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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.

Network24.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
24.0.0.0
Broadcast address
24.255.255.255
First usable
24.0.0.1
Last usable
24.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 18000000 · Integer 402653184 to 419430399
Reverse DNS zone
24.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00011000..00000000.00000000.0000000024.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network00011000..00000000.00000000.0000000024.0.0.0
Broadcast00011000..11111111.11111111.1111111124.255.255.255
Split into smaller subnets/20
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

24.0.0.0/8 makes 4,096 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
124.0.0.0/2024.0.0.1 to 24.0.15.25424.0.15.2554,094
224.0.16.0/2024.0.16.1 to 24.0.31.25424.0.31.2554,094
324.0.32.0/2024.0.32.1 to 24.0.47.25424.0.47.2554,094
424.0.48.0/2024.0.48.1 to 24.0.63.25424.0.63.2554,094
524.0.64.0/2024.0.64.1 to 24.0.79.25424.0.79.2554,094
624.0.80.0/2024.0.80.1 to 24.0.95.25424.0.95.2554,094
724.0.96.0/2024.0.96.1 to 24.0.111.25424.0.111.2554,094
824.0.112.0/2024.0.112.1 to 24.0.127.25424.0.127.2554,094
924.0.128.0/2024.0.128.1 to 24.0.143.25424.0.143.2554,094
1024.0.144.0/2024.0.144.1 to 24.0.159.25424.0.159.2554,094
1124.0.160.0/2024.0.160.1 to 24.0.175.25424.0.175.2554,094
1224.0.176.0/2024.0.176.1 to 24.0.191.25424.0.191.2554,094
1324.0.192.0/2024.0.192.1 to 24.0.207.25424.0.207.2554,094
1424.0.208.0/2024.0.208.1 to 24.0.223.25424.0.223.2554,094
1524.0.224.0/2024.0.224.1 to 24.0.239.25424.0.239.2554,094
1624.0.240.0/2024.0.240.1 to 24.0.255.25424.0.255.2554,094
1724.1.0.0/2024.1.0.1 to 24.1.15.25424.1.15.2554,094
1824.1.16.0/2024.1.16.1 to 24.1.31.25424.1.31.2554,094
1924.1.32.0/2024.1.32.1 to 24.1.47.25424.1.47.2554,094
2024.1.48.0/2024.1.48.1 to 24.1.63.25424.1.63.2554,094
2124.1.64.0/2024.1.64.1 to 24.1.79.25424.1.79.2554,094
2224.1.80.0/2024.1.80.1 to 24.1.95.25424.1.95.2554,094
2324.1.96.0/2024.1.96.1 to 24.1.111.25424.1.111.2554,094
2424.1.112.0/2024.1.112.1 to 24.1.127.25424.1.127.2554,094
2524.1.128.0/2024.1.128.1 to 24.1.143.25424.1.143.2554,094
2624.1.144.0/2024.1.144.1 to 24.1.159.25424.1.159.2554,094
2724.1.160.0/2024.1.160.1 to 24.1.175.25424.1.175.2554,094
2824.1.176.0/2024.1.176.1 to 24.1.191.25424.1.191.2554,094
2924.1.192.0/2024.1.192.1 to 24.1.207.25424.1.207.2554,094
3024.1.208.0/2024.1.208.1 to 24.1.223.25424.1.223.2554,094
3124.1.224.0/2024.1.224.1 to 24.1.239.25424.1.239.2554,094
3224.1.240.0/2024.1.240.1 to 24.1.255.25424.1.255.2554,094
3324.2.0.0/2024.2.0.1 to 24.2.15.25424.2.15.2554,094
