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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.

Network85.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
85.0.0.0
Broadcast address
85.127.255.255
First usable
85.0.0.1
Last usable
85.127.255.254
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 55000000 · Integer 1426063360 to 1434451967
Reverse DNS zones
0.85.in-addr.arpa
1.85.in-addr.arpa
2.85.in-addr.arpa
3.85.in-addr.arpa
4.85.in-addr.arpa
5.85.in-addr.arpa
6.85.in-addr.arpa
7.85.in-addr.arpa
8.85.in-addr.arpa
9.85.in-addr.arpa
10.85.in-addr.arpa
11.85.in-addr.arpa
12.85.in-addr.arpa
13.85.in-addr.arpa
14.85.in-addr.arpa
15.85.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
Address01010101.00000000.00000000.0000000085.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01010101.00000000.00000000.0000000085.0.0.0
Broadcast01010101.01111111.11111111.1111111185.127.255.255
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)

85.0.0.0/9 makes 2,048 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
185.0.0.0/2085.0.0.1 to 85.0.15.25485.0.15.2554,094
285.0.16.0/2085.0.16.1 to 85.0.31.25485.0.31.2554,094
385.0.32.0/2085.0.32.1 to 85.0.47.25485.0.47.2554,094
485.0.48.0/2085.0.48.1 to 85.0.63.25485.0.63.2554,094
585.0.64.0/2085.0.64.1 to 85.0.79.25485.0.79.2554,094
685.0.80.0/2085.0.80.1 to 85.0.95.25485.0.95.2554,094
785.0.96.0/2085.0.96.1 to 85.0.111.25485.0.111.2554,094
885.0.112.0/2085.0.112.1 to 85.0.127.25485.0.127.2554,094
985.0.128.0/2085.0.128.1 to 85.0.143.25485.0.143.2554,094
1085.0.144.0/2085.0.144.1 to 85.0.159.25485.0.159.2554,094
1185.0.160.0/2085.0.160.1 to 85.0.175.25485.0.175.2554,094
1285.0.176.0/2085.0.176.1 to 85.0.191.25485.0.191.2554,094
1385.0.192.0/2085.0.192.1 to 85.0.207.25485.0.207.2554,094
1485.0.208.0/2085.0.208.1 to 85.0.223.25485.0.223.2554,094
1585.0.224.0/2085.0.224.1 to 85.0.239.25485.0.239.2554,094
1685.0.240.0/2085.0.240.1 to 85.0.255.25485.0.255.2554,094
1785.1.0.0/2085.1.0.1 to 85.1.15.25485.1.15.2554,094
1885.1.16.0/2085.1.16.1 to 85.1.31.25485.1.31.2554,094
1985.1.32.0/2085.1.32.1 to 85.1.47.25485.1.47.2554,094
2085.1.48.0/2085.1.48.1 to 85.1.63.25485.1.63.2554,094
2185.1.64.0/2085.1.64.1 to 85.1.79.25485.1.79.2554,094
2285.1.80.0/2085.1.80.1 to 85.1.95.25485.1.95.2554,094
2385.1.96.0/2085.1.96.1 to 85.1.111.25485.1.111.2554,094
2485.1.112.0/2085.1.112.1 to 85.1.127.25485.1.127.2554,094
2585.1.128.0/2085.1.128.1 to 85.1.143.25485.1.143.2554,094
2685.1.144.0/2085.1.144.1 to 85.1.159.25485.1.159.2554,094
2785.1.160.0/2085.1.160.1 to 85.1.175.25485.1.175.2554,094
2885.1.176.0/2085.1.176.1 to 85.1.191.25485.1.191.2554,094
2985.1.192.0/2085.1.192.1 to 85.1.207.25485.1.207.2554,094
