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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.

Network11.64.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
11.64.0.0
Broadcast address
11.79.255.255
First usable
11.64.0.1
Last usable
11.79.255.254
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 0B400000 · Integer 188743680 to 189792255
Reverse DNS zones
64.11.in-addr.arpa
65.11.in-addr.arpa
66.11.in-addr.arpa
67.11.in-addr.arpa
68.11.in-addr.arpa
69.11.in-addr.arpa
70.11.in-addr.arpa
71.11.in-addr.arpa
72.11.in-addr.arpa
73.11.in-addr.arpa
74.11.in-addr.arpa
75.11.in-addr.arpa
76.11.in-addr.arpa
77.11.in-addr.arpa
78.11.in-addr.arpa
79.11.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
Address00001011.01000000.00000000.0000000011.64.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network00001011.01000000.00000000.0000000011.64.0.0
Broadcast00001011.01001111.11111111.1111111111.79.255.255
Split into smaller subnets/22
/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)

11.64.0.0/12 makes 1,024 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
111.64.0.0/2211.64.0.1 to 11.64.3.25411.64.3.2551,022
211.64.4.0/2211.64.4.1 to 11.64.7.25411.64.7.2551,022
311.64.8.0/2211.64.8.1 to 11.64.11.25411.64.11.2551,022
411.64.12.0/2211.64.12.1 to 11.64.15.25411.64.15.2551,022
511.64.16.0/2211.64.16.1 to 11.64.19.25411.64.19.2551,022
611.64.20.0/2211.64.20.1 to 11.64.23.25411.64.23.2551,022
711.64.24.0/2211.64.24.1 to 11.64.27.25411.64.27.2551,022
811.64.28.0/2211.64.28.1 to 11.64.31.25411.64.31.2551,022
911.64.32.0/2211.64.32.1 to 11.64.35.25411.64.35.2551,022
1011.64.36.0/2211.64.36.1 to 11.64.39.25411.64.39.2551,022
1111.64.40.0/2211.64.40.1 to 11.64.43.25411.64.43.2551,022
1211.64.44.0/2211.64.44.1 to 11.64.47.25411.64.47.2551,022
1311.64.48.0/2211.64.48.1 to 11.64.51.25411.64.51.2551,022
1411.64.52.0/2211.64.52.1 to 11.64.55.25411.64.55.2551,022
1511.64.56.0/2211.64.56.1 to 11.64.59.25411.64.59.2551,022
1611.64.60.0/2211.64.60.1 to 11.64.63.25411.64.63.2551,022
1711.64.64.0/2211.64.64.1 to 11.64.67.25411.64.67.2551,022
1811.64.68.0/2211.64.68.1 to 11.64.71.25411.64.71.2551,022
1911.64.72.0/2211.64.72.1 to 11.64.75.25411.64.75.2551,022
2011.64.76.0/2211.64.76.1 to 11.64.79.25411.64.79.2551,022
2111.64.80.0/2211.64.80.1 to 11.64.83.25411.64.83.2551,022
2211.64.84.0/2211.64.84.1 to 11.64.87.25411.64.87.2551,022
2311.64.88.0/2211.64.88.1 to 11.64.91.25411.64.91.2551,022
2411.64.92.0/2211.64.92.1 to 11.64.95.25411.64.95.2551,022
2511.64.96.0/2211.64.96.1 to 11.64.99.25411.64.99.2551,022
2611.64.100.0/2211.64.100.1 to 11.64.103.25411.64.103.2551,022
2711.64.104.0/2211.64.104.1 to 11.64.107.25411.64.107.2551,022
2811.64.108.0/2211.64.108.1 to 11.64.111.25411.64.111.2551,022
2911.64.112.0/2211.64.112.1 to 11.64.115.25411.64.115.2551,022
