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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.

Network71.48.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
71.48.0.0
Broadcast address
71.55.255.255
First usable
71.48.0.1
Last usable
71.55.255.254
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 47300000 · Integer 1194328064 to 1194852351
Reverse DNS zones
48.71.in-addr.arpa
49.71.in-addr.arpa
50.71.in-addr.arpa
51.71.in-addr.arpa
52.71.in-addr.arpa
53.71.in-addr.arpa
54.71.in-addr.arpa
55.71.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
Address01000111.00110000.00000000.0000000071.48.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network01000111.00110000.00000000.0000000071.48.0.0
Broadcast01000111.00110111.11111111.1111111171.55.255.255
Split into smaller subnets/23
/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)

71.48.0.0/13 makes 1,024 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
171.48.0.0/2371.48.0.1 to 71.48.1.25471.48.1.255510
271.48.2.0/2371.48.2.1 to 71.48.3.25471.48.3.255510
371.48.4.0/2371.48.4.1 to 71.48.5.25471.48.5.255510
471.48.6.0/2371.48.6.1 to 71.48.7.25471.48.7.255510
571.48.8.0/2371.48.8.1 to 71.48.9.25471.48.9.255510
671.48.10.0/2371.48.10.1 to 71.48.11.25471.48.11.255510
771.48.12.0/2371.48.12.1 to 71.48.13.25471.48.13.255510
871.48.14.0/2371.48.14.1 to 71.48.15.25471.48.15.255510
971.48.16.0/2371.48.16.1 to 71.48.17.25471.48.17.255510
1071.48.18.0/2371.48.18.1 to 71.48.19.25471.48.19.255510
1171.48.20.0/2371.48.20.1 to 71.48.21.25471.48.21.255510
1271.48.22.0/2371.48.22.1 to 71.48.23.25471.48.23.255510
1371.48.24.0/2371.48.24.1 to 71.48.25.25471.48.25.255510
1471.48.26.0/2371.48.26.1 to 71.48.27.25471.48.27.255510
1571.48.28.0/2371.48.28.1 to 71.48.29.25471.48.29.255510
1671.48.30.0/2371.48.30.1 to 71.48.31.25471.48.31.255510
1771.48.32.0/2371.48.32.1 to 71.48.33.25471.48.33.255510
1871.48.34.0/2371.48.34.1 to 71.48.35.25471.48.35.255510
1971.48.36.0/2371.48.36.1 to 71.48.37.25471.48.37.255510
2071.48.38.0/2371.48.38.1 to 71.48.39.25471.48.39.255510
2171.48.40.0/2371.48.40.1 to 71.48.41.25471.48.41.255510
2271.48.42.0/2371.48.42.1 to 71.48.43.25471.48.43.255510
2371.48.44.0/2371.48.44.1 to 71.48.45.25471.48.45.255510
2471.48.46.0/2371.48.46.1 to 71.48.47.25471.48.47.255510
2571.48.48.0/2371.48.48.1 to 71.48.49.25471.48.49.255510
2671.48.50.0/2371.48.50.1 to 71.48.51.25471.48.51.255510
2771.48.52.0/2371.48.52.1 to 71.48.53.25471.48.53.255510
2871.48.54.0/2371.48.54.1 to 71.48.55.25471.48.55.255510
2971.48.56.0/2371.48.56.1 to 71.48.57.25471.48.57.255510
3071.48.58.0/2371.48.58.1 to 71.48.59.25471.48.59.255510
3171.48.60.0/2371.48.60.1 to 71.48.61.25471.48.61.255510
3271.48.62.0/2371.48.62.1 to 71.48.63.25471.48.63.255510
