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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.

Network62.78.0.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
62.78.0.0
Broadcast address
62.78.63.255
First usable
62.78.0.1
Last usable
62.78.63.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Public public
Old class
A (default /8)
As numbers
Hex 3E4E0000 · Integer 1045299200 to 1045315583
Reverse DNS zones
0.78.62.in-addr.arpa
1.78.62.in-addr.arpa
2.78.62.in-addr.arpa
3.78.62.in-addr.arpa
4.78.62.in-addr.arpa
5.78.62.in-addr.arpa
6.78.62.in-addr.arpa
7.78.62.in-addr.arpa
8.78.62.in-addr.arpa
9.78.62.in-addr.arpa
10.78.62.in-addr.arpa
11.78.62.in-addr.arpa
12.78.62.in-addr.arpa
13.78.62.in-addr.arpa
14.78.62.in-addr.arpa
15.78.62.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111110.01001110.00000000.0000000062.78.0.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network00111110.01001110.00000000.0000000062.78.0.0
Broadcast00111110.01001110.00111111.1111111162.78.63.255
Split into smaller subnets/28
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

62.78.0.0/18 makes 1,024 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
162.78.0.0/2862.78.0.1 to 62.78.0.1462.78.0.1514
262.78.0.16/2862.78.0.17 to 62.78.0.3062.78.0.3114
362.78.0.32/2862.78.0.33 to 62.78.0.4662.78.0.4714
462.78.0.48/2862.78.0.49 to 62.78.0.6262.78.0.6314
562.78.0.64/2862.78.0.65 to 62.78.0.7862.78.0.7914
662.78.0.80/2862.78.0.81 to 62.78.0.9462.78.0.9514
762.78.0.96/2862.78.0.97 to 62.78.0.11062.78.0.11114
862.78.0.112/2862.78.0.113 to 62.78.0.12662.78.0.12714
962.78.0.128/2862.78.0.129 to 62.78.0.14262.78.0.14314
1062.78.0.144/2862.78.0.145 to 62.78.0.15862.78.0.15914
1162.78.0.160/2862.78.0.161 to 62.78.0.17462.78.0.17514
1262.78.0.176/2862.78.0.177 to 62.78.0.19062.78.0.19114
1362.78.0.192/2862.78.0.193 to 62.78.0.20662.78.0.20714
1462.78.0.208/2862.78.0.209 to 62.78.0.22262.78.0.22314
1562.78.0.224/2862.78.0.225 to 62.78.0.23862.78.0.23914
1662.78.0.240/2862.78.0.241 to 62.78.0.25462.78.0.25514
1762.78.1.0/2862.78.1.1 to 62.78.1.1462.78.1.1514
1862.78.1.16/2862.78.1.17 to 62.78.1.3062.78.1.3114
1962.78.1.32/2862.78.1.33 to 62.78.1.4662.78.1.4714
2062.78.1.48/2862.78.1.49 to 62.78.1.6262.78.1.6314
2162.78.1.64/2862.78.1.65 to 62.78.1.7862.78.1.7914
2262.78.1.80/2862.78.1.81 to 62.78.1.9462.78.1.9514
2362.78.1.96/2862.78.1.97 to 62.78.1.11062.78.1.11114
2462.78.1.112/2862.78.1.113 to 62.78.1.12662.78.1.12714
2562.78.1.128/2862.78.1.129 to 62.78.1.14262.78.1.14314
2662.78.1.144/2862.78.1.145 to 62.78.1.15862.78.1.15914
2762.78.1.160/2862.78.1.161 to 62.78.1.17462.78.1.17514
