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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.

Network52.64.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
52.64.0.0
Broadcast address
52.79.255.255
First usable
52.64.0.1
Last usable
52.79.255.254
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 34400000 · Integer 876609536 to 877658111
Reverse DNS zones
64.52.in-addr.arpa
65.52.in-addr.arpa
66.52.in-addr.arpa
67.52.in-addr.arpa
68.52.in-addr.arpa
69.52.in-addr.arpa
70.52.in-addr.arpa
71.52.in-addr.arpa
72.52.in-addr.arpa
73.52.in-addr.arpa
74.52.in-addr.arpa
75.52.in-addr.arpa
76.52.in-addr.arpa
77.52.in-addr.arpa
78.52.in-addr.arpa
79.52.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
Address00110100.01000000.00000000.0000000052.64.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network00110100.01000000.00000000.0000000052.64.0.0
Broadcast00110100.01001111.11111111.1111111152.79.255.255
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)

52.64.0.0/12 makes 2,048 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
152.64.0.0/2352.64.0.1 to 52.64.1.25452.64.1.255510
252.64.2.0/2352.64.2.1 to 52.64.3.25452.64.3.255510
352.64.4.0/2352.64.4.1 to 52.64.5.25452.64.5.255510
452.64.6.0/2352.64.6.1 to 52.64.7.25452.64.7.255510
552.64.8.0/2352.64.8.1 to 52.64.9.25452.64.9.255510
652.64.10.0/2352.64.10.1 to 52.64.11.25452.64.11.255510
752.64.12.0/2352.64.12.1 to 52.64.13.25452.64.13.255510
852.64.14.0/2352.64.14.1 to 52.64.15.25452.64.15.255510
952.64.16.0/2352.64.16.1 to 52.64.17.25452.64.17.255510
1052.64.18.0/2352.64.18.1 to 52.64.19.25452.64.19.255510
1152.64.20.0/2352.64.20.1 to 52.64.21.25452.64.21.255510
1252.64.22.0/2352.64.22.1 to 52.64.23.25452.64.23.255510
1352.64.24.0/2352.64.24.1 to 52.64.25.25452.64.25.255510
1452.64.26.0/2352.64.26.1 to 52.64.27.25452.64.27.255510
1552.64.28.0/2352.64.28.1 to 52.64.29.25452.64.29.255510
1652.64.30.0/2352.64.30.1 to 52.64.31.25452.64.31.255510
1752.64.32.0/2352.64.32.1 to 52.64.33.25452.64.33.255510
1852.64.34.0/2352.64.34.1 to 52.64.35.25452.64.35.255510
1952.64.36.0/2352.64.36.1 to 52.64.37.25452.64.37.255510
2052.64.38.0/2352.64.38.1 to 52.64.39.25452.64.39.255510
2152.64.40.0/2352.64.40.1 to 52.64.41.25452.64.41.255510
2252.64.42.0/2352.64.42.1 to 52.64.43.25452.64.43.255510
2352.64.44.0/2352.64.44.1 to 52.64.45.25452.64.45.255510
2452.64.46.0/2352.64.46.1 to 52.64.47.25452.64.47.255510
2552.64.48.0/2352.64.48.1 to 52.64.49.25452.64.49.255510
2652.64.50.0/2352.64.50.1 to 52.64.51.25452.64.51.255510
2752.64.52.0/2352.64.52.1 to 52.64.53.25452.64.53.255510
2852.64.54.0/2352.64.54.1 to 52.64.55.25452.64.55.255510
2952.64.56.0/2352.64.56.1 to 52.64.57.25452.64.57.255510
3052.64.58.0/2352.64.58.1 to 52.64.59.25452.64.59.255510
