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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.

Network13.224.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
13.224.0.0
Broadcast address
13.231.255.255
First usable
13.224.0.1
Last usable
13.231.255.254
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 0DE00000 · Integer 232783872 to 233308159
Reverse DNS zones
224.13.in-addr.arpa
225.13.in-addr.arpa
226.13.in-addr.arpa
227.13.in-addr.arpa
228.13.in-addr.arpa
229.13.in-addr.arpa
230.13.in-addr.arpa
231.13.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
Address00001101.11100000.00000000.0000000013.224.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network00001101.11100000.00000000.0000000013.224.0.0
Broadcast00001101.11100111.11111111.1111111113.231.255.255
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)

13.224.0.0/13 makes 256 subnets of /21.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
113.224.0.0/2113.224.0.1 to 13.224.7.25413.224.7.2552,046
213.224.8.0/2113.224.8.1 to 13.224.15.25413.224.15.2552,046
313.224.16.0/2113.224.16.1 to 13.224.23.25413.224.23.2552,046
413.224.24.0/2113.224.24.1 to 13.224.31.25413.224.31.2552,046
513.224.32.0/2113.224.32.1 to 13.224.39.25413.224.39.2552,046
613.224.40.0/2113.224.40.1 to 13.224.47.25413.224.47.2552,046
713.224.48.0/2113.224.48.1 to 13.224.55.25413.224.55.2552,046
813.224.56.0/2113.224.56.1 to 13.224.63.25413.224.63.2552,046
913.224.64.0/2113.224.64.1 to 13.224.71.25413.224.71.2552,046
1013.224.72.0/2113.224.72.1 to 13.224.79.25413.224.79.2552,046
1113.224.80.0/2113.224.80.1 to 13.224.87.25413.224.87.2552,046
1213.224.88.0/2113.224.88.1 to 13.224.95.25413.224.95.2552,046
1313.224.96.0/2113.224.96.1 to 13.224.103.25413.224.103.2552,046
1413.224.104.0/2113.224.104.1 to 13.224.111.25413.224.111.2552,046
1513.224.112.0/2113.224.112.1 to 13.224.119.25413.224.119.2552,046
1613.224.120.0/2113.224.120.1 to 13.224.127.25413.224.127.2552,046
1713.224.128.0/2113.224.128.1 to 13.224.135.25413.224.135.2552,046
1813.224.136.0/2113.224.136.1 to 13.224.143.25413.224.143.2552,046
1913.224.144.0/2113.224.144.1 to 13.224.151.25413.224.151.2552,046
2013.224.152.0/2113.224.152.1 to 13.224.159.25413.224.159.2552,046
2113.224.160.0/2113.224.160.1 to 13.224.167.25413.224.167.2552,046
2213.224.168.0/2113.224.168.1 to 13.224.175.25413.224.175.2552,046
2313.224.176.0/2113.224.176.1 to 13.224.183.25413.224.183.2552,046
2413.224.184.0/2113.224.184.1 to 13.224.191.25413.224.191.2552,046
2513.224.192.0/2113.224.192.1 to 13.224.199.25413.224.199.2552,046
2613.224.200.0/2113.224.200.1 to 13.224.207.25413.224.207.2552,046
2713.224.208.0/2113.224.208.1 to 13.224.215.25413.224.215.2552,046
2813.224.216.0/2113.224.216.1 to 13.224.223.25413.224.223.2552,046
2913.224.224.0/2113.224.224.1 to 13.224.231.25413.224.231.2552,046
3013.224.232.0/2113.224.232.1 to 13.224.239.25413.224.239.2552,046
3113.224.240.0/2113.224.240.1 to 13.224.247.25413.224.247.2552,046
