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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.

Network49.72.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
49.72.0.0
Broadcast address
49.79.255.255
First usable
49.72.0.1
Last usable
49.79.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
A (default /8)
As numbers
Hex 31480000 · Integer 826802176 to 827326463
Reverse DNS zones
72.49.in-addr.arpa
73.49.in-addr.arpa
74.49.in-addr.arpa
75.49.in-addr.arpa
76.49.in-addr.arpa
77.49.in-addr.arpa
78.49.in-addr.arpa
79.49.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00110001.01001000.00000000.0000000049.72.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network00110001.01001000.00000000.0000000049.72.0.0
Broadcast00110001.01001111.11111111.1111111149.79.255.255
Split into smaller subnets/21
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

49.72.0.0/13 makes 256 subnets of /21.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
149.72.0.0/2149.72.0.1 to 49.72.7.25449.72.7.2552,046
249.72.8.0/2149.72.8.1 to 49.72.15.25449.72.15.2552,046
349.72.16.0/2149.72.16.1 to 49.72.23.25449.72.23.2552,046
449.72.24.0/2149.72.24.1 to 49.72.31.25449.72.31.2552,046
549.72.32.0/2149.72.32.1 to 49.72.39.25449.72.39.2552,046
649.72.40.0/2149.72.40.1 to 49.72.47.25449.72.47.2552,046
749.72.48.0/2149.72.48.1 to 49.72.55.25449.72.55.2552,046
849.72.56.0/2149.72.56.1 to 49.72.63.25449.72.63.2552,046
949.72.64.0/2149.72.64.1 to 49.72.71.25449.72.71.2552,046
1049.72.72.0/2149.72.72.1 to 49.72.79.25449.72.79.2552,046
1149.72.80.0/2149.72.80.1 to 49.72.87.25449.72.87.2552,046
1249.72.88.0/2149.72.88.1 to 49.72.95.25449.72.95.2552,046
1349.72.96.0/2149.72.96.1 to 49.72.103.25449.72.103.2552,046
1449.72.104.0/2149.72.104.1 to 49.72.111.25449.72.111.2552,046
1549.72.112.0/2149.72.112.1 to 49.72.119.25449.72.119.2552,046
1649.72.120.0/2149.72.120.1 to 49.72.127.25449.72.127.2552,046
1749.72.128.0/2149.72.128.1 to 49.72.135.25449.72.135.2552,046
1849.72.136.0/2149.72.136.1 to 49.72.143.25449.72.143.2552,046
1949.72.144.0/2149.72.144.1 to 49.72.151.25449.72.151.2552,046
2049.72.152.0/2149.72.152.1 to 49.72.159.25449.72.159.2552,046
2149.72.160.0/2149.72.160.1 to 49.72.167.25449.72.167.2552,046
2249.72.168.0/2149.72.168.1 to 49.72.175.25449.72.175.2552,046
2349.72.176.0/2149.72.176.1 to 49.72.183.25449.72.183.2552,046
2449.72.184.0/2149.72.184.1 to 49.72.191.25449.72.191.2552,046
2549.72.192.0/2149.72.192.1 to 49.72.199.25449.72.199.2552,046
2649.72.200.0/2149.72.200.1 to 49.72.207.25449.72.207.2552,046
2749.72.208.0/2149.72.208.1 to 49.72.215.25449.72.215.2552,046
2849.72.216.0/2149.72.216.1 to 49.72.223.25449.72.223.2552,046
2949.72.224.0/2149.72.224.1 to 49.72.231.25449.72.231.2552,046
3049.72.232.0/2149.72.232.1 to 49.72.239.25449.72.239.2552,046