3152.64.60.0/2352.64.60.1 to 52.64.61.25452.64.61.255510
3252.64.62.0/2352.64.62.1 to 52.64.63.25452.64.63.255510
3352.64.64.0/2352.64.64.1 to 52.64.65.25452.64.65.255510
3452.64.66.0/2352.64.66.1 to 52.64.67.25452.64.67.255510
3552.64.68.0/2352.64.68.1 to 52.64.69.25452.64.69.255510
3652.64.70.0/2352.64.70.1 to 52.64.71.25452.64.71.255510
3752.64.72.0/2352.64.72.1 to 52.64.73.25452.64.73.255510
3852.64.74.0/2352.64.74.1 to 52.64.75.25452.64.75.255510
3952.64.76.0/2352.64.76.1 to 52.64.77.25452.64.77.255510
4052.64.78.0/2352.64.78.1 to 52.64.79.25452.64.79.255510
4152.64.80.0/2352.64.80.1 to 52.64.81.25452.64.81.255510
4252.64.82.0/2352.64.82.1 to 52.64.83.25452.64.83.255510
4352.64.84.0/2352.64.84.1 to 52.64.85.25452.64.85.255510
4452.64.86.0/2352.64.86.1 to 52.64.87.25452.64.87.255510
4552.64.88.0/2352.64.88.1 to 52.64.89.25452.64.89.255510
4652.64.90.0/2352.64.90.1 to 52.64.91.25452.64.91.255510
4752.64.92.0/2352.64.92.1 to 52.64.93.25452.64.93.255510
4852.64.94.0/2352.64.94.1 to 52.64.95.25452.64.95.255510
4952.64.96.0/2352.64.96.1 to 52.64.97.25452.64.97.255510
5052.64.98.0/2352.64.98.1 to 52.64.99.25452.64.99.255510
5152.64.100.0/2352.64.100.1 to 52.64.101.25452.64.101.255510
5252.64.102.0/2352.64.102.1 to 52.64.103.25452.64.103.255510
5352.64.104.0/2352.64.104.1 to 52.64.105.25452.64.105.255510
5452.64.106.0/2352.64.106.1 to 52.64.107.25452.64.107.255510
5552.64.108.0/2352.64.108.1 to 52.64.109.25452.64.109.255510
5652.64.110.0/2352.64.110.1 to 52.64.111.25452.64.111.255510
5752.64.112.0/2352.64.112.1 to 52.64.113.25452.64.113.255510
5852.64.114.0/2352.64.114.1 to 52.64.115.25452.64.115.255510
5952.64.116.0/2352.64.116.1 to 52.64.117.25452.64.117.255510
6052.64.118.0/2352.64.118.1 to 52.64.119.25452.64.119.255510
6152.64.120.0/2352.64.120.1 to 52.64.121.25452.64.121.255510
6252.64.122.0/2352.64.122.1 to 52.64.123.25452.64.123.255510
6352.64.124.0/2352.64.124.1 to 52.64.125.25452.64.125.255510
6452.64.126.0/2352.64.126.1 to 52.64.127.25452.64.127.255510
6552.64.128.0/2352.64.128.1 to 52.64.129.25452.64.129.255510
6652.64.130.0/2352.64.130.1 to 52.64.131.25452.64.131.255510
6752.64.132.0/2352.64.132.1 to 52.64.133.25452.64.133.255510
6852.64.134.0/2352.64.134.1 to 52.64.135.25452.64.135.255510
6952.64.136.0/2352.64.136.1 to 52.64.137.25452.64.137.255510
7052.64.138.0/2352.64.138.1 to 52.64.139.25452.64.139.255510
7152.64.140.0/2352.64.140.1 to 52.64.141.25452.64.141.255510
7252.64.142.0/2352.64.142.1 to 52.64.143.25452.64.143.255510
7352.64.144.0/2352.64.144.1 to 52.64.145.25452.64.145.255510
7452.64.146.0/2352.64.146.1 to 52.64.147.25452.64.147.255510
7552.64.148.0/2352.64.148.1 to 52.64.149.25452.64.149.255510
7652.64.150.0/2352.64.150.1 to 52.64.151.25452.64.151.255510