3213.224.248.0/2113.224.248.1 to 13.224.255.25413.224.255.2552,046
3313.225.0.0/2113.225.0.1 to 13.225.7.25413.225.7.2552,046
3413.225.8.0/2113.225.8.1 to 13.225.15.25413.225.15.2552,046
3513.225.16.0/2113.225.16.1 to 13.225.23.25413.225.23.2552,046
3613.225.24.0/2113.225.24.1 to 13.225.31.25413.225.31.2552,046
3713.225.32.0/2113.225.32.1 to 13.225.39.25413.225.39.2552,046
3813.225.40.0/2113.225.40.1 to 13.225.47.25413.225.47.2552,046
3913.225.48.0/2113.225.48.1 to 13.225.55.25413.225.55.2552,046
4013.225.56.0/2113.225.56.1 to 13.225.63.25413.225.63.2552,046
4113.225.64.0/2113.225.64.1 to 13.225.71.25413.225.71.2552,046
4213.225.72.0/2113.225.72.1 to 13.225.79.25413.225.79.2552,046
4313.225.80.0/2113.225.80.1 to 13.225.87.25413.225.87.2552,046
4413.225.88.0/2113.225.88.1 to 13.225.95.25413.225.95.2552,046
4513.225.96.0/2113.225.96.1 to 13.225.103.25413.225.103.2552,046
4613.225.104.0/2113.225.104.1 to 13.225.111.25413.225.111.2552,046
4713.225.112.0/2113.225.112.1 to 13.225.119.25413.225.119.2552,046
4813.225.120.0/2113.225.120.1 to 13.225.127.25413.225.127.2552,046
4913.225.128.0/2113.225.128.1 to 13.225.135.25413.225.135.2552,046
5013.225.136.0/2113.225.136.1 to 13.225.143.25413.225.143.2552,046
5113.225.144.0/2113.225.144.1 to 13.225.151.25413.225.151.2552,046
5213.225.152.0/2113.225.152.1 to 13.225.159.25413.225.159.2552,046
5313.225.160.0/2113.225.160.1 to 13.225.167.25413.225.167.2552,046
5413.225.168.0/2113.225.168.1 to 13.225.175.25413.225.175.2552,046
5513.225.176.0/2113.225.176.1 to 13.225.183.25413.225.183.2552,046
5613.225.184.0/2113.225.184.1 to 13.225.191.25413.225.191.2552,046
5713.225.192.0/2113.225.192.1 to 13.225.199.25413.225.199.2552,046
5813.225.200.0/2113.225.200.1 to 13.225.207.25413.225.207.2552,046
5913.225.208.0/2113.225.208.1 to 13.225.215.25413.225.215.2552,046
6013.225.216.0/2113.225.216.1 to 13.225.223.25413.225.223.2552,046
6113.225.224.0/2113.225.224.1 to 13.225.231.25413.225.231.2552,046
6213.225.232.0/2113.225.232.1 to 13.225.239.25413.225.239.2552,046
6313.225.240.0/2113.225.240.1 to 13.225.247.25413.225.247.2552,046
6413.225.248.0/2113.225.248.1 to 13.225.255.25413.225.255.2552,046
6513.226.0.0/2113.226.0.1 to 13.226.7.25413.226.7.2552,046
6613.226.8.0/2113.226.8.1 to 13.226.15.25413.226.15.2552,046
6713.226.16.0/2113.226.16.1 to 13.226.23.25413.226.23.2552,046
6813.226.24.0/2113.226.24.1 to 13.226.31.25413.226.31.2552,046
6913.226.32.0/2113.226.32.1 to 13.226.39.25413.226.39.2552,046
7013.226.40.0/2113.226.40.1 to 13.226.47.25413.226.47.2552,046
7113.226.48.0/2113.226.48.1 to 13.226.55.25413.226.55.2552,046
7213.226.56.0/2113.226.56.1 to 13.226.63.25413.226.63.2552,046
7313.226.64.0/2113.226.64.1 to 13.226.71.25413.226.71.2552,046
7413.226.72.0/2113.226.72.1 to 13.226.79.25413.226.79.2552,046
7513.226.80.0/2113.226.80.1 to 13.226.87.25413.226.87.2552,046
7613.226.88.0/2113.226.88.1 to 13.226.95.25413.226.95.2552,046
7713.226.96.0/2113.226.96.1 to 13.226.103.25413.226.103.2552,046
