/2368.112.114.1 to 68.112.115.25468.112.115.255510
5968.112.116.0/2368.112.116.1 to 68.112.117.25468.112.117.255510
6068.112.118.0/2368.112.118.1 to 68.112.119.25468.112.119.255510
6168.112.120.0/2368.112.120.1 to 68.112.121.25468.112.121.255510
6268.112.122.0/2368.112.122.1 to 68.112.123.25468.112.123.255510
6368.112.124.0/2368.112.124.1 to 68.112.125.25468.112.125.255510
6468.112.126.0/2368.112.126.1 to 68.112.127.25468.112.127.255510
6568.112.128.0/2368.112.128.1 to 68.112.129.25468.112.129.255510
6668.112.130.0/2368.112.130.1 to 68.112.131.25468.112.131.255510
6768.112.132.0/2368.112.132.1 to 68.112.133.25468.112.133.255510
6868.112.134.0/2368.112.134.1 to 68.112.135.25468.112.135.255510
6968.112.136.0/2368.112.136.1 to 68.112.137.25468.112.137.255510
7068.112.138.0/2368.112.138.1 to 68.112.139.25468.112.139.255510
7168.112.140.0/2368.112.140.1 to 68.112.141.25468.112.141.255510
7268.112.142.0/2368.112.142.1 to 68.112.143.25468.112.143.255510
7368.112.144.0/2368.112.144.1 to 68.112.145.25468.112.145.255510
7468.112.146.0/2368.112.146.1 to 68.112.147.25468.112.147.255510
7568.112.148.0/2368.112.148.1 to 68.112.149.25468.112.149.255510
7668.112.150.0/2368.112.150.1 to 68.112.151.25468.112.151.255510
7768.112.152.0/2368.112.152.1 to 68.112.153.25468.112.153.255510
7868.112.154.0/2368.112.154.1 to 68.112.155.25468.112.155.255510
7968.112.156.0/2368.112.156.1 to 68.112.157.25468.112.157.255510
8068.112.158.0/2368.112.158.1 to 68.112.159.25468.112.159.255510
8168.112.160.0/2368.112.160.1 to 68.112.161.25468.112.161.255510
8268.112.162.0/2368.112.162.1 to 68.112.163.25468.112.163.255510
8368.112.164.0/2368.112.164.1 to 68.112.165.25468.112.165.255510
8468.112.166.0/2368.112.166.1 to 68.112.167.25468.112.167.255510
8568.112.168.0/2368.112.168.1 to 68.112.169.25468.112.169.255510
8668.112.170.0/2368.112.170.1 to 68.112.171.25468.112.171.255510
8768.112.172.0/2368.112.172.1 to 68.112.173.25468.112.173.255510
8868.112.174.0/2368.112.174.1 to 68.112.175.25468.112.175.255510
8968.112.176.0/2368.112.176.1 to 68.112.177.25468.112.177.255510
9068.112.178.0/2368.112.178.1 to 68.112.179.25468.112.179.255510
9168.112.180.0/2368.112.180.1 to 68.112.181.25468.112.181.255510
9268.112.182.0/2368.112.182.1 to 68.112.183.25468.112.183.255510
9368.112.184.0/2368.112.184.1 to 68.112.185.25468.112.185.255510
9468.112.186.0/2368.112.186.1 to 68.112.187.25468.112.187.255510
9568.112.188.0/2368.112.188.1 to 68.112.189.25468.112.189.255510
9668.112.190.0/2368.112.190.1 to 68.112.191.25468.112.191.255510
9768.112.192.0/2368.112.192.1 to 68.112.193.25468.112.193.255510
9868.112.194.0/2368.112.194.1 to 68.112.195.25468.112.195.255510
9968.112.196.0/2368.112.196.1 to 68.112.197.25468.112.197.255510
10068.112.198.0/2368.112.198.1 to 68.112.199.25468.112.199.255510
10168.112.200.0/2368.112.200.1 to 68.112.201.25468.112.201.255510
10268.112.202.0/2368.112.202.1 to 68.112.203.25468.112.203.255510
10368.112.204.0/2368.112.204.1 to 68.112.205.25468.112.205.255510
10468.112.206.0/2368.112.206.1 to 68.112.207.25468.112.207.255510
10568.112.208.0/2368.112.208.1 to 68.112.209.25468.112.209.255510
10668.112.210.0/2368.112.210.1 to 68.112.211.25468.112.211.255510
10768.112.212.0/2368.112.212.1 to 68.112.213.25468.112.213.255510
