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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.

Network77.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
77.0.0.0
Broadcast address
77.127.255.255
First usable
77.0.0.1
Last usable
77.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
A (default /8)
As numbers
Hex 4D000000 · Integer 1291845632 to 1300234239
Reverse DNS zones
0.77.in-addr.arpa
1.77.in-addr.arpa
2.77.in-addr.arpa
3.77.in-addr.arpa
4.77.in-addr.arpa
5.77.in-addr.arpa
6.77.in-addr.arpa
7.77.in-addr.arpa
8.77.in-addr.arpa
9.77.in-addr.arpa
10.77.in-addr.arpa
11.77.in-addr.arpa
12.77.in-addr.arpa
13.77.in-addr.arpa
14.77.in-addr.arpa
15.77.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001101.00000000.00000000.0000000077.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01001101.00000000.00000000.0000000077.0.0.0
Broadcast01001101.01111111.11111111.1111111177.127.255.255
Split into smaller subnets/21
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

77.0.0.0/9 makes 4,096 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
177.0.0.0/2177.0.0.1 to 77.0.7.25477.0.7.2552,046
277.0.8.0/2177.0.8.1 to 77.0.15.25477.0.15.2552,046
377.0.16.0/2177.0.16.1 to 77.0.23.25477.0.23.2552,046
477.0.24.0/2177.0.24.1 to 77.0.31.25477.0.31.2552,046
577.0.32.0/2177.0.32.1 to 77.0.39.25477.0.39.2552,046
677.0.40.0/2177.0.40.1 to 77.0.47.25477.0.47.2552,046
777.0.48.0/2177.0.48.1 to 77.0.55.25477.0.55.2552,046
877.0.56.0/2177.0.56.1 to 77.0.63.25477.0.63.2552,046
977.0.64.0/2177.0.64.1 to 77.0.71.25477.0.71.2552,046
1077.0.72.0/2177.0.72.1 to 77.0.79.25477.0.79.2552,046
1177.0.80.0/2177.0.80.1 to 77.0.87.25477.0.87.2552,046
1277.0.88.0/2177.0.88.1 to 77.0.95.25477.0.95.2552,046
1377.0.96.0/2177.0.96.1 to 77.0.103.25477.0.103.2552,046
1477.0.104.0/2177.0.104.1 to 77.0.111.25477.0.111.2552,046
1577.0.112.0/2177.0.112.1 to 77.0.119.25477.0.119.2552,046
1677.0.120.0/2177.0.120.1 to 77.0.127.25477.0.127.2552,046
1777.0.128.0/2177.0.128.1 to 77.0.135.25477.0.135.2552,046
1877.0.136.0/2177.0.136.1 to 77.0.143.25477.0.143.2552,046
1977.0.144.0/2177.0.144.1 to 77.0.151.25477.0.151.2552,046
2077.0.152.0/2177.0.152.1 to 77.0.159.25477.0.159.2552,046
2177.0.160.0/2177.0.160.1 to 77.0.167.25477.0.167.2552,046
2277.0.168.0/2177.0.168.1 to 77.0.175.25477.0.175.2552,046
2377.0.176.0/2177.0.176.1 to 77.0.183.25477.0.183.2552,046
2477.0.184.0/2177.0.184.1 to 77.0.191.25477.0.191.2552,046
2577.0.192.0/2177.0.192.1 to 77.0.199.25477.0.199.2552,046
2677.0.200.0/2177.0.200.1 to 77.0.207.25477.0.207.2552,046
2777.0.208.0/2177.0.208.1 to 77.0.215.25477.0.215.2552,046
2877.0.216.0/2177.0.216.1 to 77.0.223.25477.0.223.2552,046
