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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.

Network83.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
83.0.0.0
Broadcast address
83.127.255.255
First usable
83.0.0.1
Last usable
83.127.255.254
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 53000000 · Integer 1392508928 to 1400897535
Reverse DNS zones
0.83.in-addr.arpa
1.83.in-addr.arpa
2.83.in-addr.arpa
3.83.in-addr.arpa
4.83.in-addr.arpa
5.83.in-addr.arpa
6.83.in-addr.arpa
7.83.in-addr.arpa
8.83.in-addr.arpa
9.83.in-addr.arpa
10.83.in-addr.arpa
11.83.in-addr.arpa
12.83.in-addr.arpa
13.83.in-addr.arpa
14.83.in-addr.arpa
15.83.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
Address01010011.00000000.00000000.0000000083.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01010011.00000000.00000000.0000000083.0.0.0
Broadcast01010011.01111111.11111111.1111111183.127.255.255
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)

83.0.0.0/9 makes 2,048 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
183.0.0.0/2083.0.0.1 to 83.0.15.25483.0.15.2554,094
283.0.16.0/2083.0.16.1 to 83.0.31.25483.0.31.2554,094
383.0.32.0/2083.0.32.1 to 83.0.47.25483.0.47.2554,094
483.0.48.0/2083.0.48.1 to 83.0.63.25483.0.63.2554,094
583.0.64.0/2083.0.64.1 to 83.0.79.25483.0.79.2554,094
683.0.80.0/2083.0.80.1 to 83.0.95.25483.0.95.2554,094
783.0.96.0/2083.0.96.1 to 83.0.111.25483.0.111.2554,094
883.0.112.0/2083.0.112.1 to 83.0.127.25483.0.127.2554,094
983.0.128.0/2083.0.128.1 to 83.0.143.25483.0.143.2554,094
1083.0.144.0/2083.0.144.1 to 83.0.159.25483.0.159.2554,094
1183.0.160.0/2083.0.160.1 to 83.0.175.25483.0.175.2554,094
1283.0.176.0/2083.0.176.1 to 83.0.191.25483.0.191.2554,094
1383.0.192.0/2083.0.192.1 to 83.0.207.25483.0.207.2554,094
1483.0.208.0/2083.0.208.1 to 83.0.223.25483.0.223.2554,094
1583.0.224.0/2083.0.224.1 to 83.0.239.25483.0.239.2554,094
1683.0.240.0/2083.0.240.1 to 83.0.255.25483.0.255.2554,094
1783.1.0.0/2083.1.0.1 to 83.1.15.25483.1.15.2554,094
1883.1.16.0/2083.1.16.1 to 83.1.31.25483.1.31.2554,094
1983.1.32.0/2083.1.32.1 to 83.1.47.25483.1.47.2554,094
2083.1.48.0/2083.1.48.1 to 83.1.63.25483.1.63.2554,094
2183.1.64.0/2083.1.64.1 to 83.1.79.25483.1.79.2554,094
2283.1.80.0/2083.1.80.1 to 83.1.95.25483.1.95.2554,094
2383.1.96.0/2083.1.96.1 to 83.1.111.25483.1.111.2554,094
2483.1.112.0/2083.1.112.1 to 83.1.127.25483.1.127.2554,094
2583.1.128.0/2083.1.128.1 to 83.1.143.25483.1.143.2554,094
2683.1.144.0/2083.1.144.1 to 83.1.159.25483.1.159.2554,094
2783.1.160.0/2083.1.160.1 to 83.1.175.25483.1.175.2554,094
2883.1.176.0/2083.1.176.1 to 83.1.191.25483.1.191.2554,094
2983.1.192.0/2083.1.192.1 to 83.1.207.25483.1.207.2554,094
