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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network49.80.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
49.80.0.0
Broadcast address
49.95.255.255
First usable
49.80.0.1
Last usable
49.95.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Public public
Old class
A (default /8)
As numbers
Hex 31500000 · Integer 827326464 to 828375039
Reverse DNS zones
80.49.in-addr.arpa
81.49.in-addr.arpa
82.49.in-addr.arpa
83.49.in-addr.arpa
84.49.in-addr.arpa
85.49.in-addr.arpa
86.49.in-addr.arpa
87.49.in-addr.arpa
88.49.in-addr.arpa
89.49.in-addr.arpa
90.49.in-addr.arpa
91.49.in-addr.arpa
92.49.in-addr.arpa
93.49.in-addr.arpa
94.49.in-addr.arpa
95.49.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00110001.01010000.00000000.0000000049.80.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network00110001.01010000.00000000.0000000049.80.0.0
Broadcast00110001.01011111.11111111.1111111149.95.255.255
Split into smaller subnets/23
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

49.80.0.0/12 makes 2,048 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
149.80.0.0/2349.80.0.1 to 49.80.1.25449.80.1.255510
249.80.2.0/2349.80.2.1 to 49.80.3.25449.80.3.255510
349.80.4.0/2349.80.4.1 to 49.80.5.25449.80.5.255510
449.80.6.0/2349.80.6.1 to 49.80.7.25449.80.7.255510
549.80.8.0/2349.80.8.1 to 49.80.9.25449.80.9.255510
649.80.10.0/2349.80.10.1 to 49.80.11.25449.80.11.255510
749.80.12.0/2349.80.12.1 to 49.80.13.25449.80.13.255510
849.80.14.0/2349.80.14.1 to 49.80.15.25449.80.15.255510
949.80.16.0/2349.80.16.1 to 49.80.17.25449.80.17.255510
1049.80.18.0/2349.80.18.1 to 49.80.19.25449.80.19.255510
1149.80.20.0/2349.80.20.1 to 49.80.21.25449.80.21.255510
1249.80.22.0/2349.80.22.1 to 49.80.23.25449.80.23.255510
1349.80.24.0/2349.80.24.1 to 49.80.25.25449.80.25.255510
1449.80.26.0/2349.80.26.1 to 49.80.27.25449.80.27.255510
1549.80.28.0/2349.80.28.1 to 49.80.29.25449.80.29.255510
1649.80.30.0/2349.80.30.1 to 49.80.31.25449.80.31.255510
1749.80.32.0/2349.80.32.1 to 49.80.33.25449.80.33.255510
1849.80.34.0/2349.80.34.1 to 49.80.35.25449.80.35.255510
1949.80.36.0/2349.80.36.1 to 49.80.37.25449.80.37.255510
2049.80.38.0/2349.80.38.1 to 49.80.39.25449.80.39.255510
2149.80.40.0/2349.80.40.1 to 49.80.41.25449.80.41.255510
2249.80.42.0/2349.80.42.1 to 49.80.43.25449.80.43.255510
2349.80.44.0/2349.80.44.1 to 49.80.45.25449.80.45.255510
2449.80.46.0/2349.80.46.1 to 49.80.47.25449.80.47.255510
2549.80.48.0/2349.80.48.1 to 49.80.49.25449.80.49.255510
2649.80.50.0/2349.80.50.1 to 49.80.51.25449.80.51.255510
2749.80.52.0/2349.80.52.1 to 49.80.53.25449.80.53.255510
2849.80.54.0/2349.80.54.1 to 49.80.55.25449.80.55.255510
2949.80.56.0/2349.80.56.1 to 49.80.57.25449.80.57.255510