3424.2.16.0/2024.2.16.1 to 24.2.31.25424.2.31.2554,094
3524.2.32.0/2024.2.32.1 to 24.2.47.25424.2.47.2554,094
3624.2.48.0/2024.2.48.1 to 24.2.63.25424.2.63.2554,094
3724.2.64.0/2024.2.64.1 to 24.2.79.25424.2.79.2554,094
3824.2.80.0/2024.2.80.1 to 24.2.95.25424.2.95.2554,094
3924.2.96.0/2024.2.96.1 to 24.2.111.25424.2.111.2554,094
4024.2.112.0/2024.2.112.1 to 24.2.127.25424.2.127.2554,094
4124.2.128.0/2024.2.128.1 to 24.2.143.25424.2.143.2554,094
4224.2.144.0/2024.2.144.1 to 24.2.159.25424.2.159.2554,094
4324.2.160.0/2024.2.160.1 to 24.2.175.25424.2.175.2554,094
4424.2.176.0/2024.2.176.1 to 24.2.191.25424.2.191.2554,094
4524.2.192.0/2024.2.192.1 to 24.2.207.25424.2.207.2554,094
4624.2.208.0/2024.2.208.1 to 24.2.223.25424.2.223.2554,094
4724.2.224.0/2024.2.224.1 to 24.2.239.25424.2.239.2554,094
4824.2.240.0/2024.2.240.1 to 24.2.255.25424.2.255.2554,094
4924.3.0.0/2024.3.0.1 to 24.3.15.25424.3.15.2554,094
5024.3.16.0/2024.3.16.1 to 24.3.31.25424.3.31.2554,094
5124.3.32.0/2024.3.32.1 to 24.3.47.25424.3.47.2554,094
5224.3.48.0/2024.3.48.1 to 24.3.63.25424.3.63.2554,094
5324.3.64.0/2024.3.64.1 to 24.3.79.25424.3.79.2554,094
5424.3.80.0/2024.3.80.1 to 24.3.95.25424.3.95.2554,094
5524.3.96.0/2024.3.96.1 to 24.3.111.25424.3.111.2554,094
5624.3.112.0/2024.3.112.1 to 24.3.127.25424.3.127.2554,094
5724.3.128.0/2024.3.128.1 to 24.3.143.25424.3.143.2554,094
5824.3.144.0/2024.3.144.1 to 24.3.159.25424.3.159.2554,094
5924.3.160.0/2024.3.160.1 to 24.3.175.25424.3.175.2554,094
6024.3.176.0/2024.3.176.1 to 24.3.191.25424.3.191.2554,094
6124.3.192.0/2024.3.192.1 to 24.3.207.25424.3.207.2554,094
6224.3.208.0/2024.3.208.1 to 24.3.223.25424.3.223.2554,094
6324.3.224.0/2024.3.224.1 to 24.3.239.25424.3.239.2554,094
6424.3.240.0/2024.3.240.1 to 24.3.255.25424.3.255.2554,094
6524.4.0.0/2024.4.0.1 to 24.4.15.25424.4.15.2554,094
6624.4.16.0/2024.4.16.1 to 24.4.31.25424.4.31.2554,094
6724.4.32.0/2024.4.32.1 to 24.4.47.25424.4.47.2554,094
6824.4.48.0/2024.4.48.1 to 24.4.63.25424.4.63.2554,094
6924.4.64.0/2024.4.64.1 to 24.4.79.25424.4.79.2554,094
7024.4.80.0/2024.4.80.1 to 24.4.95.25424.4.95.2554,094
7124.4.96.0/2024.4.96.1 to 24.4.111.25424.4.111.2554,094
7224.4.112.0/2024.4.112.1 to 24.4.127.25424.4.127.2554,094
7324.4.128.0/2024.4.128.1 to 24.4.143.25424.4.143.2554,094
7424.4.144.0/2024.4.144.1 to 24.4.159.25424.4.159.2554,094
7524.4.160.0/2024.4.160.1 to 24.4.175.25424.4.175.2554,094
7624.4.176.0/2024.4.176.1 to 24.4.191.25424.4.191.2554,094
7724.4.192.0/2024.4.192.1 to 24.4.207.25424.4.207.2554,094
7824.4.208.0/2024.4.208.1 to 24.4.223.25424.4.223.2554,094
7924.4.224.0/2024.4.224.1 to 24.4.239.25424.4.239.2554,094
8024.4.240.0/2024.4.240.1 to 24.4.255.25424.4.255.2554,094