10868.112.214.0/2368.112.214.1 to 68.112.215.25468.112.215.255510
10968.112.216.0/2368.112.216.1 to 68.112.217.25468.112.217.255510
11068.112.218.0/2368.112.218.1 to 68.112.219.25468.112.219.255510
11168.112.220.0/2368.112.220.1 to 68.112.221.25468.112.221.255510
11268.112.222.0/2368.112.222.1 to 68.112.223.25468.112.223.255510
11368.112.224.0/2368.112.224.1 to 68.112.225.25468.112.225.255510
11468.112.226.0/2368.112.226.1 to 68.112.227.25468.112.227.255510
11568.112.228.0/2368.112.228.1 to 68.112.229.25468.112.229.255510
11668.112.230.0/2368.112.230.1 to 68.112.231.25468.112.231.255510
11768.112.232.0/2368.112.232.1 to 68.112.233.25468.112.233.255510
11868.112.234.0/2368.112.234.1 to 68.112.235.25468.112.235.255510
11968.112.236.0/2368.112.236.1 to 68.112.237.25468.112.237.255510
12068.112.238.0/2368.112.238.1 to 68.112.239.25468.112.239.255510
12168.112.240.0/2368.112.240.1 to 68.112.241.25468.112.241.255510
12268.112.242.0/2368.112.242.1 to 68.112.243.25468.112.243.255510
12368.112.244.0/2368.112.244.1 to 68.112.245.25468.112.245.255510
12468.112.246.0/2368.112.246.1 to 68.112.247.25468.112.247.255510
12568.112.248.0/2368.112.248.1 to 68.112.249.25468.112.249.255510
12668.112.250.0/2368.112.250.1 to 68.112.251.25468.112.251.255510
12768.112.252.0/2368.112.252.1 to 68.112.253.25468.112.253.255510
12868.112.254.0/2368.112.254.1 to 68.112.255.25468.112.255.255510
12968.113.0.0/2368.113.0.1 to 68.113.1.25468.113.1.255510
13068.113.2.0/2368.113.2.1 to 68.113.3.25468.113.3.255510
13168.113.4.0/2368.113.4.1 to 68.113.5.25468.113.5.255510
13268.113.6.0/2368.113.6.1 to 68.113.7.25468.113.7.255510
13368.113.8.0/2368.113.8.1 to 68.113.9.25468.113.9.255510
13468.113.10.0/2368.113.10.1 to 68.113.11.25468.113.11.255510
13568.113.12.0/2368.113.12.1 to 68.113.13.25468.113.13.255510
13668.113.14.0/2368.113.14.1 to 68.113.15.25468.113.15.255510
13768.113.16.0/2368.113.16.1 to 68.113.17.25468.113.17.255510
13868.113.18.0/2368.113.18.1 to 68.113.19.25468.113.19.255510
13968.113.20.0/2368.113.20.1 to 68.113.21.25468.113.21.255510
14068.113.22.0/2368.113.22.1 to 68.113.23.25468.113.23.255510
14168.113.24.0/2368.113.24.1 to 68.113.25.25468.113.25.255510
14268.113.26.0/2368.113.26.1 to 68.113.27.25468.113.27.255510
14368.113.28.0/2368.113.28.1 to 68.113.29.25468.113.29.255510
14468.113.30.0/2368.113.30.1 to 68.113.31.25468.113.31.255510
14568.113.32.0/2368.113.32.1 to 68.113.33.25468.113.33.255510
14668.113.34.0/2368.113.34.1 to 68.113.35.25468.113.35.255510
14768.113.36.0/2368.113.36.1 to 68.113.37.25468.113.37.255510
14868.113.38.0/2368.113.38.1 to 68.113.39.25468.113.39.255510
14968.113.40.0/2368.113.40.1 to 68.113.41.25468.113.41.255510
15068.113.42.0/2368.113.42.1 to 68.113.43.25468.113.43.255510
15168.113.44.0/2368.113.44.1 to 68.113.45.25468.113.45.255510
15268.113.46.0/2368.113.46.1 to 68.113.47.25468.113.47.255510
15368.113.48.0/2368.113.48.1 to 68.113.49.25468.113.49.255510
15468.113.50.0/2368.113.50.1 to 68.113.51.25468.113.51.255510
15568.113.52.0/2368.113.52.1 to 68.113.53.25468.113.53.255510
15668.113.54.0/2368.113.54.1 to 68.113.55.25468.113.55.255510
15768.113.56.0/2368.113.56.1 to 68.113.57.25468.113.57.255510
15868.113.58.0/2368.113.58.1 to 68.113.59.25468.113.59.255510