3083.1.208.0/2083.1.208.1 to 83.1.223.25483.1.223.2554,094
3183.1.224.0/2083.1.224.1 to 83.1.239.25483.1.239.2554,094
3283.1.240.0/2083.1.240.1 to 83.1.255.25483.1.255.2554,094
3383.2.0.0/2083.2.0.1 to 83.2.15.25483.2.15.2554,094
3483.2.16.0/2083.2.16.1 to 83.2.31.25483.2.31.2554,094
3583.2.32.0/2083.2.32.1 to 83.2.47.25483.2.47.2554,094
3683.2.48.0/2083.2.48.1 to 83.2.63.25483.2.63.2554,094
3783.2.64.0/2083.2.64.1 to 83.2.79.25483.2.79.2554,094
3883.2.80.0/2083.2.80.1 to 83.2.95.25483.2.95.2554,094
3983.2.96.0/2083.2.96.1 to 83.2.111.25483.2.111.2554,094
4083.2.112.0/2083.2.112.1 to 83.2.127.25483.2.127.2554,094
4183.2.128.0/2083.2.128.1 to 83.2.143.25483.2.143.2554,094
4283.2.144.0/2083.2.144.1 to 83.2.159.25483.2.159.2554,094
4383.2.160.0/2083.2.160.1 to 83.2.175.25483.2.175.2554,094
4483.2.176.0/2083.2.176.1 to 83.2.191.25483.2.191.2554,094
4583.2.192.0/2083.2.192.1 to 83.2.207.25483.2.207.2554,094
4683.2.208.0/2083.2.208.1 to 83.2.223.25483.2.223.2554,094
4783.2.224.0/2083.2.224.1 to 83.2.239.25483.2.239.2554,094
4883.2.240.0/2083.2.240.1 to 83.2.255.25483.2.255.2554,094
4983.3.0.0/2083.3.0.1 to 83.3.15.25483.3.15.2554,094
5083.3.16.0/2083.3.16.1 to 83.3.31.25483.3.31.2554,094
5183.3.32.0/2083.3.32.1 to 83.3.47.25483.3.47.2554,094
5283.3.48.0/2083.3.48.1 to 83.3.63.25483.3.63.2554,094
5383.3.64.0/2083.3.64.1 to 83.3.79.25483.3.79.2554,094
5483.3.80.0/2083.3.80.1 to 83.3.95.25483.3.95.2554,094
5583.3.96.0/2083.3.96.1 to 83.3.111.25483.3.111.2554,094
5683.3.112.0/2083.3.112.1 to 83.3.127.25483.3.127.2554,094
5783.3.128.0/2083.3.128.1 to 83.3.143.25483.3.143.2554,094
5883.3.144.0/2083.3.144.1 to 83.3.159.25483.3.159.2554,094
5983.3.160.0/2083.3.160.1 to 83.3.175.25483.3.175.2554,094
6083.3.176.0/2083.3.176.1 to 83.3.191.25483.3.191.2554,094
6183.3.192.0/2083.3.192.1 to 83.3.207.25483.3.207.2554,094
6283.3.208.0/2083.3.208.1 to 83.3.223.25483.3.223.2554,094
6383.3.224.0/2083.3.224.1 to 83.3.239.25483.3.239.2554,094
6483.3.240.0/2083.3.240.1 to 83.3.255.25483.3.255.2554,094
6583.4.0.0/2083.4.0.1 to 83.4.15.25483.4.15.2554,094
6683.4.16.0/2083.4.16.1 to 83.4.31.25483.4.31.2554,094
6783.4.32.0/2083.4.32.1 to 83.4.47.25483.4.47.2554,094
6883.4.48.0/2083.4.48.1 to 83.4.63.25483.4.63.2554,094
6983.4.64.0/2083.4.64.1 to 83.4.79.25483.4.79.2554,094
7083.4.80.0/2083.4.80.1 to 83.4.95.25483.4.95.2554,094
7183.4.96.0/2083.4.96.1 to 83.4.111.25483.4.111.2554,094
7283.4.112.0/2083.4.112.1 to 83.4.127.25483.4.127.2554,094
7383.4.128.0/2083.4.128.1 to 83.4.143.25483.4.143.2554,094
7483.4.144.0/2083.4.144.1 to 83.4.159.25483.4.159.2554,094
7583.4.160.0/2083.4.160.1 to 83.4.175.25483.4.175.2554,094
7683.4.176.0/2083.4.176.1 to 83.4.191.25483.4.191.2554,094
7783.4.192.0/2083.4.192.1 to 83.4.207.25483.4.207.2554,094
