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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.

Network67.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
67.0.0.0
Broadcast address
67.255.255.255
First usable
67.0.0.1
Last usable
67.255.255.254
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 43000000 · Integer 1124073472 to 1140850687
Reverse DNS zone
67.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01000011..00000000.00000000.0000000067.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01000011..00000000.00000000.0000000067.0.0.0
Broadcast01000011..11111111.11111111.1111111167.255.255.255
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)

67.0.0.0/8 makes 4,096 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
167.0.0.0/2067.0.0.1 to 67.0.15.25467.0.15.2554,094
267.0.16.0/2067.0.16.1 to 67.0.31.25467.0.31.2554,094
367.0.32.0/2067.0.32.1 to 67.0.47.25467.0.47.2554,094
467.0.48.0/2067.0.48.1 to 67.0.63.25467.0.63.2554,094
567.0.64.0/2067.0.64.1 to 67.0.79.25467.0.79.2554,094
667.0.80.0/2067.0.80.1 to 67.0.95.25467.0.95.2554,094
767.0.96.0/2067.0.96.1 to 67.0.111.25467.0.111.2554,094
867.0.112.0/2067.0.112.1 to 67.0.127.25467.0.127.2554,094
967.0.128.0/2067.0.128.1 to 67.0.143.25467.0.143.2554,094
1067.0.144.0/2067.0.144.1 to 67.0.159.25467.0.159.2554,094
1167.0.160.0/2067.0.160.1 to 67.0.175.25467.0.175.2554,094
1267.0.176.0/2067.0.176.1 to 67.0.191.25467.0.191.2554,094
1367.0.192.0/2067.0.192.1 to 67.0.207.25467.0.207.2554,094
1467.0.208.0/2067.0.208.1 to 67.0.223.25467.0.223.2554,094
1567.0.224.0/2067.0.224.1 to 67.0.239.25467.0.239.2554,094
1667.0.240.0/2067.0.240.1 to 67.0.255.25467.0.255.2554,094
1767.1.0.0/2067.1.0.1 to 67.1.15.25467.1.15.2554,094
1867.1.16.0/2067.1.16.1 to 67.1.31.25467.1.31.2554,094
1967.1.32.0/2067.1.32.1 to 67.1.47.25467.1.47.2554,094
2067.1.48.0/2067.1.48.1 to 67.1.63.25467.1.63.2554,094
2167.1.64.0/2067.1.64.1 to 67.1.79.25467.1.79.2554,094
2267.1.80.0/2067.1.80.1 to 67.1.95.25467.1.95.2554,094
2367.1.96.0/2067.1.96.1 to 67.1.111.25467.1.111.2554,094
2467.1.112.0/2067.1.112.1 to 67.1.127.25467.1.127.2554,094
2567.1.128.0/2067.1.128.1 to 67.1.143.25467.1.143.2554,094
2667.1.144.0/2067.1.144.1 to 67.1.159.25467.1.159.2554,094
2767.1.160.0/2067.1.160.1 to 67.1.175.25467.1.175.2554,094
2867.1.176.0/2067.1.176.1 to 67.1.191.25467.1.191.2554,094
2967.1.192.0/2067.1.192.1 to 67.1.207.25467.1.207.2554,094
3067.1.208.0/2067.1.208.1 to 67.1.223.25467.1.223.2554,094
3167.1.224.0/2067.1.224.1 to 67.1.239.25467.1.239.2554,094
3267.1.240.0/2067.1.240.1 to 67.1.255.25467.1.255.2554,094
3367.2.0.0/2067.2.0.1 to 67.2.15.25467.2.15.2554,094
