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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.

Network36.64.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
36.64.0.0
Broadcast address
36.71.255.255
First usable
36.64.0.1
Last usable
36.71.255.254
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 24400000 · Integer 608174080 to 608698367
Reverse DNS zones
64.36.in-addr.arpa
65.36.in-addr.arpa
66.36.in-addr.arpa
67.36.in-addr.arpa
68.36.in-addr.arpa
69.36.in-addr.arpa
70.36.in-addr.arpa
71.36.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
Address00100100.01000000.00000000.0000000036.64.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network00100100.01000000.00000000.0000000036.64.0.0
Broadcast00100100.01000111.11111111.1111111136.71.255.255
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)

36.64.0.0/13 makes 1,024 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
136.64.0.0/2336.64.0.1 to 36.64.1.25436.64.1.255510
236.64.2.0/2336.64.2.1 to 36.64.3.25436.64.3.255510
336.64.4.0/2336.64.4.1 to 36.64.5.25436.64.5.255510
436.64.6.0/2336.64.6.1 to 36.64.7.25436.64.7.255510
536.64.8.0/2336.64.8.1 to 36.64.9.25436.64.9.255510
636.64.10.0/2336.64.10.1 to 36.64.11.25436.64.11.255510
736.64.12.0/2336.64.12.1 to 36.64.13.25436.64.13.255510
836.64.14.0/2336.64.14.1 to 36.64.15.25436.64.15.255510
936.64.16.0/2336.64.16.1 to 36.64.17.25436.64.17.255510
1036.64.18.0/2336.64.18.1 to 36.64.19.25436.64.19.255510
1136.64.20.0/2336.64.20.1 to 36.64.21.25436.64.21.255510
1236.64.22.0/2336.64.22.1 to 36.64.23.25436.64.23.255510
1336.64.24.0/2336.64.24.1 to 36.64.25.25436.64.25.255510
1436.64.26.0/2336.64.26.1 to 36.64.27.25436.64.27.255510
1536.64.28.0/2336.64.28.1 to 36.64.29.25436.64.29.255510
1636.64.30.0/2336.64.30.1 to 36.64.31.25436.64.31.255510
1736.64.32.0/2336.64.32.1 to 36.64.33.25436.64.33.255510
1836.64.34.0/2336.64.34.1 to 36.64.35.25436.64.35.255510
1936.64.36.0/2336.64.36.1 to 36.64.37.25436.64.37.255510
2036.64.38.0/2336.64.38.1 to 36.64.39.25436.64.39.255510
2136.64.40.0/2336.64.40.1 to 36.64.41.25436.64.41.255510
2236.64.42.0/2336.64.42.1 to 36.64.43.25436.64.43.255510
2336.64.44.0/2336.64.44.1 to 36.64.45.25436.64.45.255510
2436.64.46.0/2336.64.46.1 to 36.64.47.25436.64.47.255510
2536.64.48.0/2336.64.48.1 to 36.64.49.25436.64.49.255510
2636.64.50.0/2336.64.50.1 to 36.64.51.25436.64.51.255510
2736.64.52.0/2336.64.52.1 to 36.64.53.25436.64.53.255510
2836.64.54.0/2336.64.54.1 to 36.64.55.25436.64.55.255510
2936.64.56.0/2336.64.56.1 to 36.64.57.25436.64.57.255510
3036.64.58.0/2336.64.58.1 to 36.64.59.25436.64.59.255510
3136.64.60.0/2336.64.60.1 to 36.64.61.25436.64.61.255510
3236.64.62.0/2336.64.62.1 to 36.64.63.25436.64.63.255510
