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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/20
/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 2,048 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
177.0.0.0/2077.0.0.1 to 77.0.15.25477.0.15.2554,094
277.0.16.0/2077.0.16.1 to 77.0.31.25477.0.31.2554,094
377.0.32.0/2077.0.32.1 to 77.0.47.25477.0.47.2554,094
477.0.48.0/2077.0.48.1 to 77.0.63.25477.0.63.2554,094
577.0.64.0/2077.0.64.1 to 77.0.79.25477.0.79.2554,094
677.0.80.0/2077.0.80.1 to 77.0.95.25477.0.95.2554,094
777.0.96.0/2077.0.96.1 to 77.0.111.25477.0.111.2554,094
877.0.112.0/2077.0.112.1 to 77.0.127.25477.0.127.2554,094
977.0.128.0/2077.0.128.1 to 77.0.143.25477.0.143.2554,094
1077.0.144.0/2077.0.144.1 to 77.0.159.25477.0.159.2554,094
1177.0.160.0/2077.0.160.1 to 77.0.175.25477.0.175.2554,094
1277.0.176.0/2077.0.176.1 to 77.0.191.25477.0.191.2554,094
1377.0.192.0/2077.0.192.1 to 77.0.207.25477.0.207.2554,094
1477.0.208.0/2077.0.208.1 to 77.0.223.25477.0.223.2554,094
1577.0.224.0/2077.0.224.1 to 77.0.239.25477.0.239.2554,094
1677.0.240.0/2077.0.240.1 to 77.0.255.25477.0.255.2554,094
1777.1.0.0/2077.1.0.1 to 77.1.15.25477.1.15.2554,094
1877.1.16.0/2077.1.16.1 to 77.1.31.25477.1.31.2554,094
1977.1.32.0/2077.1.32.1 to 77.1.47.25477.1.47.2554,094
2077.1.48.0/2077.1.48.1 to 77.1.63.25477.1.63.2554,094
2177.1.64.0/2077.1.64.1 to 77.1.79.25477.1.79.2554,094
2277.1.80.0/2077.1.80.1 to 77.1.95.25477.1.95.2554,094
2377.1.96.0/2077.1.96.1 to 77.1.111.25477.1.111.2554,094
2477.1.112.0/2077.1.112.1 to 77.1.127.25477.1.127.2554,094
2577.1.128.0/2077.1.128.1 to 77.1.143.25477.1.143.2554,094
2677.1.144.0/2077.1.144.1 to 77.1.159.25477.1.159.2554,094
2777.1.160.0/2077.1.160.1 to 77.1.175.25477.1.175.2554,094
2877.1.176.0/2077.1.176.1 to 77.1.191.25477.1.191.2554,094
2977.1.192.0/2077.1.192.1 to 77.1.207.25477.1.207.2554,094
3077.1.208.0/2077.1.208.1 to 77.1.223.25477.1.223.2554,094
3177.1.224.0/2077.1.224.1 to 77.1.239.25477.1.239.2554,094
3277.1.240.0/2077.1.240.1 to 77.1.255.25477.1.255.2554,094
3377.2.0.0/2077.2.0.1 to 77.2.15.25477.2.15.2554,094
3477.2.16.0/2077.2.16.1 to 77.2.31.25477.2.31.2554,094
3577.2.32.0/2077.2.32.1 to 77.2.47.25477.2.47.2554,094
3677.2.48.0/2077.2.48.1 to 77.2.63.25477.2.63.2554,094
3777.2.64.0/2077.2.64.1 to 77.2.79.25477.2.79.2554,094
3877.2.80.0/2077.2.80.1 to 77.2.95.25477.2.95.2554,094
3977.2.96.0/2077.2.96.1 to 77.2.111.25477.2.111.2554,094
4077.2.112.0/2077.2.112.1 to 77.2.127.25477.2.127.2554,094
4177.2.128.0/2077.2.128.1 to 77.2.143.25477.2.143.2554,094
