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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.

Network58.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
58.0.0.0
Broadcast address
58.255.255.255
First usable
58.0.0.1
Last usable
58.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 3A000000 · Integer 973078528 to 989855743
Reverse DNS zone
58.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111010..00000000.00000000.0000000058.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network00111010..00000000.00000000.0000000058.0.0.0
Broadcast00111010..11111111.11111111.1111111158.255.255.255
Split into smaller subnets/18
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

58.0.0.0/8 makes 1,024 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
158.0.0.0/1858.0.0.1 to 58.0.63.25458.0.63.25516,382
258.0.64.0/1858.0.64.1 to 58.0.127.25458.0.127.25516,382
358.0.128.0/1858.0.128.1 to 58.0.191.25458.0.191.25516,382
458.0.192.0/1858.0.192.1 to 58.0.255.25458.0.255.25516,382
558.1.0.0/1858.1.0.1 to 58.1.63.25458.1.63.25516,382
658.1.64.0/1858.1.64.1 to 58.1.127.25458.1.127.25516,382
758.1.128.0/1858.1.128.1 to 58.1.191.25458.1.191.25516,382
858.1.192.0/1858.1.192.1 to 58.1.255.25458.1.255.25516,382
958.2.0.0/1858.2.0.1 to 58.2.63.25458.2.63.25516,382
1058.2.64.0/1858.2.64.1 to 58.2.127.25458.2.127.25516,382
1158.2.128.0/1858.2.128.1 to 58.2.191.25458.2.191.25516,382
1258.2.192.0/1858.2.192.1 to 58.2.255.25458.2.255.25516,382
1358.3.0.0/1858.3.0.1 to 58.3.63.25458.3.63.25516,382
1458.3.64.0/1858.3.64.1 to 58.3.127.25458.3.127.25516,382
1558.3.128.0/1858.3.128.1 to 58.3.191.25458.3.191.25516,382
1658.3.192.0/1858.3.192.1 to 58.3.255.25458.3.255.25516,382
1758.4.0.0/1858.4.0.1 to 58.4.63.25458.4.63.25516,382
1858.4.64.0/1858.4.64.1 to 58.4.127.25458.4.127.25516,382
1958.4.128.0/1858.4.128.1 to 58.4.191.25458.4.191.25516,382
2058.4.192.0/1858.4.192.1 to 58.4.255.25458.4.255.25516,382
2158.5.0.0/1858.5.0.1 to 58.5.63.25458.5.63.25516,382
2258.5.64.0/1858.5.64.1 to 58.5.127.25458.5.127.25516,382
2358.5.128.0/1858.5.128.1 to 58.5.191.25458.5.191.25516,382
2458.5.192.0/1858.5.192.1 to 58.5.255.25458.5.255.25516,382
2558.6.0.0/1858.6.0.1 to 58.6.63.25458.6.63.25516,382
2658.6.64.0/1858.6.64.1 to 58.6.127.25458.6.127.25516,382
2758.6.128.0/1858.6.128.1 to 58.6.191.25458.6.191.25516,382
2858.6.192.0/1858.6.192.1 to 58.6.255.25458.6.255.25516,382
2958.7.0.0/1858.7.0.1 to 58.7.63.25458.7.63.25516,382
3058.7.64.0/1858.7.64.1 to 58.7.127.25458.7.127.25516,382
3158.7.128.0/1858.7.128.1 to 58.7.191.25458.7.191.25516,382
3258.7.192.0/1858.7.192.1 to 58.7.255.25458.7.255.25516,382
3358.8.0.0/1858.8.0.1 to 58.8.63.25458.8.63.25516,382
3458.8.64.0/1858.8.64.1 to 58.8.127.25458.8.127.25516,382
3558.8.128.0/1858.8.128.1 to 58.8.191.25458.8.191.25516,382
