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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.

Network58.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
58.0.0.0
Broadcast address
58.63.255.255
First usable
58.0.0.1
Last usable
58.63.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 3A000000 · Integer 973078528 to 977272831
Reverse DNS zones
0.58.in-addr.arpa
1.58.in-addr.arpa
2.58.in-addr.arpa
3.58.in-addr.arpa
4.58.in-addr.arpa
5.58.in-addr.arpa
6.58.in-addr.arpa
7.58.in-addr.arpa
8.58.in-addr.arpa
9.58.in-addr.arpa
10.58.in-addr.arpa
11.58.in-addr.arpa
12.58.in-addr.arpa
13.58.in-addr.arpa
14.58.in-addr.arpa
15.58.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111010.00000000.00000000.0000000058.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00111010.00000000.00000000.0000000058.0.0.0
Broadcast00111010.00111111.11111111.1111111158.63.255.255
Split into smaller subnets/19
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

58.0.0.0/10 makes 512 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
158.0.0.0/1958.0.0.1 to 58.0.31.25458.0.31.2558,190
258.0.32.0/1958.0.32.1 to 58.0.63.25458.0.63.2558,190
358.0.64.0/1958.0.64.1 to 58.0.95.25458.0.95.2558,190
458.0.96.0/1958.0.96.1 to 58.0.127.25458.0.127.2558,190
558.0.128.0/1958.0.128.1 to 58.0.159.25458.0.159.2558,190
658.0.160.0/1958.0.160.1 to 58.0.191.25458.0.191.2558,190
758.0.192.0/1958.0.192.1 to 58.0.223.25458.0.223.2558,190
858.0.224.0/1958.0.224.1 to 58.0.255.25458.0.255.2558,190
958.1.0.0/1958.1.0.1 to 58.1.31.25458.1.31.2558,190
1058.1.32.0/1958.1.32.1 to 58.1.63.25458.1.63.2558,190
1158.1.64.0/1958.1.64.1 to 58.1.95.25458.1.95.2558,190
1258.1.96.0/1958.1.96.1 to 58.1.127.25458.1.127.2558,190
1358.1.128.0/1958.1.128.1 to 58.1.159.25458.1.159.2558,190
1458.1.160.0/1958.1.160.1 to 58.1.191.25458.1.191.2558,190
1558.1.192.0/1958.1.192.1 to 58.1.223.25458.1.223.2558,190
1658.1.224.0/1958.1.224.1 to 58.1.255.25458.1.255.2558,190
1758.2.0.0/1958.2.0.1 to 58.2.31.25458.2.31.2558,190
1858.2.32.0/1958.2.32.1 to 58.2.63.25458.2.63.2558,190
1958.2.64.0/1958.2.64.1 to 58.2.95.25458.2.95.2558,190
2058.2.96.0/1958.2.96.1 to 58.2.127.25458.2.127.2558,190
2158.2.128.0/1958.2.128.1 to 58.2.159.25458.2.159.2558,190
2258.2.160.0/1958.2.160.1 to 58.2.191.25458.2.191.2558,190
2358.2.192.0/1958.2.192.1 to 58.2.223.25458.2.223.2558,190
2458.2.224.0/1958.2.224.1 to 58.2.255.25458.2.255.2558,190
2558.3.0.0/1958.3.0.1 to 58.3.31.25458.3.31.2558,190
2658.3.32.0/1958.3.32.1 to 58.3.63.25458.3.63.2558,190
2758.3.64.0/1958.3.64.1 to 58.3.95.25458.3.95.2558,190
2858.3.96.0/1958.3.96.1 to 58.3.127.25458.3.127.2558,190
2958.3.128.0/1958.3.128.1 to 58.3.159.25458.3.159.2558,190
3058.3.160.0/1958.3.160.1 to 58.3.191.25458.3.191.2558,190
