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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.

Network68.78.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
68.78.0.0
Broadcast address
68.78.255.255
First usable
68.78.0.1
Last usable
68.78.255.254
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 444E0000 · Integer 1145962496 to 1146028031
Reverse DNS zone
78.68.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01000100.01001110..00000000.0000000068.78.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01000100.01001110..00000000.0000000068.78.0.0
Broadcast01000100.01001110..11111111.1111111168.78.255.255
Split into smaller subnets/27
/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)

68.78.0.0/16 makes 2,048 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
168.78.0.0/2768.78.0.1 to 68.78.0.3068.78.0.3130
268.78.0.32/2768.78.0.33 to 68.78.0.6268.78.0.6330
368.78.0.64/2768.78.0.65 to 68.78.0.9468.78.0.9530
468.78.0.96/2768.78.0.97 to 68.78.0.12668.78.0.12730
568.78.0.128/2768.78.0.129 to 68.78.0.15868.78.0.15930
668.78.0.160/2768.78.0.161 to 68.78.0.19068.78.0.19130
768.78.0.192/2768.78.0.193 to 68.78.0.22268.78.0.22330
868.78.0.224/2768.78.0.225 to 68.78.0.25468.78.0.25530
968.78.1.0/2768.78.1.1 to 68.78.1.3068.78.1.3130
1068.78.1.32/2768.78.1.33 to 68.78.1.6268.78.1.6330
1168.78.1.64/2768.78.1.65 to 68.78.1.9468.78.1.9530
1268.78.1.96/2768.78.1.97 to 68.78.1.12668.78.1.12730
1368.78.1.128/2768.78.1.129 to 68.78.1.15868.78.1.15930
1468.78.1.160/2768.78.1.161 to 68.78.1.19068.78.1.19130
1568.78.1.192/2768.78.1.193 to 68.78.1.22268.78.1.22330
1668.78.1.224/2768.78.1.225 to 68.78.1.25468.78.1.25530
1768.78.2.0/2768.78.2.1 to 68.78.2.3068.78.2.3130
1868.78.2.32/2768.78.2.33 to 68.78.2.6268.78.2.6330
1968.78.2.64/2768.78.2.65 to 68.78.2.9468.78.2.9530
2068.78.2.96/2768.78.2.97 to 68.78.2.12668.78.2.12730
2168.78.2.128/2768.78.2.129 to 68.78.2.15868.78.2.15930
2268.78.2.160/2768.78.2.161 to 68.78.2.19068.78.2.19130
2368.78.2.192/2768.78.2.193 to 68.78.2.22268.78.2.22330
2468.78.2.224/2768.78.2.225 to 68.78.2.25468.78.2.25530
2568.78.3.0/2768.78.3.1 to 68.78.3.3068.78.3.3130
2668.78.3.32/2768.78.3.33 to 68.78.3.6268.78.3.6330
2768.78.3.64/2768.78.3.65 to 68.78.3.9468.78.3.9530
2868.78.3.96/2768.78.3.97 to 68.78.3.12668.78.3.12730
2968.78.3.128/2768.78.3.129 to 68.78.3.15868.78.3.15930
3068.78.3.160/2768.78.3.161 to 68.78.3.19068.78.3.19130
3168.78.3.192/2768.78.3.193 to 68.78.3.22268.78.3.22330
3268.78.3.224/2768.78.3.225 to 68.78.3.25468.78.3.25530
3368.78.4.0/2768.78.4.1 to 68.78.4.3068.78.4.3130