3011.64.116.0/2211.64.116.1 to 11.64.119.25411.64.119.2551,022
3111.64.120.0/2211.64.120.1 to 11.64.123.25411.64.123.2551,022
3211.64.124.0/2211.64.124.1 to 11.64.127.25411.64.127.2551,022
3311.64.128.0/2211.64.128.1 to 11.64.131.25411.64.131.2551,022
3411.64.132.0/2211.64.132.1 to 11.64.135.25411.64.135.2551,022
3511.64.136.0/2211.64.136.1 to 11.64.139.25411.64.139.2551,022
3611.64.140.0/2211.64.140.1 to 11.64.143.25411.64.143.2551,022
3711.64.144.0/2211.64.144.1 to 11.64.147.25411.64.147.2551,022
3811.64.148.0/2211.64.148.1 to 11.64.151.25411.64.151.2551,022
3911.64.152.0/2211.64.152.1 to 11.64.155.25411.64.155.2551,022
4011.64.156.0/2211.64.156.1 to 11.64.159.25411.64.159.2551,022
4111.64.160.0/2211.64.160.1 to 11.64.163.25411.64.163.2551,022
4211.64.164.0/2211.64.164.1 to 11.64.167.25411.64.167.2551,022
4311.64.168.0/2211.64.168.1 to 11.64.171.25411.64.171.2551,022
4411.64.172.0/2211.64.172.1 to 11.64.175.25411.64.175.2551,022
4511.64.176.0/2211.64.176.1 to 11.64.179.25411.64.179.2551,022
4611.64.180.0/2211.64.180.1 to 11.64.183.25411.64.183.2551,022
4711.64.184.0/2211.64.184.1 to 11.64.187.25411.64.187.2551,022
4811.64.188.0/2211.64.188.1 to 11.64.191.25411.64.191.2551,022
4911.64.192.0/2211.64.192.1 to 11.64.195.25411.64.195.2551,022
5011.64.196.0/2211.64.196.1 to 11.64.199.25411.64.199.2551,022
5111.64.200.0/2211.64.200.1 to 11.64.203.25411.64.203.2551,022
5211.64.204.0/2211.64.204.1 to 11.64.207.25411.64.207.2551,022
5311.64.208.0/2211.64.208.1 to 11.64.211.25411.64.211.2551,022
5411.64.212.0/2211.64.212.1 to 11.64.215.25411.64.215.2551,022
5511.64.216.0/2211.64.216.1 to 11.64.219.25411.64.219.2551,022
5611.64.220.0/2211.64.220.1 to 11.64.223.25411.64.223.2551,022
5711.64.224.0/2211.64.224.1 to 11.64.227.25411.64.227.2551,022
5811.64.228.0/2211.64.228.1 to 11.64.231.25411.64.231.2551,022
5911.64.232.0/2211.64.232.1 to 11.64.235.25411.64.235.2551,022
6011.64.236.0/2211.64.236.1 to 11.64.239.25411.64.239.2551,022
6111.64.240.0/2211.64.240.1 to 11.64.243.25411.64.243.2551,022
6211.64.244.0/2211.64.244.1 to 11.64.247.25411.64.247.2551,022
6311.64.248.0/2211.64.248.1 to 11.64.251.25411.64.251.2551,022
6411.64.252.0/2211.64.252.1 to 11.64.255.25411.64.255.2551,022
6511.65.0.0/2211.65.0.1 to 11.65.3.25411.65.3.2551,022
6611.65.4.0/2211.65.4.1 to 11.65.7.25411.65.7.2551,022
6711.65.8.0/2211.65.8.1 to 11.65.11.25411.65.11.2551,022
6811.65.12.0/2211.65.12.1 to 11.65.15.25411.65.15.2551,022
6911.65.16.0/2211.65.16.1 to 11.65.19.25411.65.19.2551,022
7011.65.20.0/2211.65.20.1 to 11.65.23.25411.65.23.2551,022
7111.65.24.0/2211.65.24.1 to 11.65.27.25411.65.27.2551,022
7211.65.28.0/2211.65.28.1 to 11.65.31.25411.65.31.2551,022
7311.65.32.0/2211.65.32.1 to 11.65.35.25411.65.35.2551,022
7411.65.36.0/2211.65.36.1 to 11.65.39.25411.65.39.2551,022
7511.65.40.0/2211.65.40.1 to 11.65.43.25411.65.43.2551,022
