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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.

Network64.232.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
64.232.0.0
Broadcast address
64.239.255.255
First usable
64.232.0.1
Last usable
64.239.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
A (default /8)
As numbers
Hex 40E80000 · Integer 1088946176 to 1089470463
Reverse DNS zones
232.64.in-addr.arpa
233.64.in-addr.arpa
234.64.in-addr.arpa
235.64.in-addr.arpa
236.64.in-addr.arpa
237.64.in-addr.arpa
238.64.in-addr.arpa
239.64.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01000000.11101000.00000000.0000000064.232.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network01000000.11101000.00000000.0000000064.232.0.0
Broadcast01000000.11101111.11111111.1111111164.239.255.255
Split into smaller subnets/23
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

64.232.0.0/13 makes 1,024 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
164.232.0.0/2364.232.0.1 to 64.232.1.25464.232.1.255510
264.232.2.0/2364.232.2.1 to 64.232.3.25464.232.3.255510
364.232.4.0/2364.232.4.1 to 64.232.5.25464.232.5.255510
464.232.6.0/2364.232.6.1 to 64.232.7.25464.232.7.255510
564.232.8.0/2364.232.8.1 to 64.232.9.25464.232.9.255510
664.232.10.0/2364.232.10.1 to 64.232.11.25464.232.11.255510
764.232.12.0/2364.232.12.1 to 64.232.13.25464.232.13.255510
864.232.14.0/2364.232.14.1 to 64.232.15.25464.232.15.255510
964.232.16.0/2364.232.16.1 to 64.232.17.25464.232.17.255510
1064.232.18.0/2364.232.18.1 to 64.232.19.25464.232.19.255510
1164.232.20.0/2364.232.20.1 to 64.232.21.25464.232.21.255510
1264.232.22.0/2364.232.22.1 to 64.232.23.25464.232.23.255510
1364.232.24.0/2364.232.24.1 to 64.232.25.25464.232.25.255510
1464.232.26.0/2364.232.26.1 to 64.232.27.25464.232.27.255510
1564.232.28.0/2364.232.28.1 to 64.232.29.25464.232.29.255510
1664.232.30.0/2364.232.30.1 to 64.232.31.25464.232.31.255510
1764.232.32.0/2364.232.32.1 to 64.232.33.25464.232.33.255510
1864.232.34.0/2364.232.34.1 to 64.232.35.25464.232.35.255510
1964.232.36.0/2364.232.36.1 to 64.232.37.25464.232.37.255510
2064.232.38.0/2364.232.38.1 to 64.232.39.25464.232.39.255510
2164.232.40.0/2364.232.40.1 to 64.232.41.25464.232.41.255510
2264.232.42.0/2364.232.42.1 to 64.232.43.25464.232.43.255510
2364.232.44.0/2364.232.44.1 to 64.232.45.25464.232.45.255510
2464.232.46.0/2364.232.46.1 to 64.232.47.25464.232.47.255510
2564.232.48.0/2364.232.48.1 to 64.232.49.25464.232.49.255510
2664.232.50.0/2364.232.50.1 to 64.232.51.25464.232.51.255510
2764.232.52.0/2364.232.52.1 to 64.232.53.25464.232.53.255510
2864.232.54.0/2364.232.54.1 to 64.232.55.25464.232.55.255510
2964.232.56.0/2364.232.56.1 to 64.232.57.25464.232.57.255510
3064.232.58.0/2364.232.58.1 to 64.232.59.25464.232.59.255510
3164.232.60.0/2364.232.60.1 to 64.232.61.25464.232.61.255510
3264.232.62.0/2364.232.62.1 to 64.232.63.25464.232.63.255510