7752.64.152.0/2352.64.152.1 to 52.64.153.25452.64.153.255510
7852.64.154.0/2352.64.154.1 to 52.64.155.25452.64.155.255510
7952.64.156.0/2352.64.156.1 to 52.64.157.25452.64.157.255510
8052.64.158.0/2352.64.158.1 to 52.64.159.25452.64.159.255510
8152.64.160.0/2352.64.160.1 to 52.64.161.25452.64.161.255510
8252.64.162.0/2352.64.162.1 to 52.64.163.25452.64.163.255510
8352.64.164.0/2352.64.164.1 to 52.64.165.25452.64.165.255510
8452.64.166.0/2352.64.166.1 to 52.64.167.25452.64.167.255510
8552.64.168.0/2352.64.168.1 to 52.64.169.25452.64.169.255510
8652.64.170.0/2352.64.170.1 to 52.64.171.25452.64.171.255510
8752.64.172.0/2352.64.172.1 to 52.64.173.25452.64.173.255510
8852.64.174.0/2352.64.174.1 to 52.64.175.25452.64.175.255510
8952.64.176.0/2352.64.176.1 to 52.64.177.25452.64.177.255510
9052.64.178.0/2352.64.178.1 to 52.64.179.25452.64.179.255510
9152.64.180.0/2352.64.180.1 to 52.64.181.25452.64.181.255510
9252.64.182.0/2352.64.182.1 to 52.64.183.25452.64.183.255510
9352.64.184.0/2352.64.184.1 to 52.64.185.25452.64.185.255510
9452.64.186.0/2352.64.186.1 to 52.64.187.25452.64.187.255510
9552.64.188.0/2352.64.188.1 to 52.64.189.25452.64.189.255510
9652.64.190.0/2352.64.190.1 to 52.64.191.25452.64.191.255510
9752.64.192.0/2352.64.192.1 to 52.64.193.25452.64.193.255510
9852.64.194.0/2352.64.194.1 to 52.64.195.25452.64.195.255510
9952.64.196.0/2352.64.196.1 to 52.64.197.25452.64.197.255510
10052.64.198.0/2352.64.198.1 to 52.64.199.25452.64.199.255510
10152.64.200.0/2352.64.200.1 to 52.64.201.25452.64.201.255510
10252.64.202.0/2352.64.202.1 to 52.64.203.25452.64.203.255510
10352.64.204.0/2352.64.204.1 to 52.64.205.25452.64.205.255510
10452.64.206.0/2352.64.206.1 to 52.64.207.25452.64.207.255510
10552.64.208.0/2352.64.208.1 to 52.64.209.25452.64.209.255510
10652.64.210.0/2352.64.210.1 to 52.64.211.25452.64.211.255510
10752.64.212.0/2352.64.212.1 to 52.64.213.25452.64.213.255510
10852.64.214.0/2352.64.214.1 to 52.64.215.25452.64.215.255510
10952.64.216.0/2352.64.216.1 to 52.64.217.25452.64.217.255510
11052.64.218.0/2352.64.218.1 to 52.64.219.25452.64.219.255510
11152.64.220.0/2352.64.220.1 to 52.64.221.25452.64.221.255510
11252.64.222.0/2352.64.222.1 to 52.64.223.25452.64.223.255510
11352.64.224.0/2352.64.224.1 to 52.64.225.25452.64.225.255510
11452.64.226.0/2352.64.226.1 to 52.64.227.25452.64.227.255510
11552.64.228.0/2352.64.228.1 to 52.64.229.25452.64.229.255510
11652.64.230.0/2352.64.230.1 to 52.64.231.25452.64.231.255510
11752.64.232.0/2352.64.232.1 to 52.64.233.25452.64.233.255510
11852.64.234.0/2352.64.234.1 to 52.64.235.25452.64.235.255510
11952.64.236.0/2352.64.236.1 to 52.64.237.25452.64.237.255510
12052.64.238.0/2352.64.238.1 to 52.64.239.25452.64.239.255510
12152.64.240.0/2352.64.240.1 to 52.64.241.25452.64.241.255510
