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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.

Network71.236.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
71.236.0.0
Broadcast address
71.239.255.255
First usable
71.236.0.1
Last usable
71.239.255.254
Usable hosts
262,142 (262,144 less the network and broadcast addresses)
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255 (Cisco ACLs, OSPF)
Prefix length
/14
Type
Public public
Old class
A (default /8)
As numbers
Hex 47EC0000 · Integer 1206648832 to 1206910975
Reverse DNS zones
236.71.in-addr.arpa
237.71.in-addr.arpa
238.71.in-addr.arpa
239.71.in-addr.arpa
/14 is not on a 8-bit boundary, so it takes 4 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01000111.11101100.00000000.0000000071.236.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network01000111.11101100.00000000.0000000071.236.0.0
Broadcast01000111.11101111.11111111.1111111171.239.255.255
Split into smaller subnets/22
/15 (2)/16 (4)/17 (8)/18 (16)/19 (32)/20 (64)/21 (128)/22 (256)/23 (512)/24 (1,024)/25 (2,048)/26 (4,096)

71.236.0.0/14 makes 256 subnets of /22.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
171.236.0.0/2271.236.0.1 to 71.236.3.25471.236.3.2551,022
271.236.4.0/2271.236.4.1 to 71.236.7.25471.236.7.2551,022
371.236.8.0/2271.236.8.1 to 71.236.11.25471.236.11.2551,022
471.236.12.0/2271.236.12.1 to 71.236.15.25471.236.15.2551,022
571.236.16.0/2271.236.16.1 to 71.236.19.25471.236.19.2551,022
671.236.20.0/2271.236.20.1 to 71.236.23.25471.236.23.2551,022
771.236.24.0/2271.236.24.1 to 71.236.27.25471.236.27.2551,022
871.236.28.0/2271.236.28.1 to 71.236.31.25471.236.31.2551,022
971.236.32.0/2271.236.32.1 to 71.236.35.25471.236.35.2551,022
1071.236.36.0/2271.236.36.1 to 71.236.39.25471.236.39.2551,022
1171.236.40.0/2271.236.40.1 to 71.236.43.25471.236.43.2551,022
1271.236.44.0/2271.236.44.1 to 71.236.47.25471.236.47.2551,022
1371.236.48.0/2271.236.48.1 to 71.236.51.25471.236.51.2551,022
1471.236.52.0/2271.236.52.1 to 71.236.55.25471.236.55.2551,022
1571.236.56.0/2271.236.56.1 to 71.236.59.25471.236.59.2551,022
1671.236.60.0/2271.236.60.1 to 71.236.63.25471.236.63.2551,022
1771.236.64.0/2271.236.64.1 to 71.236.67.25471.236.67.2551,022
1871.236.68.0/2271.236.68.1 to 71.236.71.25471.236.71.2551,022
1971.236.72.0/2271.236.72.1 to 71.236.75.25471.236.75.2551,022
2071.236.76.0/2271.236.76.1 to 71.236.79.25471.236.79.2551,022
2171.236.80.0/2271.236.80.1 to 71.236.83.25471.236.83.2551,022
2271.236.84.0/2271.236.84.1 to 71.236.87.25471.236.87.2551,022
2371.236.88.0/2271.236.88.1 to 71.236.91.25471.236.91.2551,022
2471.236.92.0/2271.236.92.1 to 71.236.95.25471.236.95.2551,022
2571.236.96.0/2271.236.96.1 to 71.236.99.25471.236.99.2551,022
2671.236.100.0/2271.236.100.1 to 71.236.103.25471.236.103.2551,022
2771.236.104.0/2271.236.104.1 to 71.236.107.25471.236.107.2551,022
2871.236.108.0/2271.236.108.1 to 71.236.111.25471.236.111.2551,022
2971.236.112.0/2271.236.112.1 to 71.236.115.25471.236.115.2551,022