3336.64.64.0/2336.64.64.1 to 36.64.65.25436.64.65.255510
3436.64.66.0/2336.64.66.1 to 36.64.67.25436.64.67.255510
3536.64.68.0/2336.64.68.1 to 36.64.69.25436.64.69.255510
3636.64.70.0/2336.64.70.1 to 36.64.71.25436.64.71.255510
3736.64.72.0/2336.64.72.1 to 36.64.73.25436.64.73.255510
3836.64.74.0/2336.64.74.1 to 36.64.75.25436.64.75.255510
3936.64.76.0/2336.64.76.1 to 36.64.77.25436.64.77.255510
4036.64.78.0/2336.64.78.1 to 36.64.79.25436.64.79.255510
4136.64.80.0/2336.64.80.1 to 36.64.81.25436.64.81.255510
4236.64.82.0/2336.64.82.1 to 36.64.83.25436.64.83.255510
4336.64.84.0/2336.64.84.1 to 36.64.85.25436.64.85.255510
4436.64.86.0/2336.64.86.1 to 36.64.87.25436.64.87.255510
4536.64.88.0/2336.64.88.1 to 36.64.89.25436.64.89.255510
4636.64.90.0/2336.64.90.1 to 36.64.91.25436.64.91.255510
4736.64.92.0/2336.64.92.1 to 36.64.93.25436.64.93.255510
4836.64.94.0/2336.64.94.1 to 36.64.95.25436.64.95.255510
4936.64.96.0/2336.64.96.1 to 36.64.97.25436.64.97.255510
5036.64.98.0/2336.64.98.1 to 36.64.99.25436.64.99.255510
5136.64.100.0/2336.64.100.1 to 36.64.101.25436.64.101.255510
5236.64.102.0/2336.64.102.1 to 36.64.103.25436.64.103.255510
5336.64.104.0/2336.64.104.1 to 36.64.105.25436.64.105.255510
5436.64.106.0/2336.64.106.1 to 36.64.107.25436.64.107.255510
5536.64.108.0/2336.64.108.1 to 36.64.109.25436.64.109.255510
5636.64.110.0/2336.64.110.1 to 36.64.111.25436.64.111.255510
5736.64.112.0/2336.64.112.1 to 36.64.113.25436.64.113.255510
5836.64.114.0/2336.64.114.1 to 36.64.115.25436.64.115.255510
5936.64.116.0/2336.64.116.1 to 36.64.117.25436.64.117.255510
6036.64.118.0/2336.64.118.1 to 36.64.119.25436.64.119.255510
6136.64.120.0/2336.64.120.1 to 36.64.121.25436.64.121.255510
6236.64.122.0/2336.64.122.1 to 36.64.123.25436.64.123.255510
6336.64.124.0/2336.64.124.1 to 36.64.125.25436.64.125.255510
6436.64.126.0/2336.64.126.1 to 36.64.127.25436.64.127.255510
6536.64.128.0/2336.64.128.1 to 36.64.129.25436.64.129.255510
6636.64.130.0/2336.64.130.1 to 36.64.131.25436.64.131.255510
6736.64.132.0/2336.64.132.1 to 36.64.133.25436.64.133.255510
6836.64.134.0/2336.64.134.1 to 36.64.135.25436.64.135.255510
6936.64.136.0/2336.64.136.1 to 36.64.137.25436.64.137.255510
7036.64.138.0/2336.64.138.1 to 36.64.139.25436.64.139.255510
7136.64.140.0/2336.64.140.1 to 36.64.141.25436.64.141.255510
7236.64.142.0/2336.64.142.1 to 36.64.143.25436.64.143.255510
7336.64.144.0/2336.64.144.1 to 36.64.145.25436.64.145.255510
7436.64.146.0/2336.64.146.1 to 36.64.147.25436.64.147.255510
7536.64.148.0/2336.64.148.1 to 36.64.149.25436.64.149.255510
7636.64.150.0/2336.64.150.1 to 36.64.151.25436.64.151.255510
7736.64.152.0/2336.64.152.1 to 36.64.153.25436.64.153.255510
7836.64.154.0/2336.64.154.1 to 36.64.155.25436.64.155.255510
