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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.

Network68.83.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
68.83.0.0
Broadcast address
68.83.255.255
First usable
68.83.0.1
Last usable
68.83.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
A (default /8)
As numbers
Hex 44530000 · Integer 1146290176 to 1146355711
Reverse DNS zone
83.68.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01000100.01010011..00000000.0000000068.83.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01000100.01010011..00000000.0000000068.83.0.0
Broadcast01000100.01010011..11111111.1111111168.83.255.255
Split into smaller subnets/26
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

68.83.0.0/16 makes 1,024 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
168.83.0.0/2668.83.0.1 to 68.83.0.6268.83.0.6362
268.83.0.64/2668.83.0.65 to 68.83.0.12668.83.0.12762
368.83.0.128/2668.83.0.129 to 68.83.0.19068.83.0.19162
468.83.0.192/2668.83.0.193 to 68.83.0.25468.83.0.25562
568.83.1.0/2668.83.1.1 to 68.83.1.6268.83.1.6362
668.83.1.64/2668.83.1.65 to 68.83.1.12668.83.1.12762
768.83.1.128/2668.83.1.129 to 68.83.1.19068.83.1.19162
868.83.1.192/2668.83.1.193 to 68.83.1.25468.83.1.25562
968.83.2.0/2668.83.2.1 to 68.83.2.6268.83.2.6362
1068.83.2.64/2668.83.2.65 to 68.83.2.12668.83.2.12762
1168.83.2.128/2668.83.2.129 to 68.83.2.19068.83.2.19162
1268.83.2.192/2668.83.2.193 to 68.83.2.25468.83.2.25562
1368.83.3.0/2668.83.3.1 to 68.83.3.6268.83.3.6362
1468.83.3.64/2668.83.3.65 to 68.83.3.12668.83.3.12762
1568.83.3.128/2668.83.3.129 to 68.83.3.19068.83.3.19162
1668.83.3.192/2668.83.3.193 to 68.83.3.25468.83.3.25562
1768.83.4.0/2668.83.4.1 to 68.83.4.6268.83.4.6362
1868.83.4.64/2668.83.4.65 to 68.83.4.12668.83.4.12762
1968.83.4.128/2668.83.4.129 to 68.83.4.19068.83.4.19162
2068.83.4.192/2668.83.4.193 to 68.83.4.25468.83.4.25562
2168.83.5.0/2668.83.5.1 to 68.83.5.6268.83.5.6362
2268.83.5.64/2668.83.5.65 to 68.83.5.12668.83.5.12762
2368.83.5.128/2668.83.5.129 to 68.83.5.19068.83.5.19162
2468.83.5.192/2668.83.5.193 to 68.83.5.25468.83.5.25562
2568.83.6.0/2668.83.6.1 to 68.83.6.6268.83.6.6362
2668.83.6.64/2668.83.6.65 to 68.83.6.12668.83.6.12762
2768.83.6.128/2668.83.6.129 to 68.83.6.19068.83.6.19162
2868.83.6.192/2668.83.6.193 to 68.83.6.25468.83.6.25562
2968.83.7.0/2668.83.7.1 to 68.83.7.6268.83.7.6362
3068.83.7.64/2668.83.7.65 to 68.83.7.12668.83.7.12762
3168.83.7.128/2668.83.7.129 to 68.83.7.19068.83.7.19162
3268.83.7.192/2668.83.7.193 to 68.83.7.25468.83.7.25562
3368.83.8.0/2668.83.8.1 to 68.83.8.6268.83.8.6362
