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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.

Network58.4.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
58.4.0.0
Broadcast address
58.4.255.255
First usable
58.4.0.1
Last usable
58.4.255.254
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 3A040000 · Integer 973340672 to 973406207
Reverse DNS zone
4.58.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111010.00000100..00000000.0000000058.4.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network00111010.00000100..00000000.0000000058.4.0.0
Broadcast00111010.00000100..11111111.1111111158.4.255.255
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)

58.4.0.0/16 makes 1,024 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
158.4.0.0/2658.4.0.1 to 58.4.0.6258.4.0.6362
258.4.0.64/2658.4.0.65 to 58.4.0.12658.4.0.12762
358.4.0.128/2658.4.0.129 to 58.4.0.19058.4.0.19162
458.4.0.192/2658.4.0.193 to 58.4.0.25458.4.0.25562
558.4.1.0/2658.4.1.1 to 58.4.1.6258.4.1.6362
658.4.1.64/2658.4.1.65 to 58.4.1.12658.4.1.12762
758.4.1.128/2658.4.1.129 to 58.4.1.19058.4.1.19162
858.4.1.192/2658.4.1.193 to 58.4.1.25458.4.1.25562
958.4.2.0/2658.4.2.1 to 58.4.2.6258.4.2.6362
1058.4.2.64/2658.4.2.65 to 58.4.2.12658.4.2.12762
1158.4.2.128/2658.4.2.129 to 58.4.2.19058.4.2.19162
1258.4.2.192/2658.4.2.193 to 58.4.2.25458.4.2.25562
1358.4.3.0/2658.4.3.1 to 58.4.3.6258.4.3.6362
1458.4.3.64/2658.4.3.65 to 58.4.3.12658.4.3.12762
1558.4.3.128/2658.4.3.129 to 58.4.3.19058.4.3.19162
1658.4.3.192/2658.4.3.193 to 58.4.3.25458.4.3.25562
1758.4.4.0/2658.4.4.1 to 58.4.4.6258.4.4.6362
1858.4.4.64/2658.4.4.65 to 58.4.4.12658.4.4.12762
1958.4.4.128/2658.4.4.129 to 58.4.4.19058.4.4.19162
2058.4.4.192/2658.4.4.193 to 58.4.4.25458.4.4.25562
2158.4.5.0/2658.4.5.1 to 58.4.5.6258.4.5.6362
2258.4.5.64/2658.4.5.65 to 58.4.5.12658.4.5.12762
2358.4.5.128/2658.4.5.129 to 58.4.5.19058.4.5.19162
2458.4.5.192/2658.4.5.193 to 58.4.5.25458.4.5.25562
2558.4.6.0/2658.4.6.1 to 58.4.6.6258.4.6.6362
2658.4.6.64/2658.4.6.65 to 58.4.6.12658.4.6.12762
2758.4.6.128/2658.4.6.129 to 58.4.6.19058.4.6.19162
2858.4.6.192/2658.4.6.193 to 58.4.6.25458.4.6.25562
2958.4.7.0/2658.4.7.1 to 58.4.7.6258.4.7.6362
3058.4.7.64/2658.4.7.65 to 58.4.7.12658.4.7.12762
3158.4.7.128/2658.4.7.129 to 58.4.7.19058.4.7.19162
3258.4.7.192/2658.4.7.193 to 58.4.7.25458.4.7.25562
3358.4.8.0/2658.4.8.1 to 58.4.8.6258.4.8.6362
3458.4.8.64/2658.4.8.65 to 58.4.8.12658.4.8.12762