7611.65.44.0/2211.65.44.1 to 11.65.47.25411.65.47.2551,022
7711.65.48.0/2211.65.48.1 to 11.65.51.25411.65.51.2551,022
7811.65.52.0/2211.65.52.1 to 11.65.55.25411.65.55.2551,022
7911.65.56.0/2211.65.56.1 to 11.65.59.25411.65.59.2551,022
8011.65.60.0/2211.65.60.1 to 11.65.63.25411.65.63.2551,022
8111.65.64.0/2211.65.64.1 to 11.65.67.25411.65.67.2551,022
8211.65.68.0/2211.65.68.1 to 11.65.71.25411.65.71.2551,022
8311.65.72.0/2211.65.72.1 to 11.65.75.25411.65.75.2551,022
8411.65.76.0/2211.65.76.1 to 11.65.79.25411.65.79.2551,022
8511.65.80.0/2211.65.80.1 to 11.65.83.25411.65.83.2551,022
8611.65.84.0/2211.65.84.1 to 11.65.87.25411.65.87.2551,022
8711.65.88.0/2211.65.88.1 to 11.65.91.25411.65.91.2551,022
8811.65.92.0/2211.65.92.1 to 11.65.95.25411.65.95.2551,022
8911.65.96.0/2211.65.96.1 to 11.65.99.25411.65.99.2551,022
9011.65.100.0/2211.65.100.1 to 11.65.103.25411.65.103.2551,022
9111.65.104.0/2211.65.104.1 to 11.65.107.25411.65.107.2551,022
9211.65.108.0/2211.65.108.1 to 11.65.111.25411.65.111.2551,022
9311.65.112.0/2211.65.112.1 to 11.65.115.25411.65.115.2551,022
9411.65.116.0/2211.65.116.1 to 11.65.119.25411.65.119.2551,022
9511.65.120.0/2211.65.120.1 to 11.65.123.25411.65.123.2551,022
9611.65.124.0/2211.65.124.1 to 11.65.127.25411.65.127.2551,022
9711.65.128.0/2211.65.128.1 to 11.65.131.25411.65.131.2551,022
9811.65.132.0/2211.65.132.1 to 11.65.135.25411.65.135.2551,022
9911.65.136.0/2211.65.136.1 to 11.65.139.25411.65.139.2551,022
10011.65.140.0/2211.65.140.1 to 11.65.143.25411.65.143.2551,022
10111.65.144.0/2211.65.144.1 to 11.65.147.25411.65.147.2551,022
10211.65.148.0/2211.65.148.1 to 11.65.151.25411.65.151.2551,022
10311.65.152.0/2211.65.152.1 to 11.65.155.25411.65.155.2551,022
10411.65.156.0/2211.65.156.1 to 11.65.159.25411.65.159.2551,022
10511.65.160.0/2211.65.160.1 to 11.65.163.25411.65.163.2551,022
10611.65.164.0/2211.65.164.1 to 11.65.167.25411.65.167.2551,022
10711.65.168.0/2211.65.168.1 to 11.65.171.25411.65.171.2551,022
10811.65.172.0/2211.65.172.1 to 11.65.175.25411.65.175.2551,022
10911.65.176.0/2211.65.176.1 to 11.65.179.25411.65.179.2551,022
11011.65.180.0/2211.65.180.1 to 11.65.183.25411.65.183.2551,022
11111.65.184.0/2211.65.184.1 to 11.65.187.25411.65.187.2551,022
11211.65.188.0/2211.65.188.1 to 11.65.191.25411.65.191.2551,022
11311.65.192.0/2211.65.192.1 to 11.65.195.25411.65.195.2551,022
11411.65.196.0/2211.65.196.1 to 11.65.199.25411.65.199.2551,022
11511.65.200.0/2211.65.200.1 to 11.65.203.25411.65.203.2551,022
11611.65.204.0/2211.65.204.1 to 11.65.207.25411.65.207.2551,022
11711.65.208.0/2211.65.208.1 to 11.65.211.25411.65.211.2551,022
11811.65.212.0/2211.65.212.1 to 11.65.215.25411.65.215.2551,022
11911.65.216.0/2211.65.216.1 to 11.65.219.25411.65.219.2551,022
12011.65.220.0/2211.65.220.1 to 11.65.223.25411.65.223.2551,022
12111.65.224.0/2211.65.224.1 to 11.65.227.25411.65.227.2551,022