3467.2.16.0/2067.2.16.1 to 67.2.31.25467.2.31.2554,094
3567.2.32.0/2067.2.32.1 to 67.2.47.25467.2.47.2554,094
3667.2.48.0/2067.2.48.1 to 67.2.63.25467.2.63.2554,094
3767.2.64.0/2067.2.64.1 to 67.2.79.25467.2.79.2554,094
3867.2.80.0/2067.2.80.1 to 67.2.95.25467.2.95.2554,094
3967.2.96.0/2067.2.96.1 to 67.2.111.25467.2.111.2554,094
4067.2.112.0/2067.2.112.1 to 67.2.127.25467.2.127.2554,094
4167.2.128.0/2067.2.128.1 to 67.2.143.25467.2.143.2554,094
4267.2.144.0/2067.2.144.1 to 67.2.159.25467.2.159.2554,094
4367.2.160.0/2067.2.160.1 to 67.2.175.25467.2.175.2554,094
4467.2.176.0/2067.2.176.1 to 67.2.191.25467.2.191.2554,094
4567.2.192.0/2067.2.192.1 to 67.2.207.25467.2.207.2554,094
4667.2.208.0/2067.2.208.1 to 67.2.223.25467.2.223.2554,094
4767.2.224.0/2067.2.224.1 to 67.2.239.25467.2.239.2554,094
4867.2.240.0/2067.2.240.1 to 67.2.255.25467.2.255.2554,094
4967.3.0.0/2067.3.0.1 to 67.3.15.25467.3.15.2554,094
5067.3.16.0/2067.3.16.1 to 67.3.31.25467.3.31.2554,094
5167.3.32.0/2067.3.32.1 to 67.3.47.25467.3.47.2554,094
5267.3.48.0/2067.3.48.1 to 67.3.63.25467.3.63.2554,094
5367.3.64.0/2067.3.64.1 to 67.3.79.25467.3.79.2554,094
5467.3.80.0/2067.3.80.1 to 67.3.95.25467.3.95.2554,094
5567.3.96.0/2067.3.96.1 to 67.3.111.25467.3.111.2554,094
5667.3.112.0/2067.3.112.1 to 67.3.127.25467.3.127.2554,094
5767.3.128.0/2067.3.128.1 to 67.3.143.25467.3.143.2554,094
5867.3.144.0/2067.3.144.1 to 67.3.159.25467.3.159.2554,094
5967.3.160.0/2067.3.160.1 to 67.3.175.25467.3.175.2554,094
6067.3.176.0/2067.3.176.1 to 67.3.191.25467.3.191.2554,094
6167.3.192.0/2067.3.192.1 to 67.3.207.25467.3.207.2554,094
6267.3.208.0/2067.3.208.1 to 67.3.223.25467.3.223.2554,094
6367.3.224.0/2067.3.224.1 to 67.3.239.25467.3.239.2554,094
6467.3.240.0/2067.3.240.1 to 67.3.255.25467.3.255.2554,094
6567.4.0.0/2067.4.0.1 to 67.4.15.25467.4.15.2554,094
6667.4.16.0/2067.4.16.1 to 67.4.31.25467.4.31.2554,094
6767.4.32.0/2067.4.32.1 to 67.4.47.25467.4.47.2554,094
6867.4.48.0/2067.4.48.1 to 67.4.63.25467.4.63.2554,094
6967.4.64.0/2067.4.64.1 to 67.4.79.25467.4.79.2554,094
7067.4.80.0/2067.4.80.1 to 67.4.95.25467.4.95.2554,094
7167.4.96.0/2067.4.96.1 to 67.4.111.25467.4.111.2554,094
7267.4.112.0/2067.4.112.1 to 67.4.127.25467.4.127.2554,094
7367.4.128.0/2067.4.128.1 to 67.4.143.25467.4.143.2554,094
7467.4.144.0/2067.4.144.1 to 67.4.159.25467.4.159.2554,094
7567.4.160.0/2067.4.160.1 to 67.4.175.25467.4.175.2554,094
7667.4.176.0/2067.4.176.1 to 67.4.191.25467.4.191.2554,094
7767.4.192.0/2067.4.192.1 to 67.4.207.25467.4.207.2554,094
7867.4.208.0/2067.4.208.1 to 67.4.223.25467.4.223.2554,094
7967.4.224.0/2067.4.224.1 to 67.4.239.25467.4.239.2554,094
8067.4.240.0/2067.4.240.1 to 67.4.255.25467.4.255.2554,094
