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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.

Network18.96.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
18.96.0.0
Broadcast address
18.127.255.255
First usable
18.96.0.1
Last usable
18.127.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Public public
Old class
A (default /8)
As numbers
Hex 12600000 · Integer 308281344 to 310378495
Reverse DNS zones
96.18.in-addr.arpa
97.18.in-addr.arpa
98.18.in-addr.arpa
99.18.in-addr.arpa
100.18.in-addr.arpa
101.18.in-addr.arpa
102.18.in-addr.arpa
103.18.in-addr.arpa
104.18.in-addr.arpa
105.18.in-addr.arpa
106.18.in-addr.arpa
107.18.in-addr.arpa
108.18.in-addr.arpa
109.18.in-addr.arpa
110.18.in-addr.arpa
111.18.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00010010.01100000.00000000.0000000018.96.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network00010010.01100000.00000000.0000000018.96.0.0
Broadcast00010010.01111111.11111111.1111111118.127.255.255
Split into smaller subnets/23
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

18.96.0.0/11 makes 4,096 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
118.96.0.0/2318.96.0.1 to 18.96.1.25418.96.1.255510
218.96.2.0/2318.96.2.1 to 18.96.3.25418.96.3.255510
318.96.4.0/2318.96.4.1 to 18.96.5.25418.96.5.255510
418.96.6.0/2318.96.6.1 to 18.96.7.25418.96.7.255510
518.96.8.0/2318.96.8.1 to 18.96.9.25418.96.9.255510
618.96.10.0/2318.96.10.1 to 18.96.11.25418.96.11.255510
718.96.12.0/2318.96.12.1 to 18.96.13.25418.96.13.255510
818.96.14.0/2318.96.14.1 to 18.96.15.25418.96.15.255510
918.96.16.0/2318.96.16.1 to 18.96.17.25418.96.17.255510
1018.96.18.0/2318.96.18.1 to 18.96.19.25418.96.19.255510
1118.96.20.0/2318.96.20.1 to 18.96.21.25418.96.21.255510
1218.96.22.0/2318.96.22.1 to 18.96.23.25418.96.23.255510
1318.96.24.0/2318.96.24.1 to 18.96.25.25418.96.25.255510
1418.96.26.0/2318.96.26.1 to 18.96.27.25418.96.27.255510
1518.96.28.0/2318.96.28.1 to 18.96.29.25418.96.29.255510
1618.96.30.0/2318.96.30.1 to 18.96.31.25418.96.31.255510
1718.96.32.0/2318.96.32.1 to 18.96.33.25418.96.33.255510
1818.96.34.0/2318.96.34.1 to 18.96.35.25418.96.35.255510
1918.96.36.0/2318.96.36.1 to 18.96.37.25418.96.37.255510
2018.96.38.0/2318.96.38.1 to 18.96.39.25418.96.39.255510
2118.96.40.0/2318.96.40.1 to 18.96.41.25418.96.41.255510
2218.96.42.0/2318.96.42.1 to 18.96.43.25418.96.43.255510
2318.96.44.0/2318.96.44.1 to 18.96.45.25418.96.45.255510
2418.96.46.0/2318.96.46.1 to 18.96.47.25418.96.47.255510
2518.96.48.0/2318.96.48.1 to 18.96.49.25418.96.49.255510
2618.96.50.0/2318.96.50.1 to 18.96.51.25418.96.51.255510
2718.96.52.0/2318.96.52.1 to 18.96.53.25418.96.53.255510
2818.96.54.0/2318.96.54.1 to 18.96.55.25418.96.55.255510
2918.96.56.0/2318.96.56.1 to 18.96.57.25418.96.57.255510