3364.232.64.0/2364.232.64.1 to 64.232.65.25464.232.65.255510
3464.232.66.0/2364.232.66.1 to 64.232.67.25464.232.67.255510
3564.232.68.0/2364.232.68.1 to 64.232.69.25464.232.69.255510
3664.232.70.0/2364.232.70.1 to 64.232.71.25464.232.71.255510
3764.232.72.0/2364.232.72.1 to 64.232.73.25464.232.73.255510
3864.232.74.0/2364.232.74.1 to 64.232.75.25464.232.75.255510
3964.232.76.0/2364.232.76.1 to 64.232.77.25464.232.77.255510
4064.232.78.0/2364.232.78.1 to 64.232.79.25464.232.79.255510
4164.232.80.0/2364.232.80.1 to 64.232.81.25464.232.81.255510
4264.232.82.0/2364.232.82.1 to 64.232.83.25464.232.83.255510
4364.232.84.0/2364.232.84.1 to 64.232.85.25464.232.85.255510
4464.232.86.0/2364.232.86.1 to 64.232.87.25464.232.87.255510
4564.232.88.0/2364.232.88.1 to 64.232.89.25464.232.89.255510
4664.232.90.0/2364.232.90.1 to 64.232.91.25464.232.91.255510
4764.232.92.0/2364.232.92.1 to 64.232.93.25464.232.93.255510
4864.232.94.0/2364.232.94.1 to 64.232.95.25464.232.95.255510
4964.232.96.0/2364.232.96.1 to 64.232.97.25464.232.97.255510
5064.232.98.0/2364.232.98.1 to 64.232.99.25464.232.99.255510
5164.232.100.0/2364.232.100.1 to 64.232.101.25464.232.101.255510
5264.232.102.0/2364.232.102.1 to 64.232.103.25464.232.103.255510
5364.232.104.0/2364.232.104.1 to 64.232.105.25464.232.105.255510
5464.232.106.0/2364.232.106.1 to 64.232.107.25464.232.107.255510
5564.232.108.0/2364.232.108.1 to 64.232.109.25464.232.109.255510
5664.232.110.0/2364.232.110.1 to 64.232.111.25464.232.111.255510
5764.232.112.0/2364.232.112.1 to 64.232.113.25464.232.113.255510
5864.232.114.0/2364.232.114.1 to 64.232.115.25464.232.115.255510
5964.232.116.0/2364.232.116.1 to 64.232.117.25464.232.117.255510
6064.232.118.0/2364.232.118.1 to 64.232.119.25464.232.119.255510
6164.232.120.0/2364.232.120.1 to 64.232.121.25464.232.121.255510
6264.232.122.0/2364.232.122.1 to 64.232.123.25464.232.123.255510
6364.232.124.0/2364.232.124.1 to 64.232.125.25464.232.125.255510
6464.232.126.0/2364.232.126.1 to 64.232.127.25464.232.127.255510
6564.232.128.0/2364.232.128.1 to 64.232.129.25464.232.129.255510
6664.232.130.0/2364.232.130.1 to 64.232.131.25464.232.131.255510
6764.232.132.0/2364.232.132.1 to 64.232.133.25464.232.133.255510
6864.232.134.0/2364.232.134.1 to 64.232.135.25464.232.135.255510
6964.232.136.0/2364.232.136.1 to 64.232.137.25464.232.137.255510
7064.232.138.0/2364.232.138.1 to 64.232.139.25464.232.139.255510
7164.232.140.0/2364.232.140.1 to 64.232.141.25464.232.141.255510
7264.232.142.0/2364.232.142.1 to 64.232.143.25464.232.143.255510
7364.232.144.0/2364.232.144.1 to 64.232.145.25464.232.145.255510
7464.232.146.0/2364.232.146.1 to 64.232.147.25464.232.147.255510
7564.232.148.0/2364.232.148.1 to 64.232.149.25464.232.149.255510
7664.232.150.0/2364.232.150.1 to 64.232.151.25464.232.151.255510
7764.232.152.0/2364.232.152.1 to 64.232.153.25464.232.153.255510
7864.232.154.0/2364.232.154.1 to 64.232.155.25464.232.155.255510