3468.83.8.64/2668.83.8.65 to 68.83.8.12668.83.8.12762
3568.83.8.128/2668.83.8.129 to 68.83.8.19068.83.8.19162
3668.83.8.192/2668.83.8.193 to 68.83.8.25468.83.8.25562
3768.83.9.0/2668.83.9.1 to 68.83.9.6268.83.9.6362
3868.83.9.64/2668.83.9.65 to 68.83.9.12668.83.9.12762
3968.83.9.128/2668.83.9.129 to 68.83.9.19068.83.9.19162
4068.83.9.192/2668.83.9.193 to 68.83.9.25468.83.9.25562
4168.83.10.0/2668.83.10.1 to 68.83.10.6268.83.10.6362
4268.83.10.64/2668.83.10.65 to 68.83.10.12668.83.10.12762
4368.83.10.128/2668.83.10.129 to 68.83.10.19068.83.10.19162
4468.83.10.192/2668.83.10.193 to 68.83.10.25468.83.10.25562
4568.83.11.0/2668.83.11.1 to 68.83.11.6268.83.11.6362
4668.83.11.64/2668.83.11.65 to 68.83.11.12668.83.11.12762
4768.83.11.128/2668.83.11.129 to 68.83.11.19068.83.11.19162
4868.83.11.192/2668.83.11.193 to 68.83.11.25468.83.11.25562
4968.83.12.0/2668.83.12.1 to 68.83.12.6268.83.12.6362
5068.83.12.64/2668.83.12.65 to 68.83.12.12668.83.12.12762
5168.83.12.128/2668.83.12.129 to 68.83.12.19068.83.12.19162
5268.83.12.192/2668.83.12.193 to 68.83.12.25468.83.12.25562
5368.83.13.0/2668.83.13.1 to 68.83.13.6268.83.13.6362
5468.83.13.64/2668.83.13.65 to 68.83.13.12668.83.13.12762
5568.83.13.128/2668.83.13.129 to 68.83.13.19068.83.13.19162
5668.83.13.192/2668.83.13.193 to 68.83.13.25468.83.13.25562
5768.83.14.0/2668.83.14.1 to 68.83.14.6268.83.14.6362
5868.83.14.64/2668.83.14.65 to 68.83.14.12668.83.14.12762
5968.83.14.128/2668.83.14.129 to 68.83.14.19068.83.14.19162
6068.83.14.192/2668.83.14.193 to 68.83.14.25468.83.14.25562
6168.83.15.0/2668.83.15.1 to 68.83.15.6268.83.15.6362
6268.83.15.64/2668.83.15.65 to 68.83.15.12668.83.15.12762
6368.83.15.128/2668.83.15.129 to 68.83.15.19068.83.15.19162
6468.83.15.192/2668.83.15.193 to 68.83.15.25468.83.15.25562
6568.83.16.0/2668.83.16.1 to 68.83.16.6268.83.16.6362
6668.83.16.64/2668.83.16.65 to 68.83.16.12668.83.16.12762
6768.83.16.128/2668.83.16.129 to 68.83.16.19068.83.16.19162
6868.83.16.192/2668.83.16.193 to 68.83.16.25468.83.16.25562
6968.83.17.0/2668.83.17.1 to 68.83.17.6268.83.17.6362
7068.83.17.64/2668.83.17.65 to 68.83.17.12668.83.17.12762
7168.83.17.128/2668.83.17.129 to 68.83.17.19068.83.17.19162
7268.83.17.192/2668.83.17.193 to 68.83.17.25468.83.17.25562
7368.83.18.0/2668.83.18.1 to 68.83.18.6268.83.18.6362
7468.83.18.64/2668.83.18.65 to 68.83.18.12668.83.18.12762
7568.83.18.128/2668.83.18.129 to 68.83.18.19068.83.18.19162
7668.83.18.192/2668.83.18.193 to 68.83.18.25468.83.18.25562
7768.83.19.0/2668.83.19.1 to 68.83.19.6268.83.19.6362
7868.83.19.64/2668.83.19.65 to 68.83.19.12668.83.19.12762
7968.83.19.128/2668.83.19.129 to 68.83.19.19068.83.19.19162