3158.3.192.0/1958.3.192.1 to 58.3.223.25458.3.223.2558,190
3258.3.224.0/1958.3.224.1 to 58.3.255.25458.3.255.2558,190
3358.4.0.0/1958.4.0.1 to 58.4.31.25458.4.31.2558,190
3458.4.32.0/1958.4.32.1 to 58.4.63.25458.4.63.2558,190
3558.4.64.0/1958.4.64.1 to 58.4.95.25458.4.95.2558,190
3658.4.96.0/1958.4.96.1 to 58.4.127.25458.4.127.2558,190
3758.4.128.0/1958.4.128.1 to 58.4.159.25458.4.159.2558,190
3858.4.160.0/1958.4.160.1 to 58.4.191.25458.4.191.2558,190
3958.4.192.0/1958.4.192.1 to 58.4.223.25458.4.223.2558,190
4058.4.224.0/1958.4.224.1 to 58.4.255.25458.4.255.2558,190
4158.5.0.0/1958.5.0.1 to 58.5.31.25458.5.31.2558,190
4258.5.32.0/1958.5.32.1 to 58.5.63.25458.5.63.2558,190
4358.5.64.0/1958.5.64.1 to 58.5.95.25458.5.95.2558,190
4458.5.96.0/1958.5.96.1 to 58.5.127.25458.5.127.2558,190
4558.5.128.0/1958.5.128.1 to 58.5.159.25458.5.159.2558,190
4658.5.160.0/1958.5.160.1 to 58.5.191.25458.5.191.2558,190
4758.5.192.0/1958.5.192.1 to 58.5.223.25458.5.223.2558,190
4858.5.224.0/1958.5.224.1 to 58.5.255.25458.5.255.2558,190
4958.6.0.0/1958.6.0.1 to 58.6.31.25458.6.31.2558,190
5058.6.32.0/1958.6.32.1 to 58.6.63.25458.6.63.2558,190
5158.6.64.0/1958.6.64.1 to 58.6.95.25458.6.95.2558,190
5258.6.96.0/1958.6.96.1 to 58.6.127.25458.6.127.2558,190
5358.6.128.0/1958.6.128.1 to 58.6.159.25458.6.159.2558,190
5458.6.160.0/1958.6.160.1 to 58.6.191.25458.6.191.2558,190
5558.6.192.0/1958.6.192.1 to 58.6.223.25458.6.223.2558,190
5658.6.224.0/1958.6.224.1 to 58.6.255.25458.6.255.2558,190
5758.7.0.0/1958.7.0.1 to 58.7.31.25458.7.31.2558,190
5858.7.32.0/1958.7.32.1 to 58.7.63.25458.7.63.2558,190
5958.7.64.0/1958.7.64.1 to 58.7.95.25458.7.95.2558,190
6058.7.96.0/1958.7.96.1 to 58.7.127.25458.7.127.2558,190
6158.7.128.0/1958.7.128.1 to 58.7.159.25458.7.159.2558,190
6258.7.160.0/1958.7.160.1 to 58.7.191.25458.7.191.2558,190
6358.7.192.0/1958.7.192.1 to 58.7.223.25458.7.223.2558,190
6458.7.224.0/1958.7.224.1 to 58.7.255.25458.7.255.2558,190
6558.8.0.0/1958.8.0.1 to 58.8.31.25458.8.31.2558,190
6658.8.32.0/1958.8.32.1 to 58.8.63.25458.8.63.2558,190
6758.8.64.0/1958.8.64.1 to 58.8.95.25458.8.95.2558,190
6858.8.96.0/1958.8.96.1 to 58.8.127.25458.8.127.2558,190
6958.8.128.0/1958.8.128.1 to 58.8.159.25458.8.159.2558,190
7058.8.160.0/1958.8.160.1 to 58.8.191.25458.8.191.2558,190
7158.8.192.0/1958.8.192.1 to 58.8.223.25458.8.223.2558,190
7258.8.224.0/1958.8.224.1 to 58.8.255.25458.8.255.2558,190
7358.9.0.0/1958.9.0.1 to 58.9.31.25458.9.31.2558,190
7458.9.32.0/1958.9.32.1 to 58.9.63.25458.9.63.2558,190
7558.9.64.0/1958.9.64.1 to 58.9.95.25458.9.95.2558,190
7658.9.96.0/1958.9.96.1 to 58.9.127.25458.9.127.2558,190
7758.9.128.0/1958.9.128.1 to 58.9.159.25458.9.159.2558,190
7858.9.160.0/1958.9.160.1 to 58.9.191.25458.9.191.2558,190
7958.9.192.0/1958.9.192.1 to 58.9.223.25458.9.223.2558,190