7964.232.156.0/2364.232.156.1 to 64.232.157.25464.232.157.255510
8064.232.158.0/2364.232.158.1 to 64.232.159.25464.232.159.255510
8164.232.160.0/2364.232.160.1 to 64.232.161.25464.232.161.255510
8264.232.162.0/2364.232.162.1 to 64.232.163.25464.232.163.255510
8364.232.164.0/2364.232.164.1 to 64.232.165.25464.232.165.255510
8464.232.166.0/2364.232.166.1 to 64.232.167.25464.232.167.255510
8564.232.168.0/2364.232.168.1 to 64.232.169.25464.232.169.255510
8664.232.170.0/2364.232.170.1 to 64.232.171.25464.232.171.255510
8764.232.172.0/2364.232.172.1 to 64.232.173.25464.232.173.255510
8864.232.174.0/2364.232.174.1 to 64.232.175.25464.232.175.255510
8964.232.176.0/2364.232.176.1 to 64.232.177.25464.232.177.255510
9064.232.178.0/2364.232.178.1 to 64.232.179.25464.232.179.255510
9164.232.180.0/2364.232.180.1 to 64.232.181.25464.232.181.255510
9264.232.182.0/2364.232.182.1 to 64.232.183.25464.232.183.255510
9364.232.184.0/2364.232.184.1 to 64.232.185.25464.232.185.255510
9464.232.186.0/2364.232.186.1 to 64.232.187.25464.232.187.255510
9564.232.188.0/2364.232.188.1 to 64.232.189.25464.232.189.255510
9664.232.190.0/2364.232.190.1 to 64.232.191.25464.232.191.255510
9764.232.192.0/2364.232.192.1 to 64.232.193.25464.232.193.255510
9864.232.194.0/2364.232.194.1 to 64.232.195.25464.232.195.255510
9964.232.196.0/2364.232.196.1 to 64.232.197.25464.232.197.255510
10064.232.198.0/2364.232.198.1 to 64.232.199.25464.232.199.255510
10164.232.200.0/2364.232.200.1 to 64.232.201.25464.232.201.255510
10264.232.202.0/2364.232.202.1 to 64.232.203.25464.232.203.255510
10364.232.204.0/2364.232.204.1 to 64.232.205.25464.232.205.255510
10464.232.206.0/2364.232.206.1 to 64.232.207.25464.232.207.255510
10564.232.208.0/2364.232.208.1 to 64.232.209.25464.232.209.255510
10664.232.210.0/2364.232.210.1 to 64.232.211.25464.232.211.255510
10764.232.212.0/2364.232.212.1 to 64.232.213.25464.232.213.255510
10864.232.214.0/2364.232.214.1 to 64.232.215.25464.232.215.255510
10964.232.216.0/2364.232.216.1 to 64.232.217.25464.232.217.255510
11064.232.218.0/2364.232.218.1 to 64.232.219.25464.232.219.255510
11164.232.220.0/2364.232.220.1 to 64.232.221.25464.232.221.255510
11264.232.222.0/2364.232.222.1 to 64.232.223.25464.232.223.255510
11364.232.224.0/2364.232.224.1 to 64.232.225.25464.232.225.255510
11464.232.226.0/2364.232.226.1 to 64.232.227.25464.232.227.255510
11564.232.228.0/2364.232.228.1 to 64.232.229.25464.232.229.255510
11664.232.230.0/2364.232.230.1 to 64.232.231.25464.232.231.255510
11764.232.232.0/2364.232.232.1 to 64.232.233.25464.232.233.255510
11864.232.234.0/2364.232.234.1 to 64.232.235.25464.232.235.255510
11964.232.236.0/2364.232.236.1 to 64.232.237.25464.232.237.255510
12064.232.238.0/2364.232.238.1 to 64.232.239.25464.232.239.255510
12164.232.240.0/2364.232.240.1 to 64.232.241.25464.232.241.255510
12264.232.242.0/2364.232.242.1 to 64.232.243.25464.232.243.255510