8167.5.0.0/2067.5.0.1 to 67.5.15.25467.5.15.2554,094
8267.5.16.0/2067.5.16.1 to 67.5.31.25467.5.31.2554,094
8367.5.32.0/2067.5.32.1 to 67.5.47.25467.5.47.2554,094
8467.5.48.0/2067.5.48.1 to 67.5.63.25467.5.63.2554,094
8567.5.64.0/2067.5.64.1 to 67.5.79.25467.5.79.2554,094
8667.5.80.0/2067.5.80.1 to 67.5.95.25467.5.95.2554,094
8767.5.96.0/2067.5.96.1 to 67.5.111.25467.5.111.2554,094
8867.5.112.0/2067.5.112.1 to 67.5.127.25467.5.127.2554,094
8967.5.128.0/2067.5.128.1 to 67.5.143.25467.5.143.2554,094
9067.5.144.0/2067.5.144.1 to 67.5.159.25467.5.159.2554,094
9167.5.160.0/2067.5.160.1 to 67.5.175.25467.5.175.2554,094
9267.5.176.0/2067.5.176.1 to 67.5.191.25467.5.191.2554,094
9367.5.192.0/2067.5.192.1 to 67.5.207.25467.5.207.2554,094
9467.5.208.0/2067.5.208.1 to 67.5.223.25467.5.223.2554,094
9567.5.224.0/2067.5.224.1 to 67.5.239.25467.5.239.2554,094
9667.5.240.0/2067.5.240.1 to 67.5.255.25467.5.255.2554,094
9767.6.0.0/2067.6.0.1 to 67.6.15.25467.6.15.2554,094
9867.6.16.0/2067.6.16.1 to 67.6.31.25467.6.31.2554,094
9967.6.32.0/2067.6.32.1 to 67.6.47.25467.6.47.2554,094
10067.6.48.0/2067.6.48.1 to 67.6.63.25467.6.63.2554,094
10167.6.64.0/2067.6.64.1 to 67.6.79.25467.6.79.2554,094
10267.6.80.0/2067.6.80.1 to 67.6.95.25467.6.95.2554,094
10367.6.96.0/2067.6.96.1 to 67.6.111.25467.6.111.2554,094
10467.6.112.0/2067.6.112.1 to 67.6.127.25467.6.127.2554,094
10567.6.128.0/2067.6.128.1 to 67.6.143.25467.6.143.2554,094
10667.6.144.0/2067.6.144.1 to 67.6.159.25467.6.159.2554,094
10767.6.160.0/2067.6.160.1 to 67.6.175.25467.6.175.2554,094
10867.6.176.0/2067.6.176.1 to 67.6.191.25467.6.191.2554,094
10967.6.192.0/2067.6.192.1 to 67.6.207.25467.6.207.2554,094
11067.6.208.0/2067.6.208.1 to 67.6.223.25467.6.223.2554,094
11167.6.224.0/2067.6.224.1 to 67.6.239.25467.6.239.2554,094
11267.6.240.0/2067.6.240.1 to 67.6.255.25467.6.255.2554,094
11367.7.0.0/2067.7.0.1 to 67.7.15.25467.7.15.2554,094
11467.7.16.0/2067.7.16.1 to 67.7.31.25467.7.31.2554,094
11567.7.32.0/2067.7.32.1 to 67.7.47.25467.7.47.2554,094
11667.7.48.0/2067.7.48.1 to 67.7.63.25467.7.63.2554,094
11767.7.64.0/2067.7.64.1 to 67.7.79.25467.7.79.2554,094
11867.7.80.0/2067.7.80.1 to 67.7.95.25467.7.95.2554,094
11967.7.96.0/2067.7.96.1 to 67.7.111.25467.7.111.2554,094
12067.7.112.0/2067.7.112.1 to 67.7.127.25467.7.127.2554,094
12167.7.128.0/2067.7.128.1 to 67.7.143.25467.7.143.2554,094
12267.7.144.0/2067.7.144.1 to 67.7.159.25467.7.159.2554,094
12367.7.160.0/2067.7.160.1 to 67.7.175.25467.7.175.2554,094
12467.7.176.0/2067.7.176.1 to 67.7.191.25467.7.191.2554,094
12567.7.192.0/2067.7.192.1 to 67.7.207.25467.7.207.2554,094
12667.7.208.0/2067.7.208.1 to 67.7.223.25467.7.223.2554,094