4277.2.144.0/2077.2.144.1 to 77.2.159.25477.2.159.2554,094
4377.2.160.0/2077.2.160.1 to 77.2.175.25477.2.175.2554,094
4477.2.176.0/2077.2.176.1 to 77.2.191.25477.2.191.2554,094
4577.2.192.0/2077.2.192.1 to 77.2.207.25477.2.207.2554,094
4677.2.208.0/2077.2.208.1 to 77.2.223.25477.2.223.2554,094
4777.2.224.0/2077.2.224.1 to 77.2.239.25477.2.239.2554,094
4877.2.240.0/2077.2.240.1 to 77.2.255.25477.2.255.2554,094
4977.3.0.0/2077.3.0.1 to 77.3.15.25477.3.15.2554,094
5077.3.16.0/2077.3.16.1 to 77.3.31.25477.3.31.2554,094
5177.3.32.0/2077.3.32.1 to 77.3.47.25477.3.47.2554,094
5277.3.48.0/2077.3.48.1 to 77.3.63.25477.3.63.2554,094
5377.3.64.0/2077.3.64.1 to 77.3.79.25477.3.79.2554,094
5477.3.80.0/2077.3.80.1 to 77.3.95.25477.3.95.2554,094
5577.3.96.0/2077.3.96.1 to 77.3.111.25477.3.111.2554,094
5677.3.112.0/2077.3.112.1 to 77.3.127.25477.3.127.2554,094
5777.3.128.0/2077.3.128.1 to 77.3.143.25477.3.143.2554,094
5877.3.144.0/2077.3.144.1 to 77.3.159.25477.3.159.2554,094
5977.3.160.0/2077.3.160.1 to 77.3.175.25477.3.175.2554,094
6077.3.176.0/2077.3.176.1 to 77.3.191.25477.3.191.2554,094
6177.3.192.0/2077.3.192.1 to 77.3.207.25477.3.207.2554,094
6277.3.208.0/2077.3.208.1 to 77.3.223.25477.3.223.2554,094
6377.3.224.0/2077.3.224.1 to 77.3.239.25477.3.239.2554,094
6477.3.240.0/2077.3.240.1 to 77.3.255.25477.3.255.2554,094
6577.4.0.0/2077.4.0.1 to 77.4.15.25477.4.15.2554,094
6677.4.16.0/2077.4.16.1 to 77.4.31.25477.4.31.2554,094
6777.4.32.0/2077.4.32.1 to 77.4.47.25477.4.47.2554,094
6877.4.48.0/2077.4.48.1 to 77.4.63.25477.4.63.2554,094
6977.4.64.0/2077.4.64.1 to 77.4.79.25477.4.79.2554,094
7077.4.80.0/2077.4.80.1 to 77.4.95.25477.4.95.2554,094
7177.4.96.0/2077.4.96.1 to 77.4.111.25477.4.111.2554,094
7277.4.112.0/2077.4.112.1 to 77.4.127.25477.4.127.2554,094
7377.4.128.0/2077.4.128.1 to 77.4.143.25477.4.143.2554,094
7477.4.144.0/2077.4.144.1 to 77.4.159.25477.4.159.2554,094
7577.4.160.0/2077.4.160.1 to 77.4.175.25477.4.175.2554,094
7677.4.176.0/2077.4.176.1 to 77.4.191.25477.4.191.2554,094
7777.4.192.0/2077.4.192.1 to 77.4.207.25477.4.207.2554,094
7877.4.208.0/2077.4.208.1 to 77.4.223.25477.4.223.2554,094
7977.4.224.0/2077.4.224.1 to 77.4.239.25477.4.239.2554,094
8077.4.240.0/2077.4.240.1 to 77.4.255.25477.4.255.2554,094
8177.5.0.0/2077.5.0.1 to 77.5.15.25477.5.15.2554,094
8277.5.16.0/2077.5.16.1 to 77.5.31.25477.5.31.2554,094
8377.5.32.0/2077.5.32.1 to 77.5.47.25477.5.47.2554,094
8477.5.48.0/2077.5.48.1 to 77.5.63.25477.5.63.2554,094
8577.5.64.0/2077.5.64.1 to 77.5.79.25477.5.79.2554,094
8677.5.80.0/2077.5.80.1 to 77.5.95.25477.5.95.2554,094
8777.5.96.0/2077.5.96.1 to 77.5.111.25477.5.111.2554,094
