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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.

Network85.0.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
85.0.0.0
Broadcast address
85.7.255.255
First usable
85.0.0.1
Last usable
85.7.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
A (default /8)
As numbers
Hex 55000000 · Integer 1426063360 to 1426587647
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
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010101.00000000.00000000.0000000085.0.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network01010101.00000000.00000000.0000000085.0.0.0
Broadcast01010101.00000111.11111111.1111111185.7.255.255
Split into smaller subnets/21
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

85.0.0.0/13 makes 256 subnets of /21.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
185.0.0.0/2185.0.0.1 to 85.0.7.25485.0.7.2552,046
285.0.8.0/2185.0.8.1 to 85.0.15.25485.0.15.2552,046
385.0.16.0/2185.0.16.1 to 85.0.23.25485.0.23.2552,046
485.0.24.0/2185.0.24.1 to 85.0.31.25485.0.31.2552,046
585.0.32.0/2185.0.32.1 to 85.0.39.25485.0.39.2552,046
685.0.40.0/2185.0.40.1 to 85.0.47.25485.0.47.2552,046
785.0.48.0/2185.0.48.1 to 85.0.55.25485.0.55.2552,046
885.0.56.0/2185.0.56.1 to 85.0.63.25485.0.63.2552,046
985.0.64.0/2185.0.64.1 to 85.0.71.25485.0.71.2552,046
1085.0.72.0/2185.0.72.1 to 85.0.79.25485.0.79.2552,046
1185.0.80.0/2185.0.80.1 to 85.0.87.25485.0.87.2552,046
1285.0.88.0/2185.0.88.1 to 85.0.95.25485.0.95.2552,046
1385.0.96.0/2185.0.96.1 to 85.0.103.25485.0.103.2552,046
1485.0.104.0/2185.0.104.1 to 85.0.111.25485.0.111.2552,046
1585.0.112.0/2185.0.112.1 to 85.0.119.25485.0.119.2552,046
1685.0.120.0/2185.0.120.1 to 85.0.127.25485.0.127.2552,046
1785.0.128.0/2185.0.128.1 to 85.0.135.25485.0.135.2552,046
1885.0.136.0/2185.0.136.1 to 85.0.143.25485.0.143.2552,046
1985.0.144.0/2185.0.144.1 to 85.0.151.25485.0.151.2552,046
2085.0.152.0/2185.0.152.1 to 85.0.159.25485.0.159.2552,046
2185.0.160.0/2185.0.160.1 to 85.0.167.25485.0.167.2552,046
2285.0.168.0/2185.0.168.1 to 85.0.175.25485.0.175.2552,046
2385.0.176.0/2185.0.176.1 to 85.0.183.25485.0.183.2552,046
2485.0.184.0/2185.0.184.1 to 85.0.191.25485.0.191.2552,046
2585.0.192.0/2185.0.192.1 to 85.0.199.25485.0.199.2552,046
2685.0.200.0/2185.0.200.1 to 85.0.207.25485.0.207.2552,046
2785.0.208.0/2185.0.208.1 to 85.0.215.25485.0.215.2552,046
2885.0.216.0/2185.0.216.1 to 85.0.223.25485.0.223.2552,046
2985.0.224.0/2185.0.224.1 to 85.0.231.25485.0.231.2552,046
3085.0.232.0/2185.0.232.1 to 85.0.239.25485.0.239.2552,046
3185.0.240.0/2185.0.240.1 to 85.0.247.25485.0.247.2552,046