7936.64.156.0/2336.64.156.1 to 36.64.157.25436.64.157.255510
8036.64.158.0/2336.64.158.1 to 36.64.159.25436.64.159.255510
8136.64.160.0/2336.64.160.1 to 36.64.161.25436.64.161.255510
8236.64.162.0/2336.64.162.1 to 36.64.163.25436.64.163.255510
8336.64.164.0/2336.64.164.1 to 36.64.165.25436.64.165.255510
8436.64.166.0/2336.64.166.1 to 36.64.167.25436.64.167.255510
8536.64.168.0/2336.64.168.1 to 36.64.169.25436.64.169.255510
8636.64.170.0/2336.64.170.1 to 36.64.171.25436.64.171.255510
8736.64.172.0/2336.64.172.1 to 36.64.173.25436.64.173.255510
8836.64.174.0/2336.64.174.1 to 36.64.175.25436.64.175.255510
8936.64.176.0/2336.64.176.1 to 36.64.177.25436.64.177.255510
9036.64.178.0/2336.64.178.1 to 36.64.179.25436.64.179.255510
9136.64.180.0/2336.64.180.1 to 36.64.181.25436.64.181.255510
9236.64.182.0/2336.64.182.1 to 36.64.183.25436.64.183.255510
9336.64.184.0/2336.64.184.1 to 36.64.185.25436.64.185.255510
9436.64.186.0/2336.64.186.1 to 36.64.187.25436.64.187.255510
9536.64.188.0/2336.64.188.1 to 36.64.189.25436.64.189.255510
9636.64.190.0/2336.64.190.1 to 36.64.191.25436.64.191.255510
9736.64.192.0/2336.64.192.1 to 36.64.193.25436.64.193.255510
9836.64.194.0/2336.64.194.1 to 36.64.195.25436.64.195.255510
9936.64.196.0/2336.64.196.1 to 36.64.197.25436.64.197.255510
10036.64.198.0/2336.64.198.1 to 36.64.199.25436.64.199.255510
10136.64.200.0/2336.64.200.1 to 36.64.201.25436.64.201.255510
10236.64.202.0/2336.64.202.1 to 36.64.203.25436.64.203.255510
10336.64.204.0/2336.64.204.1 to 36.64.205.25436.64.205.255510
10436.64.206.0/2336.64.206.1 to 36.64.207.25436.64.207.255510
10536.64.208.0/2336.64.208.1 to 36.64.209.25436.64.209.255510
10636.64.210.0/2336.64.210.1 to 36.64.211.25436.64.211.255510
10736.64.212.0/2336.64.212.1 to 36.64.213.25436.64.213.255510
10836.64.214.0/2336.64.214.1 to 36.64.215.25436.64.215.255510
10936.64.216.0/2336.64.216.1 to 36.64.217.25436.64.217.255510
11036.64.218.0/2336.64.218.1 to 36.64.219.25436.64.219.255510
11136.64.220.0/2336.64.220.1 to 36.64.221.25436.64.221.255510
11236.64.222.0/2336.64.222.1 to 36.64.223.25436.64.223.255510
11336.64.224.0/2336.64.224.1 to 36.64.225.25436.64.225.255510
11436.64.226.0/2336.64.226.1 to 36.64.227.25436.64.227.255510
11536.64.228.0/2336.64.228.1 to 36.64.229.25436.64.229.255510
11636.64.230.0/2336.64.230.1 to 36.64.231.25436.64.231.255510
11736.64.232.0/2336.64.232.1 to 36.64.233.25436.64.233.255510
11836.64.234.0/2336.64.234.1 to 36.64.235.25436.64.235.255510
11936.64.236.0/2336.64.236.1 to 36.64.237.25436.64.237.255510
12036.64.238.0/2336.64.238.1 to 36.64.239.25436.64.239.255510
12136.64.240.0/2336.64.240.1 to 36.64.241.25436.64.241.255510
12236.64.242.0/2336.64.242.1 to 36.64.243.25436.64.243.255510