8877.5.112.0/2077.5.112.1 to 77.5.127.25477.5.127.2554,094
8977.5.128.0/2077.5.128.1 to 77.5.143.25477.5.143.2554,094
9077.5.144.0/2077.5.144.1 to 77.5.159.25477.5.159.2554,094
9177.5.160.0/2077.5.160.1 to 77.5.175.25477.5.175.2554,094
9277.5.176.0/2077.5.176.1 to 77.5.191.25477.5.191.2554,094
9377.5.192.0/2077.5.192.1 to 77.5.207.25477.5.207.2554,094
9477.5.208.0/2077.5.208.1 to 77.5.223.25477.5.223.2554,094
9577.5.224.0/2077.5.224.1 to 77.5.239.25477.5.239.2554,094
9677.5.240.0/2077.5.240.1 to 77.5.255.25477.5.255.2554,094
9777.6.0.0/2077.6.0.1 to 77.6.15.25477.6.15.2554,094
9877.6.16.0/2077.6.16.1 to 77.6.31.25477.6.31.2554,094
9977.6.32.0/2077.6.32.1 to 77.6.47.25477.6.47.2554,094
10077.6.48.0/2077.6.48.1 to 77.6.63.25477.6.63.2554,094
10177.6.64.0/2077.6.64.1 to 77.6.79.25477.6.79.2554,094
10277.6.80.0/2077.6.80.1 to 77.6.95.25477.6.95.2554,094
10377.6.96.0/2077.6.96.1 to 77.6.111.25477.6.111.2554,094
10477.6.112.0/2077.6.112.1 to 77.6.127.25477.6.127.2554,094
10577.6.128.0/2077.6.128.1 to 77.6.143.25477.6.143.2554,094
10677.6.144.0/2077.6.144.1 to 77.6.159.25477.6.159.2554,094
10777.6.160.0/2077.6.160.1 to 77.6.175.25477.6.175.2554,094
10877.6.176.0/2077.6.176.1 to 77.6.191.25477.6.191.2554,094
10977.6.192.0/2077.6.192.1 to 77.6.207.25477.6.207.2554,094
11077.6.208.0/2077.6.208.1 to 77.6.223.25477.6.223.2554,094
11177.6.224.0/2077.6.224.1 to 77.6.239.25477.6.239.2554,094
11277.6.240.0/2077.6.240.1 to 77.6.255.25477.6.255.2554,094
11377.7.0.0/2077.7.0.1 to 77.7.15.25477.7.15.2554,094
11477.7.16.0/2077.7.16.1 to 77.7.31.25477.7.31.2554,094
11577.7.32.0/2077.7.32.1 to 77.7.47.25477.7.47.2554,094
11677.7.48.0/2077.7.48.1 to 77.7.63.25477.7.63.2554,094
11777.7.64.0/2077.7.64.1 to 77.7.79.25477.7.79.2554,094
11877.7.80.0/2077.7.80.1 to 77.7.95.25477.7.95.2554,094
11977.7.96.0/2077.7.96.1 to 77.7.111.25477.7.111.2554,094
12077.7.112.0/2077.7.112.1 to 77.7.127.25477.7.127.2554,094
12177.7.128.0/2077.7.128.1 to 77.7.143.25477.7.143.2554,094
12277.7.144.0/2077.7.144.1 to 77.7.159.25477.7.159.2554,094
12377.7.160.0/2077.7.160.1 to 77.7.175.25477.7.175.2554,094
12477.7.176.0/2077.7.176.1 to 77.7.191.25477.7.191.2554,094
12577.7.192.0/2077.7.192.1 to 77.7.207.25477.7.207.2554,094
12677.7.208.0/2077.7.208.1 to 77.7.223.25477.7.223.2554,094
12777.7.224.0/2077.7.224.1 to 77.7.239.25477.7.239.2554,094
12877.7.240.0/2077.7.240.1 to 77.7.255.25477.7.255.2554,094
12977.8.0.0/2077.8.0.1 to 77.8.15.25477.8.15.2554,094
13077.8.16.0/2077.8.16.1 to 77.8.31.25477.8.31.2554,094
13177.8.32.0/2077.8.32.1 to 77.8.47.25477.8.47.2554,094