2862.78.1.176/2862.78.1.177 to 62.78.1.19062.78.1.19114
2962.78.1.192/2862.78.1.193 to 62.78.1.20662.78.1.20714
3062.78.1.208/2862.78.1.209 to 62.78.1.22262.78.1.22314
3162.78.1.224/2862.78.1.225 to 62.78.1.23862.78.1.23914
3262.78.1.240/2862.78.1.241 to 62.78.1.25462.78.1.25514
3362.78.2.0/2862.78.2.1 to 62.78.2.1462.78.2.1514
3462.78.2.16/2862.78.2.17 to 62.78.2.3062.78.2.3114
3562.78.2.32/2862.78.2.33 to 62.78.2.4662.78.2.4714
3662.78.2.48/2862.78.2.49 to 62.78.2.6262.78.2.6314
3762.78.2.64/2862.78.2.65 to 62.78.2.7862.78.2.7914
3862.78.2.80/2862.78.2.81 to 62.78.2.9462.78.2.9514
3962.78.2.96/2862.78.2.97 to 62.78.2.11062.78.2.11114
4062.78.2.112/2862.78.2.113 to 62.78.2.12662.78.2.12714
4162.78.2.128/2862.78.2.129 to 62.78.2.14262.78.2.14314
4262.78.2.144/2862.78.2.145 to 62.78.2.15862.78.2.15914
4362.78.2.160/2862.78.2.161 to 62.78.2.17462.78.2.17514
4462.78.2.176/2862.78.2.177 to 62.78.2.19062.78.2.19114
4562.78.2.192/2862.78.2.193 to 62.78.2.20662.78.2.20714
4662.78.2.208/2862.78.2.209 to 62.78.2.22262.78.2.22314
4762.78.2.224/2862.78.2.225 to 62.78.2.23862.78.2.23914
4862.78.2.240/2862.78.2.241 to 62.78.2.25462.78.2.25514
4962.78.3.0/2862.78.3.1 to 62.78.3.1462.78.3.1514
5062.78.3.16/2862.78.3.17 to 62.78.3.3062.78.3.3114
5162.78.3.32/2862.78.3.33 to 62.78.3.4662.78.3.4714
5262.78.3.48/2862.78.3.49 to 62.78.3.6262.78.3.6314
5362.78.3.64/2862.78.3.65 to 62.78.3.7862.78.3.7914
5462.78.3.80/2862.78.3.81 to 62.78.3.9462.78.3.9514
5562.78.3.96/2862.78.3.97 to 62.78.3.11062.78.3.11114
5662.78.3.112/2862.78.3.113 to 62.78.3.12662.78.3.12714
5762.78.3.128/2862.78.3.129 to 62.78.3.14262.78.3.14314
5862.78.3.144/2862.78.3.145 to 62.78.3.15862.78.3.15914
5962.78.3.160/2862.78.3.161 to 62.78.3.17462.78.3.17514
6062.78.3.176/2862.78.3.177 to 62.78.3.19062.78.3.19114
6162.78.3.192/2862.78.3.193 to 62.78.3.20662.78.3.20714
6262.78.3.208/2862.78.3.209 to 62.78.3.22262.78.3.22314
6362.78.3.224/2862.78.3.225 to 62.78.3.23862.78.3.23914
6462.78.3.240/2862.78.3.241 to 62.78.3.25462.78.3.25514
6562.78.4.0/2862.78.4.1 to 62.78.4.1462.78.4.1514
6662.78.4.16/2862.78.4.17 to 62.78.4.3062.78.4.3114
6762.78.4.32/2862.78.4.33 to 62.78.4.4662.78.4.4714
6862.78.4.48/2862.78.4.49 to 62.78.4.6262.78.4.6314
6962.78.4.64/2862.78.4.65 to 62.78.4.7862.78.4.7914
7062.78.4.80/2862.78.4.81 to 62.78.4.9462.78.4.9514
7162.78.4.96/2862.78.4.97 to 62.78.4.11062.78.4.11114
7262.78.4.112/2862.78.4.113 to 62.78.4.12662.78.4.12714
7362.78.4.128/2862.78.4.129 to 62.78.4.14262.78.4.14314
7462.78.4.144/2862.78.4.145 to 62.78.4.15862.78.4.15914
7562.78.4.160/2862.78.4.161 to 62.78.4.17462.78.4.17514