12211.65.228.0/2211.65.228.1 to 11.65.231.25411.65.231.2551,022
12311.65.232.0/2211.65.232.1 to 11.65.235.25411.65.235.2551,022
12411.65.236.0/2211.65.236.1 to 11.65.239.25411.65.239.2551,022
12511.65.240.0/2211.65.240.1 to 11.65.243.25411.65.243.2551,022
12611.65.244.0/2211.65.244.1 to 11.65.247.25411.65.247.2551,022
12711.65.248.0/2211.65.248.1 to 11.65.251.25411.65.251.2551,022
12811.65.252.0/2211.65.252.1 to 11.65.255.25411.65.255.2551,022
12911.66.0.0/2211.66.0.1 to 11.66.3.25411.66.3.2551,022
13011.66.4.0/2211.66.4.1 to 11.66.7.25411.66.7.2551,022
13111.66.8.0/2211.66.8.1 to 11.66.11.25411.66.11.2551,022
13211.66.12.0/2211.66.12.1 to 11.66.15.25411.66.15.2551,022
13311.66.16.0/2211.66.16.1 to 11.66.19.25411.66.19.2551,022
13411.66.20.0/2211.66.20.1 to 11.66.23.25411.66.23.2551,022
13511.66.24.0/2211.66.24.1 to 11.66.27.25411.66.27.2551,022
13611.66.28.0/2211.66.28.1 to 11.66.31.25411.66.31.2551,022
13711.66.32.0/2211.66.32.1 to 11.66.35.25411.66.35.2551,022
13811.66.36.0/2211.66.36.1 to 11.66.39.25411.66.39.2551,022
13911.66.40.0/2211.66.40.1 to 11.66.43.25411.66.43.2551,022
14011.66.44.0/2211.66.44.1 to 11.66.47.25411.66.47.2551,022
14111.66.48.0/2211.66.48.1 to 11.66.51.25411.66.51.2551,022
14211.66.52.0/2211.66.52.1 to 11.66.55.25411.66.55.2551,022
14311.66.56.0/2211.66.56.1 to 11.66.59.25411.66.59.2551,022
14411.66.60.0/2211.66.60.1 to 11.66.63.25411.66.63.2551,022
14511.66.64.0/2211.66.64.1 to 11.66.67.25411.66.67.2551,022
14611.66.68.0/2211.66.68.1 to 11.66.71.25411.66.71.2551,022
14711.66.72.0/2211.66.72.1 to 11.66.75.25411.66.75.2551,022
14811.66.76.0/2211.66.76.1 to 11.66.79.25411.66.79.2551,022
14911.66.80.0/2211.66.80.1 to 11.66.83.25411.66.83.2551,022
15011.66.84.0/2211.66.84.1 to 11.66.87.25411.66.87.2551,022
15111.66.88.0/2211.66.88.1 to 11.66.91.25411.66.91.2551,022
15211.66.92.0/2211.66.92.1 to 11.66.95.25411.66.95.2551,022
15311.66.96.0/2211.66.96.1 to 11.66.99.25411.66.99.2551,022
15411.66.100.0/2211.66.100.1 to 11.66.103.25411.66.103.2551,022
15511.66.104.0/2211.66.104.1 to 11.66.107.25411.66.107.2551,022
15611.66.108.0/2211.66.108.1 to 11.66.111.25411.66.111.2551,022
15711.66.112.0/2211.66.112.1 to 11.66.115.25411.66.115.2551,022
15811.66.116.0/2211.66.116.1 to 11.66.119.25411.66.119.2551,022
15911.66.120.0/2211.66.120.1 to 11.66.123.25411.66.123.2551,022
16011.66.124.0/2211.66.124.1 to 11.66.127.25411.66.127.2551,022
16111.66.128.0/2211.66.128.1 to 11.66.131.25411.66.131.2551,022
16211.66.132.0/2211.66.132.1 to 11.66.135.25411.66.135.2551,022
16311.66.136.0/2211.66.136.1 to 11.66.139.25411.66.139.2551,022
16411.66.140.0/2211.66.140.1 to 11.66.143.25411.66.143.2551,022
16511.66.144.0/2211.66.144.1 to 11.66.147.25411.66.147.2551,022
16611.66.148.0/2211.66.148.1 to 11.66.151.25411.66.151.2551,022
16711.66.152.0/2211.66.152.1 to 11.66.155.25411.66.155.2551,022