3658.8.192.0/1858.8.192.1 to 58.8.255.25458.8.255.25516,382
3758.9.0.0/1858.9.0.1 to 58.9.63.25458.9.63.25516,382
3858.9.64.0/1858.9.64.1 to 58.9.127.25458.9.127.25516,382
3958.9.128.0/1858.9.128.1 to 58.9.191.25458.9.191.25516,382
4058.9.192.0/1858.9.192.1 to 58.9.255.25458.9.255.25516,382
4158.10.0.0/1858.10.0.1 to 58.10.63.25458.10.63.25516,382
4258.10.64.0/1858.10.64.1 to 58.10.127.25458.10.127.25516,382
4358.10.128.0/1858.10.128.1 to 58.10.191.25458.10.191.25516,382
4458.10.192.0/1858.10.192.1 to 58.10.255.25458.10.255.25516,382
4558.11.0.0/1858.11.0.1 to 58.11.63.25458.11.63.25516,382
4658.11.64.0/1858.11.64.1 to 58.11.127.25458.11.127.25516,382
4758.11.128.0/1858.11.128.1 to 58.11.191.25458.11.191.25516,382
4858.11.192.0/1858.11.192.1 to 58.11.255.25458.11.255.25516,382
4958.12.0.0/1858.12.0.1 to 58.12.63.25458.12.63.25516,382
5058.12.64.0/1858.12.64.1 to 58.12.127.25458.12.127.25516,382
5158.12.128.0/1858.12.128.1 to 58.12.191.25458.12.191.25516,382
5258.12.192.0/1858.12.192.1 to 58.12.255.25458.12.255.25516,382
5358.13.0.0/1858.13.0.1 to 58.13.63.25458.13.63.25516,382
5458.13.64.0/1858.13.64.1 to 58.13.127.25458.13.127.25516,382
5558.13.128.0/1858.13.128.1 to 58.13.191.25458.13.191.25516,382
5658.13.192.0/1858.13.192.1 to 58.13.255.25458.13.255.25516,382
5758.14.0.0/1858.14.0.1 to 58.14.63.25458.14.63.25516,382
5858.14.64.0/1858.14.64.1 to 58.14.127.25458.14.127.25516,382
5958.14.128.0/1858.14.128.1 to 58.14.191.25458.14.191.25516,382
6058.14.192.0/1858.14.192.1 to 58.14.255.25458.14.255.25516,382
6158.15.0.0/1858.15.0.1 to 58.15.63.25458.15.63.25516,382
6258.15.64.0/1858.15.64.1 to 58.15.127.25458.15.127.25516,382
6358.15.128.0/1858.15.128.1 to 58.15.191.25458.15.191.25516,382
6458.15.192.0/1858.15.192.1 to 58.15.255.25458.15.255.25516,382
6558.16.0.0/1858.16.0.1 to 58.16.63.25458.16.63.25516,382
6658.16.64.0/1858.16.64.1 to 58.16.127.25458.16.127.25516,382
6758.16.128.0/1858.16.128.1 to 58.16.191.25458.16.191.25516,382
6858.16.192.0/1858.16.192.1 to 58.16.255.25458.16.255.25516,382
6958.17.0.0/1858.17.0.1 to 58.17.63.25458.17.63.25516,382
7058.17.64.0/1858.17.64.1 to 58.17.127.25458.17.127.25516,382
7158.17.128.0/1858.17.128.1 to 58.17.191.25458.17.191.25516,382
7258.17.192.0/1858.17.192.1 to 58.17.255.25458.17.255.25516,382
7358.18.0.0/1858.18.0.1 to 58.18.63.25458.18.63.25516,382
7458.18.64.0/1858.18.64.1 to 58.18.127.25458.18.127.25516,382
7558.18.128.0/1858.18.128.1 to 58.18.191.25458.18.191.25516,382
7658.18.192.0/1858.18.192.1 to 58.18.255.25458.18.255.25516,382
7758.19.0.0/1858.19.0.1 to 58.19.63.25458.19.63.25516,382
7858.19.64.0/1858.19.64.1 to 58.19.127.25458.19.127.25516,382
7958.19.128.0/1858.19.128.1 to 58.19.191.25458.19.191.25516,382
8058.19.192.0/1858.19.192.1 to 58.19.255.25458.19.255.25516,382
