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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.

Network34.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
34.0.0.0
Broadcast address
35.255.255.255
First usable
34.0.0.1
Last usable
35.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
A (default /8)
As numbers
Hex 22000000 · Integer 570425344 to 603979775
Reverse DNS zones
34.in-addr.arpa
35.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00100010.00000000.00000000.0000000034.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network00100010.00000000.00000000.0000000034.0.0.0
Broadcast00100011.11111111.11111111.1111111135.255.255.255
Split into smaller subnets/16
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

34.0.0.0/7 makes 512 subnets of /16; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
134.0.0.0/1634.0.0.1 to 34.0.255.25434.0.255.25565,534
234.1.0.0/1634.1.0.1 to 34.1.255.25434.1.255.25565,534
334.2.0.0/1634.2.0.1 to 34.2.255.25434.2.255.25565,534
434.3.0.0/1634.3.0.1 to 34.3.255.25434.3.255.25565,534
534.4.0.0/1634.4.0.1 to 34.4.255.25434.4.255.25565,534
634.5.0.0/1634.5.0.1 to 34.5.255.25434.5.255.25565,534
734.6.0.0/1634.6.0.1 to 34.6.255.25434.6.255.25565,534
834.7.0.0/1634.7.0.1 to 34.7.255.25434.7.255.25565,534
934.8.0.0/1634.8.0.1 to 34.8.255.25434.8.255.25565,534
1034.9.0.0/1634.9.0.1 to 34.9.255.25434.9.255.25565,534
1134.10.0.0/1634.10.0.1 to 34.10.255.25434.10.255.25565,534
1234.11.0.0/1634.11.0.1 to 34.11.255.25434.11.255.25565,534
1334.12.0.0/1634.12.0.1 to 34.12.255.25434.12.255.25565,534
1434.13.0.0/1634.13.0.1 to 34.13.255.25434.13.255.25565,534
1534.14.0.0/1634.14.0.1 to 34.14.255.25434.14.255.25565,534
1634.15.0.0/1634.15.0.1 to 34.15.255.25434.15.255.25565,534
1734.16.0.0/1634.16.0.1 to 34.16.255.25434.16.255.25565,534
1834.17.0.0/1634.17.0.1 to 34.17.255.25434.17.255.25565,534
1934.18.0.0/1634.18.0.1 to 34.18.255.25434.18.255.25565,534
2034.19.0.0/1634.19.0.1 to 34.19.255.25434.19.255.25565,534
2134.20.0.0/1634.20.0.1 to 34.20.255.25434.20.255.25565,534
2234.21.0.0/1634.21.0.1 to 34.21.255.25434.21.255.25565,534
2334.22.0.0/1634.22.0.1 to 34.22.255.25434.22.255.25565,534
2434.23.0.0/1634.23.0.1 to 34.23.255.25434.23.255.25565,534
2534.24.0.0/1634.24.0.1 to 34.24.255.25434.24.255.25565,534
2634.25.0.0/1634.25.0.1 to 34.25.255.25434.25.255.25565,534
2734.26.0.0/1634.26.0.1 to 34.26.255.25434.26.255.25565,534
2834.27.0.0/1634.27.0.1 to 34.27.255.25434.27.255.25565,534
2934.28.0.0/1634.28.0.1 to 34.28.255.25434.28.255.25565,534
3034.29.0.0/1634.29.0.1 to 34.29.255.25434.29.255.25565,534
3134.30.0.0/1634.30.0.1 to 34.30.255.25434.30.255.25565,534
3234.31.0.0/1634.31.0.1 to 34.31.255.25434.31.255.25565,534
3334.32.0.0/1634.32.0.1 to 34.32.255.25434.32.255.25565,534