7883.4.208.0/2083.4.208.1 to 83.4.223.25483.4.223.2554,094
7983.4.224.0/2083.4.224.1 to 83.4.239.25483.4.239.2554,094
8083.4.240.0/2083.4.240.1 to 83.4.255.25483.4.255.2554,094
8183.5.0.0/2083.5.0.1 to 83.5.15.25483.5.15.2554,094
8283.5.16.0/2083.5.16.1 to 83.5.31.25483.5.31.2554,094
8383.5.32.0/2083.5.32.1 to 83.5.47.25483.5.47.2554,094
8483.5.48.0/2083.5.48.1 to 83.5.63.25483.5.63.2554,094
8583.5.64.0/2083.5.64.1 to 83.5.79.25483.5.79.2554,094
8683.5.80.0/2083.5.80.1 to 83.5.95.25483.5.95.2554,094
8783.5.96.0/2083.5.96.1 to 83.5.111.25483.5.111.2554,094
8883.5.112.0/2083.5.112.1 to 83.5.127.25483.5.127.2554,094
8983.5.128.0/2083.5.128.1 to 83.5.143.25483.5.143.2554,094
9083.5.144.0/2083.5.144.1 to 83.5.159.25483.5.159.2554,094
9183.5.160.0/2083.5.160.1 to 83.5.175.25483.5.175.2554,094
9283.5.176.0/2083.5.176.1 to 83.5.191.25483.5.191.2554,094
9383.5.192.0/2083.5.192.1 to 83.5.207.25483.5.207.2554,094
9483.5.208.0/2083.5.208.1 to 83.5.223.25483.5.223.2554,094
9583.5.224.0/2083.5.224.1 to 83.5.239.25483.5.239.2554,094
9683.5.240.0/2083.5.240.1 to 83.5.255.25483.5.255.2554,094
9783.6.0.0/2083.6.0.1 to 83.6.15.25483.6.15.2554,094
9883.6.16.0/2083.6.16.1 to 83.6.31.25483.6.31.2554,094
9983.6.32.0/2083.6.32.1 to 83.6.47.25483.6.47.2554,094
10083.6.48.0/2083.6.48.1 to 83.6.63.25483.6.63.2554,094
10183.6.64.0/2083.6.64.1 to 83.6.79.25483.6.79.2554,094
10283.6.80.0/2083.6.80.1 to 83.6.95.25483.6.95.2554,094
10383.6.96.0/2083.6.96.1 to 83.6.111.25483.6.111.2554,094
10483.6.112.0/2083.6.112.1 to 83.6.127.25483.6.127.2554,094
10583.6.128.0/2083.6.128.1 to 83.6.143.25483.6.143.2554,094
10683.6.144.0/2083.6.144.1 to 83.6.159.25483.6.159.2554,094
10783.6.160.0/2083.6.160.1 to 83.6.175.25483.6.175.2554,094
10883.6.176.0/2083.6.176.1 to 83.6.191.25483.6.191.2554,094
10983.6.192.0/2083.6.192.1 to 83.6.207.25483.6.207.2554,094
11083.6.208.0/2083.6.208.1 to 83.6.223.25483.6.223.2554,094
11183.6.224.0/2083.6.224.1 to 83.6.239.25483.6.239.2554,094
11283.6.240.0/2083.6.240.1 to 83.6.255.25483.6.255.2554,094
11383.7.0.0/2083.7.0.1 to 83.7.15.25483.7.15.2554,094
11483.7.16.0/2083.7.16.1 to 83.7.31.25483.7.31.2554,094
11583.7.32.0/2083.7.32.1 to 83.7.47.25483.7.47.2554,094
11683.7.48.0/2083.7.48.1 to 83.7.63.25483.7.63.2554,094
11783.7.64.0/2083.7.64.1 to 83.7.79.25483.7.79.2554,094
11883.7.80.0/2083.7.80.1 to 83.7.95.25483.7.95.2554,094
11983.7.96.0/2083.7.96.1 to 83.7.111.25483.7.111.2554,094
12083.7.112.0/2083.7.112.1 to 83.7.127.25483.7.127.2554,094
12183.7.128.0/2083.7.128.1 to 83.7.143.25483.7.143.2554,094
12283.7.144.0/2083.7.144.1 to 83.7.159.25483.7.159.2554,094
12383.7.160.0/2083.7.160.1 to 83.7.175.25483.7.175.2554,094
12483.7.176.0/2083.7.176.1 to 83.7.191.25483.7.191.2554,094