3085.1.208.0/2085.1.208.1 to 85.1.223.25485.1.223.2554,094
3185.1.224.0/2085.1.224.1 to 85.1.239.25485.1.239.2554,094
3285.1.240.0/2085.1.240.1 to 85.1.255.25485.1.255.2554,094
3385.2.0.0/2085.2.0.1 to 85.2.15.25485.2.15.2554,094
3485.2.16.0/2085.2.16.1 to 85.2.31.25485.2.31.2554,094
3585.2.32.0/2085.2.32.1 to 85.2.47.25485.2.47.2554,094
3685.2.48.0/2085.2.48.1 to 85.2.63.25485.2.63.2554,094
3785.2.64.0/2085.2.64.1 to 85.2.79.25485.2.79.2554,094
3885.2.80.0/2085.2.80.1 to 85.2.95.25485.2.95.2554,094
3985.2.96.0/2085.2.96.1 to 85.2.111.25485.2.111.2554,094
4085.2.112.0/2085.2.112.1 to 85.2.127.25485.2.127.2554,094
4185.2.128.0/2085.2.128.1 to 85.2.143.25485.2.143.2554,094
4285.2.144.0/2085.2.144.1 to 85.2.159.25485.2.159.2554,094
4385.2.160.0/2085.2.160.1 to 85.2.175.25485.2.175.2554,094
4485.2.176.0/2085.2.176.1 to 85.2.191.25485.2.191.2554,094
4585.2.192.0/2085.2.192.1 to 85.2.207.25485.2.207.2554,094
4685.2.208.0/2085.2.208.1 to 85.2.223.25485.2.223.2554,094
4785.2.224.0/2085.2.224.1 to 85.2.239.25485.2.239.2554,094
4885.2.240.0/2085.2.240.1 to 85.2.255.25485.2.255.2554,094
4985.3.0.0/2085.3.0.1 to 85.3.15.25485.3.15.2554,094
5085.3.16.0/2085.3.16.1 to 85.3.31.25485.3.31.2554,094
5185.3.32.0/2085.3.32.1 to 85.3.47.25485.3.47.2554,094
5285.3.48.0/2085.3.48.1 to 85.3.63.25485.3.63.2554,094
5385.3.64.0/2085.3.64.1 to 85.3.79.25485.3.79.2554,094
5485.3.80.0/2085.3.80.1 to 85.3.95.25485.3.95.2554,094
5585.3.96.0/2085.3.96.1 to 85.3.111.25485.3.111.2554,094
5685.3.112.0/2085.3.112.1 to 85.3.127.25485.3.127.2554,094
5785.3.128.0/2085.3.128.1 to 85.3.143.25485.3.143.2554,094
5885.3.144.0/2085.3.144.1 to 85.3.159.25485.3.159.2554,094
5985.3.160.0/2085.3.160.1 to 85.3.175.25485.3.175.2554,094
6085.3.176.0/2085.3.176.1 to 85.3.191.25485.3.191.2554,094
6185.3.192.0/2085.3.192.1 to 85.3.207.25485.3.207.2554,094
6285.3.208.0/2085.3.208.1 to 85.3.223.25485.3.223.2554,094
6385.3.224.0/2085.3.224.1 to 85.3.239.25485.3.239.2554,094
6485.3.240.0/2085.3.240.1 to 85.3.255.25485.3.255.2554,094
6585.4.0.0/2085.4.0.1 to 85.4.15.25485.4.15.2554,094
6685.4.16.0/2085.4.16.1 to 85.4.31.25485.4.31.2554,094
6785.4.32.0/2085.4.32.1 to 85.4.47.25485.4.47.2554,094
6885.4.48.0/2085.4.48.1 to 85.4.63.25485.4.63.2554,094
6985.4.64.0/2085.4.64.1 to 85.4.79.25485.4.79.2554,094
7085.4.80.0/2085.4.80.1 to 85.4.95.25485.4.95.2554,094
7185.4.96.0/2085.4.96.1 to 85.4.111.25485.4.111.2554,094
7285.4.112.0/2085.4.112.1 to 85.4.127.25485.4.127.2554,094
7385.4.128.0/2085.4.128.1 to 85.4.143.25485.4.143.2554,094
7485.4.144.0/2085.4.144.1 to 85.4.159.25485.4.159.2554,094
7585.4.160.0/2085.4.160.1 to 85.4.175.25485.4.175.2554,094
7685.4.176.0/2085.4.176.1 to 85.4.191.25485.4.191.2554,094
7785.4.192.0/2085.4.192.1 to 85.4.207.25485.4.207.2554,094