3468.78.4.32/2768.78.4.33 to 68.78.4.6268.78.4.6330
3568.78.4.64/2768.78.4.65 to 68.78.4.9468.78.4.9530
3668.78.4.96/2768.78.4.97 to 68.78.4.12668.78.4.12730
3768.78.4.128/2768.78.4.129 to 68.78.4.15868.78.4.15930
3868.78.4.160/2768.78.4.161 to 68.78.4.19068.78.4.19130
3968.78.4.192/2768.78.4.193 to 68.78.4.22268.78.4.22330
4068.78.4.224/2768.78.4.225 to 68.78.4.25468.78.4.25530
4168.78.5.0/2768.78.5.1 to 68.78.5.3068.78.5.3130
4268.78.5.32/2768.78.5.33 to 68.78.5.6268.78.5.6330
4368.78.5.64/2768.78.5.65 to 68.78.5.9468.78.5.9530
4468.78.5.96/2768.78.5.97 to 68.78.5.12668.78.5.12730
4568.78.5.128/2768.78.5.129 to 68.78.5.15868.78.5.15930
4668.78.5.160/2768.78.5.161 to 68.78.5.19068.78.5.19130
4768.78.5.192/2768.78.5.193 to 68.78.5.22268.78.5.22330
4868.78.5.224/2768.78.5.225 to 68.78.5.25468.78.5.25530
4968.78.6.0/2768.78.6.1 to 68.78.6.3068.78.6.3130
5068.78.6.32/2768.78.6.33 to 68.78.6.6268.78.6.6330
5168.78.6.64/2768.78.6.65 to 68.78.6.9468.78.6.9530
5268.78.6.96/2768.78.6.97 to 68.78.6.12668.78.6.12730
5368.78.6.128/2768.78.6.129 to 68.78.6.15868.78.6.15930
5468.78.6.160/2768.78.6.161 to 68.78.6.19068.78.6.19130
5568.78.6.192/2768.78.6.193 to 68.78.6.22268.78.6.22330
5668.78.6.224/2768.78.6.225 to 68.78.6.25468.78.6.25530
5768.78.7.0/2768.78.7.1 to 68.78.7.3068.78.7.3130
5868.78.7.32/2768.78.7.33 to 68.78.7.6268.78.7.6330
5968.78.7.64/2768.78.7.65 to 68.78.7.9468.78.7.9530
6068.78.7.96/2768.78.7.97 to 68.78.7.12668.78.7.12730
6168.78.7.128/2768.78.7.129 to 68.78.7.15868.78.7.15930
6268.78.7.160/2768.78.7.161 to 68.78.7.19068.78.7.19130
6368.78.7.192/2768.78.7.193 to 68.78.7.22268.78.7.22330
6468.78.7.224/2768.78.7.225 to 68.78.7.25468.78.7.25530
6568.78.8.0/2768.78.8.1 to 68.78.8.3068.78.8.3130
6668.78.8.32/2768.78.8.33 to 68.78.8.6268.78.8.6330
6768.78.8.64/2768.78.8.65 to 68.78.8.9468.78.8.9530
6868.78.8.96/2768.78.8.97 to 68.78.8.12668.78.8.12730
6968.78.8.128/2768.78.8.129 to 68.78.8.15868.78.8.15930
7068.78.8.160/2768.78.8.161 to 68.78.8.19068.78.8.19130
7168.78.8.192/2768.78.8.193 to 68.78.8.22268.78.8.22330
7268.78.8.224/2768.78.8.225 to 68.78.8.25468.78.8.25530
7368.78.9.0/2768.78.9.1 to 68.78.9.3068.78.9.3130
7468.78.9.32/2768.78.9.33 to 68.78.9.6268.78.9.6330
7568.78.9.64/2768.78.9.65 to 68.78.9.9468.78.9.9530
7668.78.9.96/2768.78.9.97 to 68.78.9.12668.78.9.12730
7768.78.9.128/2768.78.9.129 to 68.78.9.15868.78.9.15930
7868.78.9.160/2768.78.9.161 to 68.78.9.19068.78.9.19130
7968.78.9.192/2768.78.9.193 to 68.78.9.22268.78.9.22330
8068.78.9.224/2768.78.9.225 to 68.78.9.25468.78.9.25530
8168.78.10.0/2768.78.10.1 to 68.78.10.3068.78.10.3130