7662.78.4.176/2862.78.4.177 to 62.78.4.19062.78.4.19114
7762.78.4.192/2862.78.4.193 to 62.78.4.20662.78.4.20714
7862.78.4.208/2862.78.4.209 to 62.78.4.22262.78.4.22314
7962.78.4.224/2862.78.4.225 to 62.78.4.23862.78.4.23914
8062.78.4.240/2862.78.4.241 to 62.78.4.25462.78.4.25514
8162.78.5.0/2862.78.5.1 to 62.78.5.1462.78.5.1514
8262.78.5.16/2862.78.5.17 to 62.78.5.3062.78.5.3114
8362.78.5.32/2862.78.5.33 to 62.78.5.4662.78.5.4714
8462.78.5.48/2862.78.5.49 to 62.78.5.6262.78.5.6314
8562.78.5.64/2862.78.5.65 to 62.78.5.7862.78.5.7914
8662.78.5.80/2862.78.5.81 to 62.78.5.9462.78.5.9514
8762.78.5.96/2862.78.5.97 to 62.78.5.11062.78.5.11114
8862.78.5.112/2862.78.5.113 to 62.78.5.12662.78.5.12714
8962.78.5.128/2862.78.5.129 to 62.78.5.14262.78.5.14314
9062.78.5.144/2862.78.5.145 to 62.78.5.15862.78.5.15914
9162.78.5.160/2862.78.5.161 to 62.78.5.17462.78.5.17514
9262.78.5.176/2862.78.5.177 to 62.78.5.19062.78.5.19114
9362.78.5.192/2862.78.5.193 to 62.78.5.20662.78.5.20714
9462.78.5.208/2862.78.5.209 to 62.78.5.22262.78.5.22314
9562.78.5.224/2862.78.5.225 to 62.78.5.23862.78.5.23914
9662.78.5.240/2862.78.5.241 to 62.78.5.25462.78.5.25514
9762.78.6.0/2862.78.6.1 to 62.78.6.1462.78.6.1514
9862.78.6.16/2862.78.6.17 to 62.78.6.3062.78.6.3114
9962.78.6.32/2862.78.6.33 to 62.78.6.4662.78.6.4714
10062.78.6.48/2862.78.6.49 to 62.78.6.6262.78.6.6314
10162.78.6.64/2862.78.6.65 to 62.78.6.7862.78.6.7914
10262.78.6.80/2862.78.6.81 to 62.78.6.9462.78.6.9514
10362.78.6.96/2862.78.6.97 to 62.78.6.11062.78.6.11114
10462.78.6.112/2862.78.6.113 to 62.78.6.12662.78.6.12714
10562.78.6.128/2862.78.6.129 to 62.78.6.14262.78.6.14314
10662.78.6.144/2862.78.6.145 to 62.78.6.15862.78.6.15914
10762.78.6.160/2862.78.6.161 to 62.78.6.17462.78.6.17514
10862.78.6.176/2862.78.6.177 to 62.78.6.19062.78.6.19114
10962.78.6.192/2862.78.6.193 to 62.78.6.20662.78.6.20714
11062.78.6.208/2862.78.6.209 to 62.78.6.22262.78.6.22314
11162.78.6.224/2862.78.6.225 to 62.78.6.23862.78.6.23914
11262.78.6.240/2862.78.6.241 to 62.78.6.25462.78.6.25514
11362.78.7.0/2862.78.7.1 to 62.78.7.1462.78.7.1514
11462.78.7.16/2862.78.7.17 to 62.78.7.3062.78.7.3114
11562.78.7.32/2862.78.7.33 to 62.78.7.4662.78.7.4714
11662.78.7.48/2862.78.7.49 to 62.78.7.6262.78.7.6314
11762.78.7.64/2862.78.7.65 to 62.78.7.7862.78.7.7914
11862.78.7.80/2862.78.7.81 to 62.78.7.9462.78.7.9514
11962.78.7.96/2862.78.7.97 to 62.78.7.11062.78.7.11114
12062.78.7.112/2862.78.7.113 to 62.78.7.12662.78.7.12714
12162.78.7.128/2862.78.7.129 to 62.78.7.14262.78.7.14314
12262.78.7.144/2862.78.7.145 to 62.78.7.15862.78.7.15914