3371.48.64.0/2371.48.64.1 to 71.48.65.25471.48.65.255510
3471.48.66.0/2371.48.66.1 to 71.48.67.25471.48.67.255510
3571.48.68.0/2371.48.68.1 to 71.48.69.25471.48.69.255510
3671.48.70.0/2371.48.70.1 to 71.48.71.25471.48.71.255510
3771.48.72.0/2371.48.72.1 to 71.48.73.25471.48.73.255510
3871.48.74.0/2371.48.74.1 to 71.48.75.25471.48.75.255510
3971.48.76.0/2371.48.76.1 to 71.48.77.25471.48.77.255510
4071.48.78.0/2371.48.78.1 to 71.48.79.25471.48.79.255510
4171.48.80.0/2371.48.80.1 to 71.48.81.25471.48.81.255510
4271.48.82.0/2371.48.82.1 to 71.48.83.25471.48.83.255510
4371.48.84.0/2371.48.84.1 to 71.48.85.25471.48.85.255510
4471.48.86.0/2371.48.86.1 to 71.48.87.25471.48.87.255510
4571.48.88.0/2371.48.88.1 to 71.48.89.25471.48.89.255510
4671.48.90.0/2371.48.90.1 to 71.48.91.25471.48.91.255510
4771.48.92.0/2371.48.92.1 to 71.48.93.25471.48.93.255510
4871.48.94.0/2371.48.94.1 to 71.48.95.25471.48.95.255510
4971.48.96.0/2371.48.96.1 to 71.48.97.25471.48.97.255510
5071.48.98.0/2371.48.98.1 to 71.48.99.25471.48.99.255510
5171.48.100.0/2371.48.100.1 to 71.48.101.25471.48.101.255510
5271.48.102.0/2371.48.102.1 to 71.48.103.25471.48.103.255510
5371.48.104.0/2371.48.104.1 to 71.48.105.25471.48.105.255510
5471.48.106.0/2371.48.106.1 to 71.48.107.25471.48.107.255510
5571.48.108.0/2371.48.108.1 to 71.48.109.25471.48.109.255510
5671.48.110.0/2371.48.110.1 to 71.48.111.25471.48.111.255510
5771.48.112.0/2371.48.112.1 to 71.48.113.25471.48.113.255510
5871.48.114.0/2371.48.114.1 to 71.48.115.25471.48.115.255510
5971.48.116.0/2371.48.116.1 to 71.48.117.25471.48.117.255510
6071.48.118.0/2371.48.118.1 to 71.48.119.25471.48.119.255510
6171.48.120.0/2371.48.120.1 to 71.48.121.25471.48.121.255510
6271.48.122.0/2371.48.122.1 to 71.48.123.25471.48.123.255510
6371.48.124.0/2371.48.124.1 to 71.48.125.25471.48.125.255510
6471.48.126.0/2371.48.126.1 to 71.48.127.25471.48.127.255510
6571.48.128.0/2371.48.128.1 to 71.48.129.25471.48.129.255510
6671.48.130.0/2371.48.130.1 to 71.48.131.25471.48.131.255510
6771.48.132.0/2371.48.132.1 to 71.48.133.25471.48.133.255510
6871.48.134.0/2371.48.134.1 to 71.48.135.25471.48.135.255510
6971.48.136.0/2371.48.136.1 to 71.48.137.25471.48.137.255510
7071.48.138.0/2371.48.138.1 to 71.48.139.25471.48.139.255510
7171.48.140.0/2371.48.140.1 to 71.48.141.25471.48.141.255510
7271.48.142.0/2371.48.142.1 to 71.48.143.25471.48.143.255510
7371.48.144.0/2371.48.144.1 to 71.48.145.25471.48.145.255510
7471.48.146.0/2371.48.146.1 to 71.48.147.25471.48.147.255510
7571.48.148.0/2371.48.148.1 to 71.48.149.25471.48.149.255510
7671.48.150.0/2371.48.150.1 to 71.48.151.25471.48.151.255510
7771.48.152.0/2371.48.152.1 to 71.48.153.25471.48.153.255510