3149.72.240.0/2149.72.240.1 to 49.72.247.25449.72.247.2552,046
3249.72.248.0/2149.72.248.1 to 49.72.255.25449.72.255.2552,046
3349.73.0.0/2149.73.0.1 to 49.73.7.25449.73.7.2552,046
3449.73.8.0/2149.73.8.1 to 49.73.15.25449.73.15.2552,046
3549.73.16.0/2149.73.16.1 to 49.73.23.25449.73.23.2552,046
3649.73.24.0/2149.73.24.1 to 49.73.31.25449.73.31.2552,046
3749.73.32.0/2149.73.32.1 to 49.73.39.25449.73.39.2552,046
3849.73.40.0/2149.73.40.1 to 49.73.47.25449.73.47.2552,046
3949.73.48.0/2149.73.48.1 to 49.73.55.25449.73.55.2552,046
4049.73.56.0/2149.73.56.1 to 49.73.63.25449.73.63.2552,046
4149.73.64.0/2149.73.64.1 to 49.73.71.25449.73.71.2552,046
4249.73.72.0/2149.73.72.1 to 49.73.79.25449.73.79.2552,046
4349.73.80.0/2149.73.80.1 to 49.73.87.25449.73.87.2552,046
4449.73.88.0/2149.73.88.1 to 49.73.95.25449.73.95.2552,046
4549.73.96.0/2149.73.96.1 to 49.73.103.25449.73.103.2552,046
4649.73.104.0/2149.73.104.1 to 49.73.111.25449.73.111.2552,046
4749.73.112.0/2149.73.112.1 to 49.73.119.25449.73.119.2552,046
4849.73.120.0/2149.73.120.1 to 49.73.127.25449.73.127.2552,046
4949.73.128.0/2149.73.128.1 to 49.73.135.25449.73.135.2552,046
5049.73.136.0/2149.73.136.1 to 49.73.143.25449.73.143.2552,046
5149.73.144.0/2149.73.144.1 to 49.73.151.25449.73.151.2552,046
5249.73.152.0/2149.73.152.1 to 49.73.159.25449.73.159.2552,046
5349.73.160.0/2149.73.160.1 to 49.73.167.25449.73.167.2552,046
5449.73.168.0/2149.73.168.1 to 49.73.175.25449.73.175.2552,046
5549.73.176.0/2149.73.176.1 to 49.73.183.25449.73.183.2552,046
5649.73.184.0/2149.73.184.1 to 49.73.191.25449.73.191.2552,046
5749.73.192.0/2149.73.192.1 to 49.73.199.25449.73.199.2552,046
5849.73.200.0/2149.73.200.1 to 49.73.207.25449.73.207.2552,046
5949.73.208.0/2149.73.208.1 to 49.73.215.25449.73.215.2552,046
6049.73.216.0/2149.73.216.1 to 49.73.223.25449.73.223.2552,046
6149.73.224.0/2149.73.224.1 to 49.73.231.25449.73.231.2552,046
6249.73.232.0/2149.73.232.1 to 49.73.239.25449.73.239.2552,046
6349.73.240.0/2149.73.240.1 to 49.73.247.25449.73.247.2552,046
6449.73.248.0/2149.73.248.1 to 49.73.255.25449.73.255.2552,046
6549.74.0.0/2149.74.0.1 to 49.74.7.25449.74.7.2552,046
6649.74.8.0/2149.74.8.1 to 49.74.15.25449.74.15.2552,046
6749.74.16.0/2149.74.16.1 to 49.74.23.25449.74.23.2552,046
6849.74.24.0/2149.74.24.1 to 49.74.31.25449.74.31.2552,046
6949.74.32.0/2149.74.32.1 to 49.74.39.25449.74.39.2552,046
7049.74.40.0/2149.74.40.1 to 49.74.47.25449.74.47.2552,046
7149.74.48.0/2149.74.48.1 to 49.74.55.25449.74.55.2552,046
7249.74.56.0/2149.74.56.1 to 49.74.63.25449.74.63.2552,046
7349.74.64.0/2149.74.64.1 to 49.74.71.25449.74.71.2552,046
7449.74.72.0/2149.74.72.1 to 49.74.79.25449.74.79.2552,046
7549.74.80.0/2149.74.80.1 to 49.74.87.25449.74.87.2552,046
7649.74.88.0/2149.74.88.1 to 49.74.95.25449.74.95.2552,046
7749.74.96.0/2149.74.96.1 to 49.74.103.25449.74.103.2552,046