3071.236.116.0/2271.236.116.1 to 71.236.119.25471.236.119.2551,022
3171.236.120.0/2271.236.120.1 to 71.236.123.25471.236.123.2551,022
3271.236.124.0/2271.236.124.1 to 71.236.127.25471.236.127.2551,022
3371.236.128.0/2271.236.128.1 to 71.236.131.25471.236.131.2551,022
3471.236.132.0/2271.236.132.1 to 71.236.135.25471.236.135.2551,022
3571.236.136.0/2271.236.136.1 to 71.236.139.25471.236.139.2551,022
3671.236.140.0/2271.236.140.1 to 71.236.143.25471.236.143.2551,022
3771.236.144.0/2271.236.144.1 to 71.236.147.25471.236.147.2551,022
3871.236.148.0/2271.236.148.1 to 71.236.151.25471.236.151.2551,022
3971.236.152.0/2271.236.152.1 to 71.236.155.25471.236.155.2551,022
4071.236.156.0/2271.236.156.1 to 71.236.159.25471.236.159.2551,022
4171.236.160.0/2271.236.160.1 to 71.236.163.25471.236.163.2551,022
4271.236.164.0/2271.236.164.1 to 71.236.167.25471.236.167.2551,022
4371.236.168.0/2271.236.168.1 to 71.236.171.25471.236.171.2551,022
4471.236.172.0/2271.236.172.1 to 71.236.175.25471.236.175.2551,022
4571.236.176.0/2271.236.176.1 to 71.236.179.25471.236.179.2551,022
4671.236.180.0/2271.236.180.1 to 71.236.183.25471.236.183.2551,022
4771.236.184.0/2271.236.184.1 to 71.236.187.25471.236.187.2551,022
4871.236.188.0/2271.236.188.1 to 71.236.191.25471.236.191.2551,022
4971.236.192.0/2271.236.192.1 to 71.236.195.25471.236.195.2551,022
5071.236.196.0/2271.236.196.1 to 71.236.199.25471.236.199.2551,022
5171.236.200.0/2271.236.200.1 to 71.236.203.25471.236.203.2551,022
5271.236.204.0/2271.236.204.1 to 71.236.207.25471.236.207.2551,022
5371.236.208.0/2271.236.208.1 to 71.236.211.25471.236.211.2551,022
5471.236.212.0/2271.236.212.1 to 71.236.215.25471.236.215.2551,022
5571.236.216.0/2271.236.216.1 to 71.236.219.25471.236.219.2551,022
5671.236.220.0/2271.236.220.1 to 71.236.223.25471.236.223.2551,022
5771.236.224.0/2271.236.224.1 to 71.236.227.25471.236.227.2551,022
5871.236.228.0/2271.236.228.1 to 71.236.231.25471.236.231.2551,022
5971.236.232.0/2271.236.232.1 to 71.236.235.25471.236.235.2551,022
6071.236.236.0/2271.236.236.1 to 71.236.239.25471.236.239.2551,022
6171.236.240.0/2271.236.240.1 to 71.236.243.25471.236.243.2551,022
6271.236.244.0/2271.236.244.1 to 71.236.247.25471.236.247.2551,022
6371.236.248.0/2271.236.248.1 to 71.236.251.25471.236.251.2551,022
6471.236.252.0/2271.236.252.1 to 71.236.255.25471.236.255.2551,022
6571.237.0.0/2271.237.0.1 to 71.237.3.25471.237.3.2551,022
6671.237.4.0/2271.237.4.1 to 71.237.7.25471.237.7.2551,022
6771.237.8.0/2271.237.8.1 to 71.237.11.25471.237.11.2551,022
6871.237.12.0/2271.237.12.1 to 71.237.15.25471.237.15.2551,022
6971.237.16.0/2271.237.16.1 to 71.237.19.25471.237.19.2551,022
7071.237.20.0/2271.237.20.1 to 71.237.23.25471.237.23.2551,022
7171.237.24.0/2271.237.24.1 to 71.237.27.25471.237.27.2551,022
7271.237.28.0/2271.237.28.1 to 71.237.31.25471.237.31.2551,022
7371.237.32.0/2271.237.32.1 to 71.237.35.25471.237.35.2551,022
7471.237.36.0/2271.237.36.1 to 71.237.39.25471.237.39.2551,022
7571.237.40.0/2271.237.40.1 to 71.237.43.25471.237.43.2551,022