3018.96.58.0/2318.96.58.1 to 18.96.59.25418.96.59.255510
3118.96.60.0/2318.96.60.1 to 18.96.61.25418.96.61.255510
3218.96.62.0/2318.96.62.1 to 18.96.63.25418.96.63.255510
3318.96.64.0/2318.96.64.1 to 18.96.65.25418.96.65.255510
3418.96.66.0/2318.96.66.1 to 18.96.67.25418.96.67.255510
3518.96.68.0/2318.96.68.1 to 18.96.69.25418.96.69.255510
3618.96.70.0/2318.96.70.1 to 18.96.71.25418.96.71.255510
3718.96.72.0/2318.96.72.1 to 18.96.73.25418.96.73.255510
3818.96.74.0/2318.96.74.1 to 18.96.75.25418.96.75.255510
3918.96.76.0/2318.96.76.1 to 18.96.77.25418.96.77.255510
4018.96.78.0/2318.96.78.1 to 18.96.79.25418.96.79.255510
4118.96.80.0/2318.96.80.1 to 18.96.81.25418.96.81.255510
4218.96.82.0/2318.96.82.1 to 18.96.83.25418.96.83.255510
4318.96.84.0/2318.96.84.1 to 18.96.85.25418.96.85.255510
4418.96.86.0/2318.96.86.1 to 18.96.87.25418.96.87.255510
4518.96.88.0/2318.96.88.1 to 18.96.89.25418.96.89.255510
4618.96.90.0/2318.96.90.1 to 18.96.91.25418.96.91.255510
4718.96.92.0/2318.96.92.1 to 18.96.93.25418.96.93.255510
4818.96.94.0/2318.96.94.1 to 18.96.95.25418.96.95.255510
4918.96.96.0/2318.96.96.1 to 18.96.97.25418.96.97.255510
5018.96.98.0/2318.96.98.1 to 18.96.99.25418.96.99.255510
5118.96.100.0/2318.96.100.1 to 18.96.101.25418.96.101.255510
5218.96.102.0/2318.96.102.1 to 18.96.103.25418.96.103.255510
5318.96.104.0/2318.96.104.1 to 18.96.105.25418.96.105.255510
5418.96.106.0/2318.96.106.1 to 18.96.107.25418.96.107.255510
5518.96.108.0/2318.96.108.1 to 18.96.109.25418.96.109.255510
5618.96.110.0/2318.96.110.1 to 18.96.111.25418.96.111.255510
5718.96.112.0/2318.96.112.1 to 18.96.113.25418.96.113.255510
5818.96.114.0/2318.96.114.1 to 18.96.115.25418.96.115.255510
5918.96.116.0/2318.96.116.1 to 18.96.117.25418.96.117.255510
6018.96.118.0/2318.96.118.1 to 18.96.119.25418.96.119.255510
6118.96.120.0/2318.96.120.1 to 18.96.121.25418.96.121.255510
6218.96.122.0/2318.96.122.1 to 18.96.123.25418.96.123.255510
6318.96.124.0/2318.96.124.1 to 18.96.125.25418.96.125.255510
6418.96.126.0/2318.96.126.1 to 18.96.127.25418.96.127.255510
6518.96.128.0/2318.96.128.1 to 18.96.129.25418.96.129.255510
6618.96.130.0/2318.96.130.1 to 18.96.131.25418.96.131.255510
6718.96.132.0/2318.96.132.1 to 18.96.133.25418.96.133.255510
6818.96.134.0/2318.96.134.1 to 18.96.135.25418.96.135.255510
6918.96.136.0/2318.96.136.1 to 18.96.137.25418.96.137.255510
7018.96.138.0/2318.96.138.1 to 18.96.139.25418.96.139.255510
7118.96.140.0/2318.96.140.1 to 18.96.141.25418.96.141.255510
7218.96.142.0/2318.96.142.1 to 18.96.143.25418.96.143.255510
7318.96.144.0/2318.96.144.1 to 18.96.145.25418.96.145.255510
7418.96.146.0/2318.96.146.1 to 18.96.147.25418.96.147.255510
7518.96.148.0/2318.96.148.1 to 18.96.149.25418.96.149.255510