8158.20.0.0/1858.20.0.1 to 58.20.63.25458.20.63.25516,382
8258.20.64.0/1858.20.64.1 to 58.20.127.25458.20.127.25516,382
8358.20.128.0/1858.20.128.1 to 58.20.191.25458.20.191.25516,382
8458.20.192.0/1858.20.192.1 to 58.20.255.25458.20.255.25516,382
8558.21.0.0/1858.21.0.1 to 58.21.63.25458.21.63.25516,382
8658.21.64.0/1858.21.64.1 to 58.21.127.25458.21.127.25516,382
8758.21.128.0/1858.21.128.1 to 58.21.191.25458.21.191.25516,382
8858.21.192.0/1858.21.192.1 to 58.21.255.25458.21.255.25516,382
8958.22.0.0/1858.22.0.1 to 58.22.63.25458.22.63.25516,382
9058.22.64.0/1858.22.64.1 to 58.22.127.25458.22.127.25516,382
9158.22.128.0/1858.22.128.1 to 58.22.191.25458.22.191.25516,382
9258.22.192.0/1858.22.192.1 to 58.22.255.25458.22.255.25516,382
9358.23.0.0/1858.23.0.1 to 58.23.63.25458.23.63.25516,382
9458.23.64.0/1858.23.64.1 to 58.23.127.25458.23.127.25516,382
9558.23.128.0/1858.23.128.1 to 58.23.191.25458.23.191.25516,382
9658.23.192.0/1858.23.192.1 to 58.23.255.25458.23.255.25516,382
9758.24.0.0/1858.24.0.1 to 58.24.63.25458.24.63.25516,382
9858.24.64.0/1858.24.64.1 to 58.24.127.25458.24.127.25516,382
9958.24.128.0/1858.24.128.1 to 58.24.191.25458.24.191.25516,382
10058.24.192.0/1858.24.192.1 to 58.24.255.25458.24.255.25516,382
10158.25.0.0/1858.25.0.1 to 58.25.63.25458.25.63.25516,382
10258.25.64.0/1858.25.64.1 to 58.25.127.25458.25.127.25516,382
10358.25.128.0/1858.25.128.1 to 58.25.191.25458.25.191.25516,382
10458.25.192.0/1858.25.192.1 to 58.25.255.25458.25.255.25516,382
10558.26.0.0/1858.26.0.1 to 58.26.63.25458.26.63.25516,382
10658.26.64.0/1858.26.64.1 to 58.26.127.25458.26.127.25516,382
10758.26.128.0/1858.26.128.1 to 58.26.191.25458.26.191.25516,382
10858.26.192.0/1858.26.192.1 to 58.26.255.25458.26.255.25516,382
10958.27.0.0/1858.27.0.1 to 58.27.63.25458.27.63.25516,382
11058.27.64.0/1858.27.64.1 to 58.27.127.25458.27.127.25516,382
11158.27.128.0/1858.27.128.1 to 58.27.191.25458.27.191.25516,382
11258.27.192.0/1858.27.192.1 to 58.27.255.25458.27.255.25516,382
11358.28.0.0/1858.28.0.1 to 58.28.63.25458.28.63.25516,382
11458.28.64.0/1858.28.64.1 to 58.28.127.25458.28.127.25516,382
11558.28.128.0/1858.28.128.1 to 58.28.191.25458.28.191.25516,382
11658.28.192.0/1858.28.192.1 to 58.28.255.25458.28.255.25516,382
11758.29.0.0/1858.29.0.1 to 58.29.63.25458.29.63.25516,382
11858.29.64.0/1858.29.64.1 to 58.29.127.25458.29.127.25516,382
11958.29.128.0/1858.29.128.1 to 58.29.191.25458.29.191.25516,382
12058.29.192.0/1858.29.192.1 to 58.29.255.25458.29.255.25516,382
12158.30.0.0/1858.30.0.1 to 58.30.63.25458.30.63.25516,382
12258.30.64.0/1858.30.64.1 to 58.30.127.25458.30.127.25516,382
12358.30.128.0/1858.30.128.1 to 58.30.191.25458.30.191.25516,382
12458.30.192.0/1858.30.192.1 to 58.30.255.25458.30.255.25516,382