3558.4.8.128/2658.4.8.129 to 58.4.8.19058.4.8.19162
3658.4.8.192/2658.4.8.193 to 58.4.8.25458.4.8.25562
3758.4.9.0/2658.4.9.1 to 58.4.9.6258.4.9.6362
3858.4.9.64/2658.4.9.65 to 58.4.9.12658.4.9.12762
3958.4.9.128/2658.4.9.129 to 58.4.9.19058.4.9.19162
4058.4.9.192/2658.4.9.193 to 58.4.9.25458.4.9.25562
4158.4.10.0/2658.4.10.1 to 58.4.10.6258.4.10.6362
4258.4.10.64/2658.4.10.65 to 58.4.10.12658.4.10.12762
4358.4.10.128/2658.4.10.129 to 58.4.10.19058.4.10.19162
4458.4.10.192/2658.4.10.193 to 58.4.10.25458.4.10.25562
4558.4.11.0/2658.4.11.1 to 58.4.11.6258.4.11.6362
4658.4.11.64/2658.4.11.65 to 58.4.11.12658.4.11.12762
4758.4.11.128/2658.4.11.129 to 58.4.11.19058.4.11.19162
4858.4.11.192/2658.4.11.193 to 58.4.11.25458.4.11.25562
4958.4.12.0/2658.4.12.1 to 58.4.12.6258.4.12.6362
5058.4.12.64/2658.4.12.65 to 58.4.12.12658.4.12.12762
5158.4.12.128/2658.4.12.129 to 58.4.12.19058.4.12.19162
5258.4.12.192/2658.4.12.193 to 58.4.12.25458.4.12.25562
5358.4.13.0/2658.4.13.1 to 58.4.13.6258.4.13.6362
5458.4.13.64/2658.4.13.65 to 58.4.13.12658.4.13.12762
5558.4.13.128/2658.4.13.129 to 58.4.13.19058.4.13.19162
5658.4.13.192/2658.4.13.193 to 58.4.13.25458.4.13.25562
5758.4.14.0/2658.4.14.1 to 58.4.14.6258.4.14.6362
5858.4.14.64/2658.4.14.65 to 58.4.14.12658.4.14.12762
5958.4.14.128/2658.4.14.129 to 58.4.14.19058.4.14.19162
6058.4.14.192/2658.4.14.193 to 58.4.14.25458.4.14.25562
6158.4.15.0/2658.4.15.1 to 58.4.15.6258.4.15.6362
6258.4.15.64/2658.4.15.65 to 58.4.15.12658.4.15.12762
6358.4.15.128/2658.4.15.129 to 58.4.15.19058.4.15.19162
6458.4.15.192/2658.4.15.193 to 58.4.15.25458.4.15.25562
6558.4.16.0/2658.4.16.1 to 58.4.16.6258.4.16.6362
6658.4.16.64/2658.4.16.65 to 58.4.16.12658.4.16.12762
6758.4.16.128/2658.4.16.129 to 58.4.16.19058.4.16.19162
6858.4.16.192/2658.4.16.193 to 58.4.16.25458.4.16.25562
6958.4.17.0/2658.4.17.1 to 58.4.17.6258.4.17.6362
7058.4.17.64/2658.4.17.65 to 58.4.17.12658.4.17.12762
7158.4.17.128/2658.4.17.129 to 58.4.17.19058.4.17.19162
7258.4.17.192/2658.4.17.193 to 58.4.17.25458.4.17.25562
7358.4.18.0/2658.4.18.1 to 58.4.18.6258.4.18.6362
7458.4.18.64/2658.4.18.65 to 58.4.18.12658.4.18.12762
7558.4.18.128/2658.4.18.129 to 58.4.18.19058.4.18.19162
7658.4.18.192/2658.4.18.193 to 58.4.18.25458.4.18.25562
7758.4.19.0/2658.4.19.1 to 58.4.19.6258.4.19.6362
7858.4.19.64/2658.4.19.65 to 58.4.19.12658.4.19.12762
7958.4.19.128/2658.4.19.129 to 58.4.19.19058.4.19.19162