2977.0.224.0/2177.0.224.1 to 77.0.231.25477.0.231.2552,046
3077.0.232.0/2177.0.232.1 to 77.0.239.25477.0.239.2552,046
3177.0.240.0/2177.0.240.1 to 77.0.247.25477.0.247.2552,046
3277.0.248.0/2177.0.248.1 to 77.0.255.25477.0.255.2552,046
3377.1.0.0/2177.1.0.1 to 77.1.7.25477.1.7.2552,046
3477.1.8.0/2177.1.8.1 to 77.1.15.25477.1.15.2552,046
3577.1.16.0/2177.1.16.1 to 77.1.23.25477.1.23.2552,046
3677.1.24.0/2177.1.24.1 to 77.1.31.25477.1.31.2552,046
3777.1.32.0/2177.1.32.1 to 77.1.39.25477.1.39.2552,046
3877.1.40.0/2177.1.40.1 to 77.1.47.25477.1.47.2552,046
3977.1.48.0/2177.1.48.1 to 77.1.55.25477.1.55.2552,046
4077.1.56.0/2177.1.56.1 to 77.1.63.25477.1.63.2552,046
4177.1.64.0/2177.1.64.1 to 77.1.71.25477.1.71.2552,046
4277.1.72.0/2177.1.72.1 to 77.1.79.25477.1.79.2552,046
4377.1.80.0/2177.1.80.1 to 77.1.87.25477.1.87.2552,046
4477.1.88.0/2177.1.88.1 to 77.1.95.25477.1.95.2552,046
4577.1.96.0/2177.1.96.1 to 77.1.103.25477.1.103.2552,046
4677.1.104.0/2177.1.104.1 to 77.1.111.25477.1.111.2552,046
4777.1.112.0/2177.1.112.1 to 77.1.119.25477.1.119.2552,046
4877.1.120.0/2177.1.120.1 to 77.1.127.25477.1.127.2552,046
4977.1.128.0/2177.1.128.1 to 77.1.135.25477.1.135.2552,046
5077.1.136.0/2177.1.136.1 to 77.1.143.25477.1.143.2552,046
5177.1.144.0/2177.1.144.1 to 77.1.151.25477.1.151.2552,046
5277.1.152.0/2177.1.152.1 to 77.1.159.25477.1.159.2552,046
5377.1.160.0/2177.1.160.1 to 77.1.167.25477.1.167.2552,046
5477.1.168.0/2177.1.168.1 to 77.1.175.25477.1.175.2552,046
5577.1.176.0/2177.1.176.1 to 77.1.183.25477.1.183.2552,046
5677.1.184.0/2177.1.184.1 to 77.1.191.25477.1.191.2552,046
5777.1.192.0/2177.1.192.1 to 77.1.199.25477.1.199.2552,046
5877.1.200.0/2177.1.200.1 to 77.1.207.25477.1.207.2552,046
5977.1.208.0/2177.1.208.1 to 77.1.215.25477.1.215.2552,046
6077.1.216.0/2177.1.216.1 to 77.1.223.25477.1.223.2552,046
6177.1.224.0/2177.1.224.1 to 77.1.231.25477.1.231.2552,046
6277.1.232.0/2177.1.232.1 to 77.1.239.25477.1.239.2552,046
6377.1.240.0/2177.1.240.1 to 77.1.247.25477.1.247.2552,046
6477.1.248.0/2177.1.248.1 to 77.1.255.25477.1.255.2552,046
6577.2.0.0/2177.2.0.1 to 77.2.7.25477.2.7.2552,046
6677.2.8.0/2177.2.8.1 to 77.2.15.25477.2.15.2552,046
6777.2.16.0/2177.2.16.1 to 77.2.23.25477.2.23.2552,046
6877.2.24.0/2177.2.24.1 to 77.2.31.25477.2.31.2552,046
6977.2.32.0/2177.2.32.1 to 77.2.39.25477.2.39.2552,046
7077.2.40.0/2177.2.40.1 to 77.2.47.25477.2.47.2552,046
7177.2.48.0/2177.2.48.1 to 77.2.55.25477.2.55.2552,046
7277.2.56.0/2177.2.56.1 to 77.2.63.25477.2.63.2552,046
7377.2.64.0/2177.2.64.1 to 77.2.71.25477.2.71.2552,046
7477.2.72.0/2177.2.72.1 to 77.2.79.25477.2.79.2552,046
7577.2.80.0/2177.2.80.1 to 77.2.87.25477.2.87.2552,046