12583.7.192.0/2083.7.192.1 to 83.7.207.25483.7.207.2554,094
12683.7.208.0/2083.7.208.1 to 83.7.223.25483.7.223.2554,094
12783.7.224.0/2083.7.224.1 to 83.7.239.25483.7.239.2554,094
12883.7.240.0/2083.7.240.1 to 83.7.255.25483.7.255.2554,094
12983.8.0.0/2083.8.0.1 to 83.8.15.25483.8.15.2554,094
13083.8.16.0/2083.8.16.1 to 83.8.31.25483.8.31.2554,094
13183.8.32.0/2083.8.32.1 to 83.8.47.25483.8.47.2554,094
13283.8.48.0/2083.8.48.1 to 83.8.63.25483.8.63.2554,094
13383.8.64.0/2083.8.64.1 to 83.8.79.25483.8.79.2554,094
13483.8.80.0/2083.8.80.1 to 83.8.95.25483.8.95.2554,094
13583.8.96.0/2083.8.96.1 to 83.8.111.25483.8.111.2554,094
13683.8.112.0/2083.8.112.1 to 83.8.127.25483.8.127.2554,094
13783.8.128.0/2083.8.128.1 to 83.8.143.25483.8.143.2554,094
13883.8.144.0/2083.8.144.1 to 83.8.159.25483.8.159.2554,094
13983.8.160.0/2083.8.160.1 to 83.8.175.25483.8.175.2554,094
14083.8.176.0/2083.8.176.1 to 83.8.191.25483.8.191.2554,094
14183.8.192.0/2083.8.192.1 to 83.8.207.25483.8.207.2554,094
14283.8.208.0/2083.8.208.1 to 83.8.223.25483.8.223.2554,094
14383.8.224.0/2083.8.224.1 to 83.8.239.25483.8.239.2554,094
14483.8.240.0/2083.8.240.1 to 83.8.255.25483.8.255.2554,094
14583.9.0.0/2083.9.0.1 to 83.9.15.25483.9.15.2554,094
14683.9.16.0/2083.9.16.1 to 83.9.31.25483.9.31.2554,094
14783.9.32.0/2083.9.32.1 to 83.9.47.25483.9.47.2554,094
14883.9.48.0/2083.9.48.1 to 83.9.63.25483.9.63.2554,094
14983.9.64.0/2083.9.64.1 to 83.9.79.25483.9.79.2554,094
15083.9.80.0/2083.9.80.1 to 83.9.95.25483.9.95.2554,094
15183.9.96.0/2083.9.96.1 to 83.9.111.25483.9.111.2554,094
15283.9.112.0/2083.9.112.1 to 83.9.127.25483.9.127.2554,094
15383.9.128.0/2083.9.128.1 to 83.9.143.25483.9.143.2554,094
15483.9.144.0/2083.9.144.1 to 83.9.159.25483.9.159.2554,094
15583.9.160.0/2083.9.160.1 to 83.9.175.25483.9.175.2554,094
15683.9.176.0/2083.9.176.1 to 83.9.191.25483.9.191.2554,094
15783.9.192.0/2083.9.192.1 to 83.9.207.25483.9.207.2554,094
15883.9.208.0/2083.9.208.1 to 83.9.223.25483.9.223.2554,094
15983.9.224.0/2083.9.224.1 to 83.9.239.25483.9.239.2554,094
16083.9.240.0/2083.9.240.1 to 83.9.255.25483.9.255.2554,094
16183.10.0.0/2083.10.0.1 to 83.10.15.25483.10.15.2554,094
16283.10.16.0/2083.10.16.1 to 83.10.31.25483.10.31.2554,094
16383.10.32.0/2083.10.32.1 to 83.10.47.25483.10.47.2554,094
16483.10.48.0/2083.10.48.1 to 83.10.63.25483.10.63.2554,094
16583.10.64.0/2083.10.64.1 to 83.10.79.25483.10.79.2554,094
16683.10.80.0/2083.10.80.1 to 83.10.95.25483.10.95.2554,094
16783.10.96.0/2083.10.96.1 to 83.10.111.25483.10.111.2554,094
16883.10.112.0/2083.10.112.1 to 83.10.127.25483.10.127.2554,094
16983.10.128.0/2083.10.128.1 to 83.10.143.25483.10.143.2554,094
17083.10.144.0/2083.10.144.1 to 83.10.159.25483.10.159.2554,094