8058.4.19.192/2658.4.19.193 to 58.4.19.25458.4.19.25562
8158.4.20.0/2658.4.20.1 to 58.4.20.6258.4.20.6362
8258.4.20.64/2658.4.20.65 to 58.4.20.12658.4.20.12762
8358.4.20.128/2658.4.20.129 to 58.4.20.19058.4.20.19162
8458.4.20.192/2658.4.20.193 to 58.4.20.25458.4.20.25562
8558.4.21.0/2658.4.21.1 to 58.4.21.6258.4.21.6362
8658.4.21.64/2658.4.21.65 to 58.4.21.12658.4.21.12762
8758.4.21.128/2658.4.21.129 to 58.4.21.19058.4.21.19162
8858.4.21.192/2658.4.21.193 to 58.4.21.25458.4.21.25562
8958.4.22.0/2658.4.22.1 to 58.4.22.6258.4.22.6362
9058.4.22.64/2658.4.22.65 to 58.4.22.12658.4.22.12762
9158.4.22.128/2658.4.22.129 to 58.4.22.19058.4.22.19162
9258.4.22.192/2658.4.22.193 to 58.4.22.25458.4.22.25562
9358.4.23.0/2658.4.23.1 to 58.4.23.6258.4.23.6362
9458.4.23.64/2658.4.23.65 to 58.4.23.12658.4.23.12762
9558.4.23.128/2658.4.23.129 to 58.4.23.19058.4.23.19162
9658.4.23.192/2658.4.23.193 to 58.4.23.25458.4.23.25562
9758.4.24.0/2658.4.24.1 to 58.4.24.6258.4.24.6362
9858.4.24.64/2658.4.24.65 to 58.4.24.12658.4.24.12762
9958.4.24.128/2658.4.24.129 to 58.4.24.19058.4.24.19162
10058.4.24.192/2658.4.24.193 to 58.4.24.25458.4.24.25562
10158.4.25.0/2658.4.25.1 to 58.4.25.6258.4.25.6362
10258.4.25.64/2658.4.25.65 to 58.4.25.12658.4.25.12762
10358.4.25.128/2658.4.25.129 to 58.4.25.19058.4.25.19162
10458.4.25.192/2658.4.25.193 to 58.4.25.25458.4.25.25562
10558.4.26.0/2658.4.26.1 to 58.4.26.6258.4.26.6362
10658.4.26.64/2658.4.26.65 to 58.4.26.12658.4.26.12762
10758.4.26.128/2658.4.26.129 to 58.4.26.19058.4.26.19162
10858.4.26.192/2658.4.26.193 to 58.4.26.25458.4.26.25562
10958.4.27.0/2658.4.27.1 to 58.4.27.6258.4.27.6362
11058.4.27.64/2658.4.27.65 to 58.4.27.12658.4.27.12762
11158.4.27.128/2658.4.27.129 to 58.4.27.19058.4.27.19162
11258.4.27.192/2658.4.27.193 to 58.4.27.25458.4.27.25562
11358.4.28.0/2658.4.28.1 to 58.4.28.6258.4.28.6362
11458.4.28.64/2658.4.28.65 to 58.4.28.12658.4.28.12762
11558.4.28.128/2658.4.28.129 to 58.4.28.19058.4.28.19162
11658.4.28.192/2658.4.28.193 to 58.4.28.25458.4.28.25562
11758.4.29.0/2658.4.29.1 to 58.4.29.6258.4.29.6362
11858.4.29.64/2658.4.29.65 to 58.4.29.12658.4.29.12762
11958.4.29.128/2658.4.29.129 to 58.4.29.19058.4.29.19162
12058.4.29.192/2658.4.29.193 to 58.4.29.25458.4.29.25562
12158.4.30.0/2658.4.30.1 to 58.4.30.6258.4.30.6362
12258.4.30.64/2658.4.30.65 to 58.4.30.12658.4.30.12762
12358.4.30.128/2658.4.30.129 to 58.4.30.19058.4.30.19162
12458.4.30.192/2658.4.30.193 to 58.4.30.25458.4.30.25562