7871.48.154.0/2371.48.154.1 to 71.48.155.25471.48.155.255510
7971.48.156.0/2371.48.156.1 to 71.48.157.25471.48.157.255510
8071.48.158.0/2371.48.158.1 to 71.48.159.25471.48.159.255510
8171.48.160.0/2371.48.160.1 to 71.48.161.25471.48.161.255510
8271.48.162.0/2371.48.162.1 to 71.48.163.25471.48.163.255510
8371.48.164.0/2371.48.164.1 to 71.48.165.25471.48.165.255510
8471.48.166.0/2371.48.166.1 to 71.48.167.25471.48.167.255510
8571.48.168.0/2371.48.168.1 to 71.48.169.25471.48.169.255510
8671.48.170.0/2371.48.170.1 to 71.48.171.25471.48.171.255510
8771.48.172.0/2371.48.172.1 to 71.48.173.25471.48.173.255510
8871.48.174.0/2371.48.174.1 to 71.48.175.25471.48.175.255510
8971.48.176.0/2371.48.176.1 to 71.48.177.25471.48.177.255510
9071.48.178.0/2371.48.178.1 to 71.48.179.25471.48.179.255510
9171.48.180.0/2371.48.180.1 to 71.48.181.25471.48.181.255510
9271.48.182.0/2371.48.182.1 to 71.48.183.25471.48.183.255510
9371.48.184.0/2371.48.184.1 to 71.48.185.25471.48.185.255510
9471.48.186.0/2371.48.186.1 to 71.48.187.25471.48.187.255510
9571.48.188.0/2371.48.188.1 to 71.48.189.25471.48.189.255510
9671.48.190.0/2371.48.190.1 to 71.48.191.25471.48.191.255510
9771.48.192.0/2371.48.192.1 to 71.48.193.25471.48.193.255510
9871.48.194.0/2371.48.194.1 to 71.48.195.25471.48.195.255510
9971.48.196.0/2371.48.196.1 to 71.48.197.25471.48.197.255510
10071.48.198.0/2371.48.198.1 to 71.48.199.25471.48.199.255510
10171.48.200.0/2371.48.200.1 to 71.48.201.25471.48.201.255510
10271.48.202.0/2371.48.202.1 to 71.48.203.25471.48.203.255510
10371.48.204.0/2371.48.204.1 to 71.48.205.25471.48.205.255510
10471.48.206.0/2371.48.206.1 to 71.48.207.25471.48.207.255510
10571.48.208.0/2371.48.208.1 to 71.48.209.25471.48.209.255510
10671.48.210.0/2371.48.210.1 to 71.48.211.25471.48.211.255510
10771.48.212.0/2371.48.212.1 to 71.48.213.25471.48.213.255510
10871.48.214.0/2371.48.214.1 to 71.48.215.25471.48.215.255510
10971.48.216.0/2371.48.216.1 to 71.48.217.25471.48.217.255510
11071.48.218.0/2371.48.218.1 to 71.48.219.25471.48.219.255510
11171.48.220.0/2371.48.220.1 to 71.48.221.25471.48.221.255510
11271.48.222.0/2371.48.222.1 to 71.48.223.25471.48.223.255510
11371.48.224.0/2371.48.224.1 to 71.48.225.25471.48.225.255510
11471.48.226.0/2371.48.226.1 to 71.48.227.25471.48.227.255510
11571.48.228.0/2371.48.228.1 to 71.48.229.25471.48.229.255510
11671.48.230.0/2371.48.230.1 to 71.48.231.25471.48.231.255510
11771.48.232.0/2371.48.232.1 to 71.48.233.25471.48.233.255510
11871.48.234.0/2371.48.234.1 to 71.48.235.25471.48.235.255510
11971.48.236.0/2371.48.236.1 to 71.48.237.25471.48.237.255510
12071.48.238.0/2371.48.238.1 to 71.48.239.25471.48.239.255510
12171.48.240.0/2371.48.240.1 to 71.48.241.25471.48.241.255510
12271.48.242.0/2371.48.242.1 to 71.48.243.25471.48.243.255510