12252.64.242.0/2352.64.242.1 to 52.64.243.25452.64.243.255510
12352.64.244.0/2352.64.244.1 to 52.64.245.25452.64.245.255510
12452.64.246.0/2352.64.246.1 to 52.64.247.25452.64.247.255510
12552.64.248.0/2352.64.248.1 to 52.64.249.25452.64.249.255510
12652.64.250.0/2352.64.250.1 to 52.64.251.25452.64.251.255510
12752.64.252.0/2352.64.252.1 to 52.64.253.25452.64.253.255510
12852.64.254.0/2352.64.254.1 to 52.64.255.25452.64.255.255510
12952.65.0.0/2352.65.0.1 to 52.65.1.25452.65.1.255510
13052.65.2.0/2352.65.2.1 to 52.65.3.25452.65.3.255510
13152.65.4.0/2352.65.4.1 to 52.65.5.25452.65.5.255510
13252.65.6.0/2352.65.6.1 to 52.65.7.25452.65.7.255510
13352.65.8.0/2352.65.8.1 to 52.65.9.25452.65.9.255510
13452.65.10.0/2352.65.10.1 to 52.65.11.25452.65.11.255510
13552.65.12.0/2352.65.12.1 to 52.65.13.25452.65.13.255510
13652.65.14.0/2352.65.14.1 to 52.65.15.25452.65.15.255510
13752.65.16.0/2352.65.16.1 to 52.65.17.25452.65.17.255510
13852.65.18.0/2352.65.18.1 to 52.65.19.25452.65.19.255510
13952.65.20.0/2352.65.20.1 to 52.65.21.25452.65.21.255510
14052.65.22.0/2352.65.22.1 to 52.65.23.25452.65.23.255510
14152.65.24.0/2352.65.24.1 to 52.65.25.25452.65.25.255510
14252.65.26.0/2352.65.26.1 to 52.65.27.25452.65.27.255510
14352.65.28.0/2352.65.28.1 to 52.65.29.25452.65.29.255510
14452.65.30.0/2352.65.30.1 to 52.65.31.25452.65.31.255510
14552.65.32.0/2352.65.32.1 to 52.65.33.25452.65.33.255510
14652.65.34.0/2352.65.34.1 to 52.65.35.25452.65.35.255510
14752.65.36.0/2352.65.36.1 to 52.65.37.25452.65.37.255510
14852.65.38.0/2352.65.38.1 to 52.65.39.25452.65.39.255510
14952.65.40.0/2352.65.40.1 to 52.65.41.25452.65.41.255510
15052.65.42.0/2352.65.42.1 to 52.65.43.25452.65.43.255510
15152.65.44.0/2352.65.44.1 to 52.65.45.25452.65.45.255510
15252.65.46.0/2352.65.46.1 to 52.65.47.25452.65.47.255510
15352.65.48.0/2352.65.48.1 to 52.65.49.25452.65.49.255510
15452.65.50.0/2352.65.50.1 to 52.65.51.25452.65.51.255510
15552.65.52.0/2352.65.52.1 to 52.65.53.25452.65.53.255510
15652.65.54.0/2352.65.54.1 to 52.65.55.25452.65.55.255510
15752.65.56.0/2352.65.56.1 to 52.65.57.25452.65.57.255510
15852.65.58.0/2352.65.58.1 to 52.65.59.25452.65.59.255510
15952.65.60.0/2352.65.60.1 to 52.65.61.25452.65.61.255510
16052.65.62.0/2352.65.62.1 to 52.65.63.25452.65.63.255510
16152.65.64.0/2352.65.64.1 to 52.65.65.25452.65.65.255510
16252.65.66.0/2352.65.66.1 to 52.65.67.25452.65.67.255510
16352.65.68.0/2352.65.68.1 to 52.65.69.25452.65.69.255510
16452.65.70.0/2352.65.70.1 to 52.65.71.25452.65.71.255510
16552.65.72.0/2352.65.72.1 to 52.65.73.25452.65.73.255510
16652.65.74.0/2352.65.74.1 to 52.65.75.25452.65.75.255510
16752.65.76.0/2352.65.76.1 to 52.65.77.25452.65.77.255510
16852.65.78.0/2352.65.78.1 to 52.65.79.25452.65.79.255510