7813.226.104.0/2113.226.104.1 to 13.226.111.25413.226.111.2552,046
7913.226.112.0/2113.226.112.1 to 13.226.119.25413.226.119.2552,046
8013.226.120.0/2113.226.120.1 to 13.226.127.25413.226.127.2552,046
8113.226.128.0/2113.226.128.1 to 13.226.135.25413.226.135.2552,046
8213.226.136.0/2113.226.136.1 to 13.226.143.25413.226.143.2552,046
8313.226.144.0/2113.226.144.1 to 13.226.151.25413.226.151.2552,046
8413.226.152.0/2113.226.152.1 to 13.226.159.25413.226.159.2552,046
8513.226.160.0/2113.226.160.1 to 13.226.167.25413.226.167.2552,046
8613.226.168.0/2113.226.168.1 to 13.226.175.25413.226.175.2552,046
8713.226.176.0/2113.226.176.1 to 13.226.183.25413.226.183.2552,046
8813.226.184.0/2113.226.184.1 to 13.226.191.25413.226.191.2552,046
8913.226.192.0/2113.226.192.1 to 13.226.199.25413.226.199.2552,046
9013.226.200.0/2113.226.200.1 to 13.226.207.25413.226.207.2552,046
9113.226.208.0/2113.226.208.1 to 13.226.215.25413.226.215.2552,046
9213.226.216.0/2113.226.216.1 to 13.226.223.25413.226.223.2552,046
9313.226.224.0/2113.226.224.1 to 13.226.231.25413.226.231.2552,046
9413.226.232.0/2113.226.232.1 to 13.226.239.25413.226.239.2552,046
9513.226.240.0/2113.226.240.1 to 13.226.247.25413.226.247.2552,046
9613.226.248.0/2113.226.248.1 to 13.226.255.25413.226.255.2552,046
9713.227.0.0/2113.227.0.1 to 13.227.7.25413.227.7.2552,046
9813.227.8.0/2113.227.8.1 to 13.227.15.25413.227.15.2552,046
9913.227.16.0/2113.227.16.1 to 13.227.23.25413.227.23.2552,046
10013.227.24.0/2113.227.24.1 to 13.227.31.25413.227.31.2552,046
10113.227.32.0/2113.227.32.1 to 13.227.39.25413.227.39.2552,046
10213.227.40.0/2113.227.40.1 to 13.227.47.25413.227.47.2552,046
10313.227.48.0/2113.227.48.1 to 13.227.55.25413.227.55.2552,046
10413.227.56.0/2113.227.56.1 to 13.227.63.25413.227.63.2552,046
10513.227.64.0/2113.227.64.1 to 13.227.71.25413.227.71.2552,046
10613.227.72.0/2113.227.72.1 to 13.227.79.25413.227.79.2552,046
10713.227.80.0/2113.227.80.1 to 13.227.87.25413.227.87.2552,046
10813.227.88.0/2113.227.88.1 to 13.227.95.25413.227.95.2552,046
10913.227.96.0/2113.227.96.1 to 13.227.103.25413.227.103.2552,046
11013.227.104.0/2113.227.104.1 to 13.227.111.25413.227.111.2552,046
11113.227.112.0/2113.227.112.1 to 13.227.119.25413.227.119.2552,046
11213.227.120.0/2113.227.120.1 to 13.227.127.25413.227.127.2552,046
11313.227.128.0/2113.227.128.1 to 13.227.135.25413.227.135.2552,046
11413.227.136.0/2113.227.136.1 to 13.227.143.25413.227.143.2552,046
11513.227.144.0/2113.227.144.1 to 13.227.151.25413.227.151.2552,046
11613.227.152.0/2113.227.152.1 to 13.227.159.25413.227.159.2552,046
11713.227.160.0/2113.227.160.1 to 13.227.167.25413.227.167.2552,046
11813.227.168.0/2113.227.168.1 to 13.227.175.25413.227.175.2552,046
11913.227.176.0/2113.227.176.1 to 13.227.183.25413.227.183.2552,046
12013.227.184.0/2113.227.184.1 to 13.227.191.25413.227.191.2552,046
12113.227.192.0/2113.227.192.1 to 13.227.199.25413.227.199.2552,046
12213.227.200.0/2113.227.200.1 to 13.227.207.25413.227.207.2552,046