3049.80.58.0/2349.80.58.1 to 49.80.59.25449.80.59.255510
3149.80.60.0/2349.80.60.1 to 49.80.61.25449.80.61.255510
3249.80.62.0/2349.80.62.1 to 49.80.63.25449.80.63.255510
3349.80.64.0/2349.80.64.1 to 49.80.65.25449.80.65.255510
3449.80.66.0/2349.80.66.1 to 49.80.67.25449.80.67.255510
3549.80.68.0/2349.80.68.1 to 49.80.69.25449.80.69.255510
3649.80.70.0/2349.80.70.1 to 49.80.71.25449.80.71.255510
3749.80.72.0/2349.80.72.1 to 49.80.73.25449.80.73.255510
3849.80.74.0/2349.80.74.1 to 49.80.75.25449.80.75.255510
3949.80.76.0/2349.80.76.1 to 49.80.77.25449.80.77.255510
4049.80.78.0/2349.80.78.1 to 49.80.79.25449.80.79.255510
4149.80.80.0/2349.80.80.1 to 49.80.81.25449.80.81.255510
4249.80.82.0/2349.80.82.1 to 49.80.83.25449.80.83.255510
4349.80.84.0/2349.80.84.1 to 49.80.85.25449.80.85.255510
4449.80.86.0/2349.80.86.1 to 49.80.87.25449.80.87.255510
4549.80.88.0/2349.80.88.1 to 49.80.89.25449.80.89.255510
4649.80.90.0/2349.80.90.1 to 49.80.91.25449.80.91.255510
4749.80.92.0/2349.80.92.1 to 49.80.93.25449.80.93.255510
4849.80.94.0/2349.80.94.1 to 49.80.95.25449.80.95.255510
4949.80.96.0/2349.80.96.1 to 49.80.97.25449.80.97.255510
5049.80.98.0/2349.80.98.1 to 49.80.99.25449.80.99.255510
5149.80.100.0/2349.80.100.1 to 49.80.101.25449.80.101.255510
5249.80.102.0/2349.80.102.1 to 49.80.103.25449.80.103.255510
5349.80.104.0/2349.80.104.1 to 49.80.105.25449.80.105.255510
5449.80.106.0/2349.80.106.1 to 49.80.107.25449.80.107.255510
5549.80.108.0/2349.80.108.1 to 49.80.109.25449.80.109.255510
5649.80.110.0/2349.80.110.1 to 49.80.111.25449.80.111.255510
5749.80.112.0/2349.80.112.1 to 49.80.113.25449.80.113.255510
5849.80.114.0/2349.80.114.1 to 49.80.115.25449.80.115.255510
5949.80.116.0/2349.80.116.1 to 49.80.117.25449.80.117.255510
6049.80.118.0/2349.80.118.1 to 49.80.119.25449.80.119.255510
6149.80.120.0/2349.80.120.1 to 49.80.121.25449.80.121.255510
6249.80.122.0/2349.80.122.1 to 49.80.123.25449.80.123.255510
6349.80.124.0/2349.80.124.1 to 49.80.125.25449.80.125.255510
6449.80.126.0/2349.80.126.1 to 49.80.127.25449.80.127.255510
6549.80.128.0/2349.80.128.1 to 49.80.129.25449.80.129.255510
6649.80.130.0/2349.80.130.1 to 49.80.131.25449.80.131.255510
6749.80.132.0/2349.80.132.1 to 49.80.133.25449.80.133.255510
6849.80.134.0/2349.80.134.1 to 49.80.135.25449.80.135.255510
6949.80.136.0/2349.80.136.1 to 49.80.137.25449.80.137.255510
7049.80.138.0/2349.80.138.1 to 49.80.139.25449.80.139.255510
7149.80.140.0/2349.80.140.1 to 49.80.141.25449.80.141.255510
7249.80.142.0/2349.80.142.1 to 49.80.143.25449.80.143.255510
7349.80.144.0/2349.80.144.1 to 49.80.145.25449.80.145.255510
7449.80.146.0/2349.80.146.1 to 49.80.147.25449.80.147.255510
7549.80.148.0/2349.80.148.1 to 49.80.149.25449.80.149.255510