7885.4.208.0/2085.4.208.1 to 85.4.223.25485.4.223.2554,094
7985.4.224.0/2085.4.224.1 to 85.4.239.25485.4.239.2554,094
8085.4.240.0/2085.4.240.1 to 85.4.255.25485.4.255.2554,094
8185.5.0.0/2085.5.0.1 to 85.5.15.25485.5.15.2554,094
8285.5.16.0/2085.5.16.1 to 85.5.31.25485.5.31.2554,094
8385.5.32.0/2085.5.32.1 to 85.5.47.25485.5.47.2554,094
8485.5.48.0/2085.5.48.1 to 85.5.63.25485.5.63.2554,094
8585.5.64.0/2085.5.64.1 to 85.5.79.25485.5.79.2554,094
8685.5.80.0/2085.5.80.1 to 85.5.95.25485.5.95.2554,094
8785.5.96.0/2085.5.96.1 to 85.5.111.25485.5.111.2554,094
8885.5.112.0/2085.5.112.1 to 85.5.127.25485.5.127.2554,094
8985.5.128.0/2085.5.128.1 to 85.5.143.25485.5.143.2554,094
9085.5.144.0/2085.5.144.1 to 85.5.159.25485.5.159.2554,094
9185.5.160.0/2085.5.160.1 to 85.5.175.25485.5.175.2554,094
9285.5.176.0/2085.5.176.1 to 85.5.191.25485.5.191.2554,094
9385.5.192.0/2085.5.192.1 to 85.5.207.25485.5.207.2554,094
9485.5.208.0/2085.5.208.1 to 85.5.223.25485.5.223.2554,094
9585.5.224.0/2085.5.224.1 to 85.5.239.25485.5.239.2554,094
9685.5.240.0/2085.5.240.1 to 85.5.255.25485.5.255.2554,094
9785.6.0.0/2085.6.0.1 to 85.6.15.25485.6.15.2554,094
9885.6.16.0/2085.6.16.1 to 85.6.31.25485.6.31.2554,094
9985.6.32.0/2085.6.32.1 to 85.6.47.25485.6.47.2554,094
10085.6.48.0/2085.6.48.1 to 85.6.63.25485.6.63.2554,094
10185.6.64.0/2085.6.64.1 to 85.6.79.25485.6.79.2554,094
10285.6.80.0/2085.6.80.1 to 85.6.95.25485.6.95.2554,094
10385.6.96.0/2085.6.96.1 to 85.6.111.25485.6.111.2554,094
10485.6.112.0/2085.6.112.1 to 85.6.127.25485.6.127.2554,094
10585.6.128.0/2085.6.128.1 to 85.6.143.25485.6.143.2554,094
10685.6.144.0/2085.6.144.1 to 85.6.159.25485.6.159.2554,094
10785.6.160.0/2085.6.160.1 to 85.6.175.25485.6.175.2554,094
10885.6.176.0/2085.6.176.1 to 85.6.191.25485.6.191.2554,094
10985.6.192.0/2085.6.192.1 to 85.6.207.25485.6.207.2554,094
11085.6.208.0/2085.6.208.1 to 85.6.223.25485.6.223.2554,094
11185.6.224.0/2085.6.224.1 to 85.6.239.25485.6.239.2554,094
11285.6.240.0/2085.6.240.1 to 85.6.255.25485.6.255.2554,094
11385.7.0.0/2085.7.0.1 to 85.7.15.25485.7.15.2554,094
11485.7.16.0/2085.7.16.1 to 85.7.31.25485.7.31.2554,094
11585.7.32.0/2085.7.32.1 to 85.7.47.25485.7.47.2554,094
11685.7.48.0/2085.7.48.1 to 85.7.63.25485.7.63.2554,094
11785.7.64.0/2085.7.64.1 to 85.7.79.25485.7.79.2554,094
11885.7.80.0/2085.7.80.1 to 85.7.95.25485.7.95.2554,094
11985.7.96.0/2085.7.96.1 to 85.7.111.25485.7.111.2554,094
12085.7.112.0/2085.7.112.1 to 85.7.127.25485.7.127.2554,094
12185.7.128.0/2085.7.128.1 to 85.7.143.25485.7.143.2554,094
12285.7.144.0/2085.7.144.1 to 85.7.159.25485.7.159.2554,094
12385.7.160.0/2085.7.160.1 to 85.7.175.25485.7.175.2554,094
12485.7.176.0/2085.7.176.1 to 85.7.191.25485.7.191.2554,094