16811.66.156.0/2211.66.156.1 to 11.66.159.25411.66.159.2551,022
16911.66.160.0/2211.66.160.1 to 11.66.163.25411.66.163.2551,022
17011.66.164.0/2211.66.164.1 to 11.66.167.25411.66.167.2551,022
17111.66.168.0/2211.66.168.1 to 11.66.171.25411.66.171.2551,022
17211.66.172.0/2211.66.172.1 to 11.66.175.25411.66.175.2551,022
17311.66.176.0/2211.66.176.1 to 11.66.179.25411.66.179.2551,022
17411.66.180.0/2211.66.180.1 to 11.66.183.25411.66.183.2551,022
17511.66.184.0/2211.66.184.1 to 11.66.187.25411.66.187.2551,022
17611.66.188.0/2211.66.188.1 to 11.66.191.25411.66.191.2551,022
17711.66.192.0/2211.66.192.1 to 11.66.195.25411.66.195.2551,022
17811.66.196.0/2211.66.196.1 to 11.66.199.25411.66.199.2551,022
17911.66.200.0/2211.66.200.1 to 11.66.203.25411.66.203.2551,022
18011.66.204.0/2211.66.204.1 to 11.66.207.25411.66.207.2551,022
18111.66.208.0/2211.66.208.1 to 11.66.211.25411.66.211.2551,022
18211.66.212.0/2211.66.212.1 to 11.66.215.25411.66.215.2551,022
18311.66.216.0/2211.66.216.1 to 11.66.219.25411.66.219.2551,022
18411.66.220.0/2211.66.220.1 to 11.66.223.25411.66.223.2551,022
18511.66.224.0/2211.66.224.1 to 11.66.227.25411.66.227.2551,022
18611.66.228.0/2211.66.228.1 to 11.66.231.25411.66.231.2551,022
18711.66.232.0/2211.66.232.1 to 11.66.235.25411.66.235.2551,022
18811.66.236.0/2211.66.236.1 to 11.66.239.25411.66.239.2551,022
18911.66.240.0/2211.66.240.1 to 11.66.243.25411.66.243.2551,022
19011.66.244.0/2211.66.244.1 to 11.66.247.25411.66.247.2551,022
19111.66.248.0/2211.66.248.1 to 11.66.251.25411.66.251.2551,022
19211.66.252.0/2211.66.252.1 to 11.66.255.25411.66.255.2551,022
19311.67.0.0/2211.67.0.1 to 11.67.3.25411.67.3.2551,022
19411.67.4.0/2211.67.4.1 to 11.67.7.25411.67.7.2551,022
19511.67.8.0/2211.67.8.1 to 11.67.11.25411.67.11.2551,022
19611.67.12.0/2211.67.12.1 to 11.67.15.25411.67.15.2551,022
19711.67.16.0/2211.67.16.1 to 11.67.19.25411.67.19.2551,022
19811.67.20.0/2211.67.20.1 to 11.67.23.25411.67.23.2551,022
19911.67.24.0/2211.67.24.1 to 11.67.27.25411.67.27.2551,022
20011.67.28.0/2211.67.28.1 to 11.67.31.25411.67.31.2551,022
20111.67.32.0/2211.67.32.1 to 11.67.35.25411.67.35.2551,022
20211.67.36.0/2211.67.36.1 to 11.67.39.25411.67.39.2551,022
20311.67.40.0/2211.67.40.1 to 11.67.43.25411.67.43.2551,022
20411.67.44.0/2211.67.44.1 to 11.67.47.25411.67.47.2551,022
20511.67.48.0/2211.67.48.1 to 11.67.51.25411.67.51.2551,022
20611.67.52.0/2211.67.52.1 to 11.67.55.25411.67.55.2551,022
20711.67.56.0/2211.67.56.1 to 11.67.59.25411.67.59.2551,022
20811.67.60.0/2211.67.60.1 to 11.67.63.25411.67.63.2551,022
20911.67.64.0/2211.67.64.1 to 11.67.67.25411.67.67.2551,022
21011.67.68.0/2211.67.68.1 to 11.67.71.25411.67.71.2551,022
21111.67.72.0/2211.67.72.1 to 11.67.75.25411.67.75.2551,022
21211.67.76.0/2211.67.76.1 to 11.67.79.25411.67.79.2551,022