7649.80.150.0/2349.80.150.1 to 49.80.151.25449.80.151.255510
7749.80.152.0/2349.80.152.1 to 49.80.153.25449.80.153.255510
7849.80.154.0/2349.80.154.1 to 49.80.155.25449.80.155.255510
7949.80.156.0/2349.80.156.1 to 49.80.157.25449.80.157.255510
8049.80.158.0/2349.80.158.1 to 49.80.159.25449.80.159.255510
8149.80.160.0/2349.80.160.1 to 49.80.161.25449.80.161.255510
8249.80.162.0/2349.80.162.1 to 49.80.163.25449.80.163.255510
8349.80.164.0/2349.80.164.1 to 49.80.165.25449.80.165.255510
8449.80.166.0/2349.80.166.1 to 49.80.167.25449.80.167.255510
8549.80.168.0/2349.80.168.1 to 49.80.169.25449.80.169.255510
8649.80.170.0/2349.80.170.1 to 49.80.171.25449.80.171.255510
8749.80.172.0/2349.80.172.1 to 49.80.173.25449.80.173.255510
8849.80.174.0/2349.80.174.1 to 49.80.175.25449.80.175.255510
8949.80.176.0/2349.80.176.1 to 49.80.177.25449.80.177.255510
9049.80.178.0/2349.80.178.1 to 49.80.179.25449.80.179.255510
9149.80.180.0/2349.80.180.1 to 49.80.181.25449.80.181.255510
9249.80.182.0/2349.80.182.1 to 49.80.183.25449.80.183.255510
9349.80.184.0/2349.80.184.1 to 49.80.185.25449.80.185.255510
9449.80.186.0/2349.80.186.1 to 49.80.187.25449.80.187.255510
9549.80.188.0/2349.80.188.1 to 49.80.189.25449.80.189.255510
9649.80.190.0/2349.80.190.1 to 49.80.191.25449.80.191.255510
9749.80.192.0/2349.80.192.1 to 49.80.193.25449.80.193.255510
9849.80.194.0/2349.80.194.1 to 49.80.195.25449.80.195.255510
9949.80.196.0/2349.80.196.1 to 49.80.197.25449.80.197.255510
10049.80.198.0/2349.80.198.1 to 49.80.199.25449.80.199.255510
10149.80.200.0/2349.80.200.1 to 49.80.201.25449.80.201.255510
10249.80.202.0/2349.80.202.1 to 49.80.203.25449.80.203.255510
10349.80.204.0/2349.80.204.1 to 49.80.205.25449.80.205.255510
10449.80.206.0/2349.80.206.1 to 49.80.207.25449.80.207.255510
10549.80.208.0/2349.80.208.1 to 49.80.209.25449.80.209.255510
10649.80.210.0/2349.80.210.1 to 49.80.211.25449.80.211.255510
10749.80.212.0/2349.80.212.1 to 49.80.213.25449.80.213.255510
10849.80.214.0/2349.80.214.1 to 49.80.215.25449.80.215.255510
10949.80.216.0/2349.80.216.1 to 49.80.217.25449.80.217.255510
11049.80.218.0/2349.80.218.1 to 49.80.219.25449.80.219.255510
11149.80.220.0/2349.80.220.1 to 49.80.221.25449.80.221.255510
11249.80.222.0/2349.80.222.1 to 49.80.223.25449.80.223.255510
11349.80.224.0/2349.80.224.1 to 49.80.225.25449.80.225.255510
11449.80.226.0/2349.80.226.1 to 49.80.227.25449.80.227.255510
11549.80.228.0/2349.80.228.1 to 49.80.229.25449.80.229.255510
11649.80.230.0/2349.80.230.1 to 49.80.231.25449.80.231.255510
11749.80.232.0/2349.80.232.1 to 49.80.233.25449.80.233.255510
11849.80.234.0/2349.80.234.1 to 49.80.235.25449.80.235.255510
11949.80.236.0/2349.80.236.1 to 49.80.237.25449.80.237.255510
12049.80.238.0/2349.80.238.1 to 49.80.239.25449.80.239.255510
