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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.

Network91.136.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
91.136.0.0
Broadcast address
91.139.255.255
First usable
91.136.0.1
Last usable
91.139.255.254
Usable hosts
262,142 (262,144 less the network and broadcast addresses)
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255 (Cisco ACLs, OSPF)
Prefix length
/14
Type
Public public
Old class
A (default /8)
As numbers
Hex 5B880000 · Integer 1535639552 to 1535901695
Reverse DNS zones
136.91.in-addr.arpa
137.91.in-addr.arpa
138.91.in-addr.arpa
139.91.in-addr.arpa
/14 is not on a 8-bit boundary, so it takes 4 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01011011.10001000.00000000.0000000091.136.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network01011011.10001000.00000000.0000000091.136.0.0
Broadcast01011011.10001011.11111111.1111111191.139.255.255
Split into smaller subnets/23
/15 (2)/16 (4)/17 (8)/18 (16)/19 (32)/20 (64)/21 (128)/22 (256)/23 (512)/24 (1,024)/25 (2,048)/26 (4,096)

91.136.0.0/14 makes 512 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
191.136.0.0/2391.136.0.1 to 91.136.1.25491.136.1.255510
291.136.2.0/2391.136.2.1 to 91.136.3.25491.136.3.255510
391.136.4.0/2391.136.4.1 to 91.136.5.25491.136.5.255510
491.136.6.0/2391.136.6.1 to 91.136.7.25491.136.7.255510
591.136.8.0/2391.136.8.1 to 91.136.9.25491.136.9.255510
691.136.10.0/2391.136.10.1 to 91.136.11.25491.136.11.255510
791.136.12.0/2391.136.12.1 to 91.136.13.25491.136.13.255510
891.136.14.0/2391.136.14.1 to 91.136.15.25491.136.15.255510
991.136.16.0/2391.136.16.1 to 91.136.17.25491.136.17.255510
1091.136.18.0/2391.136.18.1 to 91.136.19.25491.136.19.255510
1191.136.20.0/2391.136.20.1 to 91.136.21.25491.136.21.255510
1291.136.22.0/2391.136.22.1 to 91.136.23.25491.136.23.255510
1391.136.24.0/2391.136.24.1 to 91.136.25.25491.136.25.255510
1491.136.26.0/2391.136.26.1 to 91.136.27.25491.136.27.255510
1591.136.28.0/2391.136.28.1 to 91.136.29.25491.136.29.255510
1691.136.30.0/2391.136.30.1 to 91.136.31.25491.136.31.255510
1791.136.32.0/2391.136.32.1 to 91.136.33.25491.136.33.255510
1891.136.34.0/2391.136.34.1 to 91.136.35.25491.136.35.255510
1991.136.36.0/2391.136.36.1 to 91.136.37.25491.136.37.255510
2091.136.38.0/2391.136.38.1 to 91.136.39.25491.136.39.255510
2191.136.40.0/2391.136.40.1 to 91.136.41.25491.136.41.255510
2291.136.42.0/2391.136.42.1 to 91.136.43.25491.136.43.255510
2391.136.44.0/2391.136.44.1 to 91.136.45.25491.136.45.255510
2491.136.46.0/2391.136.46.1 to 91.136.47.25491.136.47.255510
2591.136.48.0/2391.136.48.1 to 91.136.49.25491.136.49.255510
2691.136.50.0/2391.136.50.1 to 91.136.51.25491.136.51.255510
2791.136.52.0/2391.136.52.1 to 91.136.53.25491.136.53.255510
2891.136.54.0/2391.136.54.1 to 91.136.55.25491.136.55.255510
2991.136.56.0/2391.136.56.1 to 91.136.57.25491.136.57.255510