12558.4.31.0/2658.4.31.1 to 58.4.31.6258.4.31.6362
12658.4.31.64/2658.4.31.65 to 58.4.31.12658.4.31.12762
12758.4.31.128/2658.4.31.129 to 58.4.31.19058.4.31.19162
12858.4.31.192/2658.4.31.193 to 58.4.31.25458.4.31.25562
12958.4.32.0/2658.4.32.1 to 58.4.32.6258.4.32.6362
13058.4.32.64/2658.4.32.65 to 58.4.32.12658.4.32.12762
13158.4.32.128/2658.4.32.129 to 58.4.32.19058.4.32.19162
13258.4.32.192/2658.4.32.193 to 58.4.32.25458.4.32.25562
13358.4.33.0/2658.4.33.1 to 58.4.33.6258.4.33.6362
13458.4.33.64/2658.4.33.65 to 58.4.33.12658.4.33.12762
13558.4.33.128/2658.4.33.129 to 58.4.33.19058.4.33.19162
13658.4.33.192/2658.4.33.193 to 58.4.33.25458.4.33.25562
13758.4.34.0/2658.4.34.1 to 58.4.34.6258.4.34.6362
13858.4.34.64/2658.4.34.65 to 58.4.34.12658.4.34.12762
13958.4.34.128/2658.4.34.129 to 58.4.34.19058.4.34.19162
14058.4.34.192/2658.4.34.193 to 58.4.34.25458.4.34.25562
14158.4.35.0/2658.4.35.1 to 58.4.35.6258.4.35.6362
14258.4.35.64/2658.4.35.65 to 58.4.35.12658.4.35.12762
14358.4.35.128/2658.4.35.129 to 58.4.35.19058.4.35.19162
14458.4.35.192/2658.4.35.193 to 58.4.35.25458.4.35.25562
14558.4.36.0/2658.4.36.1 to 58.4.36.6258.4.36.6362
14658.4.36.64/2658.4.36.65 to 58.4.36.12658.4.36.12762
14758.4.36.128/2658.4.36.129 to 58.4.36.19058.4.36.19162
14858.4.36.192/2658.4.36.193 to 58.4.36.25458.4.36.25562
14958.4.37.0/2658.4.37.1 to 58.4.37.6258.4.37.6362
15058.4.37.64/2658.4.37.65 to 58.4.37.12658.4.37.12762
15158.4.37.128/2658.4.37.129 to 58.4.37.19058.4.37.19162
15258.4.37.192/2658.4.37.193 to 58.4.37.25458.4.37.25562
15358.4.38.0/2658.4.38.1 to 58.4.38.6258.4.38.6362
15458.4.38.64/2658.4.38.65 to 58.4.38.12658.4.38.12762
15558.4.38.128/2658.4.38.129 to 58.4.38.19058.4.38.19162
15658.4.38.192/2658.4.38.193 to 58.4.38.25458.4.38.25562
15758.4.39.0/2658.4.39.1 to 58.4.39.6258.4.39.6362
15858.4.39.64/2658.4.39.65 to 58.4.39.12658.4.39.12762
15958.4.39.128/2658.4.39.129 to 58.4.39.19058.4.39.19162
16058.4.39.192/2658.4.39.193 to 58.4.39.25458.4.39.25562
16158.4.40.0/2658.4.40.1 to 58.4.40.6258.4.40.6362
16258.4.40.64/2658.4.40.65 to 58.4.40.12658.4.40.12762
16358.4.40.128/2658.4.40.129 to 58.4.40.19058.4.40.19162
16458.4.40.192/2658.4.40.193 to 58.4.40.25458.4.40.25562
16558.4.41.0/2658.4.41.1 to 58.4.41.6258.4.41.6362
16658.4.41.64/2658.4.41.65 to 58.4.41.12658.4.41.12762
16758.4.41.128/2658.4.41.129 to 58.4.41.19058.4.41.19162
16858.4.41.192/2658.4.41.193 to 58.4.41.25458.4.41.25562