3434.33.0.0/1634.33.0.1 to 34.33.255.25434.33.255.25565,534
3534.34.0.0/1634.34.0.1 to 34.34.255.25434.34.255.25565,534
3634.35.0.0/1634.35.0.1 to 34.35.255.25434.35.255.25565,534
3734.36.0.0/1634.36.0.1 to 34.36.255.25434.36.255.25565,534
3834.37.0.0/1634.37.0.1 to 34.37.255.25434.37.255.25565,534
3934.38.0.0/1634.38.0.1 to 34.38.255.25434.38.255.25565,534
4034.39.0.0/1634.39.0.1 to 34.39.255.25434.39.255.25565,534
4134.40.0.0/1634.40.0.1 to 34.40.255.25434.40.255.25565,534
4234.41.0.0/1634.41.0.1 to 34.41.255.25434.41.255.25565,534
4334.42.0.0/1634.42.0.1 to 34.42.255.25434.42.255.25565,534
4434.43.0.0/1634.43.0.1 to 34.43.255.25434.43.255.25565,534
4534.44.0.0/1634.44.0.1 to 34.44.255.25434.44.255.25565,534
4634.45.0.0/1634.45.0.1 to 34.45.255.25434.45.255.25565,534
4734.46.0.0/1634.46.0.1 to 34.46.255.25434.46.255.25565,534
4834.47.0.0/1634.47.0.1 to 34.47.255.25434.47.255.25565,534
4934.48.0.0/1634.48.0.1 to 34.48.255.25434.48.255.25565,534
5034.49.0.0/1634.49.0.1 to 34.49.255.25434.49.255.25565,534
5134.50.0.0/1634.50.0.1 to 34.50.255.25434.50.255.25565,534
5234.51.0.0/1634.51.0.1 to 34.51.255.25434.51.255.25565,534
5334.52.0.0/1634.52.0.1 to 34.52.255.25434.52.255.25565,534
5434.53.0.0/1634.53.0.1 to 34.53.255.25434.53.255.25565,534
5534.54.0.0/1634.54.0.1 to 34.54.255.25434.54.255.25565,534
5634.55.0.0/1634.55.0.1 to 34.55.255.25434.55.255.25565,534
5734.56.0.0/1634.56.0.1 to 34.56.255.25434.56.255.25565,534
5834.57.0.0/1634.57.0.1 to 34.57.255.25434.57.255.25565,534
5934.58.0.0/1634.58.0.1 to 34.58.255.25434.58.255.25565,534
6034.59.0.0/1634.59.0.1 to 34.59.255.25434.59.255.25565,534
6134.60.0.0/1634.60.0.1 to 34.60.255.25434.60.255.25565,534
6234.61.0.0/1634.61.0.1 to 34.61.255.25434.61.255.25565,534
6334.62.0.0/1634.62.0.1 to 34.62.255.25434.62.255.25565,534
6434.63.0.0/1634.63.0.1 to 34.63.255.25434.63.255.25565,534
6534.64.0.0/1634.64.0.1 to 34.64.255.25434.64.255.25565,534
6634.65.0.0/1634.65.0.1 to 34.65.255.25434.65.255.25565,534
6734.66.0.0/1634.66.0.1 to 34.66.255.25434.66.255.25565,534
6834.67.0.0/1634.67.0.1 to 34.67.255.25434.67.255.25565,534
6934.68.0.0/1634.68.0.1 to 34.68.255.25434.68.255.25565,534
7034.69.0.0/1634.69.0.1 to 34.69.255.25434.69.255.25565,534
7134.70.0.0/1634.70.0.1 to 34.70.255.25434.70.255.25565,534
7234.71.0.0/1634.71.0.1 to 34.71.255.25434.71.255.25565,534
7334.72.0.0/1634.72.0.1 to 34.72.255.25434.72.255.25565,534
7434.73.0.0/1634.73.0.1 to 34.73.255.25434.73.255.25565,534
7534.74.0.0/1634.74.0.1 to 34.74.255.25434.74.255.25565,534
7634.75.0.0/1634.75.0.1 to 34.75.255.25434.75.255.25565,534
7734.76.0.0/1634.76.0.1 to 34.76.255.25434.76.255.25565,534
7834.77.0.0/1634.77.0.1 to 34.77.255.25434.77.255.25565,534
7934.78.0.0/1634.78.0.1 to 34.78.255.25434.78.255.25565,534