12558.31.0.0/1858.31.0.1 to 58.31.63.25458.31.63.25516,382
12658.31.64.0/1858.31.64.1 to 58.31.127.25458.31.127.25516,382
12758.31.128.0/1858.31.128.1 to 58.31.191.25458.31.191.25516,382
12858.31.192.0/1858.31.192.1 to 58.31.255.25458.31.255.25516,382
12958.32.0.0/1858.32.0.1 to 58.32.63.25458.32.63.25516,382
13058.32.64.0/1858.32.64.1 to 58.32.127.25458.32.127.25516,382
13158.32.128.0/1858.32.128.1 to 58.32.191.25458.32.191.25516,382
13258.32.192.0/1858.32.192.1 to 58.32.255.25458.32.255.25516,382
13358.33.0.0/1858.33.0.1 to 58.33.63.25458.33.63.25516,382
13458.33.64.0/1858.33.64.1 to 58.33.127.25458.33.127.25516,382
13558.33.128.0/1858.33.128.1 to 58.33.191.25458.33.191.25516,382
13658.33.192.0/1858.33.192.1 to 58.33.255.25458.33.255.25516,382
13758.34.0.0/1858.34.0.1 to 58.34.63.25458.34.63.25516,382
13858.34.64.0/1858.34.64.1 to 58.34.127.25458.34.127.25516,382
13958.34.128.0/1858.34.128.1 to 58.34.191.25458.34.191.25516,382
14058.34.192.0/1858.34.192.1 to 58.34.255.25458.34.255.25516,382
14158.35.0.0/1858.35.0.1 to 58.35.63.25458.35.63.25516,382
14258.35.64.0/1858.35.64.1 to 58.35.127.25458.35.127.25516,382
14358.35.128.0/1858.35.128.1 to 58.35.191.25458.35.191.25516,382
14458.35.192.0/1858.35.192.1 to 58.35.255.25458.35.255.25516,382
14558.36.0.0/1858.36.0.1 to 58.36.63.25458.36.63.25516,382
14658.36.64.0/1858.36.64.1 to 58.36.127.25458.36.127.25516,382
14758.36.128.0/1858.36.128.1 to 58.36.191.25458.36.191.25516,382
14858.36.192.0/1858.36.192.1 to 58.36.255.25458.36.255.25516,382
14958.37.0.0/1858.37.0.1 to 58.37.63.25458.37.63.25516,382
15058.37.64.0/1858.37.64.1 to 58.37.127.25458.37.127.25516,382
15158.37.128.0/1858.37.128.1 to 58.37.191.25458.37.191.25516,382
15258.37.192.0/1858.37.192.1 to 58.37.255.25458.37.255.25516,382
15358.38.0.0/1858.38.0.1 to 58.38.63.25458.38.63.25516,382
15458.38.64.0/1858.38.64.1 to 58.38.127.25458.38.127.25516,382
15558.38.128.0/1858.38.128.1 to 58.38.191.25458.38.191.25516,382
15658.38.192.0/1858.38.192.1 to 58.38.255.25458.38.255.25516,382
15758.39.0.0/1858.39.0.1 to 58.39.63.25458.39.63.25516,382
15858.39.64.0/1858.39.64.1 to 58.39.127.25458.39.127.25516,382
15958.39.128.0/1858.39.128.1 to 58.39.191.25458.39.191.25516,382
16058.39.192.0/1858.39.192.1 to 58.39.255.25458.39.255.25516,382
16158.40.0.0/1858.40.0.1 to 58.40.63.25458.40.63.25516,382
16258.40.64.0/1858.40.64.1 to 58.40.127.25458.40.127.25516,382
16358.40.128.0/1858.40.128.1 to 58.40.191.25458.40.191.25516,382
16458.40.192.0/1858.40.192.1 to 58.40.255.25458.40.255.25516,382
16558.41.0.0/1858.41.0.1 to 58.41.63.25458.41.63.25516,382
16658.41.64.0/1858.41.64.1 to 58.41.127.25458.41.127.25516,382
16758.41.128.0/1858.41.128.1 to 58.41.191.25458.41.191.25516,382
16858.41.192.0/1858.41.192.1 to 58.41.255.25458.41.255.25516,382
16958.42.0.0/1858.42.0.1 to 58.42.63.25458.42.63.25516,382