3285.0.248.0/2185.0.248.1 to 85.0.255.25485.0.255.2552,046
3385.1.0.0/2185.1.0.1 to 85.1.7.25485.1.7.2552,046
3485.1.8.0/2185.1.8.1 to 85.1.15.25485.1.15.2552,046
3585.1.16.0/2185.1.16.1 to 85.1.23.25485.1.23.2552,046
3685.1.24.0/2185.1.24.1 to 85.1.31.25485.1.31.2552,046
3785.1.32.0/2185.1.32.1 to 85.1.39.25485.1.39.2552,046
3885.1.40.0/2185.1.40.1 to 85.1.47.25485.1.47.2552,046
3985.1.48.0/2185.1.48.1 to 85.1.55.25485.1.55.2552,046
4085.1.56.0/2185.1.56.1 to 85.1.63.25485.1.63.2552,046
4185.1.64.0/2185.1.64.1 to 85.1.71.25485.1.71.2552,046
4285.1.72.0/2185.1.72.1 to 85.1.79.25485.1.79.2552,046
4385.1.80.0/2185.1.80.1 to 85.1.87.25485.1.87.2552,046
4485.1.88.0/2185.1.88.1 to 85.1.95.25485.1.95.2552,046
4585.1.96.0/2185.1.96.1 to 85.1.103.25485.1.103.2552,046
4685.1.104.0/2185.1.104.1 to 85.1.111.25485.1.111.2552,046
4785.1.112.0/2185.1.112.1 to 85.1.119.25485.1.119.2552,046
4885.1.120.0/2185.1.120.1 to 85.1.127.25485.1.127.2552,046
4985.1.128.0/2185.1.128.1 to 85.1.135.25485.1.135.2552,046
5085.1.136.0/2185.1.136.1 to 85.1.143.25485.1.143.2552,046
5185.1.144.0/2185.1.144.1 to 85.1.151.25485.1.151.2552,046
5285.1.152.0/2185.1.152.1 to 85.1.159.25485.1.159.2552,046
5385.1.160.0/2185.1.160.1 to 85.1.167.25485.1.167.2552,046
5485.1.168.0/2185.1.168.1 to 85.1.175.25485.1.175.2552,046
5585.1.176.0/2185.1.176.1 to 85.1.183.25485.1.183.2552,046
5685.1.184.0/2185.1.184.1 to 85.1.191.25485.1.191.2552,046
5785.1.192.0/2185.1.192.1 to 85.1.199.25485.1.199.2552,046
5885.1.200.0/2185.1.200.1 to 85.1.207.25485.1.207.2552,046
5985.1.208.0/2185.1.208.1 to 85.1.215.25485.1.215.2552,046
6085.1.216.0/2185.1.216.1 to 85.1.223.25485.1.223.2552,046
6185.1.224.0/2185.1.224.1 to 85.1.231.25485.1.231.2552,046
6285.1.232.0/2185.1.232.1 to 85.1.239.25485.1.239.2552,046
6385.1.240.0/2185.1.240.1 to 85.1.247.25485.1.247.2552,046
6485.1.248.0/2185.1.248.1 to 85.1.255.25485.1.255.2552,046
6585.2.0.0/2185.2.0.1 to 85.2.7.25485.2.7.2552,046
6685.2.8.0/2185.2.8.1 to 85.2.15.25485.2.15.2552,046
6785.2.16.0/2185.2.16.1 to 85.2.23.25485.2.23.2552,046
6885.2.24.0/2185.2.24.1 to 85.2.31.25485.2.31.2552,046
6985.2.32.0/2185.2.32.1 to 85.2.39.25485.2.39.2552,046
7085.2.40.0/2185.2.40.1 to 85.2.47.25485.2.47.2552,046
7185.2.48.0/2185.2.48.1 to 85.2.55.25485.2.55.2552,046
7285.2.56.0/2185.2.56.1 to 85.2.63.25485.2.63.2552,046
7385.2.64.0/2185.2.64.1 to 85.2.71.25485.2.71.2552,046
7485.2.72.0/2185.2.72.1 to 85.2.79.25485.2.79.2552,046
7585.2.80.0/2185.2.80.1 to 85.2.87.25485.2.87.2552,046
7685.2.88.0/2185.2.88.1 to 85.2.95.25485.2.95.2552,046
7785.2.96.0/2185.2.96.1 to 85.2.103.25485.2.103.2552,046