8124.5.0.0/2024.5.0.1 to 24.5.15.25424.5.15.2554,094
8224.5.16.0/2024.5.16.1 to 24.5.31.25424.5.31.2554,094
8324.5.32.0/2024.5.32.1 to 24.5.47.25424.5.47.2554,094
8424.5.48.0/2024.5.48.1 to 24.5.63.25424.5.63.2554,094
8524.5.64.0/2024.5.64.1 to 24.5.79.25424.5.79.2554,094
8624.5.80.0/2024.5.80.1 to 24.5.95.25424.5.95.2554,094
8724.5.96.0/2024.5.96.1 to 24.5.111.25424.5.111.2554,094
8824.5.112.0/2024.5.112.1 to 24.5.127.25424.5.127.2554,094
8924.5.128.0/2024.5.128.1 to 24.5.143.25424.5.143.2554,094
9024.5.144.0/2024.5.144.1 to 24.5.159.25424.5.159.2554,094
9124.5.160.0/2024.5.160.1 to 24.5.175.25424.5.175.2554,094
9224.5.176.0/2024.5.176.1 to 24.5.191.25424.5.191.2554,094
9324.5.192.0/2024.5.192.1 to 24.5.207.25424.5.207.2554,094
9424.5.208.0/2024.5.208.1 to 24.5.223.25424.5.223.2554,094
9524.5.224.0/2024.5.224.1 to 24.5.239.25424.5.239.2554,094
9624.5.240.0/2024.5.240.1 to 24.5.255.25424.5.255.2554,094
9724.6.0.0/2024.6.0.1 to 24.6.15.25424.6.15.2554,094
9824.6.16.0/2024.6.16.1 to 24.6.31.25424.6.31.2554,094
9924.6.32.0/2024.6.32.1 to 24.6.47.25424.6.47.2554,094
10024.6.48.0/2024.6.48.1 to 24.6.63.25424.6.63.2554,094
10124.6.64.0/2024.6.64.1 to 24.6.79.25424.6.79.2554,094
10224.6.80.0/2024.6.80.1 to 24.6.95.25424.6.95.2554,094
10324.6.96.0/2024.6.96.1 to 24.6.111.25424.6.111.2554,094
10424.6.112.0/2024.6.112.1 to 24.6.127.25424.6.127.2554,094
10524.6.128.0/2024.6.128.1 to 24.6.143.25424.6.143.2554,094
10624.6.144.0/2024.6.144.1 to 24.6.159.25424.6.159.2554,094
10724.6.160.0/2024.6.160.1 to 24.6.175.25424.6.175.2554,094
10824.6.176.0/2024.6.176.1 to 24.6.191.25424.6.191.2554,094
10924.6.192.0/2024.6.192.1 to 24.6.207.25424.6.207.2554,094
11024.6.208.0/2024.6.208.1 to 24.6.223.25424.6.223.2554,094
11124.6.224.0/2024.6.224.1 to 24.6.239.25424.6.239.2554,094
11224.6.240.0/2024.6.240.1 to 24.6.255.25424.6.255.2554,094
11324.7.0.0/2024.7.0.1 to 24.7.15.25424.7.15.2554,094
11424.7.16.0/2024.7.16.1 to 24.7.31.25424.7.31.2554,094
11524.7.32.0/2024.7.32.1 to 24.7.47.25424.7.47.2554,094
11624.7.48.0/2024.7.48.1 to 24.7.63.25424.7.63.2554,094
11724.7.64.0/2024.7.64.1 to 24.7.79.25424.7.79.2554,094
11824.7.80.0/2024.7.80.1 to 24.7.95.25424.7.95.2554,094
11924.7.96.0/2024.7.96.1 to 24.7.111.25424.7.111.2554,094
12024.7.112.0/2024.7.112.1 to 24.7.127.25424.7.127.2554,094
12124.7.128.0/2024.7.128.1 to 24.7.143.25424.7.143.2554,094
12224.7.144.0/2024.7.144.1 to 24.7.159.25424.7.159.2554,094
12324.7.160.0/2024.7.160.1 to 24.7.175.25424.7.175.2554,094
12424.7.176.0/2024.7.176.1 to 24.7.191.25424.7.191.2554,094
12524.7.192.0/2024.7.192.1 to 24.7.207.25424.7.207.2554,094
12624.7.208.0/2024.7.208.1 to 24.7.223.25424.7.223.2554,094