12767.7.224.0/2067.7.224.1 to 67.7.239.25467.7.239.2554,094
12867.7.240.0/2067.7.240.1 to 67.7.255.25467.7.255.2554,094
12967.8.0.0/2067.8.0.1 to 67.8.15.25467.8.15.2554,094
13067.8.16.0/2067.8.16.1 to 67.8.31.25467.8.31.2554,094
13167.8.32.0/2067.8.32.1 to 67.8.47.25467.8.47.2554,094
13267.8.48.0/2067.8.48.1 to 67.8.63.25467.8.63.2554,094
13367.8.64.0/2067.8.64.1 to 67.8.79.25467.8.79.2554,094
13467.8.80.0/2067.8.80.1 to 67.8.95.25467.8.95.2554,094
13567.8.96.0/2067.8.96.1 to 67.8.111.25467.8.111.2554,094
13667.8.112.0/2067.8.112.1 to 67.8.127.25467.8.127.2554,094
13767.8.128.0/2067.8.128.1 to 67.8.143.25467.8.143.2554,094
13867.8.144.0/2067.8.144.1 to 67.8.159.25467.8.159.2554,094
13967.8.160.0/2067.8.160.1 to 67.8.175.25467.8.175.2554,094
14067.8.176.0/2067.8.176.1 to 67.8.191.25467.8.191.2554,094
14167.8.192.0/2067.8.192.1 to 67.8.207.25467.8.207.2554,094
14267.8.208.0/2067.8.208.1 to 67.8.223.25467.8.223.2554,094
14367.8.224.0/2067.8.224.1 to 67.8.239.25467.8.239.2554,094
14467.8.240.0/2067.8.240.1 to 67.8.255.25467.8.255.2554,094
14567.9.0.0/2067.9.0.1 to 67.9.15.25467.9.15.2554,094
14667.9.16.0/2067.9.16.1 to 67.9.31.25467.9.31.2554,094
14767.9.32.0/2067.9.32.1 to 67.9.47.25467.9.47.2554,094
14867.9.48.0/2067.9.48.1 to 67.9.63.25467.9.63.2554,094
14967.9.64.0/2067.9.64.1 to 67.9.79.25467.9.79.2554,094
15067.9.80.0/2067.9.80.1 to 67.9.95.25467.9.95.2554,094
15167.9.96.0/2067.9.96.1 to 67.9.111.25467.9.111.2554,094
15267.9.112.0/2067.9.112.1 to 67.9.127.25467.9.127.2554,094
15367.9.128.0/2067.9.128.1 to 67.9.143.25467.9.143.2554,094
15467.9.144.0/2067.9.144.1 to 67.9.159.25467.9.159.2554,094
15567.9.160.0/2067.9.160.1 to 67.9.175.25467.9.175.2554,094
15667.9.176.0/2067.9.176.1 to 67.9.191.25467.9.191.2554,094
15767.9.192.0/2067.9.192.1 to 67.9.207.25467.9.207.2554,094
15867.9.208.0/2067.9.208.1 to 67.9.223.25467.9.223.2554,094
15967.9.224.0/2067.9.224.1 to 67.9.239.25467.9.239.2554,094
16067.9.240.0/2067.9.240.1 to 67.9.255.25467.9.255.2554,094
16167.10.0.0/2067.10.0.1 to 67.10.15.25467.10.15.2554,094
16267.10.16.0/2067.10.16.1 to 67.10.31.25467.10.31.2554,094
16367.10.32.0/2067.10.32.1 to 67.10.47.25467.10.47.2554,094
16467.10.48.0/2067.10.48.1 to 67.10.63.25467.10.63.2554,094
16567.10.64.0/2067.10.64.1 to 67.10.79.25467.10.79.2554,094
16667.10.80.0/2067.10.80.1 to 67.10.95.25467.10.95.2554,094
16767.10.96.0/2067.10.96.1 to 67.10.111.25467.10.111.2554,094
16867.10.112.0/2067.10.112.1 to 67.10.127.25467.10.127.2554,094
16967.10.128.0/2067.10.128.1 to 67.10.143.25467.10.143.2554,094
17067.10.144.0/2067.10.144.1 to 67.10.159.25467.10.159.2554,094
17167.10.160.0/2067.10.160.1 to 67.10.175.25467.10.175.2554,094