16958.4.42.0/2658.4.42.1 to 58.4.42.6258.4.42.6362
17058.4.42.64/2658.4.42.65 to 58.4.42.12658.4.42.12762
17158.4.42.128/2658.4.42.129 to 58.4.42.19058.4.42.19162
17258.4.42.192/2658.4.42.193 to 58.4.42.25458.4.42.25562
17358.4.43.0/2658.4.43.1 to 58.4.43.6258.4.43.6362
17458.4.43.64/2658.4.43.65 to 58.4.43.12658.4.43.12762
17558.4.43.128/2658.4.43.129 to 58.4.43.19058.4.43.19162
17658.4.43.192/2658.4.43.193 to 58.4.43.25458.4.43.25562
17758.4.44.0/2658.4.44.1 to 58.4.44.6258.4.44.6362
17858.4.44.64/2658.4.44.65 to 58.4.44.12658.4.44.12762
17958.4.44.128/2658.4.44.129 to 58.4.44.19058.4.44.19162
18058.4.44.192/2658.4.44.193 to 58.4.44.25458.4.44.25562
18158.4.45.0/2658.4.45.1 to 58.4.45.6258.4.45.6362
18258.4.45.64/2658.4.45.65 to 58.4.45.12658.4.45.12762
18358.4.45.128/2658.4.45.129 to 58.4.45.19058.4.45.19162
18458.4.45.192/2658.4.45.193 to 58.4.45.25458.4.45.25562
18558.4.46.0/2658.4.46.1 to 58.4.46.6258.4.46.6362
18658.4.46.64/2658.4.46.65 to 58.4.46.12658.4.46.12762
18758.4.46.128/2658.4.46.129 to 58.4.46.19058.4.46.19162
18858.4.46.192/2658.4.46.193 to 58.4.46.25458.4.46.25562
18958.4.47.0/2658.4.47.1 to 58.4.47.6258.4.47.6362
19058.4.47.64/2658.4.47.65 to 58.4.47.12658.4.47.12762
19158.4.47.128/2658.4.47.129 to 58.4.47.19058.4.47.19162
19258.4.47.192/2658.4.47.193 to 58.4.47.25458.4.47.25562
19358.4.48.0/2658.4.48.1 to 58.4.48.6258.4.48.6362
19458.4.48.64/2658.4.48.65 to 58.4.48.12658.4.48.12762
19558.4.48.128/2658.4.48.129 to 58.4.48.19058.4.48.19162
19658.4.48.192/2658.4.48.193 to 58.4.48.25458.4.48.25562
19758.4.49.0/2658.4.49.1 to 58.4.49.6258.4.49.6362
19858.4.49.64/2658.4.49.65 to 58.4.49.12658.4.49.12762
19958.4.49.128/2658.4.49.129 to 58.4.49.19058.4.49.19162
20058.4.49.192/2658.4.49.193 to 58.4.49.25458.4.49.25562
20158.4.50.0/2658.4.50.1 to 58.4.50.6258.4.50.6362
20258.4.50.64/2658.4.50.65 to 58.4.50.12658.4.50.12762
20358.4.50.128/2658.4.50.129 to 58.4.50.19058.4.50.19162
20458.4.50.192/2658.4.50.193 to 58.4.50.25458.4.50.25562
20558.4.51.0/2658.4.51.1 to 58.4.51.6258.4.51.6362
20658.4.51.64/2658.4.51.65 to 58.4.51.12658.4.51.12762
20758.4.51.128/2658.4.51.129 to 58.4.51.19058.4.51.19162
20858.4.51.192/2658.4.51.193 to 58.4.51.25458.4.51.25562
20958.4.52.0/2658.4.52.1 to 58.4.52.6258.4.52.6362
21058.4.52.64/2658.4.52.65 to 58.4.52.12658.4.52.12762
21158.4.52.128/2658.4.52.129 to 58.4.52.19058.4.52.19162
21258.4.52.192/2658.4.52.193 to 58.4.52.25458.4.52.25562
21358.4.53.0/2658.4.53.1 to 58.4.53.6258.4.53.6362
