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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.

Network63.192.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
63.192.0.0
Broadcast address
63.255.255.255
First usable
63.192.0.1
Last usable
63.255.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 3FC00000 · Integer 1069547520 to 1073741823
Reverse DNS zones
192.63.in-addr.arpa
193.63.in-addr.arpa
194.63.in-addr.arpa
195.63.in-addr.arpa
196.63.in-addr.arpa
197.63.in-addr.arpa
198.63.in-addr.arpa
199.63.in-addr.arpa
200.63.in-addr.arpa
201.63.in-addr.arpa
202.63.in-addr.arpa
203.63.in-addr.arpa
204.63.in-addr.arpa
205.63.in-addr.arpa
206.63.in-addr.arpa
207.63.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111111.11000000.00000000.0000000063.192.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00111111.11000000.00000000.0000000063.192.0.0
Broadcast00111111.11111111.11111111.1111111163.255.255.255
Split into smaller subnets/20
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

63.192.0.0/10 makes 1,024 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
163.192.0.0/2063.192.0.1 to 63.192.15.25463.192.15.2554,094
263.192.16.0/2063.192.16.1 to 63.192.31.25463.192.31.2554,094
363.192.32.0/2063.192.32.1 to 63.192.47.25463.192.47.2554,094
463.192.48.0/2063.192.48.1 to 63.192.63.25463.192.63.2554,094
563.192.64.0/2063.192.64.1 to 63.192.79.25463.192.79.2554,094
663.192.80.0/2063.192.80.1 to 63.192.95.25463.192.95.2554,094
763.192.96.0/2063.192.96.1 to 63.192.111.25463.192.111.2554,094
863.192.112.0/2063.192.112.1 to 63.192.127.25463.192.127.2554,094
963.192.128.0/2063.192.128.1 to 63.192.143.25463.192.143.2554,094
1063.192.144.0/2063.192.144.1 to 63.192.159.25463.192.159.2554,094
1163.192.160.0/2063.192.160.1 to 63.192.175.25463.192.175.2554,094
1263.192.176.0/2063.192.176.1 to 63.192.191.25463.192.191.2554,094
1363.192.192.0/2063.192.192.1 to 63.192.207.25463.192.207.2554,094
1463.192.208.0/2063.192.208.1 to 63.192.223.25463.192.223.2554,094
1563.192.224.0/2063.192.224.1 to 63.192.239.25463.192.239.2554,094
1663.192.240.0/2063.192.240.1 to 63.192.255.25463.192.255.2554,094
1763.193.0.0/2063.193.0.1 to 63.193.15.25463.193.15.2554,094
1863.193.16.0/2063.193.16.1 to 63.193.31.25463.193.31.2554,094
1963.193.32.0/2063.193.32.1 to 63.193.47.25463.193.47.2554,094
2063.193.48.0/2063.193.48.1 to 63.193.63.25463.193.63.2554,094
2163.193.64.0/2063.193.64.1 to 63.193.79.25463.193.79.2554,094
2263.193.80.0/2063.193.80.1 to 63.193.95.25463.193.95.2554,094
2363.193.96.0/2063.193.96.1 to 63.193.111.25463.193.111.2554,094
2463.193.112.0/2063.193.112.1 to 63.193.127.25463.193.127.2554,094
2563.193.128.0/2063.193.128.1 to 63.193.143.25463.193.143.2554,094
2663.193.144.0/2063.193.144.1 to 63.193.159.25463.193.159.2554,094
2763.193.160.0/2063.193.160.1 to 63.193.175.25463.193.175.2554,094
2863.193.176.0/2063.193.176.1 to 63.193.191.25463.193.191.2554,094
2963.193.192.0/2063.193.192.1 to 63.193.207.25463.193.207.2554,094