17267.10.176.0/2067.10.176.1 to 67.10.191.25467.10.191.2554,094
17367.10.192.0/2067.10.192.1 to 67.10.207.25467.10.207.2554,094
17467.10.208.0/2067.10.208.1 to 67.10.223.25467.10.223.2554,094
17567.10.224.0/2067.10.224.1 to 67.10.239.25467.10.239.2554,094
17667.10.240.0/2067.10.240.1 to 67.10.255.25467.10.255.2554,094
17767.11.0.0/2067.11.0.1 to 67.11.15.25467.11.15.2554,094
17867.11.16.0/2067.11.16.1 to 67.11.31.25467.11.31.2554,094
17967.11.32.0/2067.11.32.1 to 67.11.47.25467.11.47.2554,094
18067.11.48.0/2067.11.48.1 to 67.11.63.25467.11.63.2554,094
18167.11.64.0/2067.11.64.1 to 67.11.79.25467.11.79.2554,094
18267.11.80.0/2067.11.80.1 to 67.11.95.25467.11.95.2554,094
18367.11.96.0/2067.11.96.1 to 67.11.111.25467.11.111.2554,094
18467.11.112.0/2067.11.112.1 to 67.11.127.25467.11.127.2554,094
18567.11.128.0/2067.11.128.1 to 67.11.143.25467.11.143.2554,094
18667.11.144.0/2067.11.144.1 to 67.11.159.25467.11.159.2554,094
18767.11.160.0/2067.11.160.1 to 67.11.175.25467.11.175.2554,094
18867.11.176.0/2067.11.176.1 to 67.11.191.25467.11.191.2554,094
18967.11.192.0/2067.11.192.1 to 67.11.207.25467.11.207.2554,094
19067.11.208.0/2067.11.208.1 to 67.11.223.25467.11.223.2554,094
19167.11.224.0/2067.11.224.1 to 67.11.239.25467.11.239.2554,094
19267.11.240.0/2067.11.240.1 to 67.11.255.25467.11.255.2554,094
19367.12.0.0/2067.12.0.1 to 67.12.15.25467.12.15.2554,094
19467.12.16.0/2067.12.16.1 to 67.12.31.25467.12.31.2554,094
19567.12.32.0/2067.12.32.1 to 67.12.47.25467.12.47.2554,094
19667.12.48.0/2067.12.48.1 to 67.12.63.25467.12.63.2554,094
19767.12.64.0/2067.12.64.1 to 67.12.79.25467.12.79.2554,094
19867.12.80.0/2067.12.80.1 to 67.12.95.25467.12.95.2554,094
19967.12.96.0/2067.12.96.1 to 67.12.111.25467.12.111.2554,094
20067.12.112.0/2067.12.112.1 to 67.12.127.25467.12.127.2554,094
20167.12.128.0/2067.12.128.1 to 67.12.143.25467.12.143.2554,094
20267.12.144.0/2067.12.144.1 to 67.12.159.25467.12.159.2554,094
20367.12.160.0/2067.12.160.1 to 67.12.175.25467.12.175.2554,094
20467.12.176.0/2067.12.176.1 to 67.12.191.25467.12.191.2554,094
20567.12.192.0/2067.12.192.1 to 67.12.207.25467.12.207.2554,094
20667.12.208.0/2067.12.208.1 to 67.12.223.25467.12.223.2554,094
20767.12.224.0/2067.12.224.1 to 67.12.239.25467.12.239.2554,094
20867.12.240.0/2067.12.240.1 to 67.12.255.25467.12.255.2554,094
20967.13.0.0/2067.13.0.1 to 67.13.15.25467.13.15.2554,094
21067.13.16.0/2067.13.16.1 to 67.13.31.25467.13.31.2554,094
21167.13.32.0/2067.13.32.1 to 67.13.47.25467.13.47.2554,094
21267.13.48.0/2067.13.48.1 to 67.13.63.25467.13.63.2554,094
21367.13.64.0/2067.13.64.1 to 67.13.79.25467.13.79.2554,094
21467.13.80.0/2067.13.80.1 to 67.13.95.25467.13.95.2554,094