15968.113.60.0/2368.113.60.1 to 68.113.61.25468.113.61.255510
16068.113.62.0/2368.113.62.1 to 68.113.63.25468.113.63.255510
16168.113.64.0/2368.113.64.1 to 68.113.65.25468.113.65.255510
16268.113.66.0/2368.113.66.1 to 68.113.67.25468.113.67.255510
16368.113.68.0/2368.113.68.1 to 68.113.69.25468.113.69.255510
16468.113.70.0/2368.113.70.1 to 68.113.71.25468.113.71.255510
16568.113.72.0/2368.113.72.1 to 68.113.73.25468.113.73.255510
16668.113.74.0/2368.113.74.1 to 68.113.75.25468.113.75.255510
16768.113.76.0/2368.113.76.1 to 68.113.77.25468.113.77.255510
16868.113.78.0/2368.113.78.1 to 68.113.79.25468.113.79.255510
16968.113.80.0/2368.113.80.1 to 68.113.81.25468.113.81.255510
17068.113.82.0/2368.113.82.1 to 68.113.83.25468.113.83.255510
17168.113.84.0/2368.113.84.1 to 68.113.85.25468.113.85.255510
17268.113.86.0/2368.113.86.1 to 68.113.87.25468.113.87.255510
17368.113.88.0/2368.113.88.1 to 68.113.89.25468.113.89.255510
17468.113.90.0/2368.113.90.1 to 68.113.91.25468.113.91.255510
17568.113.92.0/2368.113.92.1 to 68.113.93.25468.113.93.255510
17668.113.94.0/2368.113.94.1 to 68.113.95.25468.113.95.255510
17768.113.96.0/2368.113.96.1 to 68.113.97.25468.113.97.255510
17868.113.98.0/2368.113.98.1 to 68.113.99.25468.113.99.255510
17968.113.100.0/2368.113.100.1 to 68.113.101.25468.113.101.255510
18068.113.102.0/2368.113.102.1 to 68.113.103.25468.113.103.255510
18168.113.104.0/2368.113.104.1 to 68.113.105.25468.113.105.255510
18268.113.106.0/2368.113.106.1 to 68.113.107.25468.113.107.255510
18368.113.108.0/2368.113.108.1 to 68.113.109.25468.113.109.255510
18468.113.110.0/2368.113.110.1 to 68.113.111.25468.113.111.255510
18568.113.112.0/2368.113.112.1 to 68.113.113.25468.113.113.255510
18668.113.114.0/2368.113.114.1 to 68.113.115.25468.113.115.255510
18768.113.116.0/2368.113.116.1 to 68.113.117.25468.113.117.255510
18868.113.118.0/2368.113.118.1 to 68.113.119.25468.113.119.255510
18968.113.120.0/2368.113.120.1 to 68.113.121.25468.113.121.255510
19068.113.122.0/2368.113.122.1 to 68.113.123.25468.113.123.255510
19168.113.124.0/2368.113.124.1 to 68.113.125.25468.113.125.255510
19268.113.126.0/2368.113.126.1 to 68.113.127.25468.113.127.255510
19368.113.128.0/2368.113.128.1 to 68.113.129.25468.113.129.255510
19468.113.130.0/2368.113.130.1 to 68.113.131.25468.113.131.255510
19568.113.132.0/2368.113.132.1 to 68.113.133.25468.113.133.255510
19668.113.134.0/2368.113.134.1 to 68.113.135.25468.113.135.255510
19768.113.136.0/2368.113.136.1 to 68.113.137.25468.113.137.255510
19868.113.138.0/2368.113.138.1 to 68.113.139.25468.113.139.255510
19968.113.140.0/2368.113.140.1 to 68.113.141.25468.113.141.255510
20068.113.142.0/2368.113.142.1 to 68.113.143.25468.113.143.255510
20168.113.144.0/2368.113.144.1 to 68.113.145.25468.113.145.255510
20268.113.146.0/2368.113.146.1 to 68.113.147.25468.113.147.255510
20368.113.148.0/2368.113.148.1 to 68.113.149.25468.113.149.255510
20468.113.150.0/2368.113.150.1 to 68.113.151.25468.113.151.255510
20568.113.152.0/2368.113.152.1 to 68.113.153.25468.113.153.255510
20668.113.154.0/2368.113.154.1 to 68.113.155.25468.113.155.255510
20768.113.156.0/2368.113.156.1 to 68.113.157.25468.113.157.255510
20868.113.158.0/2368.113.158.1 to 68.113.159.25468.113.159.255510