12371.48.244.0/2371.48.244.1 to 71.48.245.25471.48.245.255510
12471.48.246.0/2371.48.246.1 to 71.48.247.25471.48.247.255510
12571.48.248.0/2371.48.248.1 to 71.48.249.25471.48.249.255510
12671.48.250.0/2371.48.250.1 to 71.48.251.25471.48.251.255510
12771.48.252.0/2371.48.252.1 to 71.48.253.25471.48.253.255510
12871.48.254.0/2371.48.254.1 to 71.48.255.25471.48.255.255510
12971.49.0.0/2371.49.0.1 to 71.49.1.25471.49.1.255510
13071.49.2.0/2371.49.2.1 to 71.49.3.25471.49.3.255510
13171.49.4.0/2371.49.4.1 to 71.49.5.25471.49.5.255510
13271.49.6.0/2371.49.6.1 to 71.49.7.25471.49.7.255510
13371.49.8.0/2371.49.8.1 to 71.49.9.25471.49.9.255510
13471.49.10.0/2371.49.10.1 to 71.49.11.25471.49.11.255510
13571.49.12.0/2371.49.12.1 to 71.49.13.25471.49.13.255510
13671.49.14.0/2371.49.14.1 to 71.49.15.25471.49.15.255510
13771.49.16.0/2371.49.16.1 to 71.49.17.25471.49.17.255510
13871.49.18.0/2371.49.18.1 to 71.49.19.25471.49.19.255510
13971.49.20.0/2371.49.20.1 to 71.49.21.25471.49.21.255510
14071.49.22.0/2371.49.22.1 to 71.49.23.25471.49.23.255510
14171.49.24.0/2371.49.24.1 to 71.49.25.25471.49.25.255510
14271.49.26.0/2371.49.26.1 to 71.49.27.25471.49.27.255510
14371.49.28.0/2371.49.28.1 to 71.49.29.25471.49.29.255510
14471.49.30.0/2371.49.30.1 to 71.49.31.25471.49.31.255510
14571.49.32.0/2371.49.32.1 to 71.49.33.25471.49.33.255510
14671.49.34.0/2371.49.34.1 to 71.49.35.25471.49.35.255510
14771.49.36.0/2371.49.36.1 to 71.49.37.25471.49.37.255510
14871.49.38.0/2371.49.38.1 to 71.49.39.25471.49.39.255510
14971.49.40.0/2371.49.40.1 to 71.49.41.25471.49.41.255510
15071.49.42.0/2371.49.42.1 to 71.49.43.25471.49.43.255510
15171.49.44.0/2371.49.44.1 to 71.49.45.25471.49.45.255510
15271.49.46.0/2371.49.46.1 to 71.49.47.25471.49.47.255510
15371.49.48.0/2371.49.48.1 to 71.49.49.25471.49.49.255510
15471.49.50.0/2371.49.50.1 to 71.49.51.25471.49.51.255510
15571.49.52.0/2371.49.52.1 to 71.49.53.25471.49.53.255510
15671.49.54.0/2371.49.54.1 to 71.49.55.25471.49.55.255510
15771.49.56.0/2371.49.56.1 to 71.49.57.25471.49.57.255510
15871.49.58.0/2371.49.58.1 to 71.49.59.25471.49.59.255510
15971.49.60.0/2371.49.60.1 to 71.49.61.25471.49.61.255510
16071.49.62.0/2371.49.62.1 to 71.49.63.25471.49.63.255510
16171.49.64.0/2371.49.64.1 to 71.49.65.25471.49.65.255510
16271.49.66.0/2371.49.66.1 to 71.49.67.25471.49.67.255510
16371.49.68.0/2371.49.68.1 to 71.49.69.25471.49.69.255510
16471.49.70.0/2371.49.70.1 to 71.49.71.25471.49.71.255510
16571.49.72.0/2371.49.72.1 to 71.49.73.25471.49.73.255510
16671.49.74.0/2371.49.74.1 to 71.49.75.25471.49.75.255510
16771.49.76.0/2371.49.76.1 to 71.49.77.25471.49.77.255510
16871.49.78.0/2371.49.78.1 to 71.49.79.25471.49.79.255510