21311.67.80.0/2211.67.80.1 to 11.67.83.25411.67.83.2551,022
21411.67.84.0/2211.67.84.1 to 11.67.87.25411.67.87.2551,022
21511.67.88.0/2211.67.88.1 to 11.67.91.25411.67.91.2551,022
21611.67.92.0/2211.67.92.1 to 11.67.95.25411.67.95.2551,022
21711.67.96.0/2211.67.96.1 to 11.67.99.25411.67.99.2551,022
21811.67.100.0/2211.67.100.1 to 11.67.103.25411.67.103.2551,022
21911.67.104.0/2211.67.104.1 to 11.67.107.25411.67.107.2551,022
22011.67.108.0/2211.67.108.1 to 11.67.111.25411.67.111.2551,022
22111.67.112.0/2211.67.112.1 to 11.67.115.25411.67.115.2551,022
22211.67.116.0/2211.67.116.1 to 11.67.119.25411.67.119.2551,022
22311.67.120.0/2211.67.120.1 to 11.67.123.25411.67.123.2551,022
22411.67.124.0/2211.67.124.1 to 11.67.127.25411.67.127.2551,022
22511.67.128.0/2211.67.128.1 to 11.67.131.25411.67.131.2551,022
22611.67.132.0/2211.67.132.1 to 11.67.135.25411.67.135.2551,022
22711.67.136.0/2211.67.136.1 to 11.67.139.25411.67.139.2551,022
22811.67.140.0/2211.67.140.1 to 11.67.143.25411.67.143.2551,022
22911.67.144.0/2211.67.144.1 to 11.67.147.25411.67.147.2551,022
23011.67.148.0/2211.67.148.1 to 11.67.151.25411.67.151.2551,022
23111.67.152.0/2211.67.152.1 to 11.67.155.25411.67.155.2551,022
23211.67.156.0/2211.67.156.1 to 11.67.159.25411.67.159.2551,022
23311.67.160.0/2211.67.160.1 to 11.67.163.25411.67.163.2551,022
23411.67.164.0/2211.67.164.1 to 11.67.167.25411.67.167.2551,022
23511.67.168.0/2211.67.168.1 to 11.67.171.25411.67.171.2551,022
23611.67.172.0/2211.67.172.1 to 11.67.175.25411.67.175.2551,022
23711.67.176.0/2211.67.176.1 to 11.67.179.25411.67.179.2551,022
23811.67.180.0/2211.67.180.1 to 11.67.183.25411.67.183.2551,022
23911.67.184.0/2211.67.184.1 to 11.67.187.25411.67.187.2551,022
24011.67.188.0/2211.67.188.1 to 11.67.191.25411.67.191.2551,022
24111.67.192.0/2211.67.192.1 to 11.67.195.25411.67.195.2551,022
24211.67.196.0/2211.67.196.1 to 11.67.199.25411.67.199.2551,022
24311.67.200.0/2211.67.200.1 to 11.67.203.25411.67.203.2551,022
24411.67.204.0/2211.67.204.1 to 11.67.207.25411.67.207.2551,022
24511.67.208.0/2211.67.208.1 to 11.67.211.25411.67.211.2551,022
24611.67.212.0/2211.67.212.1 to 11.67.215.25411.67.215.2551,022
24711.67.216.0/2211.67.216.1 to 11.67.219.25411.67.219.2551,022
24811.67.220.0/2211.67.220.1 to 11.67.223.25411.67.223.2551,022
24911.67.224.0/2211.67.224.1 to 11.67.227.25411.67.227.2551,022
25011.67.228.0/2211.67.228.1 to 11.67.231.25411.67.231.2551,022
25111.67.232.0/2211.67.232.1 to 11.67.235.25411.67.235.2551,022
25211.67.236.0/2211.67.236.1 to 11.67.239.25411.67.239.2551,022
25311.67.240.0/2211.67.240.1 to 11.67.243.25411.67.243.2551,022
25411.67.244.0/2211.67.244.1 to 11.67.247.25411.67.247.2551,022
25511.67.248.0/2211.67.248.1 to 11.67.251.25411.67.251.2551,022
25611.67.252.0/2211.67.252.1 to 11.67.255.25411.67.255.2551,022

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.