12364.232.244.0/2364.232.244.1 to 64.232.245.25464.232.245.255510
12464.232.246.0/2364.232.246.1 to 64.232.247.25464.232.247.255510
12564.232.248.0/2364.232.248.1 to 64.232.249.25464.232.249.255510
12664.232.250.0/2364.232.250.1 to 64.232.251.25464.232.251.255510
12764.232.252.0/2364.232.252.1 to 64.232.253.25464.232.253.255510
12864.232.254.0/2364.232.254.1 to 64.232.255.25464.232.255.255510
12964.233.0.0/2364.233.0.1 to 64.233.1.25464.233.1.255510
13064.233.2.0/2364.233.2.1 to 64.233.3.25464.233.3.255510
13164.233.4.0/2364.233.4.1 to 64.233.5.25464.233.5.255510
13264.233.6.0/2364.233.6.1 to 64.233.7.25464.233.7.255510
13364.233.8.0/2364.233.8.1 to 64.233.9.25464.233.9.255510
13464.233.10.0/2364.233.10.1 to 64.233.11.25464.233.11.255510
13564.233.12.0/2364.233.12.1 to 64.233.13.25464.233.13.255510
13664.233.14.0/2364.233.14.1 to 64.233.15.25464.233.15.255510
13764.233.16.0/2364.233.16.1 to 64.233.17.25464.233.17.255510
13864.233.18.0/2364.233.18.1 to 64.233.19.25464.233.19.255510
13964.233.20.0/2364.233.20.1 to 64.233.21.25464.233.21.255510
14064.233.22.0/2364.233.22.1 to 64.233.23.25464.233.23.255510
14164.233.24.0/2364.233.24.1 to 64.233.25.25464.233.25.255510
14264.233.26.0/2364.233.26.1 to 64.233.27.25464.233.27.255510
14364.233.28.0/2364.233.28.1 to 64.233.29.25464.233.29.255510
14464.233.30.0/2364.233.30.1 to 64.233.31.25464.233.31.255510
14564.233.32.0/2364.233.32.1 to 64.233.33.25464.233.33.255510
14664.233.34.0/2364.233.34.1 to 64.233.35.25464.233.35.255510
14764.233.36.0/2364.233.36.1 to 64.233.37.25464.233.37.255510
14864.233.38.0/2364.233.38.1 to 64.233.39.25464.233.39.255510
14964.233.40.0/2364.233.40.1 to 64.233.41.25464.233.41.255510
15064.233.42.0/2364.233.42.1 to 64.233.43.25464.233.43.255510
15164.233.44.0/2364.233.44.1 to 64.233.45.25464.233.45.255510
15264.233.46.0/2364.233.46.1 to 64.233.47.25464.233.47.255510
15364.233.48.0/2364.233.48.1 to 64.233.49.25464.233.49.255510
15464.233.50.0/2364.233.50.1 to 64.233.51.25464.233.51.255510
15564.233.52.0/2364.233.52.1 to 64.233.53.25464.233.53.255510
15664.233.54.0/2364.233.54.1 to 64.233.55.25464.233.55.255510
15764.233.56.0/2364.233.56.1 to 64.233.57.25464.233.57.255510
15864.233.58.0/2364.233.58.1 to 64.233.59.25464.233.59.255510
15964.233.60.0/2364.233.60.1 to 64.233.61.25464.233.61.255510
16064.233.62.0/2364.233.62.1 to 64.233.63.25464.233.63.255510
16164.233.64.0/2364.233.64.1 to 64.233.65.25464.233.65.255510
16264.233.66.0/2364.233.66.1 to 64.233.67.25464.233.67.255510
16364.233.68.0/2364.233.68.1 to 64.233.69.25464.233.69.255510
16464.233.70.0/2364.233.70.1 to 64.233.71.25464.233.71.255510
16564.233.72.0/2364.233.72.1 to 64.233.73.25464.233.73.255510
16664.233.74.0/2364.233.74.1 to 64.233.75.25464.233.75.255510
16764.233.76.0/2364.233.76.1 to 64.233.77.25464.233.77.255510
16864.233.78.0/2364.233.78.1 to 64.233.79.25464.233.79.255510