20968.113.160.0/2368.113.160.1 to 68.113.161.25468.113.161.255510
21068.113.162.0/2368.113.162.1 to 68.113.163.25468.113.163.255510
21168.113.164.0/2368.113.164.1 to 68.113.165.25468.113.165.255510
21268.113.166.0/2368.113.166.1 to 68.113.167.25468.113.167.255510
21368.113.168.0/2368.113.168.1 to 68.113.169.25468.113.169.255510
21468.113.170.0/2368.113.170.1 to 68.113.171.25468.113.171.255510
21568.113.172.0/2368.113.172.1 to 68.113.173.25468.113.173.255510
21668.113.174.0/2368.113.174.1 to 68.113.175.25468.113.175.255510
21768.113.176.0/2368.113.176.1 to 68.113.177.25468.113.177.255510
21868.113.178.0/2368.113.178.1 to 68.113.179.25468.113.179.255510
21968.113.180.0/2368.113.180.1 to 68.113.181.25468.113.181.255510
22068.113.182.0/2368.113.182.1 to 68.113.183.25468.113.183.255510
22168.113.184.0/2368.113.184.1 to 68.113.185.25468.113.185.255510
22268.113.186.0/2368.113.186.1 to 68.113.187.25468.113.187.255510
22368.113.188.0/2368.113.188.1 to 68.113.189.25468.113.189.255510
22468.113.190.0/2368.113.190.1 to 68.113.191.25468.113.191.255510
22568.113.192.0/2368.113.192.1 to 68.113.193.25468.113.193.255510
22668.113.194.0/2368.113.194.1 to 68.113.195.25468.113.195.255510
22768.113.196.0/2368.113.196.1 to 68.113.197.25468.113.197.255510
22868.113.198.0/2368.113.198.1 to 68.113.199.25468.113.199.255510
22968.113.200.0/2368.113.200.1 to 68.113.201.25468.113.201.255510
23068.113.202.0/2368.113.202.1 to 68.113.203.25468.113.203.255510
23168.113.204.0/2368.113.204.1 to 68.113.205.25468.113.205.255510
23268.113.206.0/2368.113.206.1 to 68.113.207.25468.113.207.255510
23368.113.208.0/2368.113.208.1 to 68.113.209.25468.113.209.255510
23468.113.210.0/2368.113.210.1 to 68.113.211.25468.113.211.255510
23568.113.212.0/2368.113.212.1 to 68.113.213.25468.113.213.255510
23668.113.214.0/2368.113.214.1 to 68.113.215.25468.113.215.255510
23768.113.216.0/2368.113.216.1 to 68.113.217.25468.113.217.255510
23868.113.218.0/2368.113.218.1 to 68.113.219.25468.113.219.255510
23968.113.220.0/2368.113.220.1 to 68.113.221.25468.113.221.255510
24068.113.222.0/2368.113.222.1 to 68.113.223.25468.113.223.255510
24168.113.224.0/2368.113.224.1 to 68.113.225.25468.113.225.255510
24268.113.226.0/2368.113.226.1 to 68.113.227.25468.113.227.255510
24368.113.228.0/2368.113.228.1 to 68.113.229.25468.113.229.255510
24468.113.230.0/2368.113.230.1 to 68.113.231.25468.113.231.255510
24568.113.232.0/2368.113.232.1 to 68.113.233.25468.113.233.255510
24668.113.234.0/2368.113.234.1 to 68.113.235.25468.113.235.255510
24768.113.236.0/2368.113.236.1 to 68.113.237.25468.113.237.255510
24868.113.238.0/2368.113.238.1 to 68.113.239.25468.113.239.255510
24968.113.240.0/2368.113.240.1 to 68.113.241.25468.113.241.255510
25068.113.242.0/2368.113.242.1 to 68.113.243.25468.113.243.255510
25168.113.244.0/2368.113.244.1 to 68.113.245.25468.113.245.255510
25268.113.246.0/2368.113.246.1 to 68.113.247.25468.113.247.255510
25368.113.248.0/2368.113.248.1 to 68.113.249.25468.113.249.255510
25468.113.250.0/2368.113.250.1 to 68.113.251.25468.113.251.255510
25568.113.252.0/2368.113.252.1 to 68.113.253.25468.113.253.255510
25668.113.254.0/2368.113.254.1 to 68.113.255.25468.113.255.255510

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.