12336.64.244.0/2336.64.244.1 to 36.64.245.25436.64.245.255510
12436.64.246.0/2336.64.246.1 to 36.64.247.25436.64.247.255510
12536.64.248.0/2336.64.248.1 to 36.64.249.25436.64.249.255510
12636.64.250.0/2336.64.250.1 to 36.64.251.25436.64.251.255510
12736.64.252.0/2336.64.252.1 to 36.64.253.25436.64.253.255510
12836.64.254.0/2336.64.254.1 to 36.64.255.25436.64.255.255510
12936.65.0.0/2336.65.0.1 to 36.65.1.25436.65.1.255510
13036.65.2.0/2336.65.2.1 to 36.65.3.25436.65.3.255510
13136.65.4.0/2336.65.4.1 to 36.65.5.25436.65.5.255510
13236.65.6.0/2336.65.6.1 to 36.65.7.25436.65.7.255510
13336.65.8.0/2336.65.8.1 to 36.65.9.25436.65.9.255510
13436.65.10.0/2336.65.10.1 to 36.65.11.25436.65.11.255510
13536.65.12.0/2336.65.12.1 to 36.65.13.25436.65.13.255510
13636.65.14.0/2336.65.14.1 to 36.65.15.25436.65.15.255510
13736.65.16.0/2336.65.16.1 to 36.65.17.25436.65.17.255510
13836.65.18.0/2336.65.18.1 to 36.65.19.25436.65.19.255510
13936.65.20.0/2336.65.20.1 to 36.65.21.25436.65.21.255510
14036.65.22.0/2336.65.22.1 to 36.65.23.25436.65.23.255510
14136.65.24.0/2336.65.24.1 to 36.65.25.25436.65.25.255510
14236.65.26.0/2336.65.26.1 to 36.65.27.25436.65.27.255510
14336.65.28.0/2336.65.28.1 to 36.65.29.25436.65.29.255510
14436.65.30.0/2336.65.30.1 to 36.65.31.25436.65.31.255510
14536.65.32.0/2336.65.32.1 to 36.65.33.25436.65.33.255510
14636.65.34.0/2336.65.34.1 to 36.65.35.25436.65.35.255510
14736.65.36.0/2336.65.36.1 to 36.65.37.25436.65.37.255510
14836.65.38.0/2336.65.38.1 to 36.65.39.25436.65.39.255510
14936.65.40.0/2336.65.40.1 to 36.65.41.25436.65.41.255510
15036.65.42.0/2336.65.42.1 to 36.65.43.25436.65.43.255510
15136.65.44.0/2336.65.44.1 to 36.65.45.25436.65.45.255510
15236.65.46.0/2336.65.46.1 to 36.65.47.25436.65.47.255510
15336.65.48.0/2336.65.48.1 to 36.65.49.25436.65.49.255510
15436.65.50.0/2336.65.50.1 to 36.65.51.25436.65.51.255510
15536.65.52.0/2336.65.52.1 to 36.65.53.25436.65.53.255510
15636.65.54.0/2336.65.54.1 to 36.65.55.25436.65.55.255510
15736.65.56.0/2336.65.56.1 to 36.65.57.25436.65.57.255510
15836.65.58.0/2336.65.58.1 to 36.65.59.25436.65.59.255510
15936.65.60.0/2336.65.60.1 to 36.65.61.25436.65.61.255510
16036.65.62.0/2336.65.62.1 to 36.65.63.25436.65.63.255510
16136.65.64.0/2336.65.64.1 to 36.65.65.25436.65.65.255510
16236.65.66.0/2336.65.66.1 to 36.65.67.25436.65.67.255510
16336.65.68.0/2336.65.68.1 to 36.65.69.25436.65.69.255510
16436.65.70.0/2336.65.70.1 to 36.65.71.25436.65.71.255510
16536.65.72.0/2336.65.72.1 to 36.65.73.25436.65.73.255510
16636.65.74.0/2336.65.74.1 to 36.65.75.25436.65.75.255510
16736.65.76.0/2336.65.76.1 to 36.65.77.25436.65.77.255510
16836.65.78.0/2336.65.78.1 to 36.65.79.25436.65.79.255510
16936.65.80.0/2336.65.80.1 to 36.65.81.25436.65.81.255510