12724.7.224.0/2024.7.224.1 to 24.7.239.25424.7.239.2554,094
12824.7.240.0/2024.7.240.1 to 24.7.255.25424.7.255.2554,094
12924.8.0.0/2024.8.0.1 to 24.8.15.25424.8.15.2554,094
13024.8.16.0/2024.8.16.1 to 24.8.31.25424.8.31.2554,094
13124.8.32.0/2024.8.32.1 to 24.8.47.25424.8.47.2554,094
13224.8.48.0/2024.8.48.1 to 24.8.63.25424.8.63.2554,094
13324.8.64.0/2024.8.64.1 to 24.8.79.25424.8.79.2554,094
13424.8.80.0/2024.8.80.1 to 24.8.95.25424.8.95.2554,094
13524.8.96.0/2024.8.96.1 to 24.8.111.25424.8.111.2554,094
13624.8.112.0/2024.8.112.1 to 24.8.127.25424.8.127.2554,094
13724.8.128.0/2024.8.128.1 to 24.8.143.25424.8.143.2554,094
13824.8.144.0/2024.8.144.1 to 24.8.159.25424.8.159.2554,094
13924.8.160.0/2024.8.160.1 to 24.8.175.25424.8.175.2554,094
14024.8.176.0/2024.8.176.1 to 24.8.191.25424.8.191.2554,094
14124.8.192.0/2024.8.192.1 to 24.8.207.25424.8.207.2554,094
14224.8.208.0/2024.8.208.1 to 24.8.223.25424.8.223.2554,094
14324.8.224.0/2024.8.224.1 to 24.8.239.25424.8.239.2554,094
14424.8.240.0/2024.8.240.1 to 24.8.255.25424.8.255.2554,094
14524.9.0.0/2024.9.0.1 to 24.9.15.25424.9.15.2554,094
14624.9.16.0/2024.9.16.1 to 24.9.31.25424.9.31.2554,094
14724.9.32.0/2024.9.32.1 to 24.9.47.25424.9.47.2554,094
14824.9.48.0/2024.9.48.1 to 24.9.63.25424.9.63.2554,094
14924.9.64.0/2024.9.64.1 to 24.9.79.25424.9.79.2554,094
15024.9.80.0/2024.9.80.1 to 24.9.95.25424.9.95.2554,094
15124.9.96.0/2024.9.96.1 to 24.9.111.25424.9.111.2554,094
15224.9.112.0/2024.9.112.1 to 24.9.127.25424.9.127.2554,094
15324.9.128.0/2024.9.128.1 to 24.9.143.25424.9.143.2554,094
15424.9.144.0/2024.9.144.1 to 24.9.159.25424.9.159.2554,094
15524.9.160.0/2024.9.160.1 to 24.9.175.25424.9.175.2554,094
15624.9.176.0/2024.9.176.1 to 24.9.191.25424.9.191.2554,094
15724.9.192.0/2024.9.192.1 to 24.9.207.25424.9.207.2554,094
15824.9.208.0/2024.9.208.1 to 24.9.223.25424.9.223.2554,094
15924.9.224.0/2024.9.224.1 to 24.9.239.25424.9.239.2554,094
16024.9.240.0/2024.9.240.1 to 24.9.255.25424.9.255.2554,094
16124.10.0.0/2024.10.0.1 to 24.10.15.25424.10.15.2554,094
16224.10.16.0/2024.10.16.1 to 24.10.31.25424.10.31.2554,094
16324.10.32.0/2024.10.32.1 to 24.10.47.25424.10.47.2554,094
16424.10.48.0/2024.10.48.1 to 24.10.63.25424.10.63.2554,094
16524.10.64.0/2024.10.64.1 to 24.10.79.25424.10.79.2554,094
16624.10.80.0/2024.10.80.1 to 24.10.95.25424.10.95.2554,094
16724.10.96.0/2024.10.96.1 to 24.10.111.25424.10.111.2554,094
16824.10.112.0/2024.10.112.1 to 24.10.127.25424.10.127.2554,094
16924.10.128.0/2024.10.128.1 to 24.10.143.25424.10.143.2554,094
17024.10.144.0/2024.10.144.1 to 24.10.159.25424.10.159.2554,094
17124.10.160.0/2024.10.160.1 to 24.10.175.25424.10.175.2554,094