8068.83.19.192/2668.83.19.193 to 68.83.19.25468.83.19.25562
8168.83.20.0/2668.83.20.1 to 68.83.20.6268.83.20.6362
8268.83.20.64/2668.83.20.65 to 68.83.20.12668.83.20.12762
8368.83.20.128/2668.83.20.129 to 68.83.20.19068.83.20.19162
8468.83.20.192/2668.83.20.193 to 68.83.20.25468.83.20.25562
8568.83.21.0/2668.83.21.1 to 68.83.21.6268.83.21.6362
8668.83.21.64/2668.83.21.65 to 68.83.21.12668.83.21.12762
8768.83.21.128/2668.83.21.129 to 68.83.21.19068.83.21.19162
8868.83.21.192/2668.83.21.193 to 68.83.21.25468.83.21.25562
8968.83.22.0/2668.83.22.1 to 68.83.22.6268.83.22.6362
9068.83.22.64/2668.83.22.65 to 68.83.22.12668.83.22.12762
9168.83.22.128/2668.83.22.129 to 68.83.22.19068.83.22.19162
9268.83.22.192/2668.83.22.193 to 68.83.22.25468.83.22.25562
9368.83.23.0/2668.83.23.1 to 68.83.23.6268.83.23.6362
9468.83.23.64/2668.83.23.65 to 68.83.23.12668.83.23.12762
9568.83.23.128/2668.83.23.129 to 68.83.23.19068.83.23.19162
9668.83.23.192/2668.83.23.193 to 68.83.23.25468.83.23.25562
9768.83.24.0/2668.83.24.1 to 68.83.24.6268.83.24.6362
9868.83.24.64/2668.83.24.65 to 68.83.24.12668.83.24.12762
9968.83.24.128/2668.83.24.129 to 68.83.24.19068.83.24.19162
10068.83.24.192/2668.83.24.193 to 68.83.24.25468.83.24.25562
10168.83.25.0/2668.83.25.1 to 68.83.25.6268.83.25.6362
10268.83.25.64/2668.83.25.65 to 68.83.25.12668.83.25.12762
10368.83.25.128/2668.83.25.129 to 68.83.25.19068.83.25.19162
10468.83.25.192/2668.83.25.193 to 68.83.25.25468.83.25.25562
10568.83.26.0/2668.83.26.1 to 68.83.26.6268.83.26.6362
10668.83.26.64/2668.83.26.65 to 68.83.26.12668.83.26.12762
10768.83.26.128/2668.83.26.129 to 68.83.26.19068.83.26.19162
10868.83.26.192/2668.83.26.193 to 68.83.26.25468.83.26.25562
10968.83.27.0/2668.83.27.1 to 68.83.27.6268.83.27.6362
11068.83.27.64/2668.83.27.65 to 68.83.27.12668.83.27.12762
11168.83.27.128/2668.83.27.129 to 68.83.27.19068.83.27.19162
11268.83.27.192/2668.83.27.193 to 68.83.27.25468.83.27.25562
11368.83.28.0/2668.83.28.1 to 68.83.28.6268.83.28.6362
11468.83.28.64/2668.83.28.65 to 68.83.28.12668.83.28.12762
11568.83.28.128/2668.83.28.129 to 68.83.28.19068.83.28.19162
11668.83.28.192/2668.83.28.193 to 68.83.28.25468.83.28.25562
11768.83.29.0/2668.83.29.1 to 68.83.29.6268.83.29.6362
11868.83.29.64/2668.83.29.65 to 68.83.29.12668.83.29.12762
11968.83.29.128/2668.83.29.129 to 68.83.29.19068.83.29.19162
12068.83.29.192/2668.83.29.193 to 68.83.29.25468.83.29.25562
12168.83.30.0/2668.83.30.1 to 68.83.30.6268.83.30.6362
12268.83.30.64/2668.83.30.65 to 68.83.30.12668.83.30.12762
12368.83.30.128/2668.83.30.129 to 68.83.30.19068.83.30.19162
12468.83.30.192/2668.83.30.193 to 68.83.30.25468.83.30.25562