16971.49.80.0/2371.49.80.1 to 71.49.81.25471.49.81.255510
17071.49.82.0/2371.49.82.1 to 71.49.83.25471.49.83.255510
17171.49.84.0/2371.49.84.1 to 71.49.85.25471.49.85.255510
17271.49.86.0/2371.49.86.1 to 71.49.87.25471.49.87.255510
17371.49.88.0/2371.49.88.1 to 71.49.89.25471.49.89.255510
17471.49.90.0/2371.49.90.1 to 71.49.91.25471.49.91.255510
17571.49.92.0/2371.49.92.1 to 71.49.93.25471.49.93.255510
17671.49.94.0/2371.49.94.1 to 71.49.95.25471.49.95.255510
17771.49.96.0/2371.49.96.1 to 71.49.97.25471.49.97.255510
17871.49.98.0/2371.49.98.1 to 71.49.99.25471.49.99.255510
17971.49.100.0/2371.49.100.1 to 71.49.101.25471.49.101.255510
18071.49.102.0/2371.49.102.1 to 71.49.103.25471.49.103.255510
18171.49.104.0/2371.49.104.1 to 71.49.105.25471.49.105.255510
18271.49.106.0/2371.49.106.1 to 71.49.107.25471.49.107.255510
18371.49.108.0/2371.49.108.1 to 71.49.109.25471.49.109.255510
18471.49.110.0/2371.49.110.1 to 71.49.111.25471.49.111.255510
18571.49.112.0/2371.49.112.1 to 71.49.113.25471.49.113.255510
18671.49.114.0/2371.49.114.1 to 71.49.115.25471.49.115.255510
18771.49.116.0/2371.49.116.1 to 71.49.117.25471.49.117.255510
18871.49.118.0/2371.49.118.1 to 71.49.119.25471.49.119.255510
18971.49.120.0/2371.49.120.1 to 71.49.121.25471.49.121.255510
19071.49.122.0/2371.49.122.1 to 71.49.123.25471.49.123.255510
19171.49.124.0/2371.49.124.1 to 71.49.125.25471.49.125.255510
19271.49.126.0/2371.49.126.1 to 71.49.127.25471.49.127.255510
19371.49.128.0/2371.49.128.1 to 71.49.129.25471.49.129.255510
19471.49.130.0/2371.49.130.1 to 71.49.131.25471.49.131.255510
19571.49.132.0/2371.49.132.1 to 71.49.133.25471.49.133.255510
19671.49.134.0/2371.49.134.1 to 71.49.135.25471.49.135.255510
19771.49.136.0/2371.49.136.1 to 71.49.137.25471.49.137.255510
19871.49.138.0/2371.49.138.1 to 71.49.139.25471.49.139.255510
19971.49.140.0/2371.49.140.1 to 71.49.141.25471.49.141.255510
20071.49.142.0/2371.49.142.1 to 71.49.143.25471.49.143.255510
20171.49.144.0/2371.49.144.1 to 71.49.145.25471.49.145.255510
20271.49.146.0/2371.49.146.1 to 71.49.147.25471.49.147.255510
20371.49.148.0/2371.49.148.1 to 71.49.149.25471.49.149.255510
20471.49.150.0/2371.49.150.1 to 71.49.151.25471.49.151.255510
20571.49.152.0/2371.49.152.1 to 71.49.153.25471.49.153.255510
20671.49.154.0/2371.49.154.1 to 71.49.155.25471.49.155.255510
20771.49.156.0/2371.49.156.1 to 71.49.157.25471.49.157.255510
20871.49.158.0/2371.49.158.1 to 71.49.159.25471.49.159.255510
20971.49.160.0/2371.49.160.1 to 71.49.161.25471.49.161.255510
21071.49.162.0/2371.49.162.1 to 71.49.163.25471.49.163.255510
21171.49.164.0/2371.49.164.1 to 71.49.165.25471.49.165.255510
21271.49.166.0/2371.49.166.1 to 71.49.167.25471.49.167.255510
21371.49.168.0/2371.49.168.1 to 71.49.169.25471.49.169.255510