16952.65.80.0/2352.65.80.1 to 52.65.81.25452.65.81.255510
17052.65.82.0/2352.65.82.1 to 52.65.83.25452.65.83.255510
17152.65.84.0/2352.65.84.1 to 52.65.85.25452.65.85.255510
17252.65.86.0/2352.65.86.1 to 52.65.87.25452.65.87.255510
17352.65.88.0/2352.65.88.1 to 52.65.89.25452.65.89.255510
17452.65.90.0/2352.65.90.1 to 52.65.91.25452.65.91.255510
17552.65.92.0/2352.65.92.1 to 52.65.93.25452.65.93.255510
17652.65.94.0/2352.65.94.1 to 52.65.95.25452.65.95.255510
17752.65.96.0/2352.65.96.1 to 52.65.97.25452.65.97.255510
17852.65.98.0/2352.65.98.1 to 52.65.99.25452.65.99.255510
17952.65.100.0/2352.65.100.1 to 52.65.101.25452.65.101.255510
18052.65.102.0/2352.65.102.1 to 52.65.103.25452.65.103.255510
18152.65.104.0/2352.65.104.1 to 52.65.105.25452.65.105.255510
18252.65.106.0/2352.65.106.1 to 52.65.107.25452.65.107.255510
18352.65.108.0/2352.65.108.1 to 52.65.109.25452.65.109.255510
18452.65.110.0/2352.65.110.1 to 52.65.111.25452.65.111.255510
18552.65.112.0/2352.65.112.1 to 52.65.113.25452.65.113.255510
18652.65.114.0/2352.65.114.1 to 52.65.115.25452.65.115.255510
18752.65.116.0/2352.65.116.1 to 52.65.117.25452.65.117.255510
18852.65.118.0/2352.65.118.1 to 52.65.119.25452.65.119.255510
18952.65.120.0/2352.65.120.1 to 52.65.121.25452.65.121.255510
19052.65.122.0/2352.65.122.1 to 52.65.123.25452.65.123.255510
19152.65.124.0/2352.65.124.1 to 52.65.125.25452.65.125.255510
19252.65.126.0/2352.65.126.1 to 52.65.127.25452.65.127.255510
19352.65.128.0/2352.65.128.1 to 52.65.129.25452.65.129.255510
19452.65.130.0/2352.65.130.1 to 52.65.131.25452.65.131.255510
19552.65.132.0/2352.65.132.1 to 52.65.133.25452.65.133.255510
19652.65.134.0/2352.65.134.1 to 52.65.135.25452.65.135.255510
19752.65.136.0/2352.65.136.1 to 52.65.137.25452.65.137.255510
19852.65.138.0/2352.65.138.1 to 52.65.139.25452.65.139.255510
19952.65.140.0/2352.65.140.1 to 52.65.141.25452.65.141.255510
20052.65.142.0/2352.65.142.1 to 52.65.143.25452.65.143.255510
20152.65.144.0/2352.65.144.1 to 52.65.145.25452.65.145.255510
20252.65.146.0/2352.65.146.1 to 52.65.147.25452.65.147.255510
20352.65.148.0/2352.65.148.1 to 52.65.149.25452.65.149.255510
20452.65.150.0/2352.65.150.1 to 52.65.151.25452.65.151.255510
20552.65.152.0/2352.65.152.1 to 52.65.153.25452.65.153.255510
20652.65.154.0/2352.65.154.1 to 52.65.155.25452.65.155.255510
20752.65.156.0/2352.65.156.1 to 52.65.157.25452.65.157.255510
20852.65.158.0/2352.65.158.1 to 52.65.159.25452.65.159.255510
20952.65.160.0/2352.65.160.1 to 52.65.161.25452.65.161.255510
21052.65.162.0/2352.65.162.1 to 52.65.163.25452.65.163.255510
21152.65.164.0/2352.65.164.1 to 52.65.165.25452.65.165.255510
21252.65.166.0/2352.65.166.1 to 52.65.167.25452.65.167.255510
21352.65.168.0/2352.65.168.1 to 52.65.169.25452.65.169.255510