3063.193.208.0/2063.193.208.1 to 63.193.223.25463.193.223.2554,094
3163.193.224.0/2063.193.224.1 to 63.193.239.25463.193.239.2554,094
3263.193.240.0/2063.193.240.1 to 63.193.255.25463.193.255.2554,094
3363.194.0.0/2063.194.0.1 to 63.194.15.25463.194.15.2554,094
3463.194.16.0/2063.194.16.1 to 63.194.31.25463.194.31.2554,094
3563.194.32.0/2063.194.32.1 to 63.194.47.25463.194.47.2554,094
3663.194.48.0/2063.194.48.1 to 63.194.63.25463.194.63.2554,094
3763.194.64.0/2063.194.64.1 to 63.194.79.25463.194.79.2554,094
3863.194.80.0/2063.194.80.1 to 63.194.95.25463.194.95.2554,094
3963.194.96.0/2063.194.96.1 to 63.194.111.25463.194.111.2554,094
4063.194.112.0/2063.194.112.1 to 63.194.127.25463.194.127.2554,094
4163.194.128.0/2063.194.128.1 to 63.194.143.25463.194.143.2554,094
4263.194.144.0/2063.194.144.1 to 63.194.159.25463.194.159.2554,094
4363.194.160.0/2063.194.160.1 to 63.194.175.25463.194.175.2554,094
4463.194.176.0/2063.194.176.1 to 63.194.191.25463.194.191.2554,094
4563.194.192.0/2063.194.192.1 to 63.194.207.25463.194.207.2554,094
4663.194.208.0/2063.194.208.1 to 63.194.223.25463.194.223.2554,094
4763.194.224.0/2063.194.224.1 to 63.194.239.25463.194.239.2554,094
4863.194.240.0/2063.194.240.1 to 63.194.255.25463.194.255.2554,094
4963.195.0.0/2063.195.0.1 to 63.195.15.25463.195.15.2554,094
5063.195.16.0/2063.195.16.1 to 63.195.31.25463.195.31.2554,094
5163.195.32.0/2063.195.32.1 to 63.195.47.25463.195.47.2554,094
5263.195.48.0/2063.195.48.1 to 63.195.63.25463.195.63.2554,094
5363.195.64.0/2063.195.64.1 to 63.195.79.25463.195.79.2554,094
5463.195.80.0/2063.195.80.1 to 63.195.95.25463.195.95.2554,094
5563.195.96.0/2063.195.96.1 to 63.195.111.25463.195.111.2554,094
5663.195.112.0/2063.195.112.1 to 63.195.127.25463.195.127.2554,094
5763.195.128.0/2063.195.128.1 to 63.195.143.25463.195.143.2554,094
5863.195.144.0/2063.195.144.1 to 63.195.159.25463.195.159.2554,094
5963.195.160.0/2063.195.160.1 to 63.195.175.25463.195.175.2554,094
6063.195.176.0/2063.195.176.1 to 63.195.191.25463.195.191.2554,094
6163.195.192.0/2063.195.192.1 to 63.195.207.25463.195.207.2554,094
6263.195.208.0/2063.195.208.1 to 63.195.223.25463.195.223.2554,094
6363.195.224.0/2063.195.224.1 to 63.195.239.25463.195.239.2554,094
6463.195.240.0/2063.195.240.1 to 63.195.255.25463.195.255.2554,094
6563.196.0.0/2063.196.0.1 to 63.196.15.25463.196.15.2554,094
6663.196.16.0/2063.196.16.1 to 63.196.31.25463.196.31.2554,094
6763.196.32.0/2063.196.32.1 to 63.196.47.25463.196.47.2554,094
6863.196.48.0/2063.196.48.1 to 63.196.63.25463.196.63.2554,094
6963.196.64.0/2063.196.64.1 to 63.196.79.25463.196.79.2554,094
7063.196.80.0/2063.196.80.1 to 63.196.95.25463.196.95.2554,094
7163.196.96.0/2063.196.96.1 to 63.196.111.25463.196.111.2554,094
7263.196.112.0/2063.196.112.1 to 63.196.127.25463.196.127.2554,094
7363.196.128.0/2063.196.128.1 to 63.196.143.25463.196.143.2554,094
7463.196.144.0/2063.196.144.1 to 63.196.159.25463.196.159.2554,094
7563.196.160.0/2063.196.160.1 to 63.196.175.25463.196.175.2554,094