21567.13.96.0/2067.13.96.1 to 67.13.111.25467.13.111.2554,094
21667.13.112.0/2067.13.112.1 to 67.13.127.25467.13.127.2554,094
21767.13.128.0/2067.13.128.1 to 67.13.143.25467.13.143.2554,094
21867.13.144.0/2067.13.144.1 to 67.13.159.25467.13.159.2554,094
21967.13.160.0/2067.13.160.1 to 67.13.175.25467.13.175.2554,094
22067.13.176.0/2067.13.176.1 to 67.13.191.25467.13.191.2554,094
22167.13.192.0/2067.13.192.1 to 67.13.207.25467.13.207.2554,094
22267.13.208.0/2067.13.208.1 to 67.13.223.25467.13.223.2554,094
22367.13.224.0/2067.13.224.1 to 67.13.239.25467.13.239.2554,094
22467.13.240.0/2067.13.240.1 to 67.13.255.25467.13.255.2554,094
22567.14.0.0/2067.14.0.1 to 67.14.15.25467.14.15.2554,094
22667.14.16.0/2067.14.16.1 to 67.14.31.25467.14.31.2554,094
22767.14.32.0/2067.14.32.1 to 67.14.47.25467.14.47.2554,094
22867.14.48.0/2067.14.48.1 to 67.14.63.25467.14.63.2554,094
22967.14.64.0/2067.14.64.1 to 67.14.79.25467.14.79.2554,094
23067.14.80.0/2067.14.80.1 to 67.14.95.25467.14.95.2554,094
23167.14.96.0/2067.14.96.1 to 67.14.111.25467.14.111.2554,094
23267.14.112.0/2067.14.112.1 to 67.14.127.25467.14.127.2554,094
23367.14.128.0/2067.14.128.1 to 67.14.143.25467.14.143.2554,094
23467.14.144.0/2067.14.144.1 to 67.14.159.25467.14.159.2554,094
23567.14.160.0/2067.14.160.1 to 67.14.175.25467.14.175.2554,094
23667.14.176.0/2067.14.176.1 to 67.14.191.25467.14.191.2554,094
23767.14.192.0/2067.14.192.1 to 67.14.207.25467.14.207.2554,094
23867.14.208.0/2067.14.208.1 to 67.14.223.25467.14.223.2554,094
23967.14.224.0/2067.14.224.1 to 67.14.239.25467.14.239.2554,094
24067.14.240.0/2067.14.240.1 to 67.14.255.25467.14.255.2554,094
24167.15.0.0/2067.15.0.1 to 67.15.15.25467.15.15.2554,094
24267.15.16.0/2067.15.16.1 to 67.15.31.25467.15.31.2554,094
24367.15.32.0/2067.15.32.1 to 67.15.47.25467.15.47.2554,094
24467.15.48.0/2067.15.48.1 to 67.15.63.25467.15.63.2554,094
24567.15.64.0/2067.15.64.1 to 67.15.79.25467.15.79.2554,094
24667.15.80.0/2067.15.80.1 to 67.15.95.25467.15.95.2554,094
24767.15.96.0/2067.15.96.1 to 67.15.111.25467.15.111.2554,094
24867.15.112.0/2067.15.112.1 to 67.15.127.25467.15.127.2554,094
24967.15.128.0/2067.15.128.1 to 67.15.143.25467.15.143.2554,094
25067.15.144.0/2067.15.144.1 to 67.15.159.25467.15.159.2554,094
25167.15.160.0/2067.15.160.1 to 67.15.175.25467.15.175.2554,094
25267.15.176.0/2067.15.176.1 to 67.15.191.25467.15.191.2554,094
25367.15.192.0/2067.15.192.1 to 67.15.207.25467.15.207.2554,094
25467.15.208.0/2067.15.208.1 to 67.15.223.25467.15.223.2554,094
25567.15.224.0/2067.15.224.1 to 67.15.239.25467.15.239.2554,094
25667.15.240.0/2067.15.240.1 to 67.15.255.25467.15.255.2554,094

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.