12149.80.240.0/2349.80.240.1 to 49.80.241.25449.80.241.255510
12249.80.242.0/2349.80.242.1 to 49.80.243.25449.80.243.255510
12349.80.244.0/2349.80.244.1 to 49.80.245.25449.80.245.255510
12449.80.246.0/2349.80.246.1 to 49.80.247.25449.80.247.255510
12549.80.248.0/2349.80.248.1 to 49.80.249.25449.80.249.255510
12649.80.250.0/2349.80.250.1 to 49.80.251.25449.80.251.255510
12749.80.252.0/2349.80.252.1 to 49.80.253.25449.80.253.255510
12849.80.254.0/2349.80.254.1 to 49.80.255.25449.80.255.255510
12949.81.0.0/2349.81.0.1 to 49.81.1.25449.81.1.255510
13049.81.2.0/2349.81.2.1 to 49.81.3.25449.81.3.255510
13149.81.4.0/2349.81.4.1 to 49.81.5.25449.81.5.255510
13249.81.6.0/2349.81.6.1 to 49.81.7.25449.81.7.255510
13349.81.8.0/2349.81.8.1 to 49.81.9.25449.81.9.255510
13449.81.10.0/2349.81.10.1 to 49.81.11.25449.81.11.255510
13549.81.12.0/2349.81.12.1 to 49.81.13.25449.81.13.255510
13649.81.14.0/2349.81.14.1 to 49.81.15.25449.81.15.255510
13749.81.16.0/2349.81.16.1 to 49.81.17.25449.81.17.255510
13849.81.18.0/2349.81.18.1 to 49.81.19.25449.81.19.255510
13949.81.20.0/2349.81.20.1 to 49.81.21.25449.81.21.255510
14049.81.22.0/2349.81.22.1 to 49.81.23.25449.81.23.255510
14149.81.24.0/2349.81.24.1 to 49.81.25.25449.81.25.255510
14249.81.26.0/2349.81.26.1 to 49.81.27.25449.81.27.255510
14349.81.28.0/2349.81.28.1 to 49.81.29.25449.81.29.255510
14449.81.30.0/2349.81.30.1 to 49.81.31.25449.81.31.255510
14549.81.32.0/2349.81.32.1 to 49.81.33.25449.81.33.255510
14649.81.34.0/2349.81.34.1 to 49.81.35.25449.81.35.255510
14749.81.36.0/2349.81.36.1 to 49.81.37.25449.81.37.255510
14849.81.38.0/2349.81.38.1 to 49.81.39.25449.81.39.255510
14949.81.40.0/2349.81.40.1 to 49.81.41.25449.81.41.255510
15049.81.42.0/2349.81.42.1 to 49.81.43.25449.81.43.255510
15149.81.44.0/2349.81.44.1 to 49.81.45.25449.81.45.255510
15249.81.46.0/2349.81.46.1 to 49.81.47.25449.81.47.255510
15349.81.48.0/2349.81.48.1 to 49.81.49.25449.81.49.255510
15449.81.50.0/2349.81.50.1 to 49.81.51.25449.81.51.255510
15549.81.52.0/2349.81.52.1 to 49.81.53.25449.81.53.255510
15649.81.54.0/2349.81.54.1 to 49.81.55.25449.81.55.255510
15749.81.56.0/2349.81.56.1 to 49.81.57.25449.81.57.255510
15849.81.58.0/2349.81.58.1 to 49.81.59.25449.81.59.255510
15949.81.60.0/2349.81.60.1 to 49.81.61.25449.81.61.255510
16049.81.62.0/2349.81.62.1 to 49.81.63.25449.81.63.255510
16149.81.64.0/2349.81.64.1 to 49.81.65.25449.81.65.255510
16249.81.66.0/2349.81.66.1 to 49.81.67.25449.81.67.255510
16349.81.68.0/2349.81.68.1 to 49.81.69.25449.81.69.255510
16449.81.70.0/2349.81.70.1 to 49.81.71.25449.81.71.255510
16549.81.72.0/2349.81.72.1 to 49.81.73.25449.81.73.255510
16649.81.74.0/2349.81.74.1 to 49.81.75.25449.81.75.255510
16749.81.76.0/2349.81.76.1 to 49.81.77.25449.81.77.255510