17183.10.160.0/2083.10.160.1 to 83.10.175.25483.10.175.2554,094
17283.10.176.0/2083.10.176.1 to 83.10.191.25483.10.191.2554,094
17383.10.192.0/2083.10.192.1 to 83.10.207.25483.10.207.2554,094
17483.10.208.0/2083.10.208.1 to 83.10.223.25483.10.223.2554,094
17583.10.224.0/2083.10.224.1 to 83.10.239.25483.10.239.2554,094
17683.10.240.0/2083.10.240.1 to 83.10.255.25483.10.255.2554,094
17783.11.0.0/2083.11.0.1 to 83.11.15.25483.11.15.2554,094
17883.11.16.0/2083.11.16.1 to 83.11.31.25483.11.31.2554,094
17983.11.32.0/2083.11.32.1 to 83.11.47.25483.11.47.2554,094
18083.11.48.0/2083.11.48.1 to 83.11.63.25483.11.63.2554,094
18183.11.64.0/2083.11.64.1 to 83.11.79.25483.11.79.2554,094
18283.11.80.0/2083.11.80.1 to 83.11.95.25483.11.95.2554,094
18383.11.96.0/2083.11.96.1 to 83.11.111.25483.11.111.2554,094
18483.11.112.0/2083.11.112.1 to 83.11.127.25483.11.127.2554,094
18583.11.128.0/2083.11.128.1 to 83.11.143.25483.11.143.2554,094
18683.11.144.0/2083.11.144.1 to 83.11.159.25483.11.159.2554,094
18783.11.160.0/2083.11.160.1 to 83.11.175.25483.11.175.2554,094
18883.11.176.0/2083.11.176.1 to 83.11.191.25483.11.191.2554,094
18983.11.192.0/2083.11.192.1 to 83.11.207.25483.11.207.2554,094
19083.11.208.0/2083.11.208.1 to 83.11.223.25483.11.223.2554,094
19183.11.224.0/2083.11.224.1 to 83.11.239.25483.11.239.2554,094
19283.11.240.0/2083.11.240.1 to 83.11.255.25483.11.255.2554,094
19383.12.0.0/2083.12.0.1 to 83.12.15.25483.12.15.2554,094
19483.12.16.0/2083.12.16.1 to 83.12.31.25483.12.31.2554,094
19583.12.32.0/2083.12.32.1 to 83.12.47.25483.12.47.2554,094
19683.12.48.0/2083.12.48.1 to 83.12.63.25483.12.63.2554,094
19783.12.64.0/2083.12.64.1 to 83.12.79.25483.12.79.2554,094
19883.12.80.0/2083.12.80.1 to 83.12.95.25483.12.95.2554,094
19983.12.96.0/2083.12.96.1 to 83.12.111.25483.12.111.2554,094
20083.12.112.0/2083.12.112.1 to 83.12.127.25483.12.127.2554,094
20183.12.128.0/2083.12.128.1 to 83.12.143.25483.12.143.2554,094
20283.12.144.0/2083.12.144.1 to 83.12.159.25483.12.159.2554,094
20383.12.160.0/2083.12.160.1 to 83.12.175.25483.12.175.2554,094
20483.12.176.0/2083.12.176.1 to 83.12.191.25483.12.191.2554,094
20583.12.192.0/2083.12.192.1 to 83.12.207.25483.12.207.2554,094
20683.12.208.0/2083.12.208.1 to 83.12.223.25483.12.223.2554,094
20783.12.224.0/2083.12.224.1 to 83.12.239.25483.12.239.2554,094
20883.12.240.0/2083.12.240.1 to 83.12.255.25483.12.255.2554,094
20983.13.0.0/2083.13.0.1 to 83.13.15.25483.13.15.2554,094
21083.13.16.0/2083.13.16.1 to 83.13.31.25483.13.31.2554,094
21183.13.32.0/2083.13.32.1 to 83.13.47.25483.13.47.2554,094
21283.13.48.0/2083.13.48.1 to 83.13.63.25483.13.63.2554,094
21383.13.64.0/2083.13.64.1 to 83.13.79.25483.13.79.2554,094