17058.42.64.0/1858.42.64.1 to 58.42.127.25458.42.127.25516,382
17158.42.128.0/1858.42.128.1 to 58.42.191.25458.42.191.25516,382
17258.42.192.0/1858.42.192.1 to 58.42.255.25458.42.255.25516,382
17358.43.0.0/1858.43.0.1 to 58.43.63.25458.43.63.25516,382
17458.43.64.0/1858.43.64.1 to 58.43.127.25458.43.127.25516,382
17558.43.128.0/1858.43.128.1 to 58.43.191.25458.43.191.25516,382
17658.43.192.0/1858.43.192.1 to 58.43.255.25458.43.255.25516,382
17758.44.0.0/1858.44.0.1 to 58.44.63.25458.44.63.25516,382
17858.44.64.0/1858.44.64.1 to 58.44.127.25458.44.127.25516,382
17958.44.128.0/1858.44.128.1 to 58.44.191.25458.44.191.25516,382
18058.44.192.0/1858.44.192.1 to 58.44.255.25458.44.255.25516,382
18158.45.0.0/1858.45.0.1 to 58.45.63.25458.45.63.25516,382
18258.45.64.0/1858.45.64.1 to 58.45.127.25458.45.127.25516,382
18358.45.128.0/1858.45.128.1 to 58.45.191.25458.45.191.25516,382
18458.45.192.0/1858.45.192.1 to 58.45.255.25458.45.255.25516,382
18558.46.0.0/1858.46.0.1 to 58.46.63.25458.46.63.25516,382
18658.46.64.0/1858.46.64.1 to 58.46.127.25458.46.127.25516,382
18758.46.128.0/1858.46.128.1 to 58.46.191.25458.46.191.25516,382
18858.46.192.0/1858.46.192.1 to 58.46.255.25458.46.255.25516,382
18958.47.0.0/1858.47.0.1 to 58.47.63.25458.47.63.25516,382
19058.47.64.0/1858.47.64.1 to 58.47.127.25458.47.127.25516,382
19158.47.128.0/1858.47.128.1 to 58.47.191.25458.47.191.25516,382
19258.47.192.0/1858.47.192.1 to 58.47.255.25458.47.255.25516,382
19358.48.0.0/1858.48.0.1 to 58.48.63.25458.48.63.25516,382
19458.48.64.0/1858.48.64.1 to 58.48.127.25458.48.127.25516,382
19558.48.128.0/1858.48.128.1 to 58.48.191.25458.48.191.25516,382
19658.48.192.0/1858.48.192.1 to 58.48.255.25458.48.255.25516,382
19758.49.0.0/1858.49.0.1 to 58.49.63.25458.49.63.25516,382
19858.49.64.0/1858.49.64.1 to 58.49.127.25458.49.127.25516,382
19958.49.128.0/1858.49.128.1 to 58.49.191.25458.49.191.25516,382
20058.49.192.0/1858.49.192.1 to 58.49.255.25458.49.255.25516,382
20158.50.0.0/1858.50.0.1 to 58.50.63.25458.50.63.25516,382
20258.50.64.0/1858.50.64.1 to 58.50.127.25458.50.127.25516,382
20358.50.128.0/1858.50.128.1 to 58.50.191.25458.50.191.25516,382
20458.50.192.0/1858.50.192.1 to 58.50.255.25458.50.255.25516,382
20558.51.0.0/1858.51.0.1 to 58.51.63.25458.51.63.25516,382
20658.51.64.0/1858.51.64.1 to 58.51.127.25458.51.127.25516,382
20758.51.128.0/1858.51.128.1 to 58.51.191.25458.51.191.25516,382
20858.51.192.0/1858.51.192.1 to 58.51.255.25458.51.255.25516,382
20958.52.0.0/1858.52.0.1 to 58.52.63.25458.52.63.25516,382
21058.52.64.0/1858.52.64.1 to 58.52.127.25458.52.127.25516,382
21158.52.128.0/1858.52.128.1 to 58.52.191.25458.52.191.25516,382
21258.52.192.0/1858.52.192.1 to 58.52.255.25458.52.255.25516,382
21358.53.0.0/1858.53.0.1 to 58.53.63.25458.53.63.25516,382