7885.2.104.0/2185.2.104.1 to 85.2.111.25485.2.111.2552,046
7985.2.112.0/2185.2.112.1 to 85.2.119.25485.2.119.2552,046
8085.2.120.0/2185.2.120.1 to 85.2.127.25485.2.127.2552,046
8185.2.128.0/2185.2.128.1 to 85.2.135.25485.2.135.2552,046
8285.2.136.0/2185.2.136.1 to 85.2.143.25485.2.143.2552,046
8385.2.144.0/2185.2.144.1 to 85.2.151.25485.2.151.2552,046
8485.2.152.0/2185.2.152.1 to 85.2.159.25485.2.159.2552,046
8585.2.160.0/2185.2.160.1 to 85.2.167.25485.2.167.2552,046
8685.2.168.0/2185.2.168.1 to 85.2.175.25485.2.175.2552,046
8785.2.176.0/2185.2.176.1 to 85.2.183.25485.2.183.2552,046
8885.2.184.0/2185.2.184.1 to 85.2.191.25485.2.191.2552,046
8985.2.192.0/2185.2.192.1 to 85.2.199.25485.2.199.2552,046
9085.2.200.0/2185.2.200.1 to 85.2.207.25485.2.207.2552,046
9185.2.208.0/2185.2.208.1 to 85.2.215.25485.2.215.2552,046
9285.2.216.0/2185.2.216.1 to 85.2.223.25485.2.223.2552,046
9385.2.224.0/2185.2.224.1 to 85.2.231.25485.2.231.2552,046
9485.2.232.0/2185.2.232.1 to 85.2.239.25485.2.239.2552,046
9585.2.240.0/2185.2.240.1 to 85.2.247.25485.2.247.2552,046
9685.2.248.0/2185.2.248.1 to 85.2.255.25485.2.255.2552,046
9785.3.0.0/2185.3.0.1 to 85.3.7.25485.3.7.2552,046
9885.3.8.0/2185.3.8.1 to 85.3.15.25485.3.15.2552,046
9985.3.16.0/2185.3.16.1 to 85.3.23.25485.3.23.2552,046
10085.3.24.0/2185.3.24.1 to 85.3.31.25485.3.31.2552,046
10185.3.32.0/2185.3.32.1 to 85.3.39.25485.3.39.2552,046
10285.3.40.0/2185.3.40.1 to 85.3.47.25485.3.47.2552,046
10385.3.48.0/2185.3.48.1 to 85.3.55.25485.3.55.2552,046
10485.3.56.0/2185.3.56.1 to 85.3.63.25485.3.63.2552,046
10585.3.64.0/2185.3.64.1 to 85.3.71.25485.3.71.2552,046
10685.3.72.0/2185.3.72.1 to 85.3.79.25485.3.79.2552,046
10785.3.80.0/2185.3.80.1 to 85.3.87.25485.3.87.2552,046
10885.3.88.0/2185.3.88.1 to 85.3.95.25485.3.95.2552,046
10985.3.96.0/2185.3.96.1 to 85.3.103.25485.3.103.2552,046
11085.3.104.0/2185.3.104.1 to 85.3.111.25485.3.111.2552,046
11185.3.112.0/2185.3.112.1 to 85.3.119.25485.3.119.2552,046
11285.3.120.0/2185.3.120.1 to 85.3.127.25485.3.127.2552,046
11385.3.128.0/2185.3.128.1 to 85.3.135.25485.3.135.2552,046
11485.3.136.0/2185.3.136.1 to 85.3.143.25485.3.143.2552,046
11585.3.144.0/2185.3.144.1 to 85.3.151.25485.3.151.2552,046
11685.3.152.0/2185.3.152.1 to 85.3.159.25485.3.159.2552,046
11785.3.160.0/2185.3.160.1 to 85.3.167.25485.3.167.2552,046
11885.3.168.0/2185.3.168.1 to 85.3.175.25485.3.175.2552,046
11985.3.176.0/2185.3.176.1 to 85.3.183.25485.3.183.2552,046
12085.3.184.0/2185.3.184.1 to 85.3.191.25485.3.191.2552,046
12185.3.192.0/2185.3.192.1 to 85.3.199.25485.3.199.2552,046
12285.3.200.0/2185.3.200.1 to 85.3.207.25485.3.207.2552,046