3091.136.58.0/2391.136.58.1 to 91.136.59.25491.136.59.255510
3191.136.60.0/2391.136.60.1 to 91.136.61.25491.136.61.255510
3291.136.62.0/2391.136.62.1 to 91.136.63.25491.136.63.255510
3391.136.64.0/2391.136.64.1 to 91.136.65.25491.136.65.255510
3491.136.66.0/2391.136.66.1 to 91.136.67.25491.136.67.255510
3591.136.68.0/2391.136.68.1 to 91.136.69.25491.136.69.255510
3691.136.70.0/2391.136.70.1 to 91.136.71.25491.136.71.255510
3791.136.72.0/2391.136.72.1 to 91.136.73.25491.136.73.255510
3891.136.74.0/2391.136.74.1 to 91.136.75.25491.136.75.255510
3991.136.76.0/2391.136.76.1 to 91.136.77.25491.136.77.255510
4091.136.78.0/2391.136.78.1 to 91.136.79.25491.136.79.255510
4191.136.80.0/2391.136.80.1 to 91.136.81.25491.136.81.255510
4291.136.82.0/2391.136.82.1 to 91.136.83.25491.136.83.255510
4391.136.84.0/2391.136.84.1 to 91.136.85.25491.136.85.255510
4491.136.86.0/2391.136.86.1 to 91.136.87.25491.136.87.255510
4591.136.88.0/2391.136.88.1 to 91.136.89.25491.136.89.255510
4691.136.90.0/2391.136.90.1 to 91.136.91.25491.136.91.255510
4791.136.92.0/2391.136.92.1 to 91.136.93.25491.136.93.255510
4891.136.94.0/2391.136.94.1 to 91.136.95.25491.136.95.255510
4991.136.96.0/2391.136.96.1 to 91.136.97.25491.136.97.255510
5091.136.98.0/2391.136.98.1 to 91.136.99.25491.136.99.255510
5191.136.100.0/2391.136.100.1 to 91.136.101.25491.136.101.255510
5291.136.102.0/2391.136.102.1 to 91.136.103.25491.136.103.255510
5391.136.104.0/2391.136.104.1 to 91.136.105.25491.136.105.255510
5491.136.106.0/2391.136.106.1 to 91.136.107.25491.136.107.255510
5591.136.108.0/2391.136.108.1 to 91.136.109.25491.136.109.255510
5691.136.110.0/2391.136.110.1 to 91.136.111.25491.136.111.255510
5791.136.112.0/2391.136.112.1 to 91.136.113.25491.136.113.255510
5891.136.114.0/2391.136.114.1 to 91.136.115.25491.136.115.255510
5991.136.116.0/2391.136.116.1 to 91.136.117.25491.136.117.255510
6091.136.118.0/2391.136.118.1 to 91.136.119.25491.136.119.255510
6191.136.120.0/2391.136.120.1 to 91.136.121.25491.136.121.255510
6291.136.122.0/2391.136.122.1 to 91.136.123.25491.136.123.255510
6391.136.124.0/2391.136.124.1 to 91.136.125.25491.136.125.255510
6491.136.126.0/2391.136.126.1 to 91.136.127.25491.136.127.255510
6591.136.128.0/2391.136.128.1 to 91.136.129.25491.136.129.255510
6691.136.130.0/2391.136.130.1 to 91.136.131.25491.136.131.255510
6791.136.132.0/2391.136.132.1 to 91.136.133.25491.136.133.255510
6891.136.134.0/2391.136.134.1 to 91.136.135.25491.136.135.255510
6991.136.136.0/2391.136.136.1 to 91.136.137.25491.136.137.255510
7091.136.138.0/2391.136.138.1 to 91.136.139.25491.136.139.255510
7191.136.140.0/2391.136.140.1 to 91.136.141.25491.136.141.255510
7291.136.142.0/2391.136.142.1 to 91.136.143.25491.136.143.255510
7391.136.144.0/2391.136.144.1 to 91.136.145.25491.136.145.255510
7491.136.146.0/2391.136.146.1 to 91.136.147.25491.136.147.255510
7591.136.148.0/2391.136.148.1 to 91.136.149.25491.136.149.255510
7691.136.150.0/2391.136.150.1 to 91.136.151.25491.136.151.255510