7849.74.104.0/2149.74.104.1 to 49.74.111.25449.74.111.2552,046
7949.74.112.0/2149.74.112.1 to 49.74.119.25449.74.119.2552,046
8049.74.120.0/2149.74.120.1 to 49.74.127.25449.74.127.2552,046
8149.74.128.0/2149.74.128.1 to 49.74.135.25449.74.135.2552,046
8249.74.136.0/2149.74.136.1 to 49.74.143.25449.74.143.2552,046
8349.74.144.0/2149.74.144.1 to 49.74.151.25449.74.151.2552,046
8449.74.152.0/2149.74.152.1 to 49.74.159.25449.74.159.2552,046
8549.74.160.0/2149.74.160.1 to 49.74.167.25449.74.167.2552,046
8649.74.168.0/2149.74.168.1 to 49.74.175.25449.74.175.2552,046
8749.74.176.0/2149.74.176.1 to 49.74.183.25449.74.183.2552,046
8849.74.184.0/2149.74.184.1 to 49.74.191.25449.74.191.2552,046
8949.74.192.0/2149.74.192.1 to 49.74.199.25449.74.199.2552,046
9049.74.200.0/2149.74.200.1 to 49.74.207.25449.74.207.2552,046
9149.74.208.0/2149.74.208.1 to 49.74.215.25449.74.215.2552,046
9249.74.216.0/2149.74.216.1 to 49.74.223.25449.74.223.2552,046
9349.74.224.0/2149.74.224.1 to 49.74.231.25449.74.231.2552,046
9449.74.232.0/2149.74.232.1 to 49.74.239.25449.74.239.2552,046
9549.74.240.0/2149.74.240.1 to 49.74.247.25449.74.247.2552,046
9649.74.248.0/2149.74.248.1 to 49.74.255.25449.74.255.2552,046
9749.75.0.0/2149.75.0.1 to 49.75.7.25449.75.7.2552,046
9849.75.8.0/2149.75.8.1 to 49.75.15.25449.75.15.2552,046
9949.75.16.0/2149.75.16.1 to 49.75.23.25449.75.23.2552,046
10049.75.24.0/2149.75.24.1 to 49.75.31.25449.75.31.2552,046
10149.75.32.0/2149.75.32.1 to 49.75.39.25449.75.39.2552,046
10249.75.40.0/2149.75.40.1 to 49.75.47.25449.75.47.2552,046
10349.75.48.0/2149.75.48.1 to 49.75.55.25449.75.55.2552,046
10449.75.56.0/2149.75.56.1 to 49.75.63.25449.75.63.2552,046
10549.75.64.0/2149.75.64.1 to 49.75.71.25449.75.71.2552,046
10649.75.72.0/2149.75.72.1 to 49.75.79.25449.75.79.2552,046
10749.75.80.0/2149.75.80.1 to 49.75.87.25449.75.87.2552,046
10849.75.88.0/2149.75.88.1 to 49.75.95.25449.75.95.2552,046
10949.75.96.0/2149.75.96.1 to 49.75.103.25449.75.103.2552,046
11049.75.104.0/2149.75.104.1 to 49.75.111.25449.75.111.2552,046
11149.75.112.0/2149.75.112.1 to 49.75.119.25449.75.119.2552,046
11249.75.120.0/2149.75.120.1 to 49.75.127.25449.75.127.2552,046
11349.75.128.0/2149.75.128.1 to 49.75.135.25449.75.135.2552,046
11449.75.136.0/2149.75.136.1 to 49.75.143.25449.75.143.2552,046
11549.75.144.0/2149.75.144.1 to 49.75.151.25449.75.151.2552,046
11649.75.152.0/2149.75.152.1 to 49.75.159.25449.75.159.2552,046
11749.75.160.0/2149.75.160.1 to 49.75.167.25449.75.167.2552,046
11849.75.168.0/2149.75.168.1 to 49.75.175.25449.75.175.2552,046
11949.75.176.0/2149.75.176.1 to 49.75.183.25449.75.183.2552,046
12049.75.184.0/2149.75.184.1 to 49.75.191.25449.75.191.2552,046
12149.75.192.0/2149.75.192.1 to 49.75.199.25449.75.199.2552,046
12249.75.200.0/2149.75.200.1 to 49.75.207.25449.75.207.2552,046