7677.2.88.0/2177.2.88.1 to 77.2.95.25477.2.95.2552,046
7777.2.96.0/2177.2.96.1 to 77.2.103.25477.2.103.2552,046
7877.2.104.0/2177.2.104.1 to 77.2.111.25477.2.111.2552,046
7977.2.112.0/2177.2.112.1 to 77.2.119.25477.2.119.2552,046
8077.2.120.0/2177.2.120.1 to 77.2.127.25477.2.127.2552,046
8177.2.128.0/2177.2.128.1 to 77.2.135.25477.2.135.2552,046
8277.2.136.0/2177.2.136.1 to 77.2.143.25477.2.143.2552,046
8377.2.144.0/2177.2.144.1 to 77.2.151.25477.2.151.2552,046
8477.2.152.0/2177.2.152.1 to 77.2.159.25477.2.159.2552,046
8577.2.160.0/2177.2.160.1 to 77.2.167.25477.2.167.2552,046
8677.2.168.0/2177.2.168.1 to 77.2.175.25477.2.175.2552,046
8777.2.176.0/2177.2.176.1 to 77.2.183.25477.2.183.2552,046
8877.2.184.0/2177.2.184.1 to 77.2.191.25477.2.191.2552,046
8977.2.192.0/2177.2.192.1 to 77.2.199.25477.2.199.2552,046
9077.2.200.0/2177.2.200.1 to 77.2.207.25477.2.207.2552,046
9177.2.208.0/2177.2.208.1 to 77.2.215.25477.2.215.2552,046
9277.2.216.0/2177.2.216.1 to 77.2.223.25477.2.223.2552,046
9377.2.224.0/2177.2.224.1 to 77.2.231.25477.2.231.2552,046
9477.2.232.0/2177.2.232.1 to 77.2.239.25477.2.239.2552,046
9577.2.240.0/2177.2.240.1 to 77.2.247.25477.2.247.2552,046
9677.2.248.0/2177.2.248.1 to 77.2.255.25477.2.255.2552,046
9777.3.0.0/2177.3.0.1 to 77.3.7.25477.3.7.2552,046
9877.3.8.0/2177.3.8.1 to 77.3.15.25477.3.15.2552,046
9977.3.16.0/2177.3.16.1 to 77.3.23.25477.3.23.2552,046
10077.3.24.0/2177.3.24.1 to 77.3.31.25477.3.31.2552,046
10177.3.32.0/2177.3.32.1 to 77.3.39.25477.3.39.2552,046
10277.3.40.0/2177.3.40.1 to 77.3.47.25477.3.47.2552,046
10377.3.48.0/2177.3.48.1 to 77.3.55.25477.3.55.2552,046
10477.3.56.0/2177.3.56.1 to 77.3.63.25477.3.63.2552,046
10577.3.64.0/2177.3.64.1 to 77.3.71.25477.3.71.2552,046
10677.3.72.0/2177.3.72.1 to 77.3.79.25477.3.79.2552,046
10777.3.80.0/2177.3.80.1 to 77.3.87.25477.3.87.2552,046
10877.3.88.0/2177.3.88.1 to 77.3.95.25477.3.95.2552,046
10977.3.96.0/2177.3.96.1 to 77.3.103.25477.3.103.2552,046
11077.3.104.0/2177.3.104.1 to 77.3.111.25477.3.111.2552,046
11177.3.112.0/2177.3.112.1 to 77.3.119.25477.3.119.2552,046
11277.3.120.0/2177.3.120.1 to 77.3.127.25477.3.127.2552,046
11377.3.128.0/2177.3.128.1 to 77.3.135.25477.3.135.2552,046
11477.3.136.0/2177.3.136.1 to 77.3.143.25477.3.143.2552,046
11577.3.144.0/2177.3.144.1 to 77.3.151.25477.3.151.2552,046
11677.3.152.0/2177.3.152.1 to 77.3.159.25477.3.159.2552,046
11777.3.160.0/2177.3.160.1 to 77.3.167.25477.3.167.2552,046
11877.3.168.0/2177.3.168.1 to 77.3.175.25477.3.175.2552,046
11977.3.176.0/2177.3.176.1 to 77.3.183.25477.3.183.2552,046
12077.3.184.0/2177.3.184.1 to 77.3.191.25477.3.191.2552,046