7791.136.152.0/2391.136.152.1 to 91.136.153.25491.136.153.255510
7891.136.154.0/2391.136.154.1 to 91.136.155.25491.136.155.255510
7991.136.156.0/2391.136.156.1 to 91.136.157.25491.136.157.255510
8091.136.158.0/2391.136.158.1 to 91.136.159.25491.136.159.255510
8191.136.160.0/2391.136.160.1 to 91.136.161.25491.136.161.255510
8291.136.162.0/2391.136.162.1 to 91.136.163.25491.136.163.255510
8391.136.164.0/2391.136.164.1 to 91.136.165.25491.136.165.255510
8491.136.166.0/2391.136.166.1 to 91.136.167.25491.136.167.255510
8591.136.168.0/2391.136.168.1 to 91.136.169.25491.136.169.255510
8691.136.170.0/2391.136.170.1 to 91.136.171.25491.136.171.255510
8791.136.172.0/2391.136.172.1 to 91.136.173.25491.136.173.255510
8891.136.174.0/2391.136.174.1 to 91.136.175.25491.136.175.255510
8991.136.176.0/2391.136.176.1 to 91.136.177.25491.136.177.255510
9091.136.178.0/2391.136.178.1 to 91.136.179.25491.136.179.255510
9191.136.180.0/2391.136.180.1 to 91.136.181.25491.136.181.255510
9291.136.182.0/2391.136.182.1 to 91.136.183.25491.136.183.255510
9391.136.184.0/2391.136.184.1 to 91.136.185.25491.136.185.255510
9491.136.186.0/2391.136.186.1 to 91.136.187.25491.136.187.255510
9591.136.188.0/2391.136.188.1 to 91.136.189.25491.136.189.255510
9691.136.190.0/2391.136.190.1 to 91.136.191.25491.136.191.255510
9791.136.192.0/2391.136.192.1 to 91.136.193.25491.136.193.255510
9891.136.194.0/2391.136.194.1 to 91.136.195.25491.136.195.255510
9991.136.196.0/2391.136.196.1 to 91.136.197.25491.136.197.255510
10091.136.198.0/2391.136.198.1 to 91.136.199.25491.136.199.255510
10191.136.200.0/2391.136.200.1 to 91.136.201.25491.136.201.255510
10291.136.202.0/2391.136.202.1 to 91.136.203.25491.136.203.255510
10391.136.204.0/2391.136.204.1 to 91.136.205.25491.136.205.255510
10491.136.206.0/2391.136.206.1 to 91.136.207.25491.136.207.255510
10591.136.208.0/2391.136.208.1 to 91.136.209.25491.136.209.255510
10691.136.210.0/2391.136.210.1 to 91.136.211.25491.136.211.255510
10791.136.212.0/2391.136.212.1 to 91.136.213.25491.136.213.255510
10891.136.214.0/2391.136.214.1 to 91.136.215.25491.136.215.255510
10991.136.216.0/2391.136.216.1 to 91.136.217.25491.136.217.255510
11091.136.218.0/2391.136.218.1 to 91.136.219.25491.136.219.255510
11191.136.220.0/2391.136.220.1 to 91.136.221.25491.136.221.255510
11291.136.222.0/2391.136.222.1 to 91.136.223.25491.136.223.255510
11391.136.224.0/2391.136.224.1 to 91.136.225.25491.136.225.255510
11491.136.226.0/2391.136.226.1 to 91.136.227.25491.136.227.255510
11591.136.228.0/2391.136.228.1 to 91.136.229.25491.136.229.255510
11691.136.230.0/2391.136.230.1 to 91.136.231.25491.136.231.255510
11791.136.232.0/2391.136.232.1 to 91.136.233.25491.136.233.255510
11891.136.234.0/2391.136.234.1 to 91.136.235.25491.136.235.255510
11991.136.236.0/2391.136.236.1 to 91.136.237.25491.136.237.255510
12091.136.238.0/2391.136.238.1 to 91.136.239.25491.136.239.255510