12385.3.208.0/2185.3.208.1 to 85.3.215.25485.3.215.2552,046
12485.3.216.0/2185.3.216.1 to 85.3.223.25485.3.223.2552,046
12585.3.224.0/2185.3.224.1 to 85.3.231.25485.3.231.2552,046
12685.3.232.0/2185.3.232.1 to 85.3.239.25485.3.239.2552,046
12785.3.240.0/2185.3.240.1 to 85.3.247.25485.3.247.2552,046
12885.3.248.0/2185.3.248.1 to 85.3.255.25485.3.255.2552,046
12985.4.0.0/2185.4.0.1 to 85.4.7.25485.4.7.2552,046
13085.4.8.0/2185.4.8.1 to 85.4.15.25485.4.15.2552,046
13185.4.16.0/2185.4.16.1 to 85.4.23.25485.4.23.2552,046
13285.4.24.0/2185.4.24.1 to 85.4.31.25485.4.31.2552,046
13385.4.32.0/2185.4.32.1 to 85.4.39.25485.4.39.2552,046
13485.4.40.0/2185.4.40.1 to 85.4.47.25485.4.47.2552,046
13585.4.48.0/2185.4.48.1 to 85.4.55.25485.4.55.2552,046
13685.4.56.0/2185.4.56.1 to 85.4.63.25485.4.63.2552,046
13785.4.64.0/2185.4.64.1 to 85.4.71.25485.4.71.2552,046
13885.4.72.0/2185.4.72.1 to 85.4.79.25485.4.79.2552,046
13985.4.80.0/2185.4.80.1 to 85.4.87.25485.4.87.2552,046
14085.4.88.0/2185.4.88.1 to 85.4.95.25485.4.95.2552,046
14185.4.96.0/2185.4.96.1 to 85.4.103.25485.4.103.2552,046
14285.4.104.0/2185.4.104.1 to 85.4.111.25485.4.111.2552,046
14385.4.112.0/2185.4.112.1 to 85.4.119.25485.4.119.2552,046
14485.4.120.0/2185.4.120.1 to 85.4.127.25485.4.127.2552,046
14585.4.128.0/2185.4.128.1 to 85.4.135.25485.4.135.2552,046
14685.4.136.0/2185.4.136.1 to 85.4.143.25485.4.143.2552,046
14785.4.144.0/2185.4.144.1 to 85.4.151.25485.4.151.2552,046
14885.4.152.0/2185.4.152.1 to 85.4.159.25485.4.159.2552,046
14985.4.160.0/2185.4.160.1 to 85.4.167.25485.4.167.2552,046
15085.4.168.0/2185.4.168.1 to 85.4.175.25485.4.175.2552,046
15185.4.176.0/2185.4.176.1 to 85.4.183.25485.4.183.2552,046
15285.4.184.0/2185.4.184.1 to 85.4.191.25485.4.191.2552,046
15385.4.192.0/2185.4.192.1 to 85.4.199.25485.4.199.2552,046
15485.4.200.0/2185.4.200.1 to 85.4.207.25485.4.207.2552,046
15585.4.208.0/2185.4.208.1 to 85.4.215.25485.4.215.2552,046
15685.4.216.0/2185.4.216.1 to 85.4.223.25485.4.223.2552,046
15785.4.224.0/2185.4.224.1 to 85.4.231.25485.4.231.2552,046
15885.4.232.0/2185.4.232.1 to 85.4.239.25485.4.239.2552,046
15985.4.240.0/2185.4.240.1 to 85.4.247.25485.4.247.2552,046
16085.4.248.0/2185.4.248.1 to 85.4.255.25485.4.255.2552,046
16185.5.0.0/2185.5.0.1 to 85.5.7.25485.5.7.2552,046
16285.5.8.0/2185.5.8.1 to 85.5.15.25485.5.15.2552,046
16385.5.16.0/2185.5.16.1 to 85.5.23.25485.5.23.2552,046
16485.5.24.0/2185.5.24.1 to 85.5.31.25485.5.31.2552,046
16585.5.32.0/2185.5.32.1 to 85.5.39.25485.5.39.2552,046
16685.5.40.0/2185.5.40.1 to 85.5.47.25485.5.47.2552,046
16785.5.48.0/2185.5.48.1 to 85.5.55.25485.5.55.2552,046