7671.237.44.0/2271.237.44.1 to 71.237.47.25471.237.47.2551,022
7771.237.48.0/2271.237.48.1 to 71.237.51.25471.237.51.2551,022
7871.237.52.0/2271.237.52.1 to 71.237.55.25471.237.55.2551,022
7971.237.56.0/2271.237.56.1 to 71.237.59.25471.237.59.2551,022
8071.237.60.0/2271.237.60.1 to 71.237.63.25471.237.63.2551,022
8171.237.64.0/2271.237.64.1 to 71.237.67.25471.237.67.2551,022
8271.237.68.0/2271.237.68.1 to 71.237.71.25471.237.71.2551,022
8371.237.72.0/2271.237.72.1 to 71.237.75.25471.237.75.2551,022
8471.237.76.0/2271.237.76.1 to 71.237.79.25471.237.79.2551,022
8571.237.80.0/2271.237.80.1 to 71.237.83.25471.237.83.2551,022
8671.237.84.0/2271.237.84.1 to 71.237.87.25471.237.87.2551,022
8771.237.88.0/2271.237.88.1 to 71.237.91.25471.237.91.2551,022
8871.237.92.0/2271.237.92.1 to 71.237.95.25471.237.95.2551,022
8971.237.96.0/2271.237.96.1 to 71.237.99.25471.237.99.2551,022
9071.237.100.0/2271.237.100.1 to 71.237.103.25471.237.103.2551,022
9171.237.104.0/2271.237.104.1 to 71.237.107.25471.237.107.2551,022
9271.237.108.0/2271.237.108.1 to 71.237.111.25471.237.111.2551,022
9371.237.112.0/2271.237.112.1 to 71.237.115.25471.237.115.2551,022
9471.237.116.0/2271.237.116.1 to 71.237.119.25471.237.119.2551,022
9571.237.120.0/2271.237.120.1 to 71.237.123.25471.237.123.2551,022
9671.237.124.0/2271.237.124.1 to 71.237.127.25471.237.127.2551,022
9771.237.128.0/2271.237.128.1 to 71.237.131.25471.237.131.2551,022
9871.237.132.0/2271.237.132.1 to 71.237.135.25471.237.135.2551,022
9971.237.136.0/2271.237.136.1 to 71.237.139.25471.237.139.2551,022
10071.237.140.0/2271.237.140.1 to 71.237.143.25471.237.143.2551,022
10171.237.144.0/2271.237.144.1 to 71.237.147.25471.237.147.2551,022
10271.237.148.0/2271.237.148.1 to 71.237.151.25471.237.151.2551,022
10371.237.152.0/2271.237.152.1 to 71.237.155.25471.237.155.2551,022
10471.237.156.0/2271.237.156.1 to 71.237.159.25471.237.159.2551,022
10571.237.160.0/2271.237.160.1 to 71.237.163.25471.237.163.2551,022
10671.237.164.0/2271.237.164.1 to 71.237.167.25471.237.167.2551,022
10771.237.168.0/2271.237.168.1 to 71.237.171.25471.237.171.2551,022
10871.237.172.0/2271.237.172.1 to 71.237.175.25471.237.175.2551,022
10971.237.176.0/2271.237.176.1 to 71.237.179.25471.237.179.2551,022
11071.237.180.0/2271.237.180.1 to 71.237.183.25471.237.183.2551,022
11171.237.184.0/2271.237.184.1 to 71.237.187.25471.237.187.2551,022
11271.237.188.0/2271.237.188.1 to 71.237.191.25471.237.191.2551,022
11371.237.192.0/2271.237.192.1 to 71.237.195.25471.237.195.2551,022
11471.237.196.0/2271.237.196.1 to 71.237.199.25471.237.199.2551,022
11571.237.200.0/2271.237.200.1 to 71.237.203.25471.237.203.2551,022
11671.237.204.0/2271.237.204.1 to 71.237.207.25471.237.207.2551,022
11771.237.208.0/2271.237.208.1 to 71.237.211.25471.237.211.2551,022
11871.237.212.0/2271.237.212.1 to 71.237.215.25471.237.215.2551,022
11971.237.216.0/2271.237.216.1 to 71.237.219.25471.237.219.2551,022
12071.237.220.0/2271.237.220.1 to 71.237.223.25471.237.223.2551,022
12171.237.224.0/2271.237.224.1 to 71.237.227.25471.237.227.2551,022