12191.136.240.0/2391.136.240.1 to 91.136.241.25491.136.241.255510
12291.136.242.0/2391.136.242.1 to 91.136.243.25491.136.243.255510
12391.136.244.0/2391.136.244.1 to 91.136.245.25491.136.245.255510
12491.136.246.0/2391.136.246.1 to 91.136.247.25491.136.247.255510
12591.136.248.0/2391.136.248.1 to 91.136.249.25491.136.249.255510
12691.136.250.0/2391.136.250.1 to 91.136.251.25491.136.251.255510
12791.136.252.0/2391.136.252.1 to 91.136.253.25491.136.253.255510
12891.136.254.0/2391.136.254.1 to 91.136.255.25491.136.255.255510
12991.137.0.0/2391.137.0.1 to 91.137.1.25491.137.1.255510
13091.137.2.0/2391.137.2.1 to 91.137.3.25491.137.3.255510
13191.137.4.0/2391.137.4.1 to 91.137.5.25491.137.5.255510
13291.137.6.0/2391.137.6.1 to 91.137.7.25491.137.7.255510
13391.137.8.0/2391.137.8.1 to 91.137.9.25491.137.9.255510
13491.137.10.0/2391.137.10.1 to 91.137.11.25491.137.11.255510
13591.137.12.0/2391.137.12.1 to 91.137.13.25491.137.13.255510
13691.137.14.0/2391.137.14.1 to 91.137.15.25491.137.15.255510
13791.137.16.0/2391.137.16.1 to 91.137.17.25491.137.17.255510
13891.137.18.0/2391.137.18.1 to 91.137.19.25491.137.19.255510
13991.137.20.0/2391.137.20.1 to 91.137.21.25491.137.21.255510
14091.137.22.0/2391.137.22.1 to 91.137.23.25491.137.23.255510
14191.137.24.0/2391.137.24.1 to 91.137.25.25491.137.25.255510
14291.137.26.0/2391.137.26.1 to 91.137.27.25491.137.27.255510
14391.137.28.0/2391.137.28.1 to 91.137.29.25491.137.29.255510
14491.137.30.0/2391.137.30.1 to 91.137.31.25491.137.31.255510
14591.137.32.0/2391.137.32.1 to 91.137.33.25491.137.33.255510
14691.137.34.0/2391.137.34.1 to 91.137.35.25491.137.35.255510
14791.137.36.0/2391.137.36.1 to 91.137.37.25491.137.37.255510
14891.137.38.0/2391.137.38.1 to 91.137.39.25491.137.39.255510
14991.137.40.0/2391.137.40.1 to 91.137.41.25491.137.41.255510
15091.137.42.0/2391.137.42.1 to 91.137.43.25491.137.43.255510
15191.137.44.0/2391.137.44.1 to 91.137.45.25491.137.45.255510
15291.137.46.0/2391.137.46.1 to 91.137.47.25491.137.47.255510
15391.137.48.0/2391.137.48.1 to 91.137.49.25491.137.49.255510
15491.137.50.0/2391.137.50.1 to 91.137.51.25491.137.51.255510
15591.137.52.0/2391.137.52.1 to 91.137.53.25491.137.53.255510
15691.137.54.0/2391.137.54.1 to 91.137.55.25491.137.55.255510
15791.137.56.0/2391.137.56.1 to 91.137.57.25491.137.57.255510
15891.137.58.0/2391.137.58.1 to 91.137.59.25491.137.59.255510
15991.137.60.0/2391.137.60.1 to 91.137.61.25491.137.61.255510
16091.137.62.0/2391.137.62.1 to 91.137.63.25491.137.63.255510
16191.137.64.0/2391.137.64.1 to 91.137.65.25491.137.65.255510
16291.137.66.0/2391.137.66.1 to 91.137.67.25491.137.67.255510
16391.137.68.0/2391.137.68.1 to 91.137.69.25491.137.69.255510
16491.137.70.0/2391.137.70.1 to 91.137.71.25491.137.71.255510
16591.137.72.0/2391.137.72.1 to 91.137.73.25491.137.73.255510
16691.137.74.0/2391.137.74.1 to 91.137.75.25491.137.75.255510
16791.137.76.0/2391.137.76.1 to 91.137.77.25491.137.77.255510