13277.8.48.0/2077.8.48.1 to 77.8.63.25477.8.63.2554,094
13377.8.64.0/2077.8.64.1 to 77.8.79.25477.8.79.2554,094
13477.8.80.0/2077.8.80.1 to 77.8.95.25477.8.95.2554,094
13577.8.96.0/2077.8.96.1 to 77.8.111.25477.8.111.2554,094
13677.8.112.0/2077.8.112.1 to 77.8.127.25477.8.127.2554,094
13777.8.128.0/2077.8.128.1 to 77.8.143.25477.8.143.2554,094
13877.8.144.0/2077.8.144.1 to 77.8.159.25477.8.159.2554,094
13977.8.160.0/2077.8.160.1 to 77.8.175.25477.8.175.2554,094
14077.8.176.0/2077.8.176.1 to 77.8.191.25477.8.191.2554,094
14177.8.192.0/2077.8.192.1 to 77.8.207.25477.8.207.2554,094
14277.8.208.0/2077.8.208.1 to 77.8.223.25477.8.223.2554,094
14377.8.224.0/2077.8.224.1 to 77.8.239.25477.8.239.2554,094
14477.8.240.0/2077.8.240.1 to 77.8.255.25477.8.255.2554,094
14577.9.0.0/2077.9.0.1 to 77.9.15.25477.9.15.2554,094
14677.9.16.0/2077.9.16.1 to 77.9.31.25477.9.31.2554,094
14777.9.32.0/2077.9.32.1 to 77.9.47.25477.9.47.2554,094
14877.9.48.0/2077.9.48.1 to 77.9.63.25477.9.63.2554,094
14977.9.64.0/2077.9.64.1 to 77.9.79.25477.9.79.2554,094
15077.9.80.0/2077.9.80.1 to 77.9.95.25477.9.95.2554,094
15177.9.96.0/2077.9.96.1 to 77.9.111.25477.9.111.2554,094
15277.9.112.0/2077.9.112.1 to 77.9.127.25477.9.127.2554,094
15377.9.128.0/2077.9.128.1 to 77.9.143.25477.9.143.2554,094
15477.9.144.0/2077.9.144.1 to 77.9.159.25477.9.159.2554,094
15577.9.160.0/2077.9.160.1 to 77.9.175.25477.9.175.2554,094
15677.9.176.0/2077.9.176.1 to 77.9.191.25477.9.191.2554,094
15777.9.192.0/2077.9.192.1 to 77.9.207.25477.9.207.2554,094
15877.9.208.0/2077.9.208.1 to 77.9.223.25477.9.223.2554,094
15977.9.224.0/2077.9.224.1 to 77.9.239.25477.9.239.2554,094
16077.9.240.0/2077.9.240.1 to 77.9.255.25477.9.255.2554,094
16177.10.0.0/2077.10.0.1 to 77.10.15.25477.10.15.2554,094
16277.10.16.0/2077.10.16.1 to 77.10.31.25477.10.31.2554,094
16377.10.32.0/2077.10.32.1 to 77.10.47.25477.10.47.2554,094
16477.10.48.0/2077.10.48.1 to 77.10.63.25477.10.63.2554,094
16577.10.64.0/2077.10.64.1 to 77.10.79.25477.10.79.2554,094
16677.10.80.0/2077.10.80.1 to 77.10.95.25477.10.95.2554,094
16777.10.96.0/2077.10.96.1 to 77.10.111.25477.10.111.2554,094
16877.10.112.0/2077.10.112.1 to 77.10.127.25477.10.127.2554,094
16977.10.128.0/2077.10.128.1 to 77.10.143.25477.10.143.2554,094
17077.10.144.0/2077.10.144.1 to 77.10.159.25477.10.159.2554,094
17177.10.160.0/2077.10.160.1 to 77.10.175.25477.10.175.2554,094
17277.10.176.0/2077.10.176.1 to 77.10.191.25477.10.191.2554,094
17377.10.192.0/2077.10.192.1 to 77.10.207.25477.10.207.2554,094
17477.10.208.0/2077.10.208.1 to 77.10.223.25477.10.223.2554,094