12271.237.228.0/2271.237.228.1 to 71.237.231.25471.237.231.2551,022
12371.237.232.0/2271.237.232.1 to 71.237.235.25471.237.235.2551,022
12471.237.236.0/2271.237.236.1 to 71.237.239.25471.237.239.2551,022
12571.237.240.0/2271.237.240.1 to 71.237.243.25471.237.243.2551,022
12671.237.244.0/2271.237.244.1 to 71.237.247.25471.237.247.2551,022
12771.237.248.0/2271.237.248.1 to 71.237.251.25471.237.251.2551,022
12871.237.252.0/2271.237.252.1 to 71.237.255.25471.237.255.2551,022
12971.238.0.0/2271.238.0.1 to 71.238.3.25471.238.3.2551,022
13071.238.4.0/2271.238.4.1 to 71.238.7.25471.238.7.2551,022
13171.238.8.0/2271.238.8.1 to 71.238.11.25471.238.11.2551,022
13271.238.12.0/2271.238.12.1 to 71.238.15.25471.238.15.2551,022
13371.238.16.0/2271.238.16.1 to 71.238.19.25471.238.19.2551,022
13471.238.20.0/2271.238.20.1 to 71.238.23.25471.238.23.2551,022
13571.238.24.0/2271.238.24.1 to 71.238.27.25471.238.27.2551,022
13671.238.28.0/2271.238.28.1 to 71.238.31.25471.238.31.2551,022
13771.238.32.0/2271.238.32.1 to 71.238.35.25471.238.35.2551,022
13871.238.36.0/2271.238.36.1 to 71.238.39.25471.238.39.2551,022
13971.238.40.0/2271.238.40.1 to 71.238.43.25471.238.43.2551,022
14071.238.44.0/2271.238.44.1 to 71.238.47.25471.238.47.2551,022
14171.238.48.0/2271.238.48.1 to 71.238.51.25471.238.51.2551,022
14271.238.52.0/2271.238.52.1 to 71.238.55.25471.238.55.2551,022
14371.238.56.0/2271.238.56.1 to 71.238.59.25471.238.59.2551,022
14471.238.60.0/2271.238.60.1 to 71.238.63.25471.238.63.2551,022
14571.238.64.0/2271.238.64.1 to 71.238.67.25471.238.67.2551,022
14671.238.68.0/2271.238.68.1 to 71.238.71.25471.238.71.2551,022
14771.238.72.0/2271.238.72.1 to 71.238.75.25471.238.75.2551,022
14871.238.76.0/2271.238.76.1 to 71.238.79.25471.238.79.2551,022
14971.238.80.0/2271.238.80.1 to 71.238.83.25471.238.83.2551,022
15071.238.84.0/2271.238.84.1 to 71.238.87.25471.238.87.2551,022
15171.238.88.0/2271.238.88.1 to 71.238.91.25471.238.91.2551,022
15271.238.92.0/2271.238.92.1 to 71.238.95.25471.238.95.2551,022
15371.238.96.0/2271.238.96.1 to 71.238.99.25471.238.99.2551,022
15471.238.100.0/2271.238.100.1 to 71.238.103.25471.238.103.2551,022
15571.238.104.0/2271.238.104.1 to 71.238.107.25471.238.107.2551,022
15671.238.108.0/2271.238.108.1 to 71.238.111.25471.238.111.2551,022
15771.238.112.0/2271.238.112.1 to 71.238.115.25471.238.115.2551,022
15871.238.116.0/2271.238.116.1 to 71.238.119.25471.238.119.2551,022
15971.238.120.0/2271.238.120.1 to 71.238.123.25471.238.123.2551,022
16071.238.124.0/2271.238.124.1 to 71.238.127.25471.238.127.2551,022
16171.238.128.0/2271.238.128.1 to 71.238.131.25471.238.131.2551,022
16271.238.132.0/2271.238.132.1 to 71.238.135.25471.238.135.2551,022
16371.238.136.0/2271.238.136.1 to 71.238.139.25471.238.139.2551,022
16471.238.140.0/2271.238.140.1 to 71.238.143.25471.238.143.2551,022
16571.238.144.0/2271.238.144.1 to 71.238.147.25471.238.147.2551,022
16671.238.148.0/2271.238.148.1 to 71.238.151.25471.238.151.2551,022
16771.238.152.0/2271.238.152.1 to 71.238.155.25471.238.155.2551,022