7618.96.150.0/2318.96.150.1 to 18.96.151.25418.96.151.255510
7718.96.152.0/2318.96.152.1 to 18.96.153.25418.96.153.255510
7818.96.154.0/2318.96.154.1 to 18.96.155.25418.96.155.255510
7918.96.156.0/2318.96.156.1 to 18.96.157.25418.96.157.255510
8018.96.158.0/2318.96.158.1 to 18.96.159.25418.96.159.255510
8118.96.160.0/2318.96.160.1 to 18.96.161.25418.96.161.255510
8218.96.162.0/2318.96.162.1 to 18.96.163.25418.96.163.255510
8318.96.164.0/2318.96.164.1 to 18.96.165.25418.96.165.255510
8418.96.166.0/2318.96.166.1 to 18.96.167.25418.96.167.255510
8518.96.168.0/2318.96.168.1 to 18.96.169.25418.96.169.255510
8618.96.170.0/2318.96.170.1 to 18.96.171.25418.96.171.255510
8718.96.172.0/2318.96.172.1 to 18.96.173.25418.96.173.255510
8818.96.174.0/2318.96.174.1 to 18.96.175.25418.96.175.255510
8918.96.176.0/2318.96.176.1 to 18.96.177.25418.96.177.255510
9018.96.178.0/2318.96.178.1 to 18.96.179.25418.96.179.255510
9118.96.180.0/2318.96.180.1 to 18.96.181.25418.96.181.255510
9218.96.182.0/2318.96.182.1 to 18.96.183.25418.96.183.255510
9318.96.184.0/2318.96.184.1 to 18.96.185.25418.96.185.255510
9418.96.186.0/2318.96.186.1 to 18.96.187.25418.96.187.255510
9518.96.188.0/2318.96.188.1 to 18.96.189.25418.96.189.255510
9618.96.190.0/2318.96.190.1 to 18.96.191.25418.96.191.255510
9718.96.192.0/2318.96.192.1 to 18.96.193.25418.96.193.255510
9818.96.194.0/2318.96.194.1 to 18.96.195.25418.96.195.255510
9918.96.196.0/2318.96.196.1 to 18.96.197.25418.96.197.255510
10018.96.198.0/2318.96.198.1 to 18.96.199.25418.96.199.255510
10118.96.200.0/2318.96.200.1 to 18.96.201.25418.96.201.255510
10218.96.202.0/2318.96.202.1 to 18.96.203.25418.96.203.255510
10318.96.204.0/2318.96.204.1 to 18.96.205.25418.96.205.255510
10418.96.206.0/2318.96.206.1 to 18.96.207.25418.96.207.255510
10518.96.208.0/2318.96.208.1 to 18.96.209.25418.96.209.255510
10618.96.210.0/2318.96.210.1 to 18.96.211.25418.96.211.255510
10718.96.212.0/2318.96.212.1 to 18.96.213.25418.96.213.255510
10818.96.214.0/2318.96.214.1 to 18.96.215.25418.96.215.255510
10918.96.216.0/2318.96.216.1 to 18.96.217.25418.96.217.255510
11018.96.218.0/2318.96.218.1 to 18.96.219.25418.96.219.255510
11118.96.220.0/2318.96.220.1 to 18.96.221.25418.96.221.255510
11218.96.222.0/2318.96.222.1 to 18.96.223.25418.96.223.255510
11318.96.224.0/2318.96.224.1 to 18.96.225.25418.96.225.255510
11418.96.226.0/2318.96.226.1 to 18.96.227.25418.96.227.255510
11518.96.228.0/2318.96.228.1 to 18.96.229.25418.96.229.255510
11618.96.230.0/2318.96.230.1 to 18.96.231.25418.96.231.255510
11718.96.232.0/2318.96.232.1 to 18.96.233.25418.96.233.255510
11818.96.234.0/2318.96.234.1 to 18.96.235.25418.96.235.255510
11918.96.236.0/2318.96.236.1 to 18.96.237.25418.96.237.255510
12018.96.238.0/2318.96.238.1 to 18.96.239.25418.96.239.255510