12585.7.192.0/2085.7.192.1 to 85.7.207.25485.7.207.2554,094
12685.7.208.0/2085.7.208.1 to 85.7.223.25485.7.223.2554,094
12785.7.224.0/2085.7.224.1 to 85.7.239.25485.7.239.2554,094
12885.7.240.0/2085.7.240.1 to 85.7.255.25485.7.255.2554,094
12985.8.0.0/2085.8.0.1 to 85.8.15.25485.8.15.2554,094
13085.8.16.0/2085.8.16.1 to 85.8.31.25485.8.31.2554,094
13185.8.32.0/2085.8.32.1 to 85.8.47.25485.8.47.2554,094
13285.8.48.0/2085.8.48.1 to 85.8.63.25485.8.63.2554,094
13385.8.64.0/2085.8.64.1 to 85.8.79.25485.8.79.2554,094
13485.8.80.0/2085.8.80.1 to 85.8.95.25485.8.95.2554,094
13585.8.96.0/2085.8.96.1 to 85.8.111.25485.8.111.2554,094
13685.8.112.0/2085.8.112.1 to 85.8.127.25485.8.127.2554,094
13785.8.128.0/2085.8.128.1 to 85.8.143.25485.8.143.2554,094
13885.8.144.0/2085.8.144.1 to 85.8.159.25485.8.159.2554,094
13985.8.160.0/2085.8.160.1 to 85.8.175.25485.8.175.2554,094
14085.8.176.0/2085.8.176.1 to 85.8.191.25485.8.191.2554,094
14185.8.192.0/2085.8.192.1 to 85.8.207.25485.8.207.2554,094
14285.8.208.0/2085.8.208.1 to 85.8.223.25485.8.223.2554,094
14385.8.224.0/2085.8.224.1 to 85.8.239.25485.8.239.2554,094
14485.8.240.0/2085.8.240.1 to 85.8.255.25485.8.255.2554,094
14585.9.0.0/2085.9.0.1 to 85.9.15.25485.9.15.2554,094
14685.9.16.0/2085.9.16.1 to 85.9.31.25485.9.31.2554,094
14785.9.32.0/2085.9.32.1 to 85.9.47.25485.9.47.2554,094
14885.9.48.0/2085.9.48.1 to 85.9.63.25485.9.63.2554,094
14985.9.64.0/2085.9.64.1 to 85.9.79.25485.9.79.2554,094
15085.9.80.0/2085.9.80.1 to 85.9.95.25485.9.95.2554,094
15185.9.96.0/2085.9.96.1 to 85.9.111.25485.9.111.2554,094
15285.9.112.0/2085.9.112.1 to 85.9.127.25485.9.127.2554,094
15385.9.128.0/2085.9.128.1 to 85.9.143.25485.9.143.2554,094
15485.9.144.0/2085.9.144.1 to 85.9.159.25485.9.159.2554,094
15585.9.160.0/2085.9.160.1 to 85.9.175.25485.9.175.2554,094
15685.9.176.0/2085.9.176.1 to 85.9.191.25485.9.191.2554,094
15785.9.192.0/2085.9.192.1 to 85.9.207.25485.9.207.2554,094
15885.9.208.0/2085.9.208.1 to 85.9.223.25485.9.223.2554,094
15985.9.224.0/2085.9.224.1 to 85.9.239.25485.9.239.2554,094
16085.9.240.0/2085.9.240.1 to 85.9.255.25485.9.255.2554,094
16185.10.0.0/2085.10.0.1 to 85.10.15.25485.10.15.2554,094
16285.10.16.0/2085.10.16.1 to 85.10.31.25485.10.31.2554,094
16385.10.32.0/2085.10.32.1 to 85.10.47.25485.10.47.2554,094
16485.10.48.0/2085.10.48.1 to 85.10.63.25485.10.63.2554,094
16585.10.64.0/2085.10.64.1 to 85.10.79.25485.10.79.2554,094
16685.10.80.0/2085.10.80.1 to 85.10.95.25485.10.95.2554,094
16785.10.96.0/2085.10.96.1 to 85.10.111.25485.10.111.2554,094
16885.10.112.0/2085.10.112.1 to 85.10.127.25485.10.127.2554,094
16985.10.128.0/2085.10.128.1 to 85.10.143.25485.10.143.2554,094
17085.10.144.0/2085.10.144.1 to 85.10.159.25485.10.159.2554,094