7663.196.176.0/2063.196.176.1 to 63.196.191.25463.196.191.2554,094
7763.196.192.0/2063.196.192.1 to 63.196.207.25463.196.207.2554,094
7863.196.208.0/2063.196.208.1 to 63.196.223.25463.196.223.2554,094
7963.196.224.0/2063.196.224.1 to 63.196.239.25463.196.239.2554,094
8063.196.240.0/2063.196.240.1 to 63.196.255.25463.196.255.2554,094
8163.197.0.0/2063.197.0.1 to 63.197.15.25463.197.15.2554,094
8263.197.16.0/2063.197.16.1 to 63.197.31.25463.197.31.2554,094
8363.197.32.0/2063.197.32.1 to 63.197.47.25463.197.47.2554,094
8463.197.48.0/2063.197.48.1 to 63.197.63.25463.197.63.2554,094
8563.197.64.0/2063.197.64.1 to 63.197.79.25463.197.79.2554,094
8663.197.80.0/2063.197.80.1 to 63.197.95.25463.197.95.2554,094
8763.197.96.0/2063.197.96.1 to 63.197.111.25463.197.111.2554,094
8863.197.112.0/2063.197.112.1 to 63.197.127.25463.197.127.2554,094
8963.197.128.0/2063.197.128.1 to 63.197.143.25463.197.143.2554,094
9063.197.144.0/2063.197.144.1 to 63.197.159.25463.197.159.2554,094
9163.197.160.0/2063.197.160.1 to 63.197.175.25463.197.175.2554,094
9263.197.176.0/2063.197.176.1 to 63.197.191.25463.197.191.2554,094
9363.197.192.0/2063.197.192.1 to 63.197.207.25463.197.207.2554,094
9463.197.208.0/2063.197.208.1 to 63.197.223.25463.197.223.2554,094
9563.197.224.0/2063.197.224.1 to 63.197.239.25463.197.239.2554,094
9663.197.240.0/2063.197.240.1 to 63.197.255.25463.197.255.2554,094
9763.198.0.0/2063.198.0.1 to 63.198.15.25463.198.15.2554,094
9863.198.16.0/2063.198.16.1 to 63.198.31.25463.198.31.2554,094
9963.198.32.0/2063.198.32.1 to 63.198.47.25463.198.47.2554,094
10063.198.48.0/2063.198.48.1 to 63.198.63.25463.198.63.2554,094
10163.198.64.0/2063.198.64.1 to 63.198.79.25463.198.79.2554,094
10263.198.80.0/2063.198.80.1 to 63.198.95.25463.198.95.2554,094
10363.198.96.0/2063.198.96.1 to 63.198.111.25463.198.111.2554,094
10463.198.112.0/2063.198.112.1 to 63.198.127.25463.198.127.2554,094
10563.198.128.0/2063.198.128.1 to 63.198.143.25463.198.143.2554,094
10663.198.144.0/2063.198.144.1 to 63.198.159.25463.198.159.2554,094
10763.198.160.0/2063.198.160.1 to 63.198.175.25463.198.175.2554,094
10863.198.176.0/2063.198.176.1 to 63.198.191.25463.198.191.2554,094
10963.198.192.0/2063.198.192.1 to 63.198.207.25463.198.207.2554,094
11063.198.208.0/2063.198.208.1 to 63.198.223.25463.198.223.2554,094
11163.198.224.0/2063.198.224.1 to 63.198.239.25463.198.239.2554,094
11263.198.240.0/2063.198.240.1 to 63.198.255.25463.198.255.2554,094
11363.199.0.0/2063.199.0.1 to 63.199.15.25463.199.15.2554,094
11463.199.16.0/2063.199.16.1 to 63.199.31.25463.199.31.2554,094
11563.199.32.0/2063.199.32.1 to 63.199.47.25463.199.47.2554,094
11663.199.48.0/2063.199.48.1 to 63.199.63.25463.199.63.2554,094
11763.199.64.0/2063.199.64.1 to 63.199.79.25463.199.79.2554,094
11863.199.80.0/2063.199.80.1 to 63.199.95.25463.199.95.2554,094
11963.199.96.0/2063.199.96.1 to 63.199.111.25463.199.111.2554,094
12063.199.112.0/2063.199.112.1 to 63.199.127.25463.199.127.2554,094
12163.199.128.0/2063.199.128.1 to 63.199.143.25463.199.143.2554,094