8034.79.0.0/1634.79.0.1 to 34.79.255.25434.79.255.25565,534
8134.80.0.0/1634.80.0.1 to 34.80.255.25434.80.255.25565,534
8234.81.0.0/1634.81.0.1 to 34.81.255.25434.81.255.25565,534
8334.82.0.0/1634.82.0.1 to 34.82.255.25434.82.255.25565,534
8434.83.0.0/1634.83.0.1 to 34.83.255.25434.83.255.25565,534
8534.84.0.0/1634.84.0.1 to 34.84.255.25434.84.255.25565,534
8634.85.0.0/1634.85.0.1 to 34.85.255.25434.85.255.25565,534
8734.86.0.0/1634.86.0.1 to 34.86.255.25434.86.255.25565,534
8834.87.0.0/1634.87.0.1 to 34.87.255.25434.87.255.25565,534
8934.88.0.0/1634.88.0.1 to 34.88.255.25434.88.255.25565,534
9034.89.0.0/1634.89.0.1 to 34.89.255.25434.89.255.25565,534
9134.90.0.0/1634.90.0.1 to 34.90.255.25434.90.255.25565,534
9234.91.0.0/1634.91.0.1 to 34.91.255.25434.91.255.25565,534
9334.92.0.0/1634.92.0.1 to 34.92.255.25434.92.255.25565,534
9434.93.0.0/1634.93.0.1 to 34.93.255.25434.93.255.25565,534
9534.94.0.0/1634.94.0.1 to 34.94.255.25434.94.255.25565,534
9634.95.0.0/1634.95.0.1 to 34.95.255.25434.95.255.25565,534
9734.96.0.0/1634.96.0.1 to 34.96.255.25434.96.255.25565,534
9834.97.0.0/1634.97.0.1 to 34.97.255.25434.97.255.25565,534
9934.98.0.0/1634.98.0.1 to 34.98.255.25434.98.255.25565,534
10034.99.0.0/1634.99.0.1 to 34.99.255.25434.99.255.25565,534
10134.100.0.0/1634.100.0.1 to 34.100.255.25434.100.255.25565,534
10234.101.0.0/1634.101.0.1 to 34.101.255.25434.101.255.25565,534
10334.102.0.0/1634.102.0.1 to 34.102.255.25434.102.255.25565,534
10434.103.0.0/1634.103.0.1 to 34.103.255.25434.103.255.25565,534
10534.104.0.0/1634.104.0.1 to 34.104.255.25434.104.255.25565,534
10634.105.0.0/1634.105.0.1 to 34.105.255.25434.105.255.25565,534
10734.106.0.0/1634.106.0.1 to 34.106.255.25434.106.255.25565,534
10834.107.0.0/1634.107.0.1 to 34.107.255.25434.107.255.25565,534
10934.108.0.0/1634.108.0.1 to 34.108.255.25434.108.255.25565,534
11034.109.0.0/1634.109.0.1 to 34.109.255.25434.109.255.25565,534
11134.110.0.0/1634.110.0.1 to 34.110.255.25434.110.255.25565,534
11234.111.0.0/1634.111.0.1 to 34.111.255.25434.111.255.25565,534
11334.112.0.0/1634.112.0.1 to 34.112.255.25434.112.255.25565,534
11434.113.0.0/1634.113.0.1 to 34.113.255.25434.113.255.25565,534
11534.114.0.0/1634.114.0.1 to 34.114.255.25434.114.255.25565,534
11634.115.0.0/1634.115.0.1 to 34.115.255.25434.115.255.25565,534
11734.116.0.0/1634.116.0.1 to 34.116.255.25434.116.255.25565,534
11834.117.0.0/1634.117.0.1 to 34.117.255.25434.117.255.25565,534
11934.118.0.0/1634.118.0.1 to 34.118.255.25434.118.255.25565,534
12034.119.0.0/1634.119.0.1 to 34.119.255.25434.119.255.25565,534
12134.120.0.0/1634.120.0.1 to 34.120.255.25434.120.255.25565,534
12234.121.0.0/1634.121.0.1 to 34.121.255.25434.121.255.25565,534
12334.122.0.0/1634.122.0.1 to 34.122.255.25434.122.255.25565,534
12434.123.0.0/1634.123.0.1 to 34.123.255.25434.123.255.25565,534