16871.238.156.0/2271.238.156.1 to 71.238.159.25471.238.159.2551,022
16971.238.160.0/2271.238.160.1 to 71.238.163.25471.238.163.2551,022
17071.238.164.0/2271.238.164.1 to 71.238.167.25471.238.167.2551,022
17171.238.168.0/2271.238.168.1 to 71.238.171.25471.238.171.2551,022
17271.238.172.0/2271.238.172.1 to 71.238.175.25471.238.175.2551,022
17371.238.176.0/2271.238.176.1 to 71.238.179.25471.238.179.2551,022
17471.238.180.0/2271.238.180.1 to 71.238.183.25471.238.183.2551,022
17571.238.184.0/2271.238.184.1 to 71.238.187.25471.238.187.2551,022
17671.238.188.0/2271.238.188.1 to 71.238.191.25471.238.191.2551,022
17771.238.192.0/2271.238.192.1 to 71.238.195.25471.238.195.2551,022
17871.238.196.0/2271.238.196.1 to 71.238.199.25471.238.199.2551,022
17971.238.200.0/2271.238.200.1 to 71.238.203.25471.238.203.2551,022
18071.238.204.0/2271.238.204.1 to 71.238.207.25471.238.207.2551,022
18171.238.208.0/2271.238.208.1 to 71.238.211.25471.238.211.2551,022
18271.238.212.0/2271.238.212.1 to 71.238.215.25471.238.215.2551,022
18371.238.216.0/2271.238.216.1 to 71.238.219.25471.238.219.2551,022
18471.238.220.0/2271.238.220.1 to 71.238.223.25471.238.223.2551,022
18571.238.224.0/2271.238.224.1 to 71.238.227.25471.238.227.2551,022
18671.238.228.0/2271.238.228.1 to 71.238.231.25471.238.231.2551,022
18771.238.232.0/2271.238.232.1 to 71.238.235.25471.238.235.2551,022
18871.238.236.0/2271.238.236.1 to 71.238.239.25471.238.239.2551,022
18971.238.240.0/2271.238.240.1 to 71.238.243.25471.238.243.2551,022
19071.238.244.0/2271.238.244.1 to 71.238.247.25471.238.247.2551,022
19171.238.248.0/2271.238.248.1 to 71.238.251.25471.238.251.2551,022
19271.238.252.0/2271.238.252.1 to 71.238.255.25471.238.255.2551,022
19371.239.0.0/2271.239.0.1 to 71.239.3.25471.239.3.2551,022
19471.239.4.0/2271.239.4.1 to 71.239.7.25471.239.7.2551,022
19571.239.8.0/2271.239.8.1 to 71.239.11.25471.239.11.2551,022
19671.239.12.0/2271.239.12.1 to 71.239.15.25471.239.15.2551,022
19771.239.16.0/2271.239.16.1 to 71.239.19.25471.239.19.2551,022
19871.239.20.0/2271.239.20.1 to 71.239.23.25471.239.23.2551,022
19971.239.24.0/2271.239.24.1 to 71.239.27.25471.239.27.2551,022
20071.239.28.0/2271.239.28.1 to 71.239.31.25471.239.31.2551,022
20171.239.32.0/2271.239.32.1 to 71.239.35.25471.239.35.2551,022
20271.239.36.0/2271.239.36.1 to 71.239.39.25471.239.39.2551,022
20371.239.40.0/2271.239.40.1 to 71.239.43.25471.239.43.2551,022
20471.239.44.0/2271.239.44.1 to 71.239.47.25471.239.47.2551,022
20571.239.48.0/2271.239.48.1 to 71.239.51.25471.239.51.2551,022
20671.239.52.0/2271.239.52.1 to 71.239.55.25471.239.55.2551,022
20771.239.56.0/2271.239.56.1 to 71.239.59.25471.239.59.2551,022
20871.239.60.0/2271.239.60.1 to 71.239.63.25471.239.63.2551,022
20971.239.64.0/2271.239.64.1 to 71.239.67.25471.239.67.2551,022
21071.239.68.0/2271.239.68.1 to 71.239.71.25471.239.71.2551,022
21171.239.72.0/2271.239.72.1 to 71.239.75.25471.239.75.2551,022
21271.239.76.0/2271.239.76.1 to 71.239.79.25471.239.79.2551,022