8268.78.10.32/2768.78.10.33 to 68.78.10.6268.78.10.6330
8368.78.10.64/2768.78.10.65 to 68.78.10.9468.78.10.9530
8468.78.10.96/2768.78.10.97 to 68.78.10.12668.78.10.12730
8568.78.10.128/2768.78.10.129 to 68.78.10.15868.78.10.15930
8668.78.10.160/2768.78.10.161 to 68.78.10.19068.78.10.19130
8768.78.10.192/2768.78.10.193 to 68.78.10.22268.78.10.22330
8868.78.10.224/2768.78.10.225 to 68.78.10.25468.78.10.25530
8968.78.11.0/2768.78.11.1 to 68.78.11.3068.78.11.3130
9068.78.11.32/2768.78.11.33 to 68.78.11.6268.78.11.6330
9168.78.11.64/2768.78.11.65 to 68.78.11.9468.78.11.9530
9268.78.11.96/2768.78.11.97 to 68.78.11.12668.78.11.12730
9368.78.11.128/2768.78.11.129 to 68.78.11.15868.78.11.15930
9468.78.11.160/2768.78.11.161 to 68.78.11.19068.78.11.19130
9568.78.11.192/2768.78.11.193 to 68.78.11.22268.78.11.22330
9668.78.11.224/2768.78.11.225 to 68.78.11.25468.78.11.25530
9768.78.12.0/2768.78.12.1 to 68.78.12.3068.78.12.3130
9868.78.12.32/2768.78.12.33 to 68.78.12.6268.78.12.6330
9968.78.12.64/2768.78.12.65 to 68.78.12.9468.78.12.9530
10068.78.12.96/2768.78.12.97 to 68.78.12.12668.78.12.12730
10168.78.12.128/2768.78.12.129 to 68.78.12.15868.78.12.15930
10268.78.12.160/2768.78.12.161 to 68.78.12.19068.78.12.19130
10368.78.12.192/2768.78.12.193 to 68.78.12.22268.78.12.22330
10468.78.12.224/2768.78.12.225 to 68.78.12.25468.78.12.25530
10568.78.13.0/2768.78.13.1 to 68.78.13.3068.78.13.3130
10668.78.13.32/2768.78.13.33 to 68.78.13.6268.78.13.6330
10768.78.13.64/2768.78.13.65 to 68.78.13.9468.78.13.9530
10868.78.13.96/2768.78.13.97 to 68.78.13.12668.78.13.12730
10968.78.13.128/2768.78.13.129 to 68.78.13.15868.78.13.15930
11068.78.13.160/2768.78.13.161 to 68.78.13.19068.78.13.19130
11168.78.13.192/2768.78.13.193 to 68.78.13.22268.78.13.22330
11268.78.13.224/2768.78.13.225 to 68.78.13.25468.78.13.25530
11368.78.14.0/2768.78.14.1 to 68.78.14.3068.78.14.3130
11468.78.14.32/2768.78.14.33 to 68.78.14.6268.78.14.6330
11568.78.14.64/2768.78.14.65 to 68.78.14.9468.78.14.9530
11668.78.14.96/2768.78.14.97 to 68.78.14.12668.78.14.12730
11768.78.14.128/2768.78.14.129 to 68.78.14.15868.78.14.15930
11868.78.14.160/2768.78.14.161 to 68.78.14.19068.78.14.19130
11968.78.14.192/2768.78.14.193 to 68.78.14.22268.78.14.22330
12068.78.14.224/2768.78.14.225 to 68.78.14.25468.78.14.25530
12168.78.15.0/2768.78.15.1 to 68.78.15.3068.78.15.3130
12268.78.15.32/2768.78.15.33 to 68.78.15.6268.78.15.6330
12368.78.15.64/2768.78.15.65 to 68.78.15.9468.78.15.9530
12468.78.15.96/2768.78.15.97 to 68.78.15.12668.78.15.12730
12568.78.15.128/2768.78.15.129 to 68.78.15.15868.78.15.15930