8058.9.224.0/1958.9.224.1 to 58.9.255.25458.9.255.2558,190
8158.10.0.0/1958.10.0.1 to 58.10.31.25458.10.31.2558,190
8258.10.32.0/1958.10.32.1 to 58.10.63.25458.10.63.2558,190
8358.10.64.0/1958.10.64.1 to 58.10.95.25458.10.95.2558,190
8458.10.96.0/1958.10.96.1 to 58.10.127.25458.10.127.2558,190
8558.10.128.0/1958.10.128.1 to 58.10.159.25458.10.159.2558,190
8658.10.160.0/1958.10.160.1 to 58.10.191.25458.10.191.2558,190
8758.10.192.0/1958.10.192.1 to 58.10.223.25458.10.223.2558,190
8858.10.224.0/1958.10.224.1 to 58.10.255.25458.10.255.2558,190
8958.11.0.0/1958.11.0.1 to 58.11.31.25458.11.31.2558,190
9058.11.32.0/1958.11.32.1 to 58.11.63.25458.11.63.2558,190
9158.11.64.0/1958.11.64.1 to 58.11.95.25458.11.95.2558,190
9258.11.96.0/1958.11.96.1 to 58.11.127.25458.11.127.2558,190
9358.11.128.0/1958.11.128.1 to 58.11.159.25458.11.159.2558,190
9458.11.160.0/1958.11.160.1 to 58.11.191.25458.11.191.2558,190
9558.11.192.0/1958.11.192.1 to 58.11.223.25458.11.223.2558,190
9658.11.224.0/1958.11.224.1 to 58.11.255.25458.11.255.2558,190
9758.12.0.0/1958.12.0.1 to 58.12.31.25458.12.31.2558,190
9858.12.32.0/1958.12.32.1 to 58.12.63.25458.12.63.2558,190
9958.12.64.0/1958.12.64.1 to 58.12.95.25458.12.95.2558,190
10058.12.96.0/1958.12.96.1 to 58.12.127.25458.12.127.2558,190
10158.12.128.0/1958.12.128.1 to 58.12.159.25458.12.159.2558,190
10258.12.160.0/1958.12.160.1 to 58.12.191.25458.12.191.2558,190
10358.12.192.0/1958.12.192.1 to 58.12.223.25458.12.223.2558,190
10458.12.224.0/1958.12.224.1 to 58.12.255.25458.12.255.2558,190
10558.13.0.0/1958.13.0.1 to 58.13.31.25458.13.31.2558,190
10658.13.32.0/1958.13.32.1 to 58.13.63.25458.13.63.2558,190
10758.13.64.0/1958.13.64.1 to 58.13.95.25458.13.95.2558,190
10858.13.96.0/1958.13.96.1 to 58.13.127.25458.13.127.2558,190
10958.13.128.0/1958.13.128.1 to 58.13.159.25458.13.159.2558,190
11058.13.160.0/1958.13.160.1 to 58.13.191.25458.13.191.2558,190
11158.13.192.0/1958.13.192.1 to 58.13.223.25458.13.223.2558,190
11258.13.224.0/1958.13.224.1 to 58.13.255.25458.13.255.2558,190
11358.14.0.0/1958.14.0.1 to 58.14.31.25458.14.31.2558,190
11458.14.32.0/1958.14.32.1 to 58.14.63.25458.14.63.2558,190
11558.14.64.0/1958.14.64.1 to 58.14.95.25458.14.95.2558,190
11658.14.96.0/1958.14.96.1 to 58.14.127.25458.14.127.2558,190
11758.14.128.0/1958.14.128.1 to 58.14.159.25458.14.159.2558,190
11858.14.160.0/1958.14.160.1 to 58.14.191.25458.14.191.2558,190
11958.14.192.0/1958.14.192.1 to 58.14.223.25458.14.223.2558,190
12058.14.224.0/1958.14.224.1 to 58.14.255.25458.14.255.2558,190
12158.15.0.0/1958.15.0.1 to 58.15.31.25458.15.31.2558,190
12258.15.32.0/1958.15.32.1 to 58.15.63.25458.15.63.2558,190
12358.15.64.0/1958.15.64.1 to 58.15.95.25458.15.95.2558,190
12458.15.96.0/1958.15.96.1 to 58.15.127.25458.15.127.2558,190