12177.3.192.0/2177.3.192.1 to 77.3.199.25477.3.199.2552,046
12277.3.200.0/2177.3.200.1 to 77.3.207.25477.3.207.2552,046
12377.3.208.0/2177.3.208.1 to 77.3.215.25477.3.215.2552,046
12477.3.216.0/2177.3.216.1 to 77.3.223.25477.3.223.2552,046
12577.3.224.0/2177.3.224.1 to 77.3.231.25477.3.231.2552,046
12677.3.232.0/2177.3.232.1 to 77.3.239.25477.3.239.2552,046
12777.3.240.0/2177.3.240.1 to 77.3.247.25477.3.247.2552,046
12877.3.248.0/2177.3.248.1 to 77.3.255.25477.3.255.2552,046
12977.4.0.0/2177.4.0.1 to 77.4.7.25477.4.7.2552,046
13077.4.8.0/2177.4.8.1 to 77.4.15.25477.4.15.2552,046
13177.4.16.0/2177.4.16.1 to 77.4.23.25477.4.23.2552,046
13277.4.24.0/2177.4.24.1 to 77.4.31.25477.4.31.2552,046
13377.4.32.0/2177.4.32.1 to 77.4.39.25477.4.39.2552,046
13477.4.40.0/2177.4.40.1 to 77.4.47.25477.4.47.2552,046
13577.4.48.0/2177.4.48.1 to 77.4.55.25477.4.55.2552,046
13677.4.56.0/2177.4.56.1 to 77.4.63.25477.4.63.2552,046
13777.4.64.0/2177.4.64.1 to 77.4.71.25477.4.71.2552,046
13877.4.72.0/2177.4.72.1 to 77.4.79.25477.4.79.2552,046
13977.4.80.0/2177.4.80.1 to 77.4.87.25477.4.87.2552,046
14077.4.88.0/2177.4.88.1 to 77.4.95.25477.4.95.2552,046
14177.4.96.0/2177.4.96.1 to 77.4.103.25477.4.103.2552,046
14277.4.104.0/2177.4.104.1 to 77.4.111.25477.4.111.2552,046
14377.4.112.0/2177.4.112.1 to 77.4.119.25477.4.119.2552,046
14477.4.120.0/2177.4.120.1 to 77.4.127.25477.4.127.2552,046
14577.4.128.0/2177.4.128.1 to 77.4.135.25477.4.135.2552,046
14677.4.136.0/2177.4.136.1 to 77.4.143.25477.4.143.2552,046
14777.4.144.0/2177.4.144.1 to 77.4.151.25477.4.151.2552,046
14877.4.152.0/2177.4.152.1 to 77.4.159.25477.4.159.2552,046
14977.4.160.0/2177.4.160.1 to 77.4.167.25477.4.167.2552,046
15077.4.168.0/2177.4.168.1 to 77.4.175.25477.4.175.2552,046
15177.4.176.0/2177.4.176.1 to 77.4.183.25477.4.183.2552,046
15277.4.184.0/2177.4.184.1 to 77.4.191.25477.4.191.2552,046
15377.4.192.0/2177.4.192.1 to 77.4.199.25477.4.199.2552,046
15477.4.200.0/2177.4.200.1 to 77.4.207.25477.4.207.2552,046
15577.4.208.0/2177.4.208.1 to 77.4.215.25477.4.215.2552,046
15677.4.216.0/2177.4.216.1 to 77.4.223.25477.4.223.2552,046
15777.4.224.0/2177.4.224.1 to 77.4.231.25477.4.231.2552,046
15877.4.232.0/2177.4.232.1 to 77.4.239.25477.4.239.2552,046
15977.4.240.0/2177.4.240.1 to 77.4.247.25477.4.247.2552,046
16077.4.248.0/2177.4.248.1 to 77.4.255.25477.4.255.2552,046
16177.5.0.0/2177.5.0.1 to 77.5.7.25477.5.7.2552,046
16277.5.8.0/2177.5.8.1 to 77.5.15.25477.5.15.2552,046
16377.5.16.0/2177.5.16.1 to 77.5.23.25477.5.23.2552,046
16477.5.24.0/2177.5.24.1 to 77.5.31.25477.5.31.2552,046
16577.5.32.0/2177.5.32.1 to 77.5.39.25477.5.39.2552,046
16677.5.40.0/2177.5.40.1 to 77.5.47.25477.5.47.2552,046