12263.199.144.0/2063.199.144.1 to 63.199.159.25463.199.159.2554,094
12363.199.160.0/2063.199.160.1 to 63.199.175.25463.199.175.2554,094
12463.199.176.0/2063.199.176.1 to 63.199.191.25463.199.191.2554,094
12563.199.192.0/2063.199.192.1 to 63.199.207.25463.199.207.2554,094
12663.199.208.0/2063.199.208.1 to 63.199.223.25463.199.223.2554,094
12763.199.224.0/2063.199.224.1 to 63.199.239.25463.199.239.2554,094
12863.199.240.0/2063.199.240.1 to 63.199.255.25463.199.255.2554,094
12963.200.0.0/2063.200.0.1 to 63.200.15.25463.200.15.2554,094
13063.200.16.0/2063.200.16.1 to 63.200.31.25463.200.31.2554,094
13163.200.32.0/2063.200.32.1 to 63.200.47.25463.200.47.2554,094
13263.200.48.0/2063.200.48.1 to 63.200.63.25463.200.63.2554,094
13363.200.64.0/2063.200.64.1 to 63.200.79.25463.200.79.2554,094
13463.200.80.0/2063.200.80.1 to 63.200.95.25463.200.95.2554,094
13563.200.96.0/2063.200.96.1 to 63.200.111.25463.200.111.2554,094
13663.200.112.0/2063.200.112.1 to 63.200.127.25463.200.127.2554,094
13763.200.128.0/2063.200.128.1 to 63.200.143.25463.200.143.2554,094
13863.200.144.0/2063.200.144.1 to 63.200.159.25463.200.159.2554,094
13963.200.160.0/2063.200.160.1 to 63.200.175.25463.200.175.2554,094
14063.200.176.0/2063.200.176.1 to 63.200.191.25463.200.191.2554,094
14163.200.192.0/2063.200.192.1 to 63.200.207.25463.200.207.2554,094
14263.200.208.0/2063.200.208.1 to 63.200.223.25463.200.223.2554,094
14363.200.224.0/2063.200.224.1 to 63.200.239.25463.200.239.2554,094
14463.200.240.0/2063.200.240.1 to 63.200.255.25463.200.255.2554,094
14563.201.0.0/2063.201.0.1 to 63.201.15.25463.201.15.2554,094
14663.201.16.0/2063.201.16.1 to 63.201.31.25463.201.31.2554,094
14763.201.32.0/2063.201.32.1 to 63.201.47.25463.201.47.2554,094
14863.201.48.0/2063.201.48.1 to 63.201.63.25463.201.63.2554,094
14963.201.64.0/2063.201.64.1 to 63.201.79.25463.201.79.2554,094
15063.201.80.0/2063.201.80.1 to 63.201.95.25463.201.95.2554,094
15163.201.96.0/2063.201.96.1 to 63.201.111.25463.201.111.2554,094
15263.201.112.0/2063.201.112.1 to 63.201.127.25463.201.127.2554,094
15363.201.128.0/2063.201.128.1 to 63.201.143.25463.201.143.2554,094
15463.201.144.0/2063.201.144.1 to 63.201.159.25463.201.159.2554,094
15563.201.160.0/2063.201.160.1 to 63.201.175.25463.201.175.2554,094
15663.201.176.0/2063.201.176.1 to 63.201.191.25463.201.191.2554,094
15763.201.192.0/2063.201.192.1 to 63.201.207.25463.201.207.2554,094
15863.201.208.0/2063.201.208.1 to 63.201.223.25463.201.223.2554,094
15963.201.224.0/2063.201.224.1 to 63.201.239.25463.201.239.2554,094
16063.201.240.0/2063.201.240.1 to 63.201.255.25463.201.255.2554,094
16163.202.0.0/2063.202.0.1 to 63.202.15.25463.202.15.2554,094
16263.202.16.0/2063.202.16.1 to 63.202.31.25463.202.31.2554,094
16363.202.32.0/2063.202.32.1 to 63.202.47.25463.202.47.2554,094
16463.202.48.0/2063.202.48.1 to 63.202.63.25463.202.63.2554,094
16563.202.64.0/2063.202.64.1 to 63.202.79.25463.202.79.2554,094
16663.202.80.0/2063.202.80.1 to 63.202.95.25463.202.95.2554,094