12313.227.208.0/2113.227.208.1 to 13.227.215.25413.227.215.2552,046
12413.227.216.0/2113.227.216.1 to 13.227.223.25413.227.223.2552,046
12513.227.224.0/2113.227.224.1 to 13.227.231.25413.227.231.2552,046
12613.227.232.0/2113.227.232.1 to 13.227.239.25413.227.239.2552,046
12713.227.240.0/2113.227.240.1 to 13.227.247.25413.227.247.2552,046
12813.227.248.0/2113.227.248.1 to 13.227.255.25413.227.255.2552,046
12913.228.0.0/2113.228.0.1 to 13.228.7.25413.228.7.2552,046
13013.228.8.0/2113.228.8.1 to 13.228.15.25413.228.15.2552,046
13113.228.16.0/2113.228.16.1 to 13.228.23.25413.228.23.2552,046
13213.228.24.0/2113.228.24.1 to 13.228.31.25413.228.31.2552,046
13313.228.32.0/2113.228.32.1 to 13.228.39.25413.228.39.2552,046
13413.228.40.0/2113.228.40.1 to 13.228.47.25413.228.47.2552,046
13513.228.48.0/2113.228.48.1 to 13.228.55.25413.228.55.2552,046
13613.228.56.0/2113.228.56.1 to 13.228.63.25413.228.63.2552,046
13713.228.64.0/2113.228.64.1 to 13.228.71.25413.228.71.2552,046
13813.228.72.0/2113.228.72.1 to 13.228.79.25413.228.79.2552,046
13913.228.80.0/2113.228.80.1 to 13.228.87.25413.228.87.2552,046
14013.228.88.0/2113.228.88.1 to 13.228.95.25413.228.95.2552,046
14113.228.96.0/2113.228.96.1 to 13.228.103.25413.228.103.2552,046
14213.228.104.0/2113.228.104.1 to 13.228.111.25413.228.111.2552,046
14313.228.112.0/2113.228.112.1 to 13.228.119.25413.228.119.2552,046
14413.228.120.0/2113.228.120.1 to 13.228.127.25413.228.127.2552,046
14513.228.128.0/2113.228.128.1 to 13.228.135.25413.228.135.2552,046
14613.228.136.0/2113.228.136.1 to 13.228.143.25413.228.143.2552,046
14713.228.144.0/2113.228.144.1 to 13.228.151.25413.228.151.2552,046
14813.228.152.0/2113.228.152.1 to 13.228.159.25413.228.159.2552,046
14913.228.160.0/2113.228.160.1 to 13.228.167.25413.228.167.2552,046
15013.228.168.0/2113.228.168.1 to 13.228.175.25413.228.175.2552,046
15113.228.176.0/2113.228.176.1 to 13.228.183.25413.228.183.2552,046
15213.228.184.0/2113.228.184.1 to 13.228.191.25413.228.191.2552,046
15313.228.192.0/2113.228.192.1 to 13.228.199.25413.228.199.2552,046
15413.228.200.0/2113.228.200.1 to 13.228.207.25413.228.207.2552,046
15513.228.208.0/2113.228.208.1 to 13.228.215.25413.228.215.2552,046
15613.228.216.0/2113.228.216.1 to 13.228.223.25413.228.223.2552,046
15713.228.224.0/2113.228.224.1 to 13.228.231.25413.228.231.2552,046
15813.228.232.0/2113.228.232.1 to 13.228.239.25413.228.239.2552,046
15913.228.240.0/2113.228.240.1 to 13.228.247.25413.228.247.2552,046
16013.228.248.0/2113.228.248.1 to 13.228.255.25413.228.255.2552,046
16113.229.0.0/2113.229.0.1 to 13.229.7.25413.229.7.2552,046
16213.229.8.0/2113.229.8.1 to 13.229.15.25413.229.15.2552,046
16313.229.16.0/2113.229.16.1 to 13.229.23.25413.229.23.2552,046
16413.229.24.0/2113.229.24.1 to 13.229.31.25413.229.31.2552,046
16513.229.32.0/2113.229.32.1 to 13.229.39.25413.229.39.2552,046
16613.229.40.0/2113.229.40.1 to 13.229.47.25413.229.47.2552,046
16713.229.48.0/2113.229.48.1 to 13.229.55.25413.229.55.2552,046