12558.15.128.0/1958.15.128.1 to 58.15.159.25458.15.159.2558,190
12658.15.160.0/1958.15.160.1 to 58.15.191.25458.15.191.2558,190
12758.15.192.0/1958.15.192.1 to 58.15.223.25458.15.223.2558,190
12858.15.224.0/1958.15.224.1 to 58.15.255.25458.15.255.2558,190
12958.16.0.0/1958.16.0.1 to 58.16.31.25458.16.31.2558,190
13058.16.32.0/1958.16.32.1 to 58.16.63.25458.16.63.2558,190
13158.16.64.0/1958.16.64.1 to 58.16.95.25458.16.95.2558,190
13258.16.96.0/1958.16.96.1 to 58.16.127.25458.16.127.2558,190
13358.16.128.0/1958.16.128.1 to 58.16.159.25458.16.159.2558,190
13458.16.160.0/1958.16.160.1 to 58.16.191.25458.16.191.2558,190
13558.16.192.0/1958.16.192.1 to 58.16.223.25458.16.223.2558,190
13658.16.224.0/1958.16.224.1 to 58.16.255.25458.16.255.2558,190
13758.17.0.0/1958.17.0.1 to 58.17.31.25458.17.31.2558,190
13858.17.32.0/1958.17.32.1 to 58.17.63.25458.17.63.2558,190
13958.17.64.0/1958.17.64.1 to 58.17.95.25458.17.95.2558,190
14058.17.96.0/1958.17.96.1 to 58.17.127.25458.17.127.2558,190
14158.17.128.0/1958.17.128.1 to 58.17.159.25458.17.159.2558,190
14258.17.160.0/1958.17.160.1 to 58.17.191.25458.17.191.2558,190
14358.17.192.0/1958.17.192.1 to 58.17.223.25458.17.223.2558,190
14458.17.224.0/1958.17.224.1 to 58.17.255.25458.17.255.2558,190
14558.18.0.0/1958.18.0.1 to 58.18.31.25458.18.31.2558,190
14658.18.32.0/1958.18.32.1 to 58.18.63.25458.18.63.2558,190
14758.18.64.0/1958.18.64.1 to 58.18.95.25458.18.95.2558,190
14858.18.96.0/1958.18.96.1 to 58.18.127.25458.18.127.2558,190
14958.18.128.0/1958.18.128.1 to 58.18.159.25458.18.159.2558,190
15058.18.160.0/1958.18.160.1 to 58.18.191.25458.18.191.2558,190
15158.18.192.0/1958.18.192.1 to 58.18.223.25458.18.223.2558,190
15258.18.224.0/1958.18.224.1 to 58.18.255.25458.18.255.2558,190
15358.19.0.0/1958.19.0.1 to 58.19.31.25458.19.31.2558,190
15458.19.32.0/1958.19.32.1 to 58.19.63.25458.19.63.2558,190
15558.19.64.0/1958.19.64.1 to 58.19.95.25458.19.95.2558,190
15658.19.96.0/1958.19.96.1 to 58.19.127.25458.19.127.2558,190
15758.19.128.0/1958.19.128.1 to 58.19.159.25458.19.159.2558,190
15858.19.160.0/1958.19.160.1 to 58.19.191.25458.19.191.2558,190
15958.19.192.0/1958.19.192.1 to 58.19.223.25458.19.223.2558,190
16058.19.224.0/1958.19.224.1 to 58.19.255.25458.19.255.2558,190
16158.20.0.0/1958.20.0.1 to 58.20.31.25458.20.31.2558,190
16258.20.32.0/1958.20.32.1 to 58.20.63.25458.20.63.2558,190
16358.20.64.0/1958.20.64.1 to 58.20.95.25458.20.95.2558,190
16458.20.96.0/1958.20.96.1 to 58.20.127.25458.20.127.2558,190
16558.20.128.0/1958.20.128.1 to 58.20.159.25458.20.159.2558,190
16658.20.160.0/1958.20.160.1 to 58.20.191.25458.20.191.2558,190
16758.20.192.0/1958.20.192.1 to 58.20.223.25458.20.223.2558,190
16858.20.224.0/1958.20.224.1 to 58.20.255.25458.20.255.2558,190