16763.202.96.0/2063.202.96.1 to 63.202.111.25463.202.111.2554,094
16863.202.112.0/2063.202.112.1 to 63.202.127.25463.202.127.2554,094
16963.202.128.0/2063.202.128.1 to 63.202.143.25463.202.143.2554,094
17063.202.144.0/2063.202.144.1 to 63.202.159.25463.202.159.2554,094
17163.202.160.0/2063.202.160.1 to 63.202.175.25463.202.175.2554,094
17263.202.176.0/2063.202.176.1 to 63.202.191.25463.202.191.2554,094
17363.202.192.0/2063.202.192.1 to 63.202.207.25463.202.207.2554,094
17463.202.208.0/2063.202.208.1 to 63.202.223.25463.202.223.2554,094
17563.202.224.0/2063.202.224.1 to 63.202.239.25463.202.239.2554,094
17663.202.240.0/2063.202.240.1 to 63.202.255.25463.202.255.2554,094
17763.203.0.0/2063.203.0.1 to 63.203.15.25463.203.15.2554,094
17863.203.16.0/2063.203.16.1 to 63.203.31.25463.203.31.2554,094
17963.203.32.0/2063.203.32.1 to 63.203.47.25463.203.47.2554,094
18063.203.48.0/2063.203.48.1 to 63.203.63.25463.203.63.2554,094
18163.203.64.0/2063.203.64.1 to 63.203.79.25463.203.79.2554,094
18263.203.80.0/2063.203.80.1 to 63.203.95.25463.203.95.2554,094
18363.203.96.0/2063.203.96.1 to 63.203.111.25463.203.111.2554,094
18463.203.112.0/2063.203.112.1 to 63.203.127.25463.203.127.2554,094
18563.203.128.0/2063.203.128.1 to 63.203.143.25463.203.143.2554,094
18663.203.144.0/2063.203.144.1 to 63.203.159.25463.203.159.2554,094
18763.203.160.0/2063.203.160.1 to 63.203.175.25463.203.175.2554,094
18863.203.176.0/2063.203.176.1 to 63.203.191.25463.203.191.2554,094
18963.203.192.0/2063.203.192.1 to 63.203.207.25463.203.207.2554,094
19063.203.208.0/2063.203.208.1 to 63.203.223.25463.203.223.2554,094
19163.203.224.0/2063.203.224.1 to 63.203.239.25463.203.239.2554,094
19263.203.240.0/2063.203.240.1 to 63.203.255.25463.203.255.2554,094
19363.204.0.0/2063.204.0.1 to 63.204.15.25463.204.15.2554,094
19463.204.16.0/2063.204.16.1 to 63.204.31.25463.204.31.2554,094
19563.204.32.0/2063.204.32.1 to 63.204.47.25463.204.47.2554,094
19663.204.48.0/2063.204.48.1 to 63.204.63.25463.204.63.2554,094
19763.204.64.0/2063.204.64.1 to 63.204.79.25463.204.79.2554,094
19863.204.80.0/2063.204.80.1 to 63.204.95.25463.204.95.2554,094
19963.204.96.0/2063.204.96.1 to 63.204.111.25463.204.111.2554,094
20063.204.112.0/2063.204.112.1 to 63.204.127.25463.204.127.2554,094
20163.204.128.0/2063.204.128.1 to 63.204.143.25463.204.143.2554,094
20263.204.144.0/2063.204.144.1 to 63.204.159.25463.204.159.2554,094
20363.204.160.0/2063.204.160.1 to 63.204.175.25463.204.175.2554,094
20463.204.176.0/2063.204.176.1 to 63.204.191.25463.204.191.2554,094
20563.204.192.0/2063.204.192.1 to 63.204.207.25463.204.207.2554,094
20663.204.208.0/2063.204.208.1 to 63.204.223.25463.204.223.2554,094
20763.204.224.0/2063.204.224.1 to 63.204.239.25463.204.239.2554,094
20863.204.240.0/2063.204.240.1 to 63.204.255.25463.204.255.2554,094
20963.205.0.0/2063.205.0.1 to 63.205.15.25463.205.15.2554,094
21063.205.16.0/2063.205.16.1 to 63.205.31.25463.205.31.2554,094
21163.205.32.0/2063.205.32.1 to 63.205.47.25463.205.47.2554,094
21263.205.48.0/2063.205.48.1 to 63.205.63.25463.205.63.2554,094