21483.13.80.0/2083.13.80.1 to 83.13.95.25483.13.95.2554,094
21583.13.96.0/2083.13.96.1 to 83.13.111.25483.13.111.2554,094
21683.13.112.0/2083.13.112.1 to 83.13.127.25483.13.127.2554,094
21783.13.128.0/2083.13.128.1 to 83.13.143.25483.13.143.2554,094
21883.13.144.0/2083.13.144.1 to 83.13.159.25483.13.159.2554,094
21983.13.160.0/2083.13.160.1 to 83.13.175.25483.13.175.2554,094
22083.13.176.0/2083.13.176.1 to 83.13.191.25483.13.191.2554,094
22183.13.192.0/2083.13.192.1 to 83.13.207.25483.13.207.2554,094
22283.13.208.0/2083.13.208.1 to 83.13.223.25483.13.223.2554,094
22383.13.224.0/2083.13.224.1 to 83.13.239.25483.13.239.2554,094
22483.13.240.0/2083.13.240.1 to 83.13.255.25483.13.255.2554,094
22583.14.0.0/2083.14.0.1 to 83.14.15.25483.14.15.2554,094
22683.14.16.0/2083.14.16.1 to 83.14.31.25483.14.31.2554,094
22783.14.32.0/2083.14.32.1 to 83.14.47.25483.14.47.2554,094
22883.14.48.0/2083.14.48.1 to 83.14.63.25483.14.63.2554,094
22983.14.64.0/2083.14.64.1 to 83.14.79.25483.14.79.2554,094
23083.14.80.0/2083.14.80.1 to 83.14.95.25483.14.95.2554,094
23183.14.96.0/2083.14.96.1 to 83.14.111.25483.14.111.2554,094
23283.14.112.0/2083.14.112.1 to 83.14.127.25483.14.127.2554,094
23383.14.128.0/2083.14.128.1 to 83.14.143.25483.14.143.2554,094
23483.14.144.0/2083.14.144.1 to 83.14.159.25483.14.159.2554,094
23583.14.160.0/2083.14.160.1 to 83.14.175.25483.14.175.2554,094
23683.14.176.0/2083.14.176.1 to 83.14.191.25483.14.191.2554,094
23783.14.192.0/2083.14.192.1 to 83.14.207.25483.14.207.2554,094
23883.14.208.0/2083.14.208.1 to 83.14.223.25483.14.223.2554,094
23983.14.224.0/2083.14.224.1 to 83.14.239.25483.14.239.2554,094
24083.14.240.0/2083.14.240.1 to 83.14.255.25483.14.255.2554,094
24183.15.0.0/2083.15.0.1 to 83.15.15.25483.15.15.2554,094
24283.15.16.0/2083.15.16.1 to 83.15.31.25483.15.31.2554,094
24383.15.32.0/2083.15.32.1 to 83.15.47.25483.15.47.2554,094
24483.15.48.0/2083.15.48.1 to 83.15.63.25483.15.63.2554,094
24583.15.64.0/2083.15.64.1 to 83.15.79.25483.15.79.2554,094
24683.15.80.0/2083.15.80.1 to 83.15.95.25483.15.95.2554,094
24783.15.96.0/2083.15.96.1 to 83.15.111.25483.15.111.2554,094
24883.15.112.0/2083.15.112.1 to 83.15.127.25483.15.127.2554,094
24983.15.128.0/2083.15.128.1 to 83.15.143.25483.15.143.2554,094
25083.15.144.0/2083.15.144.1 to 83.15.159.25483.15.159.2554,094
25183.15.160.0/2083.15.160.1 to 83.15.175.25483.15.175.2554,094
25283.15.176.0/2083.15.176.1 to 83.15.191.25483.15.191.2554,094
25383.15.192.0/2083.15.192.1 to 83.15.207.25483.15.207.2554,094
25483.15.208.0/2083.15.208.1 to 83.15.223.25483.15.223.2554,094
25583.15.224.0/2083.15.224.1 to 83.15.239.25483.15.239.2554,094
25683.15.240.0/2083.15.240.1 to 83.15.255.25483.15.255.2554,094

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.