12668.78.15.160/2768.78.15.161 to 68.78.15.19068.78.15.19130
12768.78.15.192/2768.78.15.193 to 68.78.15.22268.78.15.22330
12868.78.15.224/2768.78.15.225 to 68.78.15.25468.78.15.25530
12968.78.16.0/2768.78.16.1 to 68.78.16.3068.78.16.3130
13068.78.16.32/2768.78.16.33 to 68.78.16.6268.78.16.6330
13168.78.16.64/2768.78.16.65 to 68.78.16.9468.78.16.9530
13268.78.16.96/2768.78.16.97 to 68.78.16.12668.78.16.12730
13368.78.16.128/2768.78.16.129 to 68.78.16.15868.78.16.15930
13468.78.16.160/2768.78.16.161 to 68.78.16.19068.78.16.19130
13568.78.16.192/2768.78.16.193 to 68.78.16.22268.78.16.22330
13668.78.16.224/2768.78.16.225 to 68.78.16.25468.78.16.25530
13768.78.17.0/2768.78.17.1 to 68.78.17.3068.78.17.3130
13868.78.17.32/2768.78.17.33 to 68.78.17.6268.78.17.6330
13968.78.17.64/2768.78.17.65 to 68.78.17.9468.78.17.9530
14068.78.17.96/2768.78.17.97 to 68.78.17.12668.78.17.12730
14168.78.17.128/2768.78.17.129 to 68.78.17.15868.78.17.15930
14268.78.17.160/2768.78.17.161 to 68.78.17.19068.78.17.19130
14368.78.17.192/2768.78.17.193 to 68.78.17.22268.78.17.22330
14468.78.17.224/2768.78.17.225 to 68.78.17.25468.78.17.25530
14568.78.18.0/2768.78.18.1 to 68.78.18.3068.78.18.3130
14668.78.18.32/2768.78.18.33 to 68.78.18.6268.78.18.6330
14768.78.18.64/2768.78.18.65 to 68.78.18.9468.78.18.9530
14868.78.18.96/2768.78.18.97 to 68.78.18.12668.78.18.12730
14968.78.18.128/2768.78.18.129 to 68.78.18.15868.78.18.15930
15068.78.18.160/2768.78.18.161 to 68.78.18.19068.78.18.19130
15168.78.18.192/2768.78.18.193 to 68.78.18.22268.78.18.22330
15268.78.18.224/2768.78.18.225 to 68.78.18.25468.78.18.25530
15368.78.19.0/2768.78.19.1 to 68.78.19.3068.78.19.3130
15468.78.19.32/2768.78.19.33 to 68.78.19.6268.78.19.6330
15568.78.19.64/2768.78.19.65 to 68.78.19.9468.78.19.9530
15668.78.19.96/2768.78.19.97 to 68.78.19.12668.78.19.12730
15768.78.19.128/2768.78.19.129 to 68.78.19.15868.78.19.15930
15868.78.19.160/2768.78.19.161 to 68.78.19.19068.78.19.19130
15968.78.19.192/2768.78.19.193 to 68.78.19.22268.78.19.22330
16068.78.19.224/2768.78.19.225 to 68.78.19.25468.78.19.25530
16168.78.20.0/2768.78.20.1 to 68.78.20.3068.78.20.3130
16268.78.20.32/2768.78.20.33 to 68.78.20.6268.78.20.6330
16368.78.20.64/2768.78.20.65 to 68.78.20.9468.78.20.9530
16468.78.20.96/2768.78.20.97 to 68.78.20.12668.78.20.12730
16568.78.20.128/2768.78.20.129 to 68.78.20.15868.78.20.15930
16668.78.20.160/2768.78.20.161 to 68.78.20.19068.78.20.19130
16768.78.20.192/2768.78.20.193 to 68.78.20.22268.78.20.22330
16868.78.20.224/2768.78.20.225 to 68.78.20.25468.78.20.25530
16968.78.21.0/2768.78.21.1 to 68.78.21.3068.78.21.3130