12349.75.208.0/2149.75.208.1 to 49.75.215.25449.75.215.2552,046
12449.75.216.0/2149.75.216.1 to 49.75.223.25449.75.223.2552,046
12549.75.224.0/2149.75.224.1 to 49.75.231.25449.75.231.2552,046
12649.75.232.0/2149.75.232.1 to 49.75.239.25449.75.239.2552,046
12749.75.240.0/2149.75.240.1 to 49.75.247.25449.75.247.2552,046
12849.75.248.0/2149.75.248.1 to 49.75.255.25449.75.255.2552,046
12949.76.0.0/2149.76.0.1 to 49.76.7.25449.76.7.2552,046
13049.76.8.0/2149.76.8.1 to 49.76.15.25449.76.15.2552,046
13149.76.16.0/2149.76.16.1 to 49.76.23.25449.76.23.2552,046
13249.76.24.0/2149.76.24.1 to 49.76.31.25449.76.31.2552,046
13349.76.32.0/2149.76.32.1 to 49.76.39.25449.76.39.2552,046
13449.76.40.0/2149.76.40.1 to 49.76.47.25449.76.47.2552,046
13549.76.48.0/2149.76.48.1 to 49.76.55.25449.76.55.2552,046
13649.76.56.0/2149.76.56.1 to 49.76.63.25449.76.63.2552,046
13749.76.64.0/2149.76.64.1 to 49.76.71.25449.76.71.2552,046
13849.76.72.0/2149.76.72.1 to 49.76.79.25449.76.79.2552,046
13949.76.80.0/2149.76.80.1 to 49.76.87.25449.76.87.2552,046
14049.76.88.0/2149.76.88.1 to 49.76.95.25449.76.95.2552,046
14149.76.96.0/2149.76.96.1 to 49.76.103.25449.76.103.2552,046
14249.76.104.0/2149.76.104.1 to 49.76.111.25449.76.111.2552,046
14349.76.112.0/2149.76.112.1 to 49.76.119.25449.76.119.2552,046
14449.76.120.0/2149.76.120.1 to 49.76.127.25449.76.127.2552,046
14549.76.128.0/2149.76.128.1 to 49.76.135.25449.76.135.2552,046
14649.76.136.0/2149.76.136.1 to 49.76.143.25449.76.143.2552,046
14749.76.144.0/2149.76.144.1 to 49.76.151.25449.76.151.2552,046
14849.76.152.0/2149.76.152.1 to 49.76.159.25449.76.159.2552,046
14949.76.160.0/2149.76.160.1 to 49.76.167.25449.76.167.2552,046
15049.76.168.0/2149.76.168.1 to 49.76.175.25449.76.175.2552,046
15149.76.176.0/2149.76.176.1 to 49.76.183.25449.76.183.2552,046
15249.76.184.0/2149.76.184.1 to 49.76.191.25449.76.191.2552,046
15349.76.192.0/2149.76.192.1 to 49.76.199.25449.76.199.2552,046
15449.76.200.0/2149.76.200.1 to 49.76.207.25449.76.207.2552,046
15549.76.208.0/2149.76.208.1 to 49.76.215.25449.76.215.2552,046
15649.76.216.0/2149.76.216.1 to 49.76.223.25449.76.223.2552,046
15749.76.224.0/2149.76.224.1 to 49.76.231.25449.76.231.2552,046
15849.76.232.0/2149.76.232.1 to 49.76.239.25449.76.239.2552,046
15949.76.240.0/2149.76.240.1 to 49.76.247.25449.76.247.2552,046
16049.76.248.0/2149.76.248.1 to 49.76.255.25449.76.255.2552,046
16149.77.0.0/2149.77.0.1 to 49.77.7.25449.77.7.2552,046
16249.77.8.0/2149.77.8.1 to 49.77.15.25449.77.15.2552,046
16349.77.16.0/2149.77.16.1 to 49.77.23.25449.77.23.2552,046
16449.77.24.0/2149.77.24.1 to 49.77.31.25449.77.31.2552,046
16549.77.32.0/2149.77.32.1 to 49.77.39.25449.77.39.2552,046
16649.77.40.0/2149.77.40.1 to 49.77.47.25449.77.47.2552,046
16749.77.48.0/2149.77.48.1 to 49.77.55.25449.77.55.2552,046