21471.49.170.0/2371.49.170.1 to 71.49.171.25471.49.171.255510
21571.49.172.0/2371.49.172.1 to 71.49.173.25471.49.173.255510
21671.49.174.0/2371.49.174.1 to 71.49.175.25471.49.175.255510
21771.49.176.0/2371.49.176.1 to 71.49.177.25471.49.177.255510
21871.49.178.0/2371.49.178.1 to 71.49.179.25471.49.179.255510
21971.49.180.0/2371.49.180.1 to 71.49.181.25471.49.181.255510
22071.49.182.0/2371.49.182.1 to 71.49.183.25471.49.183.255510
22171.49.184.0/2371.49.184.1 to 71.49.185.25471.49.185.255510
22271.49.186.0/2371.49.186.1 to 71.49.187.25471.49.187.255510
22371.49.188.0/2371.49.188.1 to 71.49.189.25471.49.189.255510
22471.49.190.0/2371.49.190.1 to 71.49.191.25471.49.191.255510
22571.49.192.0/2371.49.192.1 to 71.49.193.25471.49.193.255510
22671.49.194.0/2371.49.194.1 to 71.49.195.25471.49.195.255510
22771.49.196.0/2371.49.196.1 to 71.49.197.25471.49.197.255510
22871.49.198.0/2371.49.198.1 to 71.49.199.25471.49.199.255510
22971.49.200.0/2371.49.200.1 to 71.49.201.25471.49.201.255510
23071.49.202.0/2371.49.202.1 to 71.49.203.25471.49.203.255510
23171.49.204.0/2371.49.204.1 to 71.49.205.25471.49.205.255510
23271.49.206.0/2371.49.206.1 to 71.49.207.25471.49.207.255510
23371.49.208.0/2371.49.208.1 to 71.49.209.25471.49.209.255510
23471.49.210.0/2371.49.210.1 to 71.49.211.25471.49.211.255510
23571.49.212.0/2371.49.212.1 to 71.49.213.25471.49.213.255510
23671.49.214.0/2371.49.214.1 to 71.49.215.25471.49.215.255510
23771.49.216.0/2371.49.216.1 to 71.49.217.25471.49.217.255510
23871.49.218.0/2371.49.218.1 to 71.49.219.25471.49.219.255510
23971.49.220.0/2371.49.220.1 to 71.49.221.25471.49.221.255510
24071.49.222.0/2371.49.222.1 to 71.49.223.25471.49.223.255510
24171.49.224.0/2371.49.224.1 to 71.49.225.25471.49.225.255510
24271.49.226.0/2371.49.226.1 to 71.49.227.25471.49.227.255510
24371.49.228.0/2371.49.228.1 to 71.49.229.25471.49.229.255510
24471.49.230.0/2371.49.230.1 to 71.49.231.25471.49.231.255510
24571.49.232.0/2371.49.232.1 to 71.49.233.25471.49.233.255510
24671.49.234.0/2371.49.234.1 to 71.49.235.25471.49.235.255510
24771.49.236.0/2371.49.236.1 to 71.49.237.25471.49.237.255510
24871.49.238.0/2371.49.238.1 to 71.49.239.25471.49.239.255510
24971.49.240.0/2371.49.240.1 to 71.49.241.25471.49.241.255510
25071.49.242.0/2371.49.242.1 to 71.49.243.25471.49.243.255510
25171.49.244.0/2371.49.244.1 to 71.49.245.25471.49.245.255510
25271.49.246.0/2371.49.246.1 to 71.49.247.25471.49.247.255510
25371.49.248.0/2371.49.248.1 to 71.49.249.25471.49.249.255510
25471.49.250.0/2371.49.250.1 to 71.49.251.25471.49.251.255510
25571.49.252.0/2371.49.252.1 to 71.49.253.25471.49.253.255510
25671.49.254.0/2371.49.254.1 to 71.49.255.25471.49.255.255510

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.