16964.233.80.0/2364.233.80.1 to 64.233.81.25464.233.81.255510
17064.233.82.0/2364.233.82.1 to 64.233.83.25464.233.83.255510
17164.233.84.0/2364.233.84.1 to 64.233.85.25464.233.85.255510
17264.233.86.0/2364.233.86.1 to 64.233.87.25464.233.87.255510
17364.233.88.0/2364.233.88.1 to 64.233.89.25464.233.89.255510
17464.233.90.0/2364.233.90.1 to 64.233.91.25464.233.91.255510
17564.233.92.0/2364.233.92.1 to 64.233.93.25464.233.93.255510
17664.233.94.0/2364.233.94.1 to 64.233.95.25464.233.95.255510
17764.233.96.0/2364.233.96.1 to 64.233.97.25464.233.97.255510
17864.233.98.0/2364.233.98.1 to 64.233.99.25464.233.99.255510
17964.233.100.0/2364.233.100.1 to 64.233.101.25464.233.101.255510
18064.233.102.0/2364.233.102.1 to 64.233.103.25464.233.103.255510
18164.233.104.0/2364.233.104.1 to 64.233.105.25464.233.105.255510
18264.233.106.0/2364.233.106.1 to 64.233.107.25464.233.107.255510
18364.233.108.0/2364.233.108.1 to 64.233.109.25464.233.109.255510
18464.233.110.0/2364.233.110.1 to 64.233.111.25464.233.111.255510
18564.233.112.0/2364.233.112.1 to 64.233.113.25464.233.113.255510
18664.233.114.0/2364.233.114.1 to 64.233.115.25464.233.115.255510
18764.233.116.0/2364.233.116.1 to 64.233.117.25464.233.117.255510
18864.233.118.0/2364.233.118.1 to 64.233.119.25464.233.119.255510
18964.233.120.0/2364.233.120.1 to 64.233.121.25464.233.121.255510
19064.233.122.0/2364.233.122.1 to 64.233.123.25464.233.123.255510
19164.233.124.0/2364.233.124.1 to 64.233.125.25464.233.125.255510
19264.233.126.0/2364.233.126.1 to 64.233.127.25464.233.127.255510
19364.233.128.0/2364.233.128.1 to 64.233.129.25464.233.129.255510
19464.233.130.0/2364.233.130.1 to 64.233.131.25464.233.131.255510
19564.233.132.0/2364.233.132.1 to 64.233.133.25464.233.133.255510
19664.233.134.0/2364.233.134.1 to 64.233.135.25464.233.135.255510
19764.233.136.0/2364.233.136.1 to 64.233.137.25464.233.137.255510
19864.233.138.0/2364.233.138.1 to 64.233.139.25464.233.139.255510
19964.233.140.0/2364.233.140.1 to 64.233.141.25464.233.141.255510
20064.233.142.0/2364.233.142.1 to 64.233.143.25464.233.143.255510
20164.233.144.0/2364.233.144.1 to 64.233.145.25464.233.145.255510
20264.233.146.0/2364.233.146.1 to 64.233.147.25464.233.147.255510
20364.233.148.0/2364.233.148.1 to 64.233.149.25464.233.149.255510
20464.233.150.0/2364.233.150.1 to 64.233.151.25464.233.151.255510
20564.233.152.0/2364.233.152.1 to 64.233.153.25464.233.153.255510
20664.233.154.0/2364.233.154.1 to 64.233.155.25464.233.155.255510
20764.233.156.0/2364.233.156.1 to 64.233.157.25464.233.157.255510
20864.233.158.0/2364.233.158.1 to 64.233.159.25464.233.159.255510
20964.233.160.0/2364.233.160.1 to 64.233.161.25464.233.161.255510
21064.233.162.0/2364.233.162.1 to 64.233.163.25464.233.163.255510
21164.233.164.0/2364.233.164.1 to 64.233.165.25464.233.165.255510
21264.233.166.0/2364.233.166.1 to 64.233.167.25464.233.167.255510
21364.233.168.0/2364.233.168.1 to 64.233.169.25464.233.169.255510