17224.10.176.0/2024.10.176.1 to 24.10.191.25424.10.191.2554,094
17324.10.192.0/2024.10.192.1 to 24.10.207.25424.10.207.2554,094
17424.10.208.0/2024.10.208.1 to 24.10.223.25424.10.223.2554,094
17524.10.224.0/2024.10.224.1 to 24.10.239.25424.10.239.2554,094
17624.10.240.0/2024.10.240.1 to 24.10.255.25424.10.255.2554,094
17724.11.0.0/2024.11.0.1 to 24.11.15.25424.11.15.2554,094
17824.11.16.0/2024.11.16.1 to 24.11.31.25424.11.31.2554,094
17924.11.32.0/2024.11.32.1 to 24.11.47.25424.11.47.2554,094
18024.11.48.0/2024.11.48.1 to 24.11.63.25424.11.63.2554,094
18124.11.64.0/2024.11.64.1 to 24.11.79.25424.11.79.2554,094
18224.11.80.0/2024.11.80.1 to 24.11.95.25424.11.95.2554,094
18324.11.96.0/2024.11.96.1 to 24.11.111.25424.11.111.2554,094
18424.11.112.0/2024.11.112.1 to 24.11.127.25424.11.127.2554,094
18524.11.128.0/2024.11.128.1 to 24.11.143.25424.11.143.2554,094
18624.11.144.0/2024.11.144.1 to 24.11.159.25424.11.159.2554,094
18724.11.160.0/2024.11.160.1 to 24.11.175.25424.11.175.2554,094
18824.11.176.0/2024.11.176.1 to 24.11.191.25424.11.191.2554,094
18924.11.192.0/2024.11.192.1 to 24.11.207.25424.11.207.2554,094
19024.11.208.0/2024.11.208.1 to 24.11.223.25424.11.223.2554,094
19124.11.224.0/2024.11.224.1 to 24.11.239.25424.11.239.2554,094
19224.11.240.0/2024.11.240.1 to 24.11.255.25424.11.255.2554,094
19324.12.0.0/2024.12.0.1 to 24.12.15.25424.12.15.2554,094
19424.12.16.0/2024.12.16.1 to 24.12.31.25424.12.31.2554,094
19524.12.32.0/2024.12.32.1 to 24.12.47.25424.12.47.2554,094
19624.12.48.0/2024.12.48.1 to 24.12.63.25424.12.63.2554,094
19724.12.64.0/2024.12.64.1 to 24.12.79.25424.12.79.2554,094
19824.12.80.0/2024.12.80.1 to 24.12.95.25424.12.95.2554,094
19924.12.96.0/2024.12.96.1 to 24.12.111.25424.12.111.2554,094
20024.12.112.0/2024.12.112.1 to 24.12.127.25424.12.127.2554,094
20124.12.128.0/2024.12.128.1 to 24.12.143.25424.12.143.2554,094
20224.12.144.0/2024.12.144.1 to 24.12.159.25424.12.159.2554,094
20324.12.160.0/2024.12.160.1 to 24.12.175.25424.12.175.2554,094
20424.12.176.0/2024.12.176.1 to 24.12.191.25424.12.191.2554,094
20524.12.192.0/2024.12.192.1 to 24.12.207.25424.12.207.2554,094
20624.12.208.0/2024.12.208.1 to 24.12.223.25424.12.223.2554,094
20724.12.224.0/2024.12.224.1 to 24.12.239.25424.12.239.2554,094
20824.12.240.0/2024.12.240.1 to 24.12.255.25424.12.255.2554,094
20924.13.0.0/2024.13.0.1 to 24.13.15.25424.13.15.2554,094
21024.13.16.0/2024.13.16.1 to 24.13.31.25424.13.31.2554,094
21124.13.32.0/2024.13.32.1 to 24.13.47.25424.13.47.2554,094
21224.13.48.0/2024.13.48.1 to 24.13.63.25424.13.63.2554,094
21324.13.64.0/2024.13.64.1 to 24.13.79.25424.13.79.2554,094
21424.13.80.0/2024.13.80.1 to 24.13.95.25424.13.95.2554,094