16891.137.78.0/2391.137.78.1 to 91.137.79.25491.137.79.255510
16991.137.80.0/2391.137.80.1 to 91.137.81.25491.137.81.255510
17091.137.82.0/2391.137.82.1 to 91.137.83.25491.137.83.255510
17191.137.84.0/2391.137.84.1 to 91.137.85.25491.137.85.255510
17291.137.86.0/2391.137.86.1 to 91.137.87.25491.137.87.255510
17391.137.88.0/2391.137.88.1 to 91.137.89.25491.137.89.255510
17491.137.90.0/2391.137.90.1 to 91.137.91.25491.137.91.255510
17591.137.92.0/2391.137.92.1 to 91.137.93.25491.137.93.255510
17691.137.94.0/2391.137.94.1 to 91.137.95.25491.137.95.255510
17791.137.96.0/2391.137.96.1 to 91.137.97.25491.137.97.255510
17891.137.98.0/2391.137.98.1 to 91.137.99.25491.137.99.255510
17991.137.100.0/2391.137.100.1 to 91.137.101.25491.137.101.255510
18091.137.102.0/2391.137.102.1 to 91.137.103.25491.137.103.255510
18191.137.104.0/2391.137.104.1 to 91.137.105.25491.137.105.255510
18291.137.106.0/2391.137.106.1 to 91.137.107.25491.137.107.255510
18391.137.108.0/2391.137.108.1 to 91.137.109.25491.137.109.255510
18491.137.110.0/2391.137.110.1 to 91.137.111.25491.137.111.255510
18591.137.112.0/2391.137.112.1 to 91.137.113.25491.137.113.255510
18691.137.114.0/2391.137.114.1 to 91.137.115.25491.137.115.255510
18791.137.116.0/2391.137.116.1 to 91.137.117.25491.137.117.255510
18891.137.118.0/2391.137.118.1 to 91.137.119.25491.137.119.255510
18991.137.120.0/2391.137.120.1 to 91.137.121.25491.137.121.255510
19091.137.122.0/2391.137.122.1 to 91.137.123.25491.137.123.255510
19191.137.124.0/2391.137.124.1 to 91.137.125.25491.137.125.255510
19291.137.126.0/2391.137.126.1 to 91.137.127.25491.137.127.255510
19391.137.128.0/2391.137.128.1 to 91.137.129.25491.137.129.255510
19491.137.130.0/2391.137.130.1 to 91.137.131.25491.137.131.255510
19591.137.132.0/2391.137.132.1 to 91.137.133.25491.137.133.255510
19691.137.134.0/2391.137.134.1 to 91.137.135.25491.137.135.255510
19791.137.136.0/2391.137.136.1 to 91.137.137.25491.137.137.255510
19891.137.138.0/2391.137.138.1 to 91.137.139.25491.137.139.255510
19991.137.140.0/2391.137.140.1 to 91.137.141.25491.137.141.255510
20091.137.142.0/2391.137.142.1 to 91.137.143.25491.137.143.255510
20191.137.144.0/2391.137.144.1 to 91.137.145.25491.137.145.255510
20291.137.146.0/2391.137.146.1 to 91.137.147.25491.137.147.255510
20391.137.148.0/2391.137.148.1 to 91.137.149.25491.137.149.255510
20491.137.150.0/2391.137.150.1 to 91.137.151.25491.137.151.255510
20591.137.152.0/2391.137.152.1 to 91.137.153.25491.137.153.255510
20691.137.154.0/2391.137.154.1 to 91.137.155.25491.137.155.255510
20791.137.156.0/2391.137.156.1 to 91.137.157.25491.137.157.255510
20891.137.158.0/2391.137.158.1 to 91.137.159.25491.137.159.255510
20991.137.160.0/2391.137.160.1 to 91.137.161.25491.137.161.255510
21091.137.162.0/2391.137.162.1 to 91.137.163.25491.137.163.255510
21191.137.164.0/2391.137.164.1 to 91.137.165.25491.137.165.255510
21291.137.166.0/2391.137.166.1 to 91.137.167.25491.137.167.255510