12568.83.31.0/2668.83.31.1 to 68.83.31.6268.83.31.6362
12668.83.31.64/2668.83.31.65 to 68.83.31.12668.83.31.12762
12768.83.31.128/2668.83.31.129 to 68.83.31.19068.83.31.19162
12868.83.31.192/2668.83.31.193 to 68.83.31.25468.83.31.25562
12968.83.32.0/2668.83.32.1 to 68.83.32.6268.83.32.6362
13068.83.32.64/2668.83.32.65 to 68.83.32.12668.83.32.12762
13168.83.32.128/2668.83.32.129 to 68.83.32.19068.83.32.19162
13268.83.32.192/2668.83.32.193 to 68.83.32.25468.83.32.25562
13368.83.33.0/2668.83.33.1 to 68.83.33.6268.83.33.6362
13468.83.33.64/2668.83.33.65 to 68.83.33.12668.83.33.12762
13568.83.33.128/2668.83.33.129 to 68.83.33.19068.83.33.19162
13668.83.33.192/2668.83.33.193 to 68.83.33.25468.83.33.25562
13768.83.34.0/2668.83.34.1 to 68.83.34.6268.83.34.6362
13868.83.34.64/2668.83.34.65 to 68.83.34.12668.83.34.12762
13968.83.34.128/2668.83.34.129 to 68.83.34.19068.83.34.19162
14068.83.34.192/2668.83.34.193 to 68.83.34.25468.83.34.25562
14168.83.35.0/2668.83.35.1 to 68.83.35.6268.83.35.6362
14268.83.35.64/2668.83.35.65 to 68.83.35.12668.83.35.12762
14368.83.35.128/2668.83.35.129 to 68.83.35.19068.83.35.19162
14468.83.35.192/2668.83.35.193 to 68.83.35.25468.83.35.25562
14568.83.36.0/2668.83.36.1 to 68.83.36.6268.83.36.6362
14668.83.36.64/2668.83.36.65 to 68.83.36.12668.83.36.12762
14768.83.36.128/2668.83.36.129 to 68.83.36.19068.83.36.19162
14868.83.36.192/2668.83.36.193 to 68.83.36.25468.83.36.25562
14968.83.37.0/2668.83.37.1 to 68.83.37.6268.83.37.6362
15068.83.37.64/2668.83.37.65 to 68.83.37.12668.83.37.12762
15168.83.37.128/2668.83.37.129 to 68.83.37.19068.83.37.19162
15268.83.37.192/2668.83.37.193 to 68.83.37.25468.83.37.25562
15368.83.38.0/2668.83.38.1 to 68.83.38.6268.83.38.6362
15468.83.38.64/2668.83.38.65 to 68.83.38.12668.83.38.12762
15568.83.38.128/2668.83.38.129 to 68.83.38.19068.83.38.19162
15668.83.38.192/2668.83.38.193 to 68.83.38.25468.83.38.25562
15768.83.39.0/2668.83.39.1 to 68.83.39.6268.83.39.6362
15868.83.39.64/2668.83.39.65 to 68.83.39.12668.83.39.12762
15968.83.39.128/2668.83.39.129 to 68.83.39.19068.83.39.19162
16068.83.39.192/2668.83.39.193 to 68.83.39.25468.83.39.25562
16168.83.40.0/2668.83.40.1 to 68.83.40.6268.83.40.6362
16268.83.40.64/2668.83.40.65 to 68.83.40.12668.83.40.12762
16368.83.40.128/2668.83.40.129 to 68.83.40.19068.83.40.19162
16468.83.40.192/2668.83.40.193 to 68.83.40.25468.83.40.25562
16568.83.41.0/2668.83.41.1 to 68.83.41.6268.83.41.6362
16668.83.41.64/2668.83.41.65 to 68.83.41.12668.83.41.12762
16768.83.41.128/2668.83.41.129 to 68.83.41.19068.83.41.19162
16868.83.41.192/2668.83.41.193 to 68.83.41.25468.83.41.25562