21452.65.170.0/2352.65.170.1 to 52.65.171.25452.65.171.255510
21552.65.172.0/2352.65.172.1 to 52.65.173.25452.65.173.255510
21652.65.174.0/2352.65.174.1 to 52.65.175.25452.65.175.255510
21752.65.176.0/2352.65.176.1 to 52.65.177.25452.65.177.255510
21852.65.178.0/2352.65.178.1 to 52.65.179.25452.65.179.255510
21952.65.180.0/2352.65.180.1 to 52.65.181.25452.65.181.255510
22052.65.182.0/2352.65.182.1 to 52.65.183.25452.65.183.255510
22152.65.184.0/2352.65.184.1 to 52.65.185.25452.65.185.255510
22252.65.186.0/2352.65.186.1 to 52.65.187.25452.65.187.255510
22352.65.188.0/2352.65.188.1 to 52.65.189.25452.65.189.255510
22452.65.190.0/2352.65.190.1 to 52.65.191.25452.65.191.255510
22552.65.192.0/2352.65.192.1 to 52.65.193.25452.65.193.255510
22652.65.194.0/2352.65.194.1 to 52.65.195.25452.65.195.255510
22752.65.196.0/2352.65.196.1 to 52.65.197.25452.65.197.255510
22852.65.198.0/2352.65.198.1 to 52.65.199.25452.65.199.255510
22952.65.200.0/2352.65.200.1 to 52.65.201.25452.65.201.255510
23052.65.202.0/2352.65.202.1 to 52.65.203.25452.65.203.255510
23152.65.204.0/2352.65.204.1 to 52.65.205.25452.65.205.255510
23252.65.206.0/2352.65.206.1 to 52.65.207.25452.65.207.255510
23352.65.208.0/2352.65.208.1 to 52.65.209.25452.65.209.255510
23452.65.210.0/2352.65.210.1 to 52.65.211.25452.65.211.255510
23552.65.212.0/2352.65.212.1 to 52.65.213.25452.65.213.255510
23652.65.214.0/2352.65.214.1 to 52.65.215.25452.65.215.255510
23752.65.216.0/2352.65.216.1 to 52.65.217.25452.65.217.255510
23852.65.218.0/2352.65.218.1 to 52.65.219.25452.65.219.255510
23952.65.220.0/2352.65.220.1 to 52.65.221.25452.65.221.255510
24052.65.222.0/2352.65.222.1 to 52.65.223.25452.65.223.255510
24152.65.224.0/2352.65.224.1 to 52.65.225.25452.65.225.255510
24252.65.226.0/2352.65.226.1 to 52.65.227.25452.65.227.255510
24352.65.228.0/2352.65.228.1 to 52.65.229.25452.65.229.255510
24452.65.230.0/2352.65.230.1 to 52.65.231.25452.65.231.255510
24552.65.232.0/2352.65.232.1 to 52.65.233.25452.65.233.255510
24652.65.234.0/2352.65.234.1 to 52.65.235.25452.65.235.255510
24752.65.236.0/2352.65.236.1 to 52.65.237.25452.65.237.255510
24852.65.238.0/2352.65.238.1 to 52.65.239.25452.65.239.255510
24952.65.240.0/2352.65.240.1 to 52.65.241.25452.65.241.255510
25052.65.242.0/2352.65.242.1 to 52.65.243.25452.65.243.255510
25152.65.244.0/2352.65.244.1 to 52.65.245.25452.65.245.255510
25252.65.246.0/2352.65.246.1 to 52.65.247.25452.65.247.255510
25352.65.248.0/2352.65.248.1 to 52.65.249.25452.65.249.255510
25452.65.250.0/2352.65.250.1 to 52.65.251.25452.65.251.255510
25552.65.252.0/2352.65.252.1 to 52.65.253.25452.65.253.255510
25652.65.254.0/2352.65.254.1 to 52.65.255.25452.65.255.255510

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.