21458.4.53.64/2658.4.53.65 to 58.4.53.12658.4.53.12762
21558.4.53.128/2658.4.53.129 to 58.4.53.19058.4.53.19162
21658.4.53.192/2658.4.53.193 to 58.4.53.25458.4.53.25562
21758.4.54.0/2658.4.54.1 to 58.4.54.6258.4.54.6362
21858.4.54.64/2658.4.54.65 to 58.4.54.12658.4.54.12762
21958.4.54.128/2658.4.54.129 to 58.4.54.19058.4.54.19162
22058.4.54.192/2658.4.54.193 to 58.4.54.25458.4.54.25562
22158.4.55.0/2658.4.55.1 to 58.4.55.6258.4.55.6362
22258.4.55.64/2658.4.55.65 to 58.4.55.12658.4.55.12762
22358.4.55.128/2658.4.55.129 to 58.4.55.19058.4.55.19162
22458.4.55.192/2658.4.55.193 to 58.4.55.25458.4.55.25562
22558.4.56.0/2658.4.56.1 to 58.4.56.6258.4.56.6362
22658.4.56.64/2658.4.56.65 to 58.4.56.12658.4.56.12762
22758.4.56.128/2658.4.56.129 to 58.4.56.19058.4.56.19162
22858.4.56.192/2658.4.56.193 to 58.4.56.25458.4.56.25562
22958.4.57.0/2658.4.57.1 to 58.4.57.6258.4.57.6362
23058.4.57.64/2658.4.57.65 to 58.4.57.12658.4.57.12762
23158.4.57.128/2658.4.57.129 to 58.4.57.19058.4.57.19162
23258.4.57.192/2658.4.57.193 to 58.4.57.25458.4.57.25562
23358.4.58.0/2658.4.58.1 to 58.4.58.6258.4.58.6362
23458.4.58.64/2658.4.58.65 to 58.4.58.12658.4.58.12762
23558.4.58.128/2658.4.58.129 to 58.4.58.19058.4.58.19162
23658.4.58.192/2658.4.58.193 to 58.4.58.25458.4.58.25562
23758.4.59.0/2658.4.59.1 to 58.4.59.6258.4.59.6362
23858.4.59.64/2658.4.59.65 to 58.4.59.12658.4.59.12762
23958.4.59.128/2658.4.59.129 to 58.4.59.19058.4.59.19162
24058.4.59.192/2658.4.59.193 to 58.4.59.25458.4.59.25562
24158.4.60.0/2658.4.60.1 to 58.4.60.6258.4.60.6362
24258.4.60.64/2658.4.60.65 to 58.4.60.12658.4.60.12762
24358.4.60.128/2658.4.60.129 to 58.4.60.19058.4.60.19162
24458.4.60.192/2658.4.60.193 to 58.4.60.25458.4.60.25562
24558.4.61.0/2658.4.61.1 to 58.4.61.6258.4.61.6362
24658.4.61.64/2658.4.61.65 to 58.4.61.12658.4.61.12762
24758.4.61.128/2658.4.61.129 to 58.4.61.19058.4.61.19162
24858.4.61.192/2658.4.61.193 to 58.4.61.25458.4.61.25562
24958.4.62.0/2658.4.62.1 to 58.4.62.6258.4.62.6362
25058.4.62.64/2658.4.62.65 to 58.4.62.12658.4.62.12762
25158.4.62.128/2658.4.62.129 to 58.4.62.19058.4.62.19162
25258.4.62.192/2658.4.62.193 to 58.4.62.25458.4.62.25562
25358.4.63.0/2658.4.63.1 to 58.4.63.6258.4.63.6362
25458.4.63.64/2658.4.63.65 to 58.4.63.12658.4.63.12762
25558.4.63.128/2658.4.63.129 to 58.4.63.19058.4.63.19162
25658.4.63.192/2658.4.63.193 to 58.4.63.25458.4.63.25562

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.