16849.81.78.0/2349.81.78.1 to 49.81.79.25449.81.79.255510
16949.81.80.0/2349.81.80.1 to 49.81.81.25449.81.81.255510
17049.81.82.0/2349.81.82.1 to 49.81.83.25449.81.83.255510
17149.81.84.0/2349.81.84.1 to 49.81.85.25449.81.85.255510
17249.81.86.0/2349.81.86.1 to 49.81.87.25449.81.87.255510
17349.81.88.0/2349.81.88.1 to 49.81.89.25449.81.89.255510
17449.81.90.0/2349.81.90.1 to 49.81.91.25449.81.91.255510
17549.81.92.0/2349.81.92.1 to 49.81.93.25449.81.93.255510
17649.81.94.0/2349.81.94.1 to 49.81.95.25449.81.95.255510
17749.81.96.0/2349.81.96.1 to 49.81.97.25449.81.97.255510
17849.81.98.0/2349.81.98.1 to 49.81.99.25449.81.99.255510
17949.81.100.0/2349.81.100.1 to 49.81.101.25449.81.101.255510
18049.81.102.0/2349.81.102.1 to 49.81.103.25449.81.103.255510
18149.81.104.0/2349.81.104.1 to 49.81.105.25449.81.105.255510
18249.81.106.0/2349.81.106.1 to 49.81.107.25449.81.107.255510
18349.81.108.0/2349.81.108.1 to 49.81.109.25449.81.109.255510
18449.81.110.0/2349.81.110.1 to 49.81.111.25449.81.111.255510
18549.81.112.0/2349.81.112.1 to 49.81.113.25449.81.113.255510
18649.81.114.0/2349.81.114.1 to 49.81.115.25449.81.115.255510
18749.81.116.0/2349.81.116.1 to 49.81.117.25449.81.117.255510
18849.81.118.0/2349.81.118.1 to 49.81.119.25449.81.119.255510
18949.81.120.0/2349.81.120.1 to 49.81.121.25449.81.121.255510
19049.81.122.0/2349.81.122.1 to 49.81.123.25449.81.123.255510
19149.81.124.0/2349.81.124.1 to 49.81.125.25449.81.125.255510
19249.81.126.0/2349.81.126.1 to 49.81.127.25449.81.127.255510
19349.81.128.0/2349.81.128.1 to 49.81.129.25449.81.129.255510
19449.81.130.0/2349.81.130.1 to 49.81.131.25449.81.131.255510
19549.81.132.0/2349.81.132.1 to 49.81.133.25449.81.133.255510
19649.81.134.0/2349.81.134.1 to 49.81.135.25449.81.135.255510
19749.81.136.0/2349.81.136.1 to 49.81.137.25449.81.137.255510
19849.81.138.0/2349.81.138.1 to 49.81.139.25449.81.139.255510
19949.81.140.0/2349.81.140.1 to 49.81.141.25449.81.141.255510
20049.81.142.0/2349.81.142.1 to 49.81.143.25449.81.143.255510
20149.81.144.0/2349.81.144.1 to 49.81.145.25449.81.145.255510
20249.81.146.0/2349.81.146.1 to 49.81.147.25449.81.147.255510
20349.81.148.0/2349.81.148.1 to 49.81.149.25449.81.149.255510
20449.81.150.0/2349.81.150.1 to 49.81.151.25449.81.151.255510
20549.81.152.0/2349.81.152.1 to 49.81.153.25449.81.153.255510
20649.81.154.0/2349.81.154.1 to 49.81.155.25449.81.155.255510
20749.81.156.0/2349.81.156.1 to 49.81.157.25449.81.157.255510
20849.81.158.0/2349.81.158.1 to 49.81.159.25449.81.159.255510
20949.81.160.0/2349.81.160.1 to 49.81.161.25449.81.161.255510
21049.81.162.0/2349.81.162.1 to 49.81.163.25449.81.163.255510
21149.81.164.0/2349.81.164.1 to 49.81.165.25449.81.165.255510
21249.81.166.0/2349.81.166.1 to 49.81.167.25449.81.167.255510