21524.13.96.0/2024.13.96.1 to 24.13.111.25424.13.111.2554,094
21624.13.112.0/2024.13.112.1 to 24.13.127.25424.13.127.2554,094
21724.13.128.0/2024.13.128.1 to 24.13.143.25424.13.143.2554,094
21824.13.144.0/2024.13.144.1 to 24.13.159.25424.13.159.2554,094
21924.13.160.0/2024.13.160.1 to 24.13.175.25424.13.175.2554,094
22024.13.176.0/2024.13.176.1 to 24.13.191.25424.13.191.2554,094
22124.13.192.0/2024.13.192.1 to 24.13.207.25424.13.207.2554,094
22224.13.208.0/2024.13.208.1 to 24.13.223.25424.13.223.2554,094
22324.13.224.0/2024.13.224.1 to 24.13.239.25424.13.239.2554,094
22424.13.240.0/2024.13.240.1 to 24.13.255.25424.13.255.2554,094
22524.14.0.0/2024.14.0.1 to 24.14.15.25424.14.15.2554,094
22624.14.16.0/2024.14.16.1 to 24.14.31.25424.14.31.2554,094
22724.14.32.0/2024.14.32.1 to 24.14.47.25424.14.47.2554,094
22824.14.48.0/2024.14.48.1 to 24.14.63.25424.14.63.2554,094
22924.14.64.0/2024.14.64.1 to 24.14.79.25424.14.79.2554,094
23024.14.80.0/2024.14.80.1 to 24.14.95.25424.14.95.2554,094
23124.14.96.0/2024.14.96.1 to 24.14.111.25424.14.111.2554,094
23224.14.112.0/2024.14.112.1 to 24.14.127.25424.14.127.2554,094
23324.14.128.0/2024.14.128.1 to 24.14.143.25424.14.143.2554,094
23424.14.144.0/2024.14.144.1 to 24.14.159.25424.14.159.2554,094
23524.14.160.0/2024.14.160.1 to 24.14.175.25424.14.175.2554,094
23624.14.176.0/2024.14.176.1 to 24.14.191.25424.14.191.2554,094
23724.14.192.0/2024.14.192.1 to 24.14.207.25424.14.207.2554,094
23824.14.208.0/2024.14.208.1 to 24.14.223.25424.14.223.2554,094
23924.14.224.0/2024.14.224.1 to 24.14.239.25424.14.239.2554,094
24024.14.240.0/2024.14.240.1 to 24.14.255.25424.14.255.2554,094
24124.15.0.0/2024.15.0.1 to 24.15.15.25424.15.15.2554,094
24224.15.16.0/2024.15.16.1 to 24.15.31.25424.15.31.2554,094
24324.15.32.0/2024.15.32.1 to 24.15.47.25424.15.47.2554,094
24424.15.48.0/2024.15.48.1 to 24.15.63.25424.15.63.2554,094
24524.15.64.0/2024.15.64.1 to 24.15.79.25424.15.79.2554,094
24624.15.80.0/2024.15.80.1 to 24.15.95.25424.15.95.2554,094
24724.15.96.0/2024.15.96.1 to 24.15.111.25424.15.111.2554,094
24824.15.112.0/2024.15.112.1 to 24.15.127.25424.15.127.2554,094
24924.15.128.0/2024.15.128.1 to 24.15.143.25424.15.143.2554,094
25024.15.144.0/2024.15.144.1 to 24.15.159.25424.15.159.2554,094
25124.15.160.0/2024.15.160.1 to 24.15.175.25424.15.175.2554,094
25224.15.176.0/2024.15.176.1 to 24.15.191.25424.15.191.2554,094
25324.15.192.0/2024.15.192.1 to 24.15.207.25424.15.207.2554,094
25424.15.208.0/2024.15.208.1 to 24.15.223.25424.15.223.2554,094
25524.15.224.0/2024.15.224.1 to 24.15.239.25424.15.239.2554,094
25624.15.240.0/2024.15.240.1 to 24.15.255.25424.15.255.2554,094

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.