17185.10.160.0/2085.10.160.1 to 85.10.175.25485.10.175.2554,094
17285.10.176.0/2085.10.176.1 to 85.10.191.25485.10.191.2554,094
17385.10.192.0/2085.10.192.1 to 85.10.207.25485.10.207.2554,094
17485.10.208.0/2085.10.208.1 to 85.10.223.25485.10.223.2554,094
17585.10.224.0/2085.10.224.1 to 85.10.239.25485.10.239.2554,094
17685.10.240.0/2085.10.240.1 to 85.10.255.25485.10.255.2554,094
17785.11.0.0/2085.11.0.1 to 85.11.15.25485.11.15.2554,094
17885.11.16.0/2085.11.16.1 to 85.11.31.25485.11.31.2554,094
17985.11.32.0/2085.11.32.1 to 85.11.47.25485.11.47.2554,094
18085.11.48.0/2085.11.48.1 to 85.11.63.25485.11.63.2554,094
18185.11.64.0/2085.11.64.1 to 85.11.79.25485.11.79.2554,094
18285.11.80.0/2085.11.80.1 to 85.11.95.25485.11.95.2554,094
18385.11.96.0/2085.11.96.1 to 85.11.111.25485.11.111.2554,094
18485.11.112.0/2085.11.112.1 to 85.11.127.25485.11.127.2554,094
18585.11.128.0/2085.11.128.1 to 85.11.143.25485.11.143.2554,094
18685.11.144.0/2085.11.144.1 to 85.11.159.25485.11.159.2554,094
18785.11.160.0/2085.11.160.1 to 85.11.175.25485.11.175.2554,094
18885.11.176.0/2085.11.176.1 to 85.11.191.25485.11.191.2554,094
18985.11.192.0/2085.11.192.1 to 85.11.207.25485.11.207.2554,094
19085.11.208.0/2085.11.208.1 to 85.11.223.25485.11.223.2554,094
19185.11.224.0/2085.11.224.1 to 85.11.239.25485.11.239.2554,094
19285.11.240.0/2085.11.240.1 to 85.11.255.25485.11.255.2554,094
19385.12.0.0/2085.12.0.1 to 85.12.15.25485.12.15.2554,094
19485.12.16.0/2085.12.16.1 to 85.12.31.25485.12.31.2554,094
19585.12.32.0/2085.12.32.1 to 85.12.47.25485.12.47.2554,094
19685.12.48.0/2085.12.48.1 to 85.12.63.25485.12.63.2554,094
19785.12.64.0/2085.12.64.1 to 85.12.79.25485.12.79.2554,094
19885.12.80.0/2085.12.80.1 to 85.12.95.25485.12.95.2554,094
19985.12.96.0/2085.12.96.1 to 85.12.111.25485.12.111.2554,094
20085.12.112.0/2085.12.112.1 to 85.12.127.25485.12.127.2554,094
20185.12.128.0/2085.12.128.1 to 85.12.143.25485.12.143.2554,094
20285.12.144.0/2085.12.144.1 to 85.12.159.25485.12.159.2554,094
20385.12.160.0/2085.12.160.1 to 85.12.175.25485.12.175.2554,094
20485.12.176.0/2085.12.176.1 to 85.12.191.25485.12.191.2554,094
20585.12.192.0/2085.12.192.1 to 85.12.207.25485.12.207.2554,094
20685.12.208.0/2085.12.208.1 to 85.12.223.25485.12.223.2554,094
20785.12.224.0/2085.12.224.1 to 85.12.239.25485.12.239.2554,094
20885.12.240.0/2085.12.240.1 to 85.12.255.25485.12.255.2554,094
20985.13.0.0/2085.13.0.1 to 85.13.15.25485.13.15.2554,094
21085.13.16.0/2085.13.16.1 to 85.13.31.25485.13.31.2554,094
21185.13.32.0/2085.13.32.1 to 85.13.47.25485.13.47.2554,094
21285.13.48.0/2085.13.48.1 to 85.13.63.25485.13.63.2554,094
21385.13.64.0/2085.13.64.1 to 85.13.79.25485.13.79.2554,094