16885.5.56.0/2185.5.56.1 to 85.5.63.25485.5.63.2552,046
16985.5.64.0/2185.5.64.1 to 85.5.71.25485.5.71.2552,046
17085.5.72.0/2185.5.72.1 to 85.5.79.25485.5.79.2552,046
17185.5.80.0/2185.5.80.1 to 85.5.87.25485.5.87.2552,046
17285.5.88.0/2185.5.88.1 to 85.5.95.25485.5.95.2552,046
17385.5.96.0/2185.5.96.1 to 85.5.103.25485.5.103.2552,046
17485.5.104.0/2185.5.104.1 to 85.5.111.25485.5.111.2552,046
17585.5.112.0/2185.5.112.1 to 85.5.119.25485.5.119.2552,046
17685.5.120.0/2185.5.120.1 to 85.5.127.25485.5.127.2552,046
17785.5.128.0/2185.5.128.1 to 85.5.135.25485.5.135.2552,046
17885.5.136.0/2185.5.136.1 to 85.5.143.25485.5.143.2552,046
17985.5.144.0/2185.5.144.1 to 85.5.151.25485.5.151.2552,046
18085.5.152.0/2185.5.152.1 to 85.5.159.25485.5.159.2552,046
18185.5.160.0/2185.5.160.1 to 85.5.167.25485.5.167.2552,046
18285.5.168.0/2185.5.168.1 to 85.5.175.25485.5.175.2552,046
18385.5.176.0/2185.5.176.1 to 85.5.183.25485.5.183.2552,046
18485.5.184.0/2185.5.184.1 to 85.5.191.25485.5.191.2552,046
18585.5.192.0/2185.5.192.1 to 85.5.199.25485.5.199.2552,046
18685.5.200.0/2185.5.200.1 to 85.5.207.25485.5.207.2552,046
18785.5.208.0/2185.5.208.1 to 85.5.215.25485.5.215.2552,046
18885.5.216.0/2185.5.216.1 to 85.5.223.25485.5.223.2552,046
18985.5.224.0/2185.5.224.1 to 85.5.231.25485.5.231.2552,046
19085.5.232.0/2185.5.232.1 to 85.5.239.25485.5.239.2552,046
19185.5.240.0/2185.5.240.1 to 85.5.247.25485.5.247.2552,046
19285.5.248.0/2185.5.248.1 to 85.5.255.25485.5.255.2552,046
19385.6.0.0/2185.6.0.1 to 85.6.7.25485.6.7.2552,046
19485.6.8.0/2185.6.8.1 to 85.6.15.25485.6.15.2552,046
19585.6.16.0/2185.6.16.1 to 85.6.23.25485.6.23.2552,046
19685.6.24.0/2185.6.24.1 to 85.6.31.25485.6.31.2552,046
19785.6.32.0/2185.6.32.1 to 85.6.39.25485.6.39.2552,046
19885.6.40.0/2185.6.40.1 to 85.6.47.25485.6.47.2552,046
19985.6.48.0/2185.6.48.1 to 85.6.55.25485.6.55.2552,046
20085.6.56.0/2185.6.56.1 to 85.6.63.25485.6.63.2552,046
20185.6.64.0/2185.6.64.1 to 85.6.71.25485.6.71.2552,046
20285.6.72.0/2185.6.72.1 to 85.6.79.25485.6.79.2552,046
20385.6.80.0/2185.6.80.1 to 85.6.87.25485.6.87.2552,046
20485.6.88.0/2185.6.88.1 to 85.6.95.25485.6.95.2552,046
20585.6.96.0/2185.6.96.1 to 85.6.103.25485.6.103.2552,046
20685.6.104.0/2185.6.104.1 to 85.6.111.25485.6.111.2552,046
20785.6.112.0/2185.6.112.1 to 85.6.119.25485.6.119.2552,046
20885.6.120.0/2185.6.120.1 to 85.6.127.25485.6.127.2552,046
20985.6.128.0/2185.6.128.1 to 85.6.135.25485.6.135.2552,046
21085.6.136.0/2185.6.136.1 to 85.6.143.25485.6.143.2552,046
21185.6.144.0/2185.6.144.1 to 85.6.151.25485.6.151.2552,046
21285.6.152.0/2185.6.152.1 to 85.6.159.25485.6.159.2552,046