21458.53.64.0/1858.53.64.1 to 58.53.127.25458.53.127.25516,382
21558.53.128.0/1858.53.128.1 to 58.53.191.25458.53.191.25516,382
21658.53.192.0/1858.53.192.1 to 58.53.255.25458.53.255.25516,382
21758.54.0.0/1858.54.0.1 to 58.54.63.25458.54.63.25516,382
21858.54.64.0/1858.54.64.1 to 58.54.127.25458.54.127.25516,382
21958.54.128.0/1858.54.128.1 to 58.54.191.25458.54.191.25516,382
22058.54.192.0/1858.54.192.1 to 58.54.255.25458.54.255.25516,382
22158.55.0.0/1858.55.0.1 to 58.55.63.25458.55.63.25516,382
22258.55.64.0/1858.55.64.1 to 58.55.127.25458.55.127.25516,382
22358.55.128.0/1858.55.128.1 to 58.55.191.25458.55.191.25516,382
22458.55.192.0/1858.55.192.1 to 58.55.255.25458.55.255.25516,382
22558.56.0.0/1858.56.0.1 to 58.56.63.25458.56.63.25516,382
22658.56.64.0/1858.56.64.1 to 58.56.127.25458.56.127.25516,382
22758.56.128.0/1858.56.128.1 to 58.56.191.25458.56.191.25516,382
22858.56.192.0/1858.56.192.1 to 58.56.255.25458.56.255.25516,382
22958.57.0.0/1858.57.0.1 to 58.57.63.25458.57.63.25516,382
23058.57.64.0/1858.57.64.1 to 58.57.127.25458.57.127.25516,382
23158.57.128.0/1858.57.128.1 to 58.57.191.25458.57.191.25516,382
23258.57.192.0/1858.57.192.1 to 58.57.255.25458.57.255.25516,382
23358.58.0.0/1858.58.0.1 to 58.58.63.25458.58.63.25516,382
23458.58.64.0/1858.58.64.1 to 58.58.127.25458.58.127.25516,382
23558.58.128.0/1858.58.128.1 to 58.58.191.25458.58.191.25516,382
23658.58.192.0/1858.58.192.1 to 58.58.255.25458.58.255.25516,382
23758.59.0.0/1858.59.0.1 to 58.59.63.25458.59.63.25516,382
23858.59.64.0/1858.59.64.1 to 58.59.127.25458.59.127.25516,382
23958.59.128.0/1858.59.128.1 to 58.59.191.25458.59.191.25516,382
24058.59.192.0/1858.59.192.1 to 58.59.255.25458.59.255.25516,382
24158.60.0.0/1858.60.0.1 to 58.60.63.25458.60.63.25516,382
24258.60.64.0/1858.60.64.1 to 58.60.127.25458.60.127.25516,382
24358.60.128.0/1858.60.128.1 to 58.60.191.25458.60.191.25516,382
24458.60.192.0/1858.60.192.1 to 58.60.255.25458.60.255.25516,382
24558.61.0.0/1858.61.0.1 to 58.61.63.25458.61.63.25516,382
24658.61.64.0/1858.61.64.1 to 58.61.127.25458.61.127.25516,382
24758.61.128.0/1858.61.128.1 to 58.61.191.25458.61.191.25516,382
24858.61.192.0/1858.61.192.1 to 58.61.255.25458.61.255.25516,382
24958.62.0.0/1858.62.0.1 to 58.62.63.25458.62.63.25516,382
25058.62.64.0/1858.62.64.1 to 58.62.127.25458.62.127.25516,382
25158.62.128.0/1858.62.128.1 to 58.62.191.25458.62.191.25516,382
25258.62.192.0/1858.62.192.1 to 58.62.255.25458.62.255.25516,382
25358.63.0.0/1858.63.0.1 to 58.63.63.25458.63.63.25516,382
25458.63.64.0/1858.63.64.1 to 58.63.127.25458.63.127.25516,382
25558.63.128.0/1858.63.128.1 to 58.63.191.25458.63.191.25516,382
25658.63.192.0/1858.63.192.1 to 58.63.255.25458.63.255.25516,382

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.