21485.13.80.0/2085.13.80.1 to 85.13.95.25485.13.95.2554,094
21585.13.96.0/2085.13.96.1 to 85.13.111.25485.13.111.2554,094
21685.13.112.0/2085.13.112.1 to 85.13.127.25485.13.127.2554,094
21785.13.128.0/2085.13.128.1 to 85.13.143.25485.13.143.2554,094
21885.13.144.0/2085.13.144.1 to 85.13.159.25485.13.159.2554,094
21985.13.160.0/2085.13.160.1 to 85.13.175.25485.13.175.2554,094
22085.13.176.0/2085.13.176.1 to 85.13.191.25485.13.191.2554,094
22185.13.192.0/2085.13.192.1 to 85.13.207.25485.13.207.2554,094
22285.13.208.0/2085.13.208.1 to 85.13.223.25485.13.223.2554,094
22385.13.224.0/2085.13.224.1 to 85.13.239.25485.13.239.2554,094
22485.13.240.0/2085.13.240.1 to 85.13.255.25485.13.255.2554,094
22585.14.0.0/2085.14.0.1 to 85.14.15.25485.14.15.2554,094
22685.14.16.0/2085.14.16.1 to 85.14.31.25485.14.31.2554,094
22785.14.32.0/2085.14.32.1 to 85.14.47.25485.14.47.2554,094
22885.14.48.0/2085.14.48.1 to 85.14.63.25485.14.63.2554,094
22985.14.64.0/2085.14.64.1 to 85.14.79.25485.14.79.2554,094
23085.14.80.0/2085.14.80.1 to 85.14.95.25485.14.95.2554,094
23185.14.96.0/2085.14.96.1 to 85.14.111.25485.14.111.2554,094
23285.14.112.0/2085.14.112.1 to 85.14.127.25485.14.127.2554,094
23385.14.128.0/2085.14.128.1 to 85.14.143.25485.14.143.2554,094
23485.14.144.0/2085.14.144.1 to 85.14.159.25485.14.159.2554,094
23585.14.160.0/2085.14.160.1 to 85.14.175.25485.14.175.2554,094
23685.14.176.0/2085.14.176.1 to 85.14.191.25485.14.191.2554,094
23785.14.192.0/2085.14.192.1 to 85.14.207.25485.14.207.2554,094
23885.14.208.0/2085.14.208.1 to 85.14.223.25485.14.223.2554,094
23985.14.224.0/2085.14.224.1 to 85.14.239.25485.14.239.2554,094
24085.14.240.0/2085.14.240.1 to 85.14.255.25485.14.255.2554,094
24185.15.0.0/2085.15.0.1 to 85.15.15.25485.15.15.2554,094
24285.15.16.0/2085.15.16.1 to 85.15.31.25485.15.31.2554,094
24385.15.32.0/2085.15.32.1 to 85.15.47.25485.15.47.2554,094
24485.15.48.0/2085.15.48.1 to 85.15.63.25485.15.63.2554,094
24585.15.64.0/2085.15.64.1 to 85.15.79.25485.15.79.2554,094
24685.15.80.0/2085.15.80.1 to 85.15.95.25485.15.95.2554,094
24785.15.96.0/2085.15.96.1 to 85.15.111.25485.15.111.2554,094
24885.15.112.0/2085.15.112.1 to 85.15.127.25485.15.127.2554,094
24985.15.128.0/2085.15.128.1 to 85.15.143.25485.15.143.2554,094
25085.15.144.0/2085.15.144.1 to 85.15.159.25485.15.159.2554,094
25185.15.160.0/2085.15.160.1 to 85.15.175.25485.15.175.2554,094
25285.15.176.0/2085.15.176.1 to 85.15.191.25485.15.191.2554,094
25385.15.192.0/2085.15.192.1 to 85.15.207.25485.15.207.2554,094
25485.15.208.0/2085.15.208.1 to 85.15.223.25485.15.223.2554,094
25585.15.224.0/2085.15.224.1 to 85.15.239.25485.15.239.2554,094
25685.15.240.0/2085.15.240.1 to 85.15.255.25485.15.255.2554,094

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.