12534.124.0.0/1634.124.0.1 to 34.124.255.25434.124.255.25565,534
12634.125.0.0/1634.125.0.1 to 34.125.255.25434.125.255.25565,534
12734.126.0.0/1634.126.0.1 to 34.126.255.25434.126.255.25565,534
12834.127.0.0/1634.127.0.1 to 34.127.255.25434.127.255.25565,534
12934.128.0.0/1634.128.0.1 to 34.128.255.25434.128.255.25565,534
13034.129.0.0/1634.129.0.1 to 34.129.255.25434.129.255.25565,534
13134.130.0.0/1634.130.0.1 to 34.130.255.25434.130.255.25565,534
13234.131.0.0/1634.131.0.1 to 34.131.255.25434.131.255.25565,534
13334.132.0.0/1634.132.0.1 to 34.132.255.25434.132.255.25565,534
13434.133.0.0/1634.133.0.1 to 34.133.255.25434.133.255.25565,534
13534.134.0.0/1634.134.0.1 to 34.134.255.25434.134.255.25565,534
13634.135.0.0/1634.135.0.1 to 34.135.255.25434.135.255.25565,534
13734.136.0.0/1634.136.0.1 to 34.136.255.25434.136.255.25565,534
13834.137.0.0/1634.137.0.1 to 34.137.255.25434.137.255.25565,534
13934.138.0.0/1634.138.0.1 to 34.138.255.25434.138.255.25565,534
14034.139.0.0/1634.139.0.1 to 34.139.255.25434.139.255.25565,534
14134.140.0.0/1634.140.0.1 to 34.140.255.25434.140.255.25565,534
14234.141.0.0/1634.141.0.1 to 34.141.255.25434.141.255.25565,534
14334.142.0.0/1634.142.0.1 to 34.142.255.25434.142.255.25565,534
14434.143.0.0/1634.143.0.1 to 34.143.255.25434.143.255.25565,534
14534.144.0.0/1634.144.0.1 to 34.144.255.25434.144.255.25565,534
14634.145.0.0/1634.145.0.1 to 34.145.255.25434.145.255.25565,534
14734.146.0.0/1634.146.0.1 to 34.146.255.25434.146.255.25565,534
14834.147.0.0/1634.147.0.1 to 34.147.255.25434.147.255.25565,534
14934.148.0.0/1634.148.0.1 to 34.148.255.25434.148.255.25565,534
15034.149.0.0/1634.149.0.1 to 34.149.255.25434.149.255.25565,534
15134.150.0.0/1634.150.0.1 to 34.150.255.25434.150.255.25565,534
15234.151.0.0/1634.151.0.1 to 34.151.255.25434.151.255.25565,534
15334.152.0.0/1634.152.0.1 to 34.152.255.25434.152.255.25565,534
15434.153.0.0/1634.153.0.1 to 34.153.255.25434.153.255.25565,534
15534.154.0.0/1634.154.0.1 to 34.154.255.25434.154.255.25565,534
15634.155.0.0/1634.155.0.1 to 34.155.255.25434.155.255.25565,534
15734.156.0.0/1634.156.0.1 to 34.156.255.25434.156.255.25565,534
15834.157.0.0/1634.157.0.1 to 34.157.255.25434.157.255.25565,534
15934.158.0.0/1634.158.0.1 to 34.158.255.25434.158.255.25565,534
16034.159.0.0/1634.159.0.1 to 34.159.255.25434.159.255.25565,534
16134.160.0.0/1634.160.0.1 to 34.160.255.25434.160.255.25565,534
16234.161.0.0/1634.161.0.1 to 34.161.255.25434.161.255.25565,534
16334.162.0.0/1634.162.0.1 to 34.162.255.25434.162.255.25565,534
16434.163.0.0/1634.163.0.1 to 34.163.255.25434.163.255.25565,534
16534.164.0.0/1634.164.0.1 to 34.164.255.25434.164.255.25565,534
16634.165.0.0/1634.165.0.1 to 34.165.255.25434.165.255.25565,534