16958.21.0.0/1958.21.0.1 to 58.21.31.25458.21.31.2558,190
17058.21.32.0/1958.21.32.1 to 58.21.63.25458.21.63.2558,190
17158.21.64.0/1958.21.64.1 to 58.21.95.25458.21.95.2558,190
17258.21.96.0/1958.21.96.1 to 58.21.127.25458.21.127.2558,190
17358.21.128.0/1958.21.128.1 to 58.21.159.25458.21.159.2558,190
17458.21.160.0/1958.21.160.1 to 58.21.191.25458.21.191.2558,190
17558.21.192.0/1958.21.192.1 to 58.21.223.25458.21.223.2558,190
17658.21.224.0/1958.21.224.1 to 58.21.255.25458.21.255.2558,190
17758.22.0.0/1958.22.0.1 to 58.22.31.25458.22.31.2558,190
17858.22.32.0/1958.22.32.1 to 58.22.63.25458.22.63.2558,190
17958.22.64.0/1958.22.64.1 to 58.22.95.25458.22.95.2558,190
18058.22.96.0/1958.22.96.1 to 58.22.127.25458.22.127.2558,190
18158.22.128.0/1958.22.128.1 to 58.22.159.25458.22.159.2558,190
18258.22.160.0/1958.22.160.1 to 58.22.191.25458.22.191.2558,190
18358.22.192.0/1958.22.192.1 to 58.22.223.25458.22.223.2558,190
18458.22.224.0/1958.22.224.1 to 58.22.255.25458.22.255.2558,190
18558.23.0.0/1958.23.0.1 to 58.23.31.25458.23.31.2558,190
18658.23.32.0/1958.23.32.1 to 58.23.63.25458.23.63.2558,190
18758.23.64.0/1958.23.64.1 to 58.23.95.25458.23.95.2558,190
18858.23.96.0/1958.23.96.1 to 58.23.127.25458.23.127.2558,190
18958.23.128.0/1958.23.128.1 to 58.23.159.25458.23.159.2558,190
19058.23.160.0/1958.23.160.1 to 58.23.191.25458.23.191.2558,190
19158.23.192.0/1958.23.192.1 to 58.23.223.25458.23.223.2558,190
19258.23.224.0/1958.23.224.1 to 58.23.255.25458.23.255.2558,190
19358.24.0.0/1958.24.0.1 to 58.24.31.25458.24.31.2558,190
19458.24.32.0/1958.24.32.1 to 58.24.63.25458.24.63.2558,190
19558.24.64.0/1958.24.64.1 to 58.24.95.25458.24.95.2558,190
19658.24.96.0/1958.24.96.1 to 58.24.127.25458.24.127.2558,190
19758.24.128.0/1958.24.128.1 to 58.24.159.25458.24.159.2558,190
19858.24.160.0/1958.24.160.1 to 58.24.191.25458.24.191.2558,190
19958.24.192.0/1958.24.192.1 to 58.24.223.25458.24.223.2558,190
20058.24.224.0/1958.24.224.1 to 58.24.255.25458.24.255.2558,190
20158.25.0.0/1958.25.0.1 to 58.25.31.25458.25.31.2558,190
20258.25.32.0/1958.25.32.1 to 58.25.63.25458.25.63.2558,190
20358.25.64.0/1958.25.64.1 to 58.25.95.25458.25.95.2558,190
20458.25.96.0/1958.25.96.1 to 58.25.127.25458.25.127.2558,190
20558.25.128.0/1958.25.128.1 to 58.25.159.25458.25.159.2558,190
20658.25.160.0/1958.25.160.1 to 58.25.191.25458.25.191.2558,190
20758.25.192.0/1958.25.192.1 to 58.25.223.25458.25.223.2558,190
20858.25.224.0/1958.25.224.1 to 58.25.255.25458.25.255.2558,190
20958.26.0.0/1958.26.0.1 to 58.26.31.25458.26.31.2558,190
21058.26.32.0/1958.26.32.1 to 58.26.63.25458.26.63.2558,190
21158.26.64.0/1958.26.64.1 to 58.26.95.25458.26.95.2558,190
21258.26.96.0/1958.26.96.1 to 58.26.127.25458.26.127.2558,190
21358.26.128.0/1958.26.128.1 to 58.26.159.25458.26.159.2558,190