16968.83.42.0/2668.83.42.1 to 68.83.42.6268.83.42.6362
17068.83.42.64/2668.83.42.65 to 68.83.42.12668.83.42.12762
17168.83.42.128/2668.83.42.129 to 68.83.42.19068.83.42.19162
17268.83.42.192/2668.83.42.193 to 68.83.42.25468.83.42.25562
17368.83.43.0/2668.83.43.1 to 68.83.43.6268.83.43.6362
17468.83.43.64/2668.83.43.65 to 68.83.43.12668.83.43.12762
17568.83.43.128/2668.83.43.129 to 68.83.43.19068.83.43.19162
17668.83.43.192/2668.83.43.193 to 68.83.43.25468.83.43.25562
17768.83.44.0/2668.83.44.1 to 68.83.44.6268.83.44.6362
17868.83.44.64/2668.83.44.65 to 68.83.44.12668.83.44.12762
17968.83.44.128/2668.83.44.129 to 68.83.44.19068.83.44.19162
18068.83.44.192/2668.83.44.193 to 68.83.44.25468.83.44.25562
18168.83.45.0/2668.83.45.1 to 68.83.45.6268.83.45.6362
18268.83.45.64/2668.83.45.65 to 68.83.45.12668.83.45.12762
18368.83.45.128/2668.83.45.129 to 68.83.45.19068.83.45.19162
18468.83.45.192/2668.83.45.193 to 68.83.45.25468.83.45.25562
18568.83.46.0/2668.83.46.1 to 68.83.46.6268.83.46.6362
18668.83.46.64/2668.83.46.65 to 68.83.46.12668.83.46.12762
18768.83.46.128/2668.83.46.129 to 68.83.46.19068.83.46.19162
18868.83.46.192/2668.83.46.193 to 68.83.46.25468.83.46.25562
18968.83.47.0/2668.83.47.1 to 68.83.47.6268.83.47.6362
19068.83.47.64/2668.83.47.65 to 68.83.47.12668.83.47.12762
19168.83.47.128/2668.83.47.129 to 68.83.47.19068.83.47.19162
19268.83.47.192/2668.83.47.193 to 68.83.47.25468.83.47.25562
19368.83.48.0/2668.83.48.1 to 68.83.48.6268.83.48.6362
19468.83.48.64/2668.83.48.65 to 68.83.48.12668.83.48.12762
19568.83.48.128/2668.83.48.129 to 68.83.48.19068.83.48.19162
19668.83.48.192/2668.83.48.193 to 68.83.48.25468.83.48.25562
19768.83.49.0/2668.83.49.1 to 68.83.49.6268.83.49.6362
19868.83.49.64/2668.83.49.65 to 68.83.49.12668.83.49.12762
19968.83.49.128/2668.83.49.129 to 68.83.49.19068.83.49.19162
20068.83.49.192/2668.83.49.193 to 68.83.49.25468.83.49.25562
20168.83.50.0/2668.83.50.1 to 68.83.50.6268.83.50.6362
20268.83.50.64/2668.83.50.65 to 68.83.50.12668.83.50.12762
20368.83.50.128/2668.83.50.129 to 68.83.50.19068.83.50.19162
20468.83.50.192/2668.83.50.193 to 68.83.50.25468.83.50.25562
20568.83.51.0/2668.83.51.1 to 68.83.51.6268.83.51.6362
20668.83.51.64/2668.83.51.65 to 68.83.51.12668.83.51.12762
20768.83.51.128/2668.83.51.129 to 68.83.51.19068.83.51.19162
20868.83.51.192/2668.83.51.193 to 68.83.51.25468.83.51.25562
20968.83.52.0/2668.83.52.1 to 68.83.52.6268.83.52.6362
21068.83.52.64/2668.83.52.65 to 68.83.52.12668.83.52.12762
21168.83.52.128/2668.83.52.129 to 68.83.52.19068.83.52.19162
21268.83.52.192/2668.83.52.193 to 68.83.52.25468.83.52.25562
21368.83.53.0/2668.83.53.1 to 68.83.53.6268.83.53.6362