16813.229.56.0/2113.229.56.1 to 13.229.63.25413.229.63.2552,046
16913.229.64.0/2113.229.64.1 to 13.229.71.25413.229.71.2552,046
17013.229.72.0/2113.229.72.1 to 13.229.79.25413.229.79.2552,046
17113.229.80.0/2113.229.80.1 to 13.229.87.25413.229.87.2552,046
17213.229.88.0/2113.229.88.1 to 13.229.95.25413.229.95.2552,046
17313.229.96.0/2113.229.96.1 to 13.229.103.25413.229.103.2552,046
17413.229.104.0/2113.229.104.1 to 13.229.111.25413.229.111.2552,046
17513.229.112.0/2113.229.112.1 to 13.229.119.25413.229.119.2552,046
17613.229.120.0/2113.229.120.1 to 13.229.127.25413.229.127.2552,046
17713.229.128.0/2113.229.128.1 to 13.229.135.25413.229.135.2552,046
17813.229.136.0/2113.229.136.1 to 13.229.143.25413.229.143.2552,046
17913.229.144.0/2113.229.144.1 to 13.229.151.25413.229.151.2552,046
18013.229.152.0/2113.229.152.1 to 13.229.159.25413.229.159.2552,046
18113.229.160.0/2113.229.160.1 to 13.229.167.25413.229.167.2552,046
18213.229.168.0/2113.229.168.1 to 13.229.175.25413.229.175.2552,046
18313.229.176.0/2113.229.176.1 to 13.229.183.25413.229.183.2552,046
18413.229.184.0/2113.229.184.1 to 13.229.191.25413.229.191.2552,046
18513.229.192.0/2113.229.192.1 to 13.229.199.25413.229.199.2552,046
18613.229.200.0/2113.229.200.1 to 13.229.207.25413.229.207.2552,046
18713.229.208.0/2113.229.208.1 to 13.229.215.25413.229.215.2552,046
18813.229.216.0/2113.229.216.1 to 13.229.223.25413.229.223.2552,046
18913.229.224.0/2113.229.224.1 to 13.229.231.25413.229.231.2552,046
19013.229.232.0/2113.229.232.1 to 13.229.239.25413.229.239.2552,046
19113.229.240.0/2113.229.240.1 to 13.229.247.25413.229.247.2552,046
19213.229.248.0/2113.229.248.1 to 13.229.255.25413.229.255.2552,046
19313.230.0.0/2113.230.0.1 to 13.230.7.25413.230.7.2552,046
19413.230.8.0/2113.230.8.1 to 13.230.15.25413.230.15.2552,046
19513.230.16.0/2113.230.16.1 to 13.230.23.25413.230.23.2552,046
19613.230.24.0/2113.230.24.1 to 13.230.31.25413.230.31.2552,046
19713.230.32.0/2113.230.32.1 to 13.230.39.25413.230.39.2552,046
19813.230.40.0/2113.230.40.1 to 13.230.47.25413.230.47.2552,046
19913.230.48.0/2113.230.48.1 to 13.230.55.25413.230.55.2552,046
20013.230.56.0/2113.230.56.1 to 13.230.63.25413.230.63.2552,046
20113.230.64.0/2113.230.64.1 to 13.230.71.25413.230.71.2552,046
20213.230.72.0/2113.230.72.1 to 13.230.79.25413.230.79.2552,046
20313.230.80.0/2113.230.80.1 to 13.230.87.25413.230.87.2552,046
20413.230.88.0/2113.230.88.1 to 13.230.95.25413.230.95.2552,046
20513.230.96.0/2113.230.96.1 to 13.230.103.25413.230.103.2552,046
20613.230.104.0/2113.230.104.1 to 13.230.111.25413.230.111.2552,046
20713.230.112.0/2113.230.112.1 to 13.230.119.25413.230.119.2552,046
20813.230.120.0/2113.230.120.1 to 13.230.127.25413.230.127.2552,046
20913.230.128.0/2113.230.128.1 to 13.230.135.25413.230.135.2552,046
21013.230.136.0/2113.230.136.1 to 13.230.143.25413.230.143.2552,046
21113.230.144.0/2113.230.144.1 to 13.230.151.25413.230.151.2552,046
21213.230.152.0/2113.230.152.1 to 13.230.159.25413.230.159.2552,046