12118.96.240.0/2318.96.240.1 to 18.96.241.25418.96.241.255510
12218.96.242.0/2318.96.242.1 to 18.96.243.25418.96.243.255510
12318.96.244.0/2318.96.244.1 to 18.96.245.25418.96.245.255510
12418.96.246.0/2318.96.246.1 to 18.96.247.25418.96.247.255510
12518.96.248.0/2318.96.248.1 to 18.96.249.25418.96.249.255510
12618.96.250.0/2318.96.250.1 to 18.96.251.25418.96.251.255510
12718.96.252.0/2318.96.252.1 to 18.96.253.25418.96.253.255510
12818.96.254.0/2318.96.254.1 to 18.96.255.25418.96.255.255510
12918.97.0.0/2318.97.0.1 to 18.97.1.25418.97.1.255510
13018.97.2.0/2318.97.2.1 to 18.97.3.25418.97.3.255510
13118.97.4.0/2318.97.4.1 to 18.97.5.25418.97.5.255510
13218.97.6.0/2318.97.6.1 to 18.97.7.25418.97.7.255510
13318.97.8.0/2318.97.8.1 to 18.97.9.25418.97.9.255510
13418.97.10.0/2318.97.10.1 to 18.97.11.25418.97.11.255510
13518.97.12.0/2318.97.12.1 to 18.97.13.25418.97.13.255510
13618.97.14.0/2318.97.14.1 to 18.97.15.25418.97.15.255510
13718.97.16.0/2318.97.16.1 to 18.97.17.25418.97.17.255510
13818.97.18.0/2318.97.18.1 to 18.97.19.25418.97.19.255510
13918.97.20.0/2318.97.20.1 to 18.97.21.25418.97.21.255510
14018.97.22.0/2318.97.22.1 to 18.97.23.25418.97.23.255510
14118.97.24.0/2318.97.24.1 to 18.97.25.25418.97.25.255510
14218.97.26.0/2318.97.26.1 to 18.97.27.25418.97.27.255510
14318.97.28.0/2318.97.28.1 to 18.97.29.25418.97.29.255510
14418.97.30.0/2318.97.30.1 to 18.97.31.25418.97.31.255510
14518.97.32.0/2318.97.32.1 to 18.97.33.25418.97.33.255510
14618.97.34.0/2318.97.34.1 to 18.97.35.25418.97.35.255510
14718.97.36.0/2318.97.36.1 to 18.97.37.25418.97.37.255510
14818.97.38.0/2318.97.38.1 to 18.97.39.25418.97.39.255510
14918.97.40.0/2318.97.40.1 to 18.97.41.25418.97.41.255510
15018.97.42.0/2318.97.42.1 to 18.97.43.25418.97.43.255510
15118.97.44.0/2318.97.44.1 to 18.97.45.25418.97.45.255510
15218.97.46.0/2318.97.46.1 to 18.97.47.25418.97.47.255510
15318.97.48.0/2318.97.48.1 to 18.97.49.25418.97.49.255510
15418.97.50.0/2318.97.50.1 to 18.97.51.25418.97.51.255510
15518.97.52.0/2318.97.52.1 to 18.97.53.25418.97.53.255510
15618.97.54.0/2318.97.54.1 to 18.97.55.25418.97.55.255510
15718.97.56.0/2318.97.56.1 to 18.97.57.25418.97.57.255510
15818.97.58.0/2318.97.58.1 to 18.97.59.25418.97.59.255510
15918.97.60.0/2318.97.60.1 to 18.97.61.25418.97.61.255510
16018.97.62.0/2318.97.62.1 to 18.97.63.25418.97.63.255510
16118.97.64.0/2318.97.64.1 to 18.97.65.25418.97.65.255510
16218.97.66.0/2318.97.66.1 to 18.97.67.25418.97.67.255510
16318.97.68.0/2318.97.68.1 to 18.97.69.25418.97.69.255510
16418.97.70.0/2318.97.70.1 to 18.97.71.25418.97.71.255510
16518.97.72.0/2318.97.72.1 to 18.97.73.25418.97.73.255510
16618.97.74.0/2318.97.74.1 to 18.97.75.25418.97.75.255510
16718.97.76.0/2318.97.76.1 to 18.97.77.25418.97.77.255510