17577.10.224.0/2077.10.224.1 to 77.10.239.25477.10.239.2554,094
17677.10.240.0/2077.10.240.1 to 77.10.255.25477.10.255.2554,094
17777.11.0.0/2077.11.0.1 to 77.11.15.25477.11.15.2554,094
17877.11.16.0/2077.11.16.1 to 77.11.31.25477.11.31.2554,094
17977.11.32.0/2077.11.32.1 to 77.11.47.25477.11.47.2554,094
18077.11.48.0/2077.11.48.1 to 77.11.63.25477.11.63.2554,094
18177.11.64.0/2077.11.64.1 to 77.11.79.25477.11.79.2554,094
18277.11.80.0/2077.11.80.1 to 77.11.95.25477.11.95.2554,094
18377.11.96.0/2077.11.96.1 to 77.11.111.25477.11.111.2554,094
18477.11.112.0/2077.11.112.1 to 77.11.127.25477.11.127.2554,094
18577.11.128.0/2077.11.128.1 to 77.11.143.25477.11.143.2554,094
18677.11.144.0/2077.11.144.1 to 77.11.159.25477.11.159.2554,094
18777.11.160.0/2077.11.160.1 to 77.11.175.25477.11.175.2554,094
18877.11.176.0/2077.11.176.1 to 77.11.191.25477.11.191.2554,094
18977.11.192.0/2077.11.192.1 to 77.11.207.25477.11.207.2554,094
19077.11.208.0/2077.11.208.1 to 77.11.223.25477.11.223.2554,094
19177.11.224.0/2077.11.224.1 to 77.11.239.25477.11.239.2554,094
19277.11.240.0/2077.11.240.1 to 77.11.255.25477.11.255.2554,094
19377.12.0.0/2077.12.0.1 to 77.12.15.25477.12.15.2554,094
19477.12.16.0/2077.12.16.1 to 77.12.31.25477.12.31.2554,094
19577.12.32.0/2077.12.32.1 to 77.12.47.25477.12.47.2554,094
19677.12.48.0/2077.12.48.1 to 77.12.63.25477.12.63.2554,094
19777.12.64.0/2077.12.64.1 to 77.12.79.25477.12.79.2554,094
19877.12.80.0/2077.12.80.1 to 77.12.95.25477.12.95.2554,094
19977.12.96.0/2077.12.96.1 to 77.12.111.25477.12.111.2554,094
20077.12.112.0/2077.12.112.1 to 77.12.127.25477.12.127.2554,094
20177.12.128.0/2077.12.128.1 to 77.12.143.25477.12.143.2554,094
20277.12.144.0/2077.12.144.1 to 77.12.159.25477.12.159.2554,094
20377.12.160.0/2077.12.160.1 to 77.12.175.25477.12.175.2554,094
20477.12.176.0/2077.12.176.1 to 77.12.191.25477.12.191.2554,094
20577.12.192.0/2077.12.192.1 to 77.12.207.25477.12.207.2554,094
20677.12.208.0/2077.12.208.1 to 77.12.223.25477.12.223.2554,094
20777.12.224.0/2077.12.224.1 to 77.12.239.25477.12.239.2554,094
20877.12.240.0/2077.12.240.1 to 77.12.255.25477.12.255.2554,094
20977.13.0.0/2077.13.0.1 to 77.13.15.25477.13.15.2554,094
21077.13.16.0/2077.13.16.1 to 77.13.31.25477.13.31.2554,094
21177.13.32.0/2077.13.32.1 to 77.13.47.25477.13.47.2554,094
21277.13.48.0/2077.13.48.1 to 77.13.63.25477.13.63.2554,094
21377.13.64.0/2077.13.64.1 to 77.13.79.25477.13.79.2554,094
21477.13.80.0/2077.13.80.1 to 77.13.95.25477.13.95.2554,094
21577.13.96.0/2077.13.96.1 to 77.13.111.25477.13.111.2554,094
21677.13.112.0/2077.13.112.1 to 77.13.127.25477.13.127.2554,094