21349.81.168.0/2349.81.168.1 to 49.81.169.25449.81.169.255510
21449.81.170.0/2349.81.170.1 to 49.81.171.25449.81.171.255510
21549.81.172.0/2349.81.172.1 to 49.81.173.25449.81.173.255510
21649.81.174.0/2349.81.174.1 to 49.81.175.25449.81.175.255510
21749.81.176.0/2349.81.176.1 to 49.81.177.25449.81.177.255510
21849.81.178.0/2349.81.178.1 to 49.81.179.25449.81.179.255510
21949.81.180.0/2349.81.180.1 to 49.81.181.25449.81.181.255510
22049.81.182.0/2349.81.182.1 to 49.81.183.25449.81.183.255510
22149.81.184.0/2349.81.184.1 to 49.81.185.25449.81.185.255510
22249.81.186.0/2349.81.186.1 to 49.81.187.25449.81.187.255510
22349.81.188.0/2349.81.188.1 to 49.81.189.25449.81.189.255510
22449.81.190.0/2349.81.190.1 to 49.81.191.25449.81.191.255510
22549.81.192.0/2349.81.192.1 to 49.81.193.25449.81.193.255510
22649.81.194.0/2349.81.194.1 to 49.81.195.25449.81.195.255510
22749.81.196.0/2349.81.196.1 to 49.81.197.25449.81.197.255510
22849.81.198.0/2349.81.198.1 to 49.81.199.25449.81.199.255510
22949.81.200.0/2349.81.200.1 to 49.81.201.25449.81.201.255510
23049.81.202.0/2349.81.202.1 to 49.81.203.25449.81.203.255510
23149.81.204.0/2349.81.204.1 to 49.81.205.25449.81.205.255510
23249.81.206.0/2349.81.206.1 to 49.81.207.25449.81.207.255510
23349.81.208.0/2349.81.208.1 to 49.81.209.25449.81.209.255510
23449.81.210.0/2349.81.210.1 to 49.81.211.25449.81.211.255510
23549.81.212.0/2349.81.212.1 to 49.81.213.25449.81.213.255510
23649.81.214.0/2349.81.214.1 to 49.81.215.25449.81.215.255510
23749.81.216.0/2349.81.216.1 to 49.81.217.25449.81.217.255510
23849.81.218.0/2349.81.218.1 to 49.81.219.25449.81.219.255510
23949.81.220.0/2349.81.220.1 to 49.81.221.25449.81.221.255510
24049.81.222.0/2349.81.222.1 to 49.81.223.25449.81.223.255510
24149.81.224.0/2349.81.224.1 to 49.81.225.25449.81.225.255510
24249.81.226.0/2349.81.226.1 to 49.81.227.25449.81.227.255510
24349.81.228.0/2349.81.228.1 to 49.81.229.25449.81.229.255510
24449.81.230.0/2349.81.230.1 to 49.81.231.25449.81.231.255510
24549.81.232.0/2349.81.232.1 to 49.81.233.25449.81.233.255510
24649.81.234.0/2349.81.234.1 to 49.81.235.25449.81.235.255510
24749.81.236.0/2349.81.236.1 to 49.81.237.25449.81.237.255510
24849.81.238.0/2349.81.238.1 to 49.81.239.25449.81.239.255510
24949.81.240.0/2349.81.240.1 to 49.81.241.25449.81.241.255510
25049.81.242.0/2349.81.242.1 to 49.81.243.25449.81.243.255510
25149.81.244.0/2349.81.244.1 to 49.81.245.25449.81.245.255510
25249.81.246.0/2349.81.246.1 to 49.81.247.25449.81.247.255510
25349.81.248.0/2349.81.248.1 to 49.81.249.25449.81.249.255510
25449.81.250.0/2349.81.250.1 to 49.81.251.25449.81.251.255510
25549.81.252.0/2349.81.252.1 to 49.81.253.25449.81.253.255510
25649.81.254.0/2349.81.254.1 to 49.81.255.25449.81.255.255510

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.