21313.230.160.0/2113.230.160.1 to 13.230.167.25413.230.167.2552,046
21413.230.168.0/2113.230.168.1 to 13.230.175.25413.230.175.2552,046
21513.230.176.0/2113.230.176.1 to 13.230.183.25413.230.183.2552,046
21613.230.184.0/2113.230.184.1 to 13.230.191.25413.230.191.2552,046
21713.230.192.0/2113.230.192.1 to 13.230.199.25413.230.199.2552,046
21813.230.200.0/2113.230.200.1 to 13.230.207.25413.230.207.2552,046
21913.230.208.0/2113.230.208.1 to 13.230.215.25413.230.215.2552,046
22013.230.216.0/2113.230.216.1 to 13.230.223.25413.230.223.2552,046
22113.230.224.0/2113.230.224.1 to 13.230.231.25413.230.231.2552,046
22213.230.232.0/2113.230.232.1 to 13.230.239.25413.230.239.2552,046
22313.230.240.0/2113.230.240.1 to 13.230.247.25413.230.247.2552,046
22413.230.248.0/2113.230.248.1 to 13.230.255.25413.230.255.2552,046
22513.231.0.0/2113.231.0.1 to 13.231.7.25413.231.7.2552,046
22613.231.8.0/2113.231.8.1 to 13.231.15.25413.231.15.2552,046
22713.231.16.0/2113.231.16.1 to 13.231.23.25413.231.23.2552,046
22813.231.24.0/2113.231.24.1 to 13.231.31.25413.231.31.2552,046
22913.231.32.0/2113.231.32.1 to 13.231.39.25413.231.39.2552,046
23013.231.40.0/2113.231.40.1 to 13.231.47.25413.231.47.2552,046
23113.231.48.0/2113.231.48.1 to 13.231.55.25413.231.55.2552,046
23213.231.56.0/2113.231.56.1 to 13.231.63.25413.231.63.2552,046
23313.231.64.0/2113.231.64.1 to 13.231.71.25413.231.71.2552,046
23413.231.72.0/2113.231.72.1 to 13.231.79.25413.231.79.2552,046
23513.231.80.0/2113.231.80.1 to 13.231.87.25413.231.87.2552,046
23613.231.88.0/2113.231.88.1 to 13.231.95.25413.231.95.2552,046
23713.231.96.0/2113.231.96.1 to 13.231.103.25413.231.103.2552,046
23813.231.104.0/2113.231.104.1 to 13.231.111.25413.231.111.2552,046
23913.231.112.0/2113.231.112.1 to 13.231.119.25413.231.119.2552,046
24013.231.120.0/2113.231.120.1 to 13.231.127.25413.231.127.2552,046
24113.231.128.0/2113.231.128.1 to 13.231.135.25413.231.135.2552,046
24213.231.136.0/2113.231.136.1 to 13.231.143.25413.231.143.2552,046
24313.231.144.0/2113.231.144.1 to 13.231.151.25413.231.151.2552,046
24413.231.152.0/2113.231.152.1 to 13.231.159.25413.231.159.2552,046
24513.231.160.0/2113.231.160.1 to 13.231.167.25413.231.167.2552,046
24613.231.168.0/2113.231.168.1 to 13.231.175.25413.231.175.2552,046
24713.231.176.0/2113.231.176.1 to 13.231.183.25413.231.183.2552,046
24813.231.184.0/2113.231.184.1 to 13.231.191.25413.231.191.2552,046
24913.231.192.0/2113.231.192.1 to 13.231.199.25413.231.199.2552,046
25013.231.200.0/2113.231.200.1 to 13.231.207.25413.231.207.2552,046
25113.231.208.0/2113.231.208.1 to 13.231.215.25413.231.215.2552,046
25213.231.216.0/2113.231.216.1 to 13.231.223.25413.231.223.2552,046
25313.231.224.0/2113.231.224.1 to 13.231.231.25413.231.231.2552,046
25413.231.232.0/2113.231.232.1 to 13.231.239.25413.231.239.2552,046
25513.231.240.0/2113.231.240.1 to 13.231.247.25413.231.247.2552,046
25613.231.248.0/2113.231.248.1 to 13.231.255.25413.231.255.2552,046

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.