21391.137.168.0/2391.137.168.1 to 91.137.169.25491.137.169.255510
21491.137.170.0/2391.137.170.1 to 91.137.171.25491.137.171.255510
21591.137.172.0/2391.137.172.1 to 91.137.173.25491.137.173.255510
21691.137.174.0/2391.137.174.1 to 91.137.175.25491.137.175.255510
21791.137.176.0/2391.137.176.1 to 91.137.177.25491.137.177.255510
21891.137.178.0/2391.137.178.1 to 91.137.179.25491.137.179.255510
21991.137.180.0/2391.137.180.1 to 91.137.181.25491.137.181.255510
22091.137.182.0/2391.137.182.1 to 91.137.183.25491.137.183.255510
22191.137.184.0/2391.137.184.1 to 91.137.185.25491.137.185.255510
22291.137.186.0/2391.137.186.1 to 91.137.187.25491.137.187.255510
22391.137.188.0/2391.137.188.1 to 91.137.189.25491.137.189.255510
22491.137.190.0/2391.137.190.1 to 91.137.191.25491.137.191.255510
22591.137.192.0/2391.137.192.1 to 91.137.193.25491.137.193.255510
22691.137.194.0/2391.137.194.1 to 91.137.195.25491.137.195.255510
22791.137.196.0/2391.137.196.1 to 91.137.197.25491.137.197.255510
22891.137.198.0/2391.137.198.1 to 91.137.199.25491.137.199.255510
22991.137.200.0/2391.137.200.1 to 91.137.201.25491.137.201.255510
23091.137.202.0/2391.137.202.1 to 91.137.203.25491.137.203.255510
23191.137.204.0/2391.137.204.1 to 91.137.205.25491.137.205.255510
23291.137.206.0/2391.137.206.1 to 91.137.207.25491.137.207.255510
23391.137.208.0/2391.137.208.1 to 91.137.209.25491.137.209.255510
23491.137.210.0/2391.137.210.1 to 91.137.211.25491.137.211.255510
23591.137.212.0/2391.137.212.1 to 91.137.213.25491.137.213.255510
23691.137.214.0/2391.137.214.1 to 91.137.215.25491.137.215.255510
23791.137.216.0/2391.137.216.1 to 91.137.217.25491.137.217.255510
23891.137.218.0/2391.137.218.1 to 91.137.219.25491.137.219.255510
23991.137.220.0/2391.137.220.1 to 91.137.221.25491.137.221.255510
24091.137.222.0/2391.137.222.1 to 91.137.223.25491.137.223.255510
24191.137.224.0/2391.137.224.1 to 91.137.225.25491.137.225.255510
24291.137.226.0/2391.137.226.1 to 91.137.227.25491.137.227.255510
24391.137.228.0/2391.137.228.1 to 91.137.229.25491.137.229.255510
24491.137.230.0/2391.137.230.1 to 91.137.231.25491.137.231.255510
24591.137.232.0/2391.137.232.1 to 91.137.233.25491.137.233.255510
24691.137.234.0/2391.137.234.1 to 91.137.235.25491.137.235.255510
24791.137.236.0/2391.137.236.1 to 91.137.237.25491.137.237.255510
24891.137.238.0/2391.137.238.1 to 91.137.239.25491.137.239.255510
24991.137.240.0/2391.137.240.1 to 91.137.241.25491.137.241.255510
25091.137.242.0/2391.137.242.1 to 91.137.243.25491.137.243.255510
25191.137.244.0/2391.137.244.1 to 91.137.245.25491.137.245.255510
25291.137.246.0/2391.137.246.1 to 91.137.247.25491.137.247.255510
25391.137.248.0/2391.137.248.1 to 91.137.249.25491.137.249.255510
25491.137.250.0/2391.137.250.1 to 91.137.251.25491.137.251.255510
25591.137.252.0/2391.137.252.1 to 91.137.253.25491.137.253.255510
25691.137.254.0/2391.137.254.1 to 91.137.255.25491.137.255.255510

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.