12362.78.7.160/2862.78.7.161 to 62.78.7.17462.78.7.17514
12462.78.7.176/2862.78.7.177 to 62.78.7.19062.78.7.19114
12562.78.7.192/2862.78.7.193 to 62.78.7.20662.78.7.20714
12662.78.7.208/2862.78.7.209 to 62.78.7.22262.78.7.22314
12762.78.7.224/2862.78.7.225 to 62.78.7.23862.78.7.23914
12862.78.7.240/2862.78.7.241 to 62.78.7.25462.78.7.25514
12962.78.8.0/2862.78.8.1 to 62.78.8.1462.78.8.1514
13062.78.8.16/2862.78.8.17 to 62.78.8.3062.78.8.3114
13162.78.8.32/2862.78.8.33 to 62.78.8.4662.78.8.4714
13262.78.8.48/2862.78.8.49 to 62.78.8.6262.78.8.6314
13362.78.8.64/2862.78.8.65 to 62.78.8.7862.78.8.7914
13462.78.8.80/2862.78.8.81 to 62.78.8.9462.78.8.9514
13562.78.8.96/2862.78.8.97 to 62.78.8.11062.78.8.11114
13662.78.8.112/2862.78.8.113 to 62.78.8.12662.78.8.12714
13762.78.8.128/2862.78.8.129 to 62.78.8.14262.78.8.14314
13862.78.8.144/2862.78.8.145 to 62.78.8.15862.78.8.15914
13962.78.8.160/2862.78.8.161 to 62.78.8.17462.78.8.17514
14062.78.8.176/2862.78.8.177 to 62.78.8.19062.78.8.19114
14162.78.8.192/2862.78.8.193 to 62.78.8.20662.78.8.20714
14262.78.8.208/2862.78.8.209 to 62.78.8.22262.78.8.22314
14362.78.8.224/2862.78.8.225 to 62.78.8.23862.78.8.23914
14462.78.8.240/2862.78.8.241 to 62.78.8.25462.78.8.25514
14562.78.9.0/2862.78.9.1 to 62.78.9.1462.78.9.1514
14662.78.9.16/2862.78.9.17 to 62.78.9.3062.78.9.3114
14762.78.9.32/2862.78.9.33 to 62.78.9.4662.78.9.4714
14862.78.9.48/2862.78.9.49 to 62.78.9.6262.78.9.6314
14962.78.9.64/2862.78.9.65 to 62.78.9.7862.78.9.7914
15062.78.9.80/2862.78.9.81 to 62.78.9.9462.78.9.9514
15162.78.9.96/2862.78.9.97 to 62.78.9.11062.78.9.11114
15262.78.9.112/2862.78.9.113 to 62.78.9.12662.78.9.12714
15362.78.9.128/2862.78.9.129 to 62.78.9.14262.78.9.14314
15462.78.9.144/2862.78.9.145 to 62.78.9.15862.78.9.15914
15562.78.9.160/2862.78.9.161 to 62.78.9.17462.78.9.17514
15662.78.9.176/2862.78.9.177 to 62.78.9.19062.78.9.19114
15762.78.9.192/2862.78.9.193 to 62.78.9.20662.78.9.20714
15862.78.9.208/2862.78.9.209 to 62.78.9.22262.78.9.22314
15962.78.9.224/2862.78.9.225 to 62.78.9.23862.78.9.23914
16062.78.9.240/2862.78.9.241 to 62.78.9.25462.78.9.25514
16162.78.10.0/2862.78.10.1 to 62.78.10.1462.78.10.1514
16262.78.10.16/2862.78.10.17 to 62.78.10.3062.78.10.3114
16362.78.10.32/2862.78.10.33 to 62.78.10.4662.78.10.4714
16462.78.10.48/2862.78.10.49 to 62.78.10.6262.78.10.6314
16562.78.10.64/2862.78.10.65 to 62.78.10.7862.78.10.7914
16662.78.10.80/2862.78.10.81 to 62.78.10.9462.78.10.9514
16762.78.10.96/2862.78.10.97 to 62.78.10.11062.78.10.11114
16862.78.10.112/2862.78.10.113 to 62.78.10.12662.78.10.12714
16962.78.10.128/2862.78.10.129 to 62.78.10.14262.78.10.14314