16818.97.78.0/2318.97.78.1 to 18.97.79.25418.97.79.255510
16918.97.80.0/2318.97.80.1 to 18.97.81.25418.97.81.255510
17018.97.82.0/2318.97.82.1 to 18.97.83.25418.97.83.255510
17118.97.84.0/2318.97.84.1 to 18.97.85.25418.97.85.255510
17218.97.86.0/2318.97.86.1 to 18.97.87.25418.97.87.255510
17318.97.88.0/2318.97.88.1 to 18.97.89.25418.97.89.255510
17418.97.90.0/2318.97.90.1 to 18.97.91.25418.97.91.255510
17518.97.92.0/2318.97.92.1 to 18.97.93.25418.97.93.255510
17618.97.94.0/2318.97.94.1 to 18.97.95.25418.97.95.255510
17718.97.96.0/2318.97.96.1 to 18.97.97.25418.97.97.255510
17818.97.98.0/2318.97.98.1 to 18.97.99.25418.97.99.255510
17918.97.100.0/2318.97.100.1 to 18.97.101.25418.97.101.255510
18018.97.102.0/2318.97.102.1 to 18.97.103.25418.97.103.255510
18118.97.104.0/2318.97.104.1 to 18.97.105.25418.97.105.255510
18218.97.106.0/2318.97.106.1 to 18.97.107.25418.97.107.255510
18318.97.108.0/2318.97.108.1 to 18.97.109.25418.97.109.255510
18418.97.110.0/2318.97.110.1 to 18.97.111.25418.97.111.255510
18518.97.112.0/2318.97.112.1 to 18.97.113.25418.97.113.255510
18618.97.114.0/2318.97.114.1 to 18.97.115.25418.97.115.255510
18718.97.116.0/2318.97.116.1 to 18.97.117.25418.97.117.255510
18818.97.118.0/2318.97.118.1 to 18.97.119.25418.97.119.255510
18918.97.120.0/2318.97.120.1 to 18.97.121.25418.97.121.255510
19018.97.122.0/2318.97.122.1 to 18.97.123.25418.97.123.255510
19118.97.124.0/2318.97.124.1 to 18.97.125.25418.97.125.255510
19218.97.126.0/2318.97.126.1 to 18.97.127.25418.97.127.255510
19318.97.128.0/2318.97.128.1 to 18.97.129.25418.97.129.255510
19418.97.130.0/2318.97.130.1 to 18.97.131.25418.97.131.255510
19518.97.132.0/2318.97.132.1 to 18.97.133.25418.97.133.255510
19618.97.134.0/2318.97.134.1 to 18.97.135.25418.97.135.255510
19718.97.136.0/2318.97.136.1 to 18.97.137.25418.97.137.255510
19818.97.138.0/2318.97.138.1 to 18.97.139.25418.97.139.255510
19918.97.140.0/2318.97.140.1 to 18.97.141.25418.97.141.255510
20018.97.142.0/2318.97.142.1 to 18.97.143.25418.97.143.255510
20118.97.144.0/2318.97.144.1 to 18.97.145.25418.97.145.255510
20218.97.146.0/2318.97.146.1 to 18.97.147.25418.97.147.255510
20318.97.148.0/2318.97.148.1 to 18.97.149.25418.97.149.255510
20418.97.150.0/2318.97.150.1 to 18.97.151.25418.97.151.255510
20518.97.152.0/2318.97.152.1 to 18.97.153.25418.97.153.255510
20618.97.154.0/2318.97.154.1 to 18.97.155.25418.97.155.255510
20718.97.156.0/2318.97.156.1 to 18.97.157.25418.97.157.255510
20818.97.158.0/2318.97.158.1 to 18.97.159.25418.97.159.255510
20918.97.160.0/2318.97.160.1 to 18.97.161.25418.97.161.255510
21018.97.162.0/2318.97.162.1 to 18.97.163.25418.97.163.255510
21118.97.164.0/2318.97.164.1 to 18.97.165.25418.97.165.255510
21218.97.166.0/2318.97.166.1 to 18.97.167.25418.97.167.255510