21371.239.80.0/2271.239.80.1 to 71.239.83.25471.239.83.2551,022
21471.239.84.0/2271.239.84.1 to 71.239.87.25471.239.87.2551,022
21571.239.88.0/2271.239.88.1 to 71.239.91.25471.239.91.2551,022
21671.239.92.0/2271.239.92.1 to 71.239.95.25471.239.95.2551,022
21771.239.96.0/2271.239.96.1 to 71.239.99.25471.239.99.2551,022
21871.239.100.0/2271.239.100.1 to 71.239.103.25471.239.103.2551,022
21971.239.104.0/2271.239.104.1 to 71.239.107.25471.239.107.2551,022
22071.239.108.0/2271.239.108.1 to 71.239.111.25471.239.111.2551,022
22171.239.112.0/2271.239.112.1 to 71.239.115.25471.239.115.2551,022
22271.239.116.0/2271.239.116.1 to 71.239.119.25471.239.119.2551,022
22371.239.120.0/2271.239.120.1 to 71.239.123.25471.239.123.2551,022
22471.239.124.0/2271.239.124.1 to 71.239.127.25471.239.127.2551,022
22571.239.128.0/2271.239.128.1 to 71.239.131.25471.239.131.2551,022
22671.239.132.0/2271.239.132.1 to 71.239.135.25471.239.135.2551,022
22771.239.136.0/2271.239.136.1 to 71.239.139.25471.239.139.2551,022
22871.239.140.0/2271.239.140.1 to 71.239.143.25471.239.143.2551,022
22971.239.144.0/2271.239.144.1 to 71.239.147.25471.239.147.2551,022
23071.239.148.0/2271.239.148.1 to 71.239.151.25471.239.151.2551,022
23171.239.152.0/2271.239.152.1 to 71.239.155.25471.239.155.2551,022
23271.239.156.0/2271.239.156.1 to 71.239.159.25471.239.159.2551,022
23371.239.160.0/2271.239.160.1 to 71.239.163.25471.239.163.2551,022
23471.239.164.0/2271.239.164.1 to 71.239.167.25471.239.167.2551,022
23571.239.168.0/2271.239.168.1 to 71.239.171.25471.239.171.2551,022
23671.239.172.0/2271.239.172.1 to 71.239.175.25471.239.175.2551,022
23771.239.176.0/2271.239.176.1 to 71.239.179.25471.239.179.2551,022
23871.239.180.0/2271.239.180.1 to 71.239.183.25471.239.183.2551,022
23971.239.184.0/2271.239.184.1 to 71.239.187.25471.239.187.2551,022
24071.239.188.0/2271.239.188.1 to 71.239.191.25471.239.191.2551,022
24171.239.192.0/2271.239.192.1 to 71.239.195.25471.239.195.2551,022
24271.239.196.0/2271.239.196.1 to 71.239.199.25471.239.199.2551,022
24371.239.200.0/2271.239.200.1 to 71.239.203.25471.239.203.2551,022
24471.239.204.0/2271.239.204.1 to 71.239.207.25471.239.207.2551,022
24571.239.208.0/2271.239.208.1 to 71.239.211.25471.239.211.2551,022
24671.239.212.0/2271.239.212.1 to 71.239.215.25471.239.215.2551,022
24771.239.216.0/2271.239.216.1 to 71.239.219.25471.239.219.2551,022
24871.239.220.0/2271.239.220.1 to 71.239.223.25471.239.223.2551,022
24971.239.224.0/2271.239.224.1 to 71.239.227.25471.239.227.2551,022
25071.239.228.0/2271.239.228.1 to 71.239.231.25471.239.231.2551,022
25171.239.232.0/2271.239.232.1 to 71.239.235.25471.239.235.2551,022
25271.239.236.0/2271.239.236.1 to 71.239.239.25471.239.239.2551,022
25371.239.240.0/2271.239.240.1 to 71.239.243.25471.239.243.2551,022
25471.239.244.0/2271.239.244.1 to 71.239.247.25471.239.247.2551,022
25571.239.248.0/2271.239.248.1 to 71.239.251.25471.239.251.2551,022
25671.239.252.0/2271.239.252.1 to 71.239.255.25471.239.255.2551,022

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.