17062.78.10.144/2862.78.10.145 to 62.78.10.15862.78.10.15914
17162.78.10.160/2862.78.10.161 to 62.78.10.17462.78.10.17514
17262.78.10.176/2862.78.10.177 to 62.78.10.19062.78.10.19114
17362.78.10.192/2862.78.10.193 to 62.78.10.20662.78.10.20714
17462.78.10.208/2862.78.10.209 to 62.78.10.22262.78.10.22314
17562.78.10.224/2862.78.10.225 to 62.78.10.23862.78.10.23914
17662.78.10.240/2862.78.10.241 to 62.78.10.25462.78.10.25514
17762.78.11.0/2862.78.11.1 to 62.78.11.1462.78.11.1514
17862.78.11.16/2862.78.11.17 to 62.78.11.3062.78.11.3114
17962.78.11.32/2862.78.11.33 to 62.78.11.4662.78.11.4714
18062.78.11.48/2862.78.11.49 to 62.78.11.6262.78.11.6314
18162.78.11.64/2862.78.11.65 to 62.78.11.7862.78.11.7914
18262.78.11.80/2862.78.11.81 to 62.78.11.9462.78.11.9514
18362.78.11.96/2862.78.11.97 to 62.78.11.11062.78.11.11114
18462.78.11.112/2862.78.11.113 to 62.78.11.12662.78.11.12714
18562.78.11.128/2862.78.11.129 to 62.78.11.14262.78.11.14314
18662.78.11.144/2862.78.11.145 to 62.78.11.15862.78.11.15914
18762.78.11.160/2862.78.11.161 to 62.78.11.17462.78.11.17514
18862.78.11.176/2862.78.11.177 to 62.78.11.19062.78.11.19114
18962.78.11.192/2862.78.11.193 to 62.78.11.20662.78.11.20714
19062.78.11.208/2862.78.11.209 to 62.78.11.22262.78.11.22314
19162.78.11.224/2862.78.11.225 to 62.78.11.23862.78.11.23914
19262.78.11.240/2862.78.11.241 to 62.78.11.25462.78.11.25514
19362.78.12.0/2862.78.12.1 to 62.78.12.1462.78.12.1514
19462.78.12.16/2862.78.12.17 to 62.78.12.3062.78.12.3114
19562.78.12.32/2862.78.12.33 to 62.78.12.4662.78.12.4714
19662.78.12.48/2862.78.12.49 to 62.78.12.6262.78.12.6314
19762.78.12.64/2862.78.12.65 to 62.78.12.7862.78.12.7914
19862.78.12.80/2862.78.12.81 to 62.78.12.9462.78.12.9514
19962.78.12.96/2862.78.12.97 to 62.78.12.11062.78.12.11114
20062.78.12.112/2862.78.12.113 to 62.78.12.12662.78.12.12714
20162.78.12.128/2862.78.12.129 to 62.78.12.14262.78.12.14314
20262.78.12.144/2862.78.12.145 to 62.78.12.15862.78.12.15914
20362.78.12.160/2862.78.12.161 to 62.78.12.17462.78.12.17514
20462.78.12.176/2862.78.12.177 to 62.78.12.19062.78.12.19114
20562.78.12.192/2862.78.12.193 to 62.78.12.20662.78.12.20714
20662.78.12.208/2862.78.12.209 to 62.78.12.22262.78.12.22314
20762.78.12.224/2862.78.12.225 to 62.78.12.23862.78.12.23914
20862.78.12.240/2862.78.12.241 to 62.78.12.25462.78.12.25514
20962.78.13.0/2862.78.13.1 to 62.78.13.1462.78.13.1514
21062.78.13.16/2862.78.13.17 to 62.78.13.3062.78.13.3114
21162.78.13.32/2862.78.13.33 to 62.78.13.4662.78.13.4714
21262.78.13.48/2862.78.13.49 to 62.78.13.6262.78.13.6314
21362.78.13.64/2862.78.13.65 to 62.78.13.7862.78.13.7914