16849.77.56.0/2149.77.56.1 to 49.77.63.25449.77.63.2552,046
16949.77.64.0/2149.77.64.1 to 49.77.71.25449.77.71.2552,046
17049.77.72.0/2149.77.72.1 to 49.77.79.25449.77.79.2552,046
17149.77.80.0/2149.77.80.1 to 49.77.87.25449.77.87.2552,046
17249.77.88.0/2149.77.88.1 to 49.77.95.25449.77.95.2552,046
17349.77.96.0/2149.77.96.1 to 49.77.103.25449.77.103.2552,046
17449.77.104.0/2149.77.104.1 to 49.77.111.25449.77.111.2552,046
17549.77.112.0/2149.77.112.1 to 49.77.119.25449.77.119.2552,046
17649.77.120.0/2149.77.120.1 to 49.77.127.25449.77.127.2552,046
17749.77.128.0/2149.77.128.1 to 49.77.135.25449.77.135.2552,046
17849.77.136.0/2149.77.136.1 to 49.77.143.25449.77.143.2552,046
17949.77.144.0/2149.77.144.1 to 49.77.151.25449.77.151.2552,046
18049.77.152.0/2149.77.152.1 to 49.77.159.25449.77.159.2552,046
18149.77.160.0/2149.77.160.1 to 49.77.167.25449.77.167.2552,046
18249.77.168.0/2149.77.168.1 to 49.77.175.25449.77.175.2552,046
18349.77.176.0/2149.77.176.1 to 49.77.183.25449.77.183.2552,046
18449.77.184.0/2149.77.184.1 to 49.77.191.25449.77.191.2552,046
18549.77.192.0/2149.77.192.1 to 49.77.199.25449.77.199.2552,046
18649.77.200.0/2149.77.200.1 to 49.77.207.25449.77.207.2552,046
18749.77.208.0/2149.77.208.1 to 49.77.215.25449.77.215.2552,046
18849.77.216.0/2149.77.216.1 to 49.77.223.25449.77.223.2552,046
18949.77.224.0/2149.77.224.1 to 49.77.231.25449.77.231.2552,046
19049.77.232.0/2149.77.232.1 to 49.77.239.25449.77.239.2552,046
19149.77.240.0/2149.77.240.1 to 49.77.247.25449.77.247.2552,046
19249.77.248.0/2149.77.248.1 to 49.77.255.25449.77.255.2552,046
19349.78.0.0/2149.78.0.1 to 49.78.7.25449.78.7.2552,046
19449.78.8.0/2149.78.8.1 to 49.78.15.25449.78.15.2552,046
19549.78.16.0/2149.78.16.1 to 49.78.23.25449.78.23.2552,046
19649.78.24.0/2149.78.24.1 to 49.78.31.25449.78.31.2552,046
19749.78.32.0/2149.78.32.1 to 49.78.39.25449.78.39.2552,046
19849.78.40.0/2149.78.40.1 to 49.78.47.25449.78.47.2552,046
19949.78.48.0/2149.78.48.1 to 49.78.55.25449.78.55.2552,046
20049.78.56.0/2149.78.56.1 to 49.78.63.25449.78.63.2552,046
20149.78.64.0/2149.78.64.1 to 49.78.71.25449.78.71.2552,046
20249.78.72.0/2149.78.72.1 to 49.78.79.25449.78.79.2552,046
20349.78.80.0/2149.78.80.1 to 49.78.87.25449.78.87.2552,046
20449.78.88.0/2149.78.88.1 to 49.78.95.25449.78.95.2552,046
20549.78.96.0/2149.78.96.1 to 49.78.103.25449.78.103.2552,046
20649.78.104.0/2149.78.104.1 to 49.78.111.25449.78.111.2552,046
20749.78.112.0/2149.78.112.1 to 49.78.119.25449.78.119.2552,046
20849.78.120.0/2149.78.120.1 to 49.78.127.25449.78.127.2552,046
20949.78.128.0/2149.78.128.1 to 49.78.135.25449.78.135.2552,046
21049.78.136.0/2149.78.136.1 to 49.78.143.25449.78.143.2552,046
21149.78.144.0/2149.78.144.1 to 49.78.151.25449.78.151.2552,046
21249.78.152.0/2149.78.152.1 to 49.78.159.25449.78.159.2552,046