16777.5.48.0/2177.5.48.1 to 77.5.55.25477.5.55.2552,046
16877.5.56.0/2177.5.56.1 to 77.5.63.25477.5.63.2552,046
16977.5.64.0/2177.5.64.1 to 77.5.71.25477.5.71.2552,046
17077.5.72.0/2177.5.72.1 to 77.5.79.25477.5.79.2552,046
17177.5.80.0/2177.5.80.1 to 77.5.87.25477.5.87.2552,046
17277.5.88.0/2177.5.88.1 to 77.5.95.25477.5.95.2552,046
17377.5.96.0/2177.5.96.1 to 77.5.103.25477.5.103.2552,046
17477.5.104.0/2177.5.104.1 to 77.5.111.25477.5.111.2552,046
17577.5.112.0/2177.5.112.1 to 77.5.119.25477.5.119.2552,046
17677.5.120.0/2177.5.120.1 to 77.5.127.25477.5.127.2552,046
17777.5.128.0/2177.5.128.1 to 77.5.135.25477.5.135.2552,046
17877.5.136.0/2177.5.136.1 to 77.5.143.25477.5.143.2552,046
17977.5.144.0/2177.5.144.1 to 77.5.151.25477.5.151.2552,046
18077.5.152.0/2177.5.152.1 to 77.5.159.25477.5.159.2552,046
18177.5.160.0/2177.5.160.1 to 77.5.167.25477.5.167.2552,046
18277.5.168.0/2177.5.168.1 to 77.5.175.25477.5.175.2552,046
18377.5.176.0/2177.5.176.1 to 77.5.183.25477.5.183.2552,046
18477.5.184.0/2177.5.184.1 to 77.5.191.25477.5.191.2552,046
18577.5.192.0/2177.5.192.1 to 77.5.199.25477.5.199.2552,046
18677.5.200.0/2177.5.200.1 to 77.5.207.25477.5.207.2552,046
18777.5.208.0/2177.5.208.1 to 77.5.215.25477.5.215.2552,046
18877.5.216.0/2177.5.216.1 to 77.5.223.25477.5.223.2552,046
18977.5.224.0/2177.5.224.1 to 77.5.231.25477.5.231.2552,046
19077.5.232.0/2177.5.232.1 to 77.5.239.25477.5.239.2552,046
19177.5.240.0/2177.5.240.1 to 77.5.247.25477.5.247.2552,046
19277.5.248.0/2177.5.248.1 to 77.5.255.25477.5.255.2552,046
19377.6.0.0/2177.6.0.1 to 77.6.7.25477.6.7.2552,046
19477.6.8.0/2177.6.8.1 to 77.6.15.25477.6.15.2552,046
19577.6.16.0/2177.6.16.1 to 77.6.23.25477.6.23.2552,046
19677.6.24.0/2177.6.24.1 to 77.6.31.25477.6.31.2552,046
19777.6.32.0/2177.6.32.1 to 77.6.39.25477.6.39.2552,046
19877.6.40.0/2177.6.40.1 to 77.6.47.25477.6.47.2552,046
19977.6.48.0/2177.6.48.1 to 77.6.55.25477.6.55.2552,046
20077.6.56.0/2177.6.56.1 to 77.6.63.25477.6.63.2552,046
20177.6.64.0/2177.6.64.1 to 77.6.71.25477.6.71.2552,046
20277.6.72.0/2177.6.72.1 to 77.6.79.25477.6.79.2552,046
20377.6.80.0/2177.6.80.1 to 77.6.87.25477.6.87.2552,046
20477.6.88.0/2177.6.88.1 to 77.6.95.25477.6.95.2552,046
20577.6.96.0/2177.6.96.1 to 77.6.103.25477.6.103.2552,046
20677.6.104.0/2177.6.104.1 to 77.6.111.25477.6.111.2552,046
20777.6.112.0/2177.6.112.1 to 77.6.119.25477.6.119.2552,046
20877.6.120.0/2177.6.120.1 to 77.6.127.25477.6.127.2552,046
20977.6.128.0/2177.6.128.1 to 77.6.135.25477.6.135.2552,046
21077.6.136.0/2177.6.136.1 to 77.6.143.25477.6.143.2552,046
21177.6.144.0/2177.6.144.1 to 77.6.151.25477.6.151.2552,046
21277.6.152.0/2177.6.152.1 to 77.6.159.25477.6.159.2552,046