21458.26.160.0/1958.26.160.1 to 58.26.191.25458.26.191.2558,190
21558.26.192.0/1958.26.192.1 to 58.26.223.25458.26.223.2558,190
21658.26.224.0/1958.26.224.1 to 58.26.255.25458.26.255.2558,190
21758.27.0.0/1958.27.0.1 to 58.27.31.25458.27.31.2558,190
21858.27.32.0/1958.27.32.1 to 58.27.63.25458.27.63.2558,190
21958.27.64.0/1958.27.64.1 to 58.27.95.25458.27.95.2558,190
22058.27.96.0/1958.27.96.1 to 58.27.127.25458.27.127.2558,190
22158.27.128.0/1958.27.128.1 to 58.27.159.25458.27.159.2558,190
22258.27.160.0/1958.27.160.1 to 58.27.191.25458.27.191.2558,190
22358.27.192.0/1958.27.192.1 to 58.27.223.25458.27.223.2558,190
22458.27.224.0/1958.27.224.1 to 58.27.255.25458.27.255.2558,190
22558.28.0.0/1958.28.0.1 to 58.28.31.25458.28.31.2558,190
22658.28.32.0/1958.28.32.1 to 58.28.63.25458.28.63.2558,190
22758.28.64.0/1958.28.64.1 to 58.28.95.25458.28.95.2558,190
22858.28.96.0/1958.28.96.1 to 58.28.127.25458.28.127.2558,190
22958.28.128.0/1958.28.128.1 to 58.28.159.25458.28.159.2558,190
23058.28.160.0/1958.28.160.1 to 58.28.191.25458.28.191.2558,190
23158.28.192.0/1958.28.192.1 to 58.28.223.25458.28.223.2558,190
23258.28.224.0/1958.28.224.1 to 58.28.255.25458.28.255.2558,190
23358.29.0.0/1958.29.0.1 to 58.29.31.25458.29.31.2558,190
23458.29.32.0/1958.29.32.1 to 58.29.63.25458.29.63.2558,190
23558.29.64.0/1958.29.64.1 to 58.29.95.25458.29.95.2558,190
23658.29.96.0/1958.29.96.1 to 58.29.127.25458.29.127.2558,190
23758.29.128.0/1958.29.128.1 to 58.29.159.25458.29.159.2558,190
23858.29.160.0/1958.29.160.1 to 58.29.191.25458.29.191.2558,190
23958.29.192.0/1958.29.192.1 to 58.29.223.25458.29.223.2558,190
24058.29.224.0/1958.29.224.1 to 58.29.255.25458.29.255.2558,190
24158.30.0.0/1958.30.0.1 to 58.30.31.25458.30.31.2558,190
24258.30.32.0/1958.30.32.1 to 58.30.63.25458.30.63.2558,190
24358.30.64.0/1958.30.64.1 to 58.30.95.25458.30.95.2558,190
24458.30.96.0/1958.30.96.1 to 58.30.127.25458.30.127.2558,190
24558.30.128.0/1958.30.128.1 to 58.30.159.25458.30.159.2558,190
24658.30.160.0/1958.30.160.1 to 58.30.191.25458.30.191.2558,190
24758.30.192.0/1958.30.192.1 to 58.30.223.25458.30.223.2558,190
24858.30.224.0/1958.30.224.1 to 58.30.255.25458.30.255.2558,190
24958.31.0.0/1958.31.0.1 to 58.31.31.25458.31.31.2558,190
25058.31.32.0/1958.31.32.1 to 58.31.63.25458.31.63.2558,190
25158.31.64.0/1958.31.64.1 to 58.31.95.25458.31.95.2558,190
25258.31.96.0/1958.31.96.1 to 58.31.127.25458.31.127.2558,190
25358.31.128.0/1958.31.128.1 to 58.31.159.25458.31.159.2558,190
25458.31.160.0/1958.31.160.1 to 58.31.191.25458.31.191.2558,190
25558.31.192.0/1958.31.192.1 to 58.31.223.25458.31.223.2558,190
25658.31.224.0/1958.31.224.1 to 58.31.255.25458.31.255.2558,190

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.