21464.233.170.0/2364.233.170.1 to 64.233.171.25464.233.171.255510
21564.233.172.0/2364.233.172.1 to 64.233.173.25464.233.173.255510
21664.233.174.0/2364.233.174.1 to 64.233.175.25464.233.175.255510
21764.233.176.0/2364.233.176.1 to 64.233.177.25464.233.177.255510
21864.233.178.0/2364.233.178.1 to 64.233.179.25464.233.179.255510
21964.233.180.0/2364.233.180.1 to 64.233.181.25464.233.181.255510
22064.233.182.0/2364.233.182.1 to 64.233.183.25464.233.183.255510
22164.233.184.0/2364.233.184.1 to 64.233.185.25464.233.185.255510
22264.233.186.0/2364.233.186.1 to 64.233.187.25464.233.187.255510
22364.233.188.0/2364.233.188.1 to 64.233.189.25464.233.189.255510
22464.233.190.0/2364.233.190.1 to 64.233.191.25464.233.191.255510
22564.233.192.0/2364.233.192.1 to 64.233.193.25464.233.193.255510
22664.233.194.0/2364.233.194.1 to 64.233.195.25464.233.195.255510
22764.233.196.0/2364.233.196.1 to 64.233.197.25464.233.197.255510
22864.233.198.0/2364.233.198.1 to 64.233.199.25464.233.199.255510
22964.233.200.0/2364.233.200.1 to 64.233.201.25464.233.201.255510
23064.233.202.0/2364.233.202.1 to 64.233.203.25464.233.203.255510
23164.233.204.0/2364.233.204.1 to 64.233.205.25464.233.205.255510
23264.233.206.0/2364.233.206.1 to 64.233.207.25464.233.207.255510
23364.233.208.0/2364.233.208.1 to 64.233.209.25464.233.209.255510
23464.233.210.0/2364.233.210.1 to 64.233.211.25464.233.211.255510
23564.233.212.0/2364.233.212.1 to 64.233.213.25464.233.213.255510
23664.233.214.0/2364.233.214.1 to 64.233.215.25464.233.215.255510
23764.233.216.0/2364.233.216.1 to 64.233.217.25464.233.217.255510
23864.233.218.0/2364.233.218.1 to 64.233.219.25464.233.219.255510
23964.233.220.0/2364.233.220.1 to 64.233.221.25464.233.221.255510
24064.233.222.0/2364.233.222.1 to 64.233.223.25464.233.223.255510
24164.233.224.0/2364.233.224.1 to 64.233.225.25464.233.225.255510
24264.233.226.0/2364.233.226.1 to 64.233.227.25464.233.227.255510
24364.233.228.0/2364.233.228.1 to 64.233.229.25464.233.229.255510
24464.233.230.0/2364.233.230.1 to 64.233.231.25464.233.231.255510
24564.233.232.0/2364.233.232.1 to 64.233.233.25464.233.233.255510
24664.233.234.0/2364.233.234.1 to 64.233.235.25464.233.235.255510
24764.233.236.0/2364.233.236.1 to 64.233.237.25464.233.237.255510
24864.233.238.0/2364.233.238.1 to 64.233.239.25464.233.239.255510
24964.233.240.0/2364.233.240.1 to 64.233.241.25464.233.241.255510
25064.233.242.0/2364.233.242.1 to 64.233.243.25464.233.243.255510
25164.233.244.0/2364.233.244.1 to 64.233.245.25464.233.245.255510
25264.233.246.0/2364.233.246.1 to 64.233.247.25464.233.247.255510
25364.233.248.0/2364.233.248.1 to 64.233.249.25464.233.249.255510
25464.233.250.0/2364.233.250.1 to 64.233.251.25464.233.251.255510
25564.233.252.0/2364.233.252.1 to 64.233.253.25464.233.253.255510
25664.233.254.0/2364.233.254.1 to 64.233.255.25464.233.255.255510

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.