21349.78.160.0/2149.78.160.1 to 49.78.167.25449.78.167.2552,046
21449.78.168.0/2149.78.168.1 to 49.78.175.25449.78.175.2552,046
21549.78.176.0/2149.78.176.1 to 49.78.183.25449.78.183.2552,046
21649.78.184.0/2149.78.184.1 to 49.78.191.25449.78.191.2552,046
21749.78.192.0/2149.78.192.1 to 49.78.199.25449.78.199.2552,046
21849.78.200.0/2149.78.200.1 to 49.78.207.25449.78.207.2552,046
21949.78.208.0/2149.78.208.1 to 49.78.215.25449.78.215.2552,046
22049.78.216.0/2149.78.216.1 to 49.78.223.25449.78.223.2552,046
22149.78.224.0/2149.78.224.1 to 49.78.231.25449.78.231.2552,046
22249.78.232.0/2149.78.232.1 to 49.78.239.25449.78.239.2552,046
22349.78.240.0/2149.78.240.1 to 49.78.247.25449.78.247.2552,046
22449.78.248.0/2149.78.248.1 to 49.78.255.25449.78.255.2552,046
22549.79.0.0/2149.79.0.1 to 49.79.7.25449.79.7.2552,046
22649.79.8.0/2149.79.8.1 to 49.79.15.25449.79.15.2552,046
22749.79.16.0/2149.79.16.1 to 49.79.23.25449.79.23.2552,046
22849.79.24.0/2149.79.24.1 to 49.79.31.25449.79.31.2552,046
22949.79.32.0/2149.79.32.1 to 49.79.39.25449.79.39.2552,046
23049.79.40.0/2149.79.40.1 to 49.79.47.25449.79.47.2552,046
23149.79.48.0/2149.79.48.1 to 49.79.55.25449.79.55.2552,046
23249.79.56.0/2149.79.56.1 to 49.79.63.25449.79.63.2552,046
23349.79.64.0/2149.79.64.1 to 49.79.71.25449.79.71.2552,046
23449.79.72.0/2149.79.72.1 to 49.79.79.25449.79.79.2552,046
23549.79.80.0/2149.79.80.1 to 49.79.87.25449.79.87.2552,046
23649.79.88.0/2149.79.88.1 to 49.79.95.25449.79.95.2552,046
23749.79.96.0/2149.79.96.1 to 49.79.103.25449.79.103.2552,046
23849.79.104.0/2149.79.104.1 to 49.79.111.25449.79.111.2552,046
23949.79.112.0/2149.79.112.1 to 49.79.119.25449.79.119.2552,046
24049.79.120.0/2149.79.120.1 to 49.79.127.25449.79.127.2552,046
24149.79.128.0/2149.79.128.1 to 49.79.135.25449.79.135.2552,046
24249.79.136.0/2149.79.136.1 to 49.79.143.25449.79.143.2552,046
24349.79.144.0/2149.79.144.1 to 49.79.151.25449.79.151.2552,046
24449.79.152.0/2149.79.152.1 to 49.79.159.25449.79.159.2552,046
24549.79.160.0/2149.79.160.1 to 49.79.167.25449.79.167.2552,046
24649.79.168.0/2149.79.168.1 to 49.79.175.25449.79.175.2552,046
24749.79.176.0/2149.79.176.1 to 49.79.183.25449.79.183.2552,046
24849.79.184.0/2149.79.184.1 to 49.79.191.25449.79.191.2552,046
24949.79.192.0/2149.79.192.1 to 49.79.199.25449.79.199.2552,046
25049.79.200.0/2149.79.200.1 to 49.79.207.25449.79.207.2552,046
25149.79.208.0/2149.79.208.1 to 49.79.215.25449.79.215.2552,046
25249.79.216.0/2149.79.216.1 to 49.79.223.25449.79.223.2552,046
25349.79.224.0/2149.79.224.1 to 49.79.231.25449.79.231.2552,046
25449.79.232.0/2149.79.232.1 to 49.79.239.25449.79.239.2552,046
25549.79.240.0/2149.79.240.1 to 49.79.247.25449.79.247.2552,046
25649.79.248.0/2149.79.248.1 to 49.79.255.25449.79.255.2552,046

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.