17036.65.82.0/2336.65.82.1 to 36.65.83.25436.65.83.255510
17136.65.84.0/2336.65.84.1 to 36.65.85.25436.65.85.255510
17236.65.86.0/2336.65.86.1 to 36.65.87.25436.65.87.255510
17336.65.88.0/2336.65.88.1 to 36.65.89.25436.65.89.255510
17436.65.90.0/2336.65.90.1 to 36.65.91.25436.65.91.255510
17536.65.92.0/2336.65.92.1 to 36.65.93.25436.65.93.255510
17636.65.94.0/2336.65.94.1 to 36.65.95.25436.65.95.255510
17736.65.96.0/2336.65.96.1 to 36.65.97.25436.65.97.255510
17836.65.98.0/2336.65.98.1 to 36.65.99.25436.65.99.255510
17936.65.100.0/2336.65.100.1 to 36.65.101.25436.65.101.255510
18036.65.102.0/2336.65.102.1 to 36.65.103.25436.65.103.255510
18136.65.104.0/2336.65.104.1 to 36.65.105.25436.65.105.255510
18236.65.106.0/2336.65.106.1 to 36.65.107.25436.65.107.255510
18336.65.108.0/2336.65.108.1 to 36.65.109.25436.65.109.255510
18436.65.110.0/2336.65.110.1 to 36.65.111.25436.65.111.255510
18536.65.112.0/2336.65.112.1 to 36.65.113.25436.65.113.255510
18636.65.114.0/2336.65.114.1 to 36.65.115.25436.65.115.255510
18736.65.116.0/2336.65.116.1 to 36.65.117.25436.65.117.255510
18836.65.118.0/2336.65.118.1 to 36.65.119.25436.65.119.255510
18936.65.120.0/2336.65.120.1 to 36.65.121.25436.65.121.255510
19036.65.122.0/2336.65.122.1 to 36.65.123.25436.65.123.255510
19136.65.124.0/2336.65.124.1 to 36.65.125.25436.65.125.255510
19236.65.126.0/2336.65.126.1 to 36.65.127.25436.65.127.255510
19336.65.128.0/2336.65.128.1 to 36.65.129.25436.65.129.255510
19436.65.130.0/2336.65.130.1 to 36.65.131.25436.65.131.255510
19536.65.132.0/2336.65.132.1 to 36.65.133.25436.65.133.255510
19636.65.134.0/2336.65.134.1 to 36.65.135.25436.65.135.255510
19736.65.136.0/2336.65.136.1 to 36.65.137.25436.65.137.255510
19836.65.138.0/2336.65.138.1 to 36.65.139.25436.65.139.255510
19936.65.140.0/2336.65.140.1 to 36.65.141.25436.65.141.255510
20036.65.142.0/2336.65.142.1 to 36.65.143.25436.65.143.255510
20136.65.144.0/2336.65.144.1 to 36.65.145.25436.65.145.255510
20236.65.146.0/2336.65.146.1 to 36.65.147.25436.65.147.255510
20336.65.148.0/2336.65.148.1 to 36.65.149.25436.65.149.255510
20436.65.150.0/2336.65.150.1 to 36.65.151.25436.65.151.255510
20536.65.152.0/2336.65.152.1 to 36.65.153.25436.65.153.255510
20636.65.154.0/2336.65.154.1 to 36.65.155.25436.65.155.255510
20736.65.156.0/2336.65.156.1 to 36.65.157.25436.65.157.255510
20836.65.158.0/2336.65.158.1 to 36.65.159.25436.65.159.255510
20936.65.160.0/2336.65.160.1 to 36.65.161.25436.65.161.255510
21036.65.162.0/2336.65.162.1 to 36.65.163.25436.65.163.255510
21136.65.164.0/2336.65.164.1 to 36.65.165.25436.65.165.255510
21236.65.166.0/2336.65.166.1 to 36.65.167.25436.65.167.255510
21336.65.168.0/2336.65.168.1 to 36.65.169.25436.65.169.255510