21318.97.168.0/2318.97.168.1 to 18.97.169.25418.97.169.255510
21418.97.170.0/2318.97.170.1 to 18.97.171.25418.97.171.255510
21518.97.172.0/2318.97.172.1 to 18.97.173.25418.97.173.255510
21618.97.174.0/2318.97.174.1 to 18.97.175.25418.97.175.255510
21718.97.176.0/2318.97.176.1 to 18.97.177.25418.97.177.255510
21818.97.178.0/2318.97.178.1 to 18.97.179.25418.97.179.255510
21918.97.180.0/2318.97.180.1 to 18.97.181.25418.97.181.255510
22018.97.182.0/2318.97.182.1 to 18.97.183.25418.97.183.255510
22118.97.184.0/2318.97.184.1 to 18.97.185.25418.97.185.255510
22218.97.186.0/2318.97.186.1 to 18.97.187.25418.97.187.255510
22318.97.188.0/2318.97.188.1 to 18.97.189.25418.97.189.255510
22418.97.190.0/2318.97.190.1 to 18.97.191.25418.97.191.255510
22518.97.192.0/2318.97.192.1 to 18.97.193.25418.97.193.255510
22618.97.194.0/2318.97.194.1 to 18.97.195.25418.97.195.255510
22718.97.196.0/2318.97.196.1 to 18.97.197.25418.97.197.255510
22818.97.198.0/2318.97.198.1 to 18.97.199.25418.97.199.255510
22918.97.200.0/2318.97.200.1 to 18.97.201.25418.97.201.255510
23018.97.202.0/2318.97.202.1 to 18.97.203.25418.97.203.255510
23118.97.204.0/2318.97.204.1 to 18.97.205.25418.97.205.255510
23218.97.206.0/2318.97.206.1 to 18.97.207.25418.97.207.255510
23318.97.208.0/2318.97.208.1 to 18.97.209.25418.97.209.255510
23418.97.210.0/2318.97.210.1 to 18.97.211.25418.97.211.255510
23518.97.212.0/2318.97.212.1 to 18.97.213.25418.97.213.255510
23618.97.214.0/2318.97.214.1 to 18.97.215.25418.97.215.255510
23718.97.216.0/2318.97.216.1 to 18.97.217.25418.97.217.255510
23818.97.218.0/2318.97.218.1 to 18.97.219.25418.97.219.255510
23918.97.220.0/2318.97.220.1 to 18.97.221.25418.97.221.255510
24018.97.222.0/2318.97.222.1 to 18.97.223.25418.97.223.255510
24118.97.224.0/2318.97.224.1 to 18.97.225.25418.97.225.255510
24218.97.226.0/2318.97.226.1 to 18.97.227.25418.97.227.255510
24318.97.228.0/2318.97.228.1 to 18.97.229.25418.97.229.255510
24418.97.230.0/2318.97.230.1 to 18.97.231.25418.97.231.255510
24518.97.232.0/2318.97.232.1 to 18.97.233.25418.97.233.255510
24618.97.234.0/2318.97.234.1 to 18.97.235.25418.97.235.255510
24718.97.236.0/2318.97.236.1 to 18.97.237.25418.97.237.255510
24818.97.238.0/2318.97.238.1 to 18.97.239.25418.97.239.255510
24918.97.240.0/2318.97.240.1 to 18.97.241.25418.97.241.255510
25018.97.242.0/2318.97.242.1 to 18.97.243.25418.97.243.255510
25118.97.244.0/2318.97.244.1 to 18.97.245.25418.97.245.255510
25218.97.246.0/2318.97.246.1 to 18.97.247.25418.97.247.255510
25318.97.248.0/2318.97.248.1 to 18.97.249.25418.97.249.255510
25418.97.250.0/2318.97.250.1 to 18.97.251.25418.97.251.255510
25518.97.252.0/2318.97.252.1 to 18.97.253.25418.97.253.255510
25618.97.254.0/2318.97.254.1 to 18.97.255.25418.97.255.255510

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.