16734.166.0.0/1634.166.0.1 to 34.166.255.25434.166.255.25565,534
16834.167.0.0/1634.167.0.1 to 34.167.255.25434.167.255.25565,534
16934.168.0.0/1634.168.0.1 to 34.168.255.25434.168.255.25565,534
17034.169.0.0/1634.169.0.1 to 34.169.255.25434.169.255.25565,534
17134.170.0.0/1634.170.0.1 to 34.170.255.25434.170.255.25565,534
17234.171.0.0/1634.171.0.1 to 34.171.255.25434.171.255.25565,534
17334.172.0.0/1634.172.0.1 to 34.172.255.25434.172.255.25565,534
17434.173.0.0/1634.173.0.1 to 34.173.255.25434.173.255.25565,534
17534.174.0.0/1634.174.0.1 to 34.174.255.25434.174.255.25565,534
17634.175.0.0/1634.175.0.1 to 34.175.255.25434.175.255.25565,534
17734.176.0.0/1634.176.0.1 to 34.176.255.25434.176.255.25565,534
17834.177.0.0/1634.177.0.1 to 34.177.255.25434.177.255.25565,534
17934.178.0.0/1634.178.0.1 to 34.178.255.25434.178.255.25565,534
18034.179.0.0/1634.179.0.1 to 34.179.255.25434.179.255.25565,534
18134.180.0.0/1634.180.0.1 to 34.180.255.25434.180.255.25565,534
18234.181.0.0/1634.181.0.1 to 34.181.255.25434.181.255.25565,534
18334.182.0.0/1634.182.0.1 to 34.182.255.25434.182.255.25565,534
18434.183.0.0/1634.183.0.1 to 34.183.255.25434.183.255.25565,534
18534.184.0.0/1634.184.0.1 to 34.184.255.25434.184.255.25565,534
18634.185.0.0/1634.185.0.1 to 34.185.255.25434.185.255.25565,534
18734.186.0.0/1634.186.0.1 to 34.186.255.25434.186.255.25565,534
18834.187.0.0/1634.187.0.1 to 34.187.255.25434.187.255.25565,534
18934.188.0.0/1634.188.0.1 to 34.188.255.25434.188.255.25565,534
19034.189.0.0/1634.189.0.1 to 34.189.255.25434.189.255.25565,534
19134.190.0.0/1634.190.0.1 to 34.190.255.25434.190.255.25565,534
19234.191.0.0/1634.191.0.1 to 34.191.255.25434.191.255.25565,534
19334.192.0.0/1634.192.0.1 to 34.192.255.25434.192.255.25565,534
19434.193.0.0/1634.193.0.1 to 34.193.255.25434.193.255.25565,534
19534.194.0.0/1634.194.0.1 to 34.194.255.25434.194.255.25565,534
19634.195.0.0/1634.195.0.1 to 34.195.255.25434.195.255.25565,534
19734.196.0.0/1634.196.0.1 to 34.196.255.25434.196.255.25565,534
19834.197.0.0/1634.197.0.1 to 34.197.255.25434.197.255.25565,534
19934.198.0.0/1634.198.0.1 to 34.198.255.25434.198.255.25565,534
20034.199.0.0/1634.199.0.1 to 34.199.255.25434.199.255.25565,534
20134.200.0.0/1634.200.0.1 to 34.200.255.25434.200.255.25565,534
20234.201.0.0/1634.201.0.1 to 34.201.255.25434.201.255.25565,534
20334.202.0.0/1634.202.0.1 to 34.202.255.25434.202.255.25565,534
20434.203.0.0/1634.203.0.1 to 34.203.255.25434.203.255.25565,534
20534.204.0.0/1634.204.0.1 to 34.204.255.25434.204.255.25565,534
20634.205.0.0/1634.205.0.1 to 34.205.255.25434.205.255.25565,534
20734.206.0.0/1634.206.0.1 to 34.206.255.25434.206.255.25565,534
20834.207.0.0/1634.207.0.1 to 34.207.255.25434.207.255.25565,534
20934.208.0.0/1634.208.0.1 to 34.208.255.25434.208.255.25565,534