17068.78.21.32/2768.78.21.33 to 68.78.21.6268.78.21.6330
17168.78.21.64/2768.78.21.65 to 68.78.21.9468.78.21.9530
17268.78.21.96/2768.78.21.97 to 68.78.21.12668.78.21.12730
17368.78.21.128/2768.78.21.129 to 68.78.21.15868.78.21.15930
17468.78.21.160/2768.78.21.161 to 68.78.21.19068.78.21.19130
17568.78.21.192/2768.78.21.193 to 68.78.21.22268.78.21.22330
17668.78.21.224/2768.78.21.225 to 68.78.21.25468.78.21.25530
17768.78.22.0/2768.78.22.1 to 68.78.22.3068.78.22.3130
17868.78.22.32/2768.78.22.33 to 68.78.22.6268.78.22.6330
17968.78.22.64/2768.78.22.65 to 68.78.22.9468.78.22.9530
18068.78.22.96/2768.78.22.97 to 68.78.22.12668.78.22.12730
18168.78.22.128/2768.78.22.129 to 68.78.22.15868.78.22.15930
18268.78.22.160/2768.78.22.161 to 68.78.22.19068.78.22.19130
18368.78.22.192/2768.78.22.193 to 68.78.22.22268.78.22.22330
18468.78.22.224/2768.78.22.225 to 68.78.22.25468.78.22.25530
18568.78.23.0/2768.78.23.1 to 68.78.23.3068.78.23.3130
18668.78.23.32/2768.78.23.33 to 68.78.23.6268.78.23.6330
18768.78.23.64/2768.78.23.65 to 68.78.23.9468.78.23.9530
18868.78.23.96/2768.78.23.97 to 68.78.23.12668.78.23.12730
18968.78.23.128/2768.78.23.129 to 68.78.23.15868.78.23.15930
19068.78.23.160/2768.78.23.161 to 68.78.23.19068.78.23.19130
19168.78.23.192/2768.78.23.193 to 68.78.23.22268.78.23.22330
19268.78.23.224/2768.78.23.225 to 68.78.23.25468.78.23.25530
19368.78.24.0/2768.78.24.1 to 68.78.24.3068.78.24.3130
19468.78.24.32/2768.78.24.33 to 68.78.24.6268.78.24.6330
19568.78.24.64/2768.78.24.65 to 68.78.24.9468.78.24.9530
19668.78.24.96/2768.78.24.97 to 68.78.24.12668.78.24.12730
19768.78.24.128/2768.78.24.129 to 68.78.24.15868.78.24.15930
19868.78.24.160/2768.78.24.161 to 68.78.24.19068.78.24.19130
19968.78.24.192/2768.78.24.193 to 68.78.24.22268.78.24.22330
20068.78.24.224/2768.78.24.225 to 68.78.24.25468.78.24.25530
20168.78.25.0/2768.78.25.1 to 68.78.25.3068.78.25.3130
20268.78.25.32/2768.78.25.33 to 68.78.25.6268.78.25.6330
20368.78.25.64/2768.78.25.65 to 68.78.25.9468.78.25.9530
20468.78.25.96/2768.78.25.97 to 68.78.25.12668.78.25.12730
20568.78.25.128/2768.78.25.129 to 68.78.25.15868.78.25.15930
20668.78.25.160/2768.78.25.161 to 68.78.25.19068.78.25.19130
20768.78.25.192/2768.78.25.193 to 68.78.25.22268.78.25.22330
20868.78.25.224/2768.78.25.225 to 68.78.25.25468.78.25.25530
20968.78.26.0/2768.78.26.1 to 68.78.26.3068.78.26.3130
21068.78.26.32/2768.78.26.33 to 68.78.26.6268.78.26.6330
21168.78.26.64/2768.78.26.65 to 68.78.26.9468.78.26.9530
21268.78.26.96/2768.78.26.97 to 68.78.26.12668.78.26.12730
21368.78.26.128/2768.78.26.129 to 68.78.26.15868.78.26.15930