21462.78.13.80/2862.78.13.81 to 62.78.13.9462.78.13.9514
21562.78.13.96/2862.78.13.97 to 62.78.13.11062.78.13.11114
21662.78.13.112/2862.78.13.113 to 62.78.13.12662.78.13.12714
21762.78.13.128/2862.78.13.129 to 62.78.13.14262.78.13.14314
21862.78.13.144/2862.78.13.145 to 62.78.13.15862.78.13.15914
21962.78.13.160/2862.78.13.161 to 62.78.13.17462.78.13.17514
22062.78.13.176/2862.78.13.177 to 62.78.13.19062.78.13.19114
22162.78.13.192/2862.78.13.193 to 62.78.13.20662.78.13.20714
22262.78.13.208/2862.78.13.209 to 62.78.13.22262.78.13.22314
22362.78.13.224/2862.78.13.225 to 62.78.13.23862.78.13.23914
22462.78.13.240/2862.78.13.241 to 62.78.13.25462.78.13.25514
22562.78.14.0/2862.78.14.1 to 62.78.14.1462.78.14.1514
22662.78.14.16/2862.78.14.17 to 62.78.14.3062.78.14.3114
22762.78.14.32/2862.78.14.33 to 62.78.14.4662.78.14.4714
22862.78.14.48/2862.78.14.49 to 62.78.14.6262.78.14.6314
22962.78.14.64/2862.78.14.65 to 62.78.14.7862.78.14.7914
23062.78.14.80/2862.78.14.81 to 62.78.14.9462.78.14.9514
23162.78.14.96/2862.78.14.97 to 62.78.14.11062.78.14.11114
23262.78.14.112/2862.78.14.113 to 62.78.14.12662.78.14.12714
23362.78.14.128/2862.78.14.129 to 62.78.14.14262.78.14.14314
23462.78.14.144/2862.78.14.145 to 62.78.14.15862.78.14.15914
23562.78.14.160/2862.78.14.161 to 62.78.14.17462.78.14.17514
23662.78.14.176/2862.78.14.177 to 62.78.14.19062.78.14.19114
23762.78.14.192/2862.78.14.193 to 62.78.14.20662.78.14.20714
23862.78.14.208/2862.78.14.209 to 62.78.14.22262.78.14.22314
23962.78.14.224/2862.78.14.225 to 62.78.14.23862.78.14.23914
24062.78.14.240/2862.78.14.241 to 62.78.14.25462.78.14.25514
24162.78.15.0/2862.78.15.1 to 62.78.15.1462.78.15.1514
24262.78.15.16/2862.78.15.17 to 62.78.15.3062.78.15.3114
24362.78.15.32/2862.78.15.33 to 62.78.15.4662.78.15.4714
24462.78.15.48/2862.78.15.49 to 62.78.15.6262.78.15.6314
24562.78.15.64/2862.78.15.65 to 62.78.15.7862.78.15.7914
24662.78.15.80/2862.78.15.81 to 62.78.15.9462.78.15.9514
24762.78.15.96/2862.78.15.97 to 62.78.15.11062.78.15.11114
24862.78.15.112/2862.78.15.113 to 62.78.15.12662.78.15.12714
24962.78.15.128/2862.78.15.129 to 62.78.15.14262.78.15.14314
25062.78.15.144/2862.78.15.145 to 62.78.15.15862.78.15.15914
25162.78.15.160/2862.78.15.161 to 62.78.15.17462.78.15.17514
25262.78.15.176/2862.78.15.177 to 62.78.15.19062.78.15.19114
25362.78.15.192/2862.78.15.193 to 62.78.15.20662.78.15.20714
25462.78.15.208/2862.78.15.209 to 62.78.15.22262.78.15.22314
25562.78.15.224/2862.78.15.225 to 62.78.15.23862.78.15.23914
25662.78.15.240/2862.78.15.241 to 62.78.15.25462.78.15.25514

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.