21468.83.53.64/2668.83.53.65 to 68.83.53.12668.83.53.12762
21568.83.53.128/2668.83.53.129 to 68.83.53.19068.83.53.19162
21668.83.53.192/2668.83.53.193 to 68.83.53.25468.83.53.25562
21768.83.54.0/2668.83.54.1 to 68.83.54.6268.83.54.6362
21868.83.54.64/2668.83.54.65 to 68.83.54.12668.83.54.12762
21968.83.54.128/2668.83.54.129 to 68.83.54.19068.83.54.19162
22068.83.54.192/2668.83.54.193 to 68.83.54.25468.83.54.25562
22168.83.55.0/2668.83.55.1 to 68.83.55.6268.83.55.6362
22268.83.55.64/2668.83.55.65 to 68.83.55.12668.83.55.12762
22368.83.55.128/2668.83.55.129 to 68.83.55.19068.83.55.19162
22468.83.55.192/2668.83.55.193 to 68.83.55.25468.83.55.25562
22568.83.56.0/2668.83.56.1 to 68.83.56.6268.83.56.6362
22668.83.56.64/2668.83.56.65 to 68.83.56.12668.83.56.12762
22768.83.56.128/2668.83.56.129 to 68.83.56.19068.83.56.19162
22868.83.56.192/2668.83.56.193 to 68.83.56.25468.83.56.25562
22968.83.57.0/2668.83.57.1 to 68.83.57.6268.83.57.6362
23068.83.57.64/2668.83.57.65 to 68.83.57.12668.83.57.12762
23168.83.57.128/2668.83.57.129 to 68.83.57.19068.83.57.19162
23268.83.57.192/2668.83.57.193 to 68.83.57.25468.83.57.25562
23368.83.58.0/2668.83.58.1 to 68.83.58.6268.83.58.6362
23468.83.58.64/2668.83.58.65 to 68.83.58.12668.83.58.12762
23568.83.58.128/2668.83.58.129 to 68.83.58.19068.83.58.19162
23668.83.58.192/2668.83.58.193 to 68.83.58.25468.83.58.25562
23768.83.59.0/2668.83.59.1 to 68.83.59.6268.83.59.6362
23868.83.59.64/2668.83.59.65 to 68.83.59.12668.83.59.12762
23968.83.59.128/2668.83.59.129 to 68.83.59.19068.83.59.19162
24068.83.59.192/2668.83.59.193 to 68.83.59.25468.83.59.25562
24168.83.60.0/2668.83.60.1 to 68.83.60.6268.83.60.6362
24268.83.60.64/2668.83.60.65 to 68.83.60.12668.83.60.12762
24368.83.60.128/2668.83.60.129 to 68.83.60.19068.83.60.19162
24468.83.60.192/2668.83.60.193 to 68.83.60.25468.83.60.25562
24568.83.61.0/2668.83.61.1 to 68.83.61.6268.83.61.6362
24668.83.61.64/2668.83.61.65 to 68.83.61.12668.83.61.12762
24768.83.61.128/2668.83.61.129 to 68.83.61.19068.83.61.19162
24868.83.61.192/2668.83.61.193 to 68.83.61.25468.83.61.25562
24968.83.62.0/2668.83.62.1 to 68.83.62.6268.83.62.6362
25068.83.62.64/2668.83.62.65 to 68.83.62.12668.83.62.12762
25168.83.62.128/2668.83.62.129 to 68.83.62.19068.83.62.19162
25268.83.62.192/2668.83.62.193 to 68.83.62.25468.83.62.25562
25368.83.63.0/2668.83.63.1 to 68.83.63.6268.83.63.6362
25468.83.63.64/2668.83.63.65 to 68.83.63.12668.83.63.12762
25568.83.63.128/2668.83.63.129 to 68.83.63.19068.83.63.19162
25668.83.63.192/2668.83.63.193 to 68.83.63.25468.83.63.25562

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.