21436.65.170.0/2336.65.170.1 to 36.65.171.25436.65.171.255510
21536.65.172.0/2336.65.172.1 to 36.65.173.25436.65.173.255510
21636.65.174.0/2336.65.174.1 to 36.65.175.25436.65.175.255510
21736.65.176.0/2336.65.176.1 to 36.65.177.25436.65.177.255510
21836.65.178.0/2336.65.178.1 to 36.65.179.25436.65.179.255510
21936.65.180.0/2336.65.180.1 to 36.65.181.25436.65.181.255510
22036.65.182.0/2336.65.182.1 to 36.65.183.25436.65.183.255510
22136.65.184.0/2336.65.184.1 to 36.65.185.25436.65.185.255510
22236.65.186.0/2336.65.186.1 to 36.65.187.25436.65.187.255510
22336.65.188.0/2336.65.188.1 to 36.65.189.25436.65.189.255510
22436.65.190.0/2336.65.190.1 to 36.65.191.25436.65.191.255510
22536.65.192.0/2336.65.192.1 to 36.65.193.25436.65.193.255510
22636.65.194.0/2336.65.194.1 to 36.65.195.25436.65.195.255510
22736.65.196.0/2336.65.196.1 to 36.65.197.25436.65.197.255510
22836.65.198.0/2336.65.198.1 to 36.65.199.25436.65.199.255510
22936.65.200.0/2336.65.200.1 to 36.65.201.25436.65.201.255510
23036.65.202.0/2336.65.202.1 to 36.65.203.25436.65.203.255510
23136.65.204.0/2336.65.204.1 to 36.65.205.25436.65.205.255510
23236.65.206.0/2336.65.206.1 to 36.65.207.25436.65.207.255510
23336.65.208.0/2336.65.208.1 to 36.65.209.25436.65.209.255510
23436.65.210.0/2336.65.210.1 to 36.65.211.25436.65.211.255510
23536.65.212.0/2336.65.212.1 to 36.65.213.25436.65.213.255510
23636.65.214.0/2336.65.214.1 to 36.65.215.25436.65.215.255510
23736.65.216.0/2336.65.216.1 to 36.65.217.25436.65.217.255510
23836.65.218.0/2336.65.218.1 to 36.65.219.25436.65.219.255510
23936.65.220.0/2336.65.220.1 to 36.65.221.25436.65.221.255510
24036.65.222.0/2336.65.222.1 to 36.65.223.25436.65.223.255510
24136.65.224.0/2336.65.224.1 to 36.65.225.25436.65.225.255510
24236.65.226.0/2336.65.226.1 to 36.65.227.25436.65.227.255510
24336.65.228.0/2336.65.228.1 to 36.65.229.25436.65.229.255510
24436.65.230.0/2336.65.230.1 to 36.65.231.25436.65.231.255510
24536.65.232.0/2336.65.232.1 to 36.65.233.25436.65.233.255510
24636.65.234.0/2336.65.234.1 to 36.65.235.25436.65.235.255510
24736.65.236.0/2336.65.236.1 to 36.65.237.25436.65.237.255510
24836.65.238.0/2336.65.238.1 to 36.65.239.25436.65.239.255510
24936.65.240.0/2336.65.240.1 to 36.65.241.25436.65.241.255510
25036.65.242.0/2336.65.242.1 to 36.65.243.25436.65.243.255510
25136.65.244.0/2336.65.244.1 to 36.65.245.25436.65.245.255510
25236.65.246.0/2336.65.246.1 to 36.65.247.25436.65.247.255510
25336.65.248.0/2336.65.248.1 to 36.65.249.25436.65.249.255510
25436.65.250.0/2336.65.250.1 to 36.65.251.25436.65.251.255510
25536.65.252.0/2336.65.252.1 to 36.65.253.25436.65.253.255510
25636.65.254.0/2336.65.254.1 to 36.65.255.25436.65.255.255510

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.