21377.6.160.0/2177.6.160.1 to 77.6.167.25477.6.167.2552,046
21477.6.168.0/2177.6.168.1 to 77.6.175.25477.6.175.2552,046
21577.6.176.0/2177.6.176.1 to 77.6.183.25477.6.183.2552,046
21677.6.184.0/2177.6.184.1 to 77.6.191.25477.6.191.2552,046
21777.6.192.0/2177.6.192.1 to 77.6.199.25477.6.199.2552,046
21877.6.200.0/2177.6.200.1 to 77.6.207.25477.6.207.2552,046
21977.6.208.0/2177.6.208.1 to 77.6.215.25477.6.215.2552,046
22077.6.216.0/2177.6.216.1 to 77.6.223.25477.6.223.2552,046
22177.6.224.0/2177.6.224.1 to 77.6.231.25477.6.231.2552,046
22277.6.232.0/2177.6.232.1 to 77.6.239.25477.6.239.2552,046
22377.6.240.0/2177.6.240.1 to 77.6.247.25477.6.247.2552,046
22477.6.248.0/2177.6.248.1 to 77.6.255.25477.6.255.2552,046
22577.7.0.0/2177.7.0.1 to 77.7.7.25477.7.7.2552,046
22677.7.8.0/2177.7.8.1 to 77.7.15.25477.7.15.2552,046
22777.7.16.0/2177.7.16.1 to 77.7.23.25477.7.23.2552,046
22877.7.24.0/2177.7.24.1 to 77.7.31.25477.7.31.2552,046
22977.7.32.0/2177.7.32.1 to 77.7.39.25477.7.39.2552,046
23077.7.40.0/2177.7.40.1 to 77.7.47.25477.7.47.2552,046
23177.7.48.0/2177.7.48.1 to 77.7.55.25477.7.55.2552,046
23277.7.56.0/2177.7.56.1 to 77.7.63.25477.7.63.2552,046
23377.7.64.0/2177.7.64.1 to 77.7.71.25477.7.71.2552,046
23477.7.72.0/2177.7.72.1 to 77.7.79.25477.7.79.2552,046
23577.7.80.0/2177.7.80.1 to 77.7.87.25477.7.87.2552,046
23677.7.88.0/2177.7.88.1 to 77.7.95.25477.7.95.2552,046
23777.7.96.0/2177.7.96.1 to 77.7.103.25477.7.103.2552,046
23877.7.104.0/2177.7.104.1 to 77.7.111.25477.7.111.2552,046
23977.7.112.0/2177.7.112.1 to 77.7.119.25477.7.119.2552,046
24077.7.120.0/2177.7.120.1 to 77.7.127.25477.7.127.2552,046
24177.7.128.0/2177.7.128.1 to 77.7.135.25477.7.135.2552,046
24277.7.136.0/2177.7.136.1 to 77.7.143.25477.7.143.2552,046
24377.7.144.0/2177.7.144.1 to 77.7.151.25477.7.151.2552,046
24477.7.152.0/2177.7.152.1 to 77.7.159.25477.7.159.2552,046
24577.7.160.0/2177.7.160.1 to 77.7.167.25477.7.167.2552,046
24677.7.168.0/2177.7.168.1 to 77.7.175.25477.7.175.2552,046
24777.7.176.0/2177.7.176.1 to 77.7.183.25477.7.183.2552,046
24877.7.184.0/2177.7.184.1 to 77.7.191.25477.7.191.2552,046
24977.7.192.0/2177.7.192.1 to 77.7.199.25477.7.199.2552,046
25077.7.200.0/2177.7.200.1 to 77.7.207.25477.7.207.2552,046
25177.7.208.0/2177.7.208.1 to 77.7.215.25477.7.215.2552,046
25277.7.216.0/2177.7.216.1 to 77.7.223.25477.7.223.2552,046
25377.7.224.0/2177.7.224.1 to 77.7.231.25477.7.231.2552,046
25477.7.232.0/2177.7.232.1 to 77.7.239.25477.7.239.2552,046
25577.7.240.0/2177.7.240.1 to 77.7.247.25477.7.247.2552,046
25677.7.248.0/2177.7.248.1 to 77.7.255.25477.7.255.2552,046

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.