21385.6.160.0/2185.6.160.1 to 85.6.167.25485.6.167.2552,046
21485.6.168.0/2185.6.168.1 to 85.6.175.25485.6.175.2552,046
21585.6.176.0/2185.6.176.1 to 85.6.183.25485.6.183.2552,046
21685.6.184.0/2185.6.184.1 to 85.6.191.25485.6.191.2552,046
21785.6.192.0/2185.6.192.1 to 85.6.199.25485.6.199.2552,046
21885.6.200.0/2185.6.200.1 to 85.6.207.25485.6.207.2552,046
21985.6.208.0/2185.6.208.1 to 85.6.215.25485.6.215.2552,046
22085.6.216.0/2185.6.216.1 to 85.6.223.25485.6.223.2552,046
22185.6.224.0/2185.6.224.1 to 85.6.231.25485.6.231.2552,046
22285.6.232.0/2185.6.232.1 to 85.6.239.25485.6.239.2552,046
22385.6.240.0/2185.6.240.1 to 85.6.247.25485.6.247.2552,046
22485.6.248.0/2185.6.248.1 to 85.6.255.25485.6.255.2552,046
22585.7.0.0/2185.7.0.1 to 85.7.7.25485.7.7.2552,046
22685.7.8.0/2185.7.8.1 to 85.7.15.25485.7.15.2552,046
22785.7.16.0/2185.7.16.1 to 85.7.23.25485.7.23.2552,046
22885.7.24.0/2185.7.24.1 to 85.7.31.25485.7.31.2552,046
22985.7.32.0/2185.7.32.1 to 85.7.39.25485.7.39.2552,046
23085.7.40.0/2185.7.40.1 to 85.7.47.25485.7.47.2552,046
23185.7.48.0/2185.7.48.1 to 85.7.55.25485.7.55.2552,046
23285.7.56.0/2185.7.56.1 to 85.7.63.25485.7.63.2552,046
23385.7.64.0/2185.7.64.1 to 85.7.71.25485.7.71.2552,046
23485.7.72.0/2185.7.72.1 to 85.7.79.25485.7.79.2552,046
23585.7.80.0/2185.7.80.1 to 85.7.87.25485.7.87.2552,046
23685.7.88.0/2185.7.88.1 to 85.7.95.25485.7.95.2552,046
23785.7.96.0/2185.7.96.1 to 85.7.103.25485.7.103.2552,046
23885.7.104.0/2185.7.104.1 to 85.7.111.25485.7.111.2552,046
23985.7.112.0/2185.7.112.1 to 85.7.119.25485.7.119.2552,046
24085.7.120.0/2185.7.120.1 to 85.7.127.25485.7.127.2552,046
24185.7.128.0/2185.7.128.1 to 85.7.135.25485.7.135.2552,046
24285.7.136.0/2185.7.136.1 to 85.7.143.25485.7.143.2552,046
24385.7.144.0/2185.7.144.1 to 85.7.151.25485.7.151.2552,046
24485.7.152.0/2185.7.152.1 to 85.7.159.25485.7.159.2552,046
24585.7.160.0/2185.7.160.1 to 85.7.167.25485.7.167.2552,046
24685.7.168.0/2185.7.168.1 to 85.7.175.25485.7.175.2552,046
24785.7.176.0/2185.7.176.1 to 85.7.183.25485.7.183.2552,046
24885.7.184.0/2185.7.184.1 to 85.7.191.25485.7.191.2552,046
24985.7.192.0/2185.7.192.1 to 85.7.199.25485.7.199.2552,046
25085.7.200.0/2185.7.200.1 to 85.7.207.25485.7.207.2552,046
25185.7.208.0/2185.7.208.1 to 85.7.215.25485.7.215.2552,046
25285.7.216.0/2185.7.216.1 to 85.7.223.25485.7.223.2552,046
25385.7.224.0/2185.7.224.1 to 85.7.231.25485.7.231.2552,046
25485.7.232.0/2185.7.232.1 to 85.7.239.25485.7.239.2552,046
25585.7.240.0/2185.7.240.1 to 85.7.247.25485.7.247.2552,046
25685.7.248.0/2185.7.248.1 to 85.7.255.25485.7.255.2552,046

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.