21363.205.64.0/2063.205.64.1 to 63.205.79.25463.205.79.2554,094
21463.205.80.0/2063.205.80.1 to 63.205.95.25463.205.95.2554,094
21563.205.96.0/2063.205.96.1 to 63.205.111.25463.205.111.2554,094
21663.205.112.0/2063.205.112.1 to 63.205.127.25463.205.127.2554,094
21763.205.128.0/2063.205.128.1 to 63.205.143.25463.205.143.2554,094
21863.205.144.0/2063.205.144.1 to 63.205.159.25463.205.159.2554,094
21963.205.160.0/2063.205.160.1 to 63.205.175.25463.205.175.2554,094
22063.205.176.0/2063.205.176.1 to 63.205.191.25463.205.191.2554,094
22163.205.192.0/2063.205.192.1 to 63.205.207.25463.205.207.2554,094
22263.205.208.0/2063.205.208.1 to 63.205.223.25463.205.223.2554,094
22363.205.224.0/2063.205.224.1 to 63.205.239.25463.205.239.2554,094
22463.205.240.0/2063.205.240.1 to 63.205.255.25463.205.255.2554,094
22563.206.0.0/2063.206.0.1 to 63.206.15.25463.206.15.2554,094
22663.206.16.0/2063.206.16.1 to 63.206.31.25463.206.31.2554,094
22763.206.32.0/2063.206.32.1 to 63.206.47.25463.206.47.2554,094
22863.206.48.0/2063.206.48.1 to 63.206.63.25463.206.63.2554,094
22963.206.64.0/2063.206.64.1 to 63.206.79.25463.206.79.2554,094
23063.206.80.0/2063.206.80.1 to 63.206.95.25463.206.95.2554,094
23163.206.96.0/2063.206.96.1 to 63.206.111.25463.206.111.2554,094
23263.206.112.0/2063.206.112.1 to 63.206.127.25463.206.127.2554,094
23363.206.128.0/2063.206.128.1 to 63.206.143.25463.206.143.2554,094
23463.206.144.0/2063.206.144.1 to 63.206.159.25463.206.159.2554,094
23563.206.160.0/2063.206.160.1 to 63.206.175.25463.206.175.2554,094
23663.206.176.0/2063.206.176.1 to 63.206.191.25463.206.191.2554,094
23763.206.192.0/2063.206.192.1 to 63.206.207.25463.206.207.2554,094
23863.206.208.0/2063.206.208.1 to 63.206.223.25463.206.223.2554,094
23963.206.224.0/2063.206.224.1 to 63.206.239.25463.206.239.2554,094
24063.206.240.0/2063.206.240.1 to 63.206.255.25463.206.255.2554,094
24163.207.0.0/2063.207.0.1 to 63.207.15.25463.207.15.2554,094
24263.207.16.0/2063.207.16.1 to 63.207.31.25463.207.31.2554,094
24363.207.32.0/2063.207.32.1 to 63.207.47.25463.207.47.2554,094
24463.207.48.0/2063.207.48.1 to 63.207.63.25463.207.63.2554,094
24563.207.64.0/2063.207.64.1 to 63.207.79.25463.207.79.2554,094
24663.207.80.0/2063.207.80.1 to 63.207.95.25463.207.95.2554,094
24763.207.96.0/2063.207.96.1 to 63.207.111.25463.207.111.2554,094
24863.207.112.0/2063.207.112.1 to 63.207.127.25463.207.127.2554,094
24963.207.128.0/2063.207.128.1 to 63.207.143.25463.207.143.2554,094
25063.207.144.0/2063.207.144.1 to 63.207.159.25463.207.159.2554,094
25163.207.160.0/2063.207.160.1 to 63.207.175.25463.207.175.2554,094
25263.207.176.0/2063.207.176.1 to 63.207.191.25463.207.191.2554,094
25363.207.192.0/2063.207.192.1 to 63.207.207.25463.207.207.2554,094
25463.207.208.0/2063.207.208.1 to 63.207.223.25463.207.223.2554,094
25563.207.224.0/2063.207.224.1 to 63.207.239.25463.207.239.2554,094
25663.207.240.0/2063.207.240.1 to 63.207.255.25463.207.255.2554,094

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.