21777.13.128.0/2077.13.128.1 to 77.13.143.25477.13.143.2554,094
21877.13.144.0/2077.13.144.1 to 77.13.159.25477.13.159.2554,094
21977.13.160.0/2077.13.160.1 to 77.13.175.25477.13.175.2554,094
22077.13.176.0/2077.13.176.1 to 77.13.191.25477.13.191.2554,094
22177.13.192.0/2077.13.192.1 to 77.13.207.25477.13.207.2554,094
22277.13.208.0/2077.13.208.1 to 77.13.223.25477.13.223.2554,094
22377.13.224.0/2077.13.224.1 to 77.13.239.25477.13.239.2554,094
22477.13.240.0/2077.13.240.1 to 77.13.255.25477.13.255.2554,094
22577.14.0.0/2077.14.0.1 to 77.14.15.25477.14.15.2554,094
22677.14.16.0/2077.14.16.1 to 77.14.31.25477.14.31.2554,094
22777.14.32.0/2077.14.32.1 to 77.14.47.25477.14.47.2554,094
22877.14.48.0/2077.14.48.1 to 77.14.63.25477.14.63.2554,094
22977.14.64.0/2077.14.64.1 to 77.14.79.25477.14.79.2554,094
23077.14.80.0/2077.14.80.1 to 77.14.95.25477.14.95.2554,094
23177.14.96.0/2077.14.96.1 to 77.14.111.25477.14.111.2554,094
23277.14.112.0/2077.14.112.1 to 77.14.127.25477.14.127.2554,094
23377.14.128.0/2077.14.128.1 to 77.14.143.25477.14.143.2554,094
23477.14.144.0/2077.14.144.1 to 77.14.159.25477.14.159.2554,094
23577.14.160.0/2077.14.160.1 to 77.14.175.25477.14.175.2554,094
23677.14.176.0/2077.14.176.1 to 77.14.191.25477.14.191.2554,094
23777.14.192.0/2077.14.192.1 to 77.14.207.25477.14.207.2554,094
23877.14.208.0/2077.14.208.1 to 77.14.223.25477.14.223.2554,094
23977.14.224.0/2077.14.224.1 to 77.14.239.25477.14.239.2554,094
24077.14.240.0/2077.14.240.1 to 77.14.255.25477.14.255.2554,094
24177.15.0.0/2077.15.0.1 to 77.15.15.25477.15.15.2554,094
24277.15.16.0/2077.15.16.1 to 77.15.31.25477.15.31.2554,094
24377.15.32.0/2077.15.32.1 to 77.15.47.25477.15.47.2554,094
24477.15.48.0/2077.15.48.1 to 77.15.63.25477.15.63.2554,094
24577.15.64.0/2077.15.64.1 to 77.15.79.25477.15.79.2554,094
24677.15.80.0/2077.15.80.1 to 77.15.95.25477.15.95.2554,094
24777.15.96.0/2077.15.96.1 to 77.15.111.25477.15.111.2554,094
24877.15.112.0/2077.15.112.1 to 77.15.127.25477.15.127.2554,094
24977.15.128.0/2077.15.128.1 to 77.15.143.25477.15.143.2554,094
25077.15.144.0/2077.15.144.1 to 77.15.159.25477.15.159.2554,094
25177.15.160.0/2077.15.160.1 to 77.15.175.25477.15.175.2554,094
25277.15.176.0/2077.15.176.1 to 77.15.191.25477.15.191.2554,094
25377.15.192.0/2077.15.192.1 to 77.15.207.25477.15.207.2554,094
25477.15.208.0/2077.15.208.1 to 77.15.223.25477.15.223.2554,094
25577.15.224.0/2077.15.224.1 to 77.15.239.25477.15.239.2554,094
25677.15.240.0/2077.15.240.1 to 77.15.255.25477.15.255.2554,094

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.