21468.78.26.160/2768.78.26.161 to 68.78.26.19068.78.26.19130
21568.78.26.192/2768.78.26.193 to 68.78.26.22268.78.26.22330
21668.78.26.224/2768.78.26.225 to 68.78.26.25468.78.26.25530
21768.78.27.0/2768.78.27.1 to 68.78.27.3068.78.27.3130
21868.78.27.32/2768.78.27.33 to 68.78.27.6268.78.27.6330
21968.78.27.64/2768.78.27.65 to 68.78.27.9468.78.27.9530
22068.78.27.96/2768.78.27.97 to 68.78.27.12668.78.27.12730
22168.78.27.128/2768.78.27.129 to 68.78.27.15868.78.27.15930
22268.78.27.160/2768.78.27.161 to 68.78.27.19068.78.27.19130
22368.78.27.192/2768.78.27.193 to 68.78.27.22268.78.27.22330
22468.78.27.224/2768.78.27.225 to 68.78.27.25468.78.27.25530
22568.78.28.0/2768.78.28.1 to 68.78.28.3068.78.28.3130
22668.78.28.32/2768.78.28.33 to 68.78.28.6268.78.28.6330
22768.78.28.64/2768.78.28.65 to 68.78.28.9468.78.28.9530
22868.78.28.96/2768.78.28.97 to 68.78.28.12668.78.28.12730
22968.78.28.128/2768.78.28.129 to 68.78.28.15868.78.28.15930
23068.78.28.160/2768.78.28.161 to 68.78.28.19068.78.28.19130
23168.78.28.192/2768.78.28.193 to 68.78.28.22268.78.28.22330
23268.78.28.224/2768.78.28.225 to 68.78.28.25468.78.28.25530
23368.78.29.0/2768.78.29.1 to 68.78.29.3068.78.29.3130
23468.78.29.32/2768.78.29.33 to 68.78.29.6268.78.29.6330
23568.78.29.64/2768.78.29.65 to 68.78.29.9468.78.29.9530
23668.78.29.96/2768.78.29.97 to 68.78.29.12668.78.29.12730
23768.78.29.128/2768.78.29.129 to 68.78.29.15868.78.29.15930
23868.78.29.160/2768.78.29.161 to 68.78.29.19068.78.29.19130
23968.78.29.192/2768.78.29.193 to 68.78.29.22268.78.29.22330
24068.78.29.224/2768.78.29.225 to 68.78.29.25468.78.29.25530
24168.78.30.0/2768.78.30.1 to 68.78.30.3068.78.30.3130
24268.78.30.32/2768.78.30.33 to 68.78.30.6268.78.30.6330
24368.78.30.64/2768.78.30.65 to 68.78.30.9468.78.30.9530
24468.78.30.96/2768.78.30.97 to 68.78.30.12668.78.30.12730
24568.78.30.128/2768.78.30.129 to 68.78.30.15868.78.30.15930
24668.78.30.160/2768.78.30.161 to 68.78.30.19068.78.30.19130
24768.78.30.192/2768.78.30.193 to 68.78.30.22268.78.30.22330
24868.78.30.224/2768.78.30.225 to 68.78.30.25468.78.30.25530
24968.78.31.0/2768.78.31.1 to 68.78.31.3068.78.31.3130
25068.78.31.32/2768.78.31.33 to 68.78.31.6268.78.31.6330
25168.78.31.64/2768.78.31.65 to 68.78.31.9468.78.31.9530
25268.78.31.96/2768.78.31.97 to 68.78.31.12668.78.31.12730
25368.78.31.128/2768.78.31.129 to 68.78.31.15868.78.31.15930
25468.78.31.160/2768.78.31.161 to 68.78.31.19068.78.31.19130
25568.78.31.192/2768.78.31.193 to 68.78.31.22268.78.31.22330
25668.78.31.224/2768.78.31.225 to 68.78.31.25468.78.31.25530

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.