21034.209.0.0/1634.209.0.1 to 34.209.255.25434.209.255.25565,534
21134.210.0.0/1634.210.0.1 to 34.210.255.25434.210.255.25565,534
21234.211.0.0/1634.211.0.1 to 34.211.255.25434.211.255.25565,534
21334.212.0.0/1634.212.0.1 to 34.212.255.25434.212.255.25565,534
21434.213.0.0/1634.213.0.1 to 34.213.255.25434.213.255.25565,534
21534.214.0.0/1634.214.0.1 to 34.214.255.25434.214.255.25565,534
21634.215.0.0/1634.215.0.1 to 34.215.255.25434.215.255.25565,534
21734.216.0.0/1634.216.0.1 to 34.216.255.25434.216.255.25565,534
21834.217.0.0/1634.217.0.1 to 34.217.255.25434.217.255.25565,534
21934.218.0.0/1634.218.0.1 to 34.218.255.25434.218.255.25565,534
22034.219.0.0/1634.219.0.1 to 34.219.255.25434.219.255.25565,534
22134.220.0.0/1634.220.0.1 to 34.220.255.25434.220.255.25565,534
22234.221.0.0/1634.221.0.1 to 34.221.255.25434.221.255.25565,534
22334.222.0.0/1634.222.0.1 to 34.222.255.25434.222.255.25565,534
22434.223.0.0/1634.223.0.1 to 34.223.255.25434.223.255.25565,534
22534.224.0.0/1634.224.0.1 to 34.224.255.25434.224.255.25565,534
22634.225.0.0/1634.225.0.1 to 34.225.255.25434.225.255.25565,534
22734.226.0.0/1634.226.0.1 to 34.226.255.25434.226.255.25565,534
22834.227.0.0/1634.227.0.1 to 34.227.255.25434.227.255.25565,534
22934.228.0.0/1634.228.0.1 to 34.228.255.25434.228.255.25565,534
23034.229.0.0/1634.229.0.1 to 34.229.255.25434.229.255.25565,534
23134.230.0.0/1634.230.0.1 to 34.230.255.25434.230.255.25565,534
23234.231.0.0/1634.231.0.1 to 34.231.255.25434.231.255.25565,534
23334.232.0.0/1634.232.0.1 to 34.232.255.25434.232.255.25565,534
23434.233.0.0/1634.233.0.1 to 34.233.255.25434.233.255.25565,534
23534.234.0.0/1634.234.0.1 to 34.234.255.25434.234.255.25565,534
23634.235.0.0/1634.235.0.1 to 34.235.255.25434.235.255.25565,534
23734.236.0.0/1634.236.0.1 to 34.236.255.25434.236.255.25565,534
23834.237.0.0/1634.237.0.1 to 34.237.255.25434.237.255.25565,534
23934.238.0.0/1634.238.0.1 to 34.238.255.25434.238.255.25565,534
24034.239.0.0/1634.239.0.1 to 34.239.255.25434.239.255.25565,534
24134.240.0.0/1634.240.0.1 to 34.240.255.25434.240.255.25565,534
24234.241.0.0/1634.241.0.1 to 34.241.255.25434.241.255.25565,534
24334.242.0.0/1634.242.0.1 to 34.242.255.25434.242.255.25565,534
24434.243.0.0/1634.243.0.1 to 34.243.255.25434.243.255.25565,534
24534.244.0.0/1634.244.0.1 to 34.244.255.25434.244.255.25565,534
24634.245.0.0/1634.245.0.1 to 34.245.255.25434.245.255.25565,534
24734.246.0.0/1634.246.0.1 to 34.246.255.25434.246.255.25565,534
24834.247.0.0/1634.247.0.1 to 34.247.255.25434.247.255.25565,534
24934.248.0.0/1634.248.0.1 to 34.248.255.25434.248.255.25565,534
25034.249.0.0/1634.249.0.1 to 34.249.255.25434.249.255.25565,534
25134.250.0.0/1634.250.0.1 to 34.250.255.25434.250.255.25565,534
25234.251.0.0/1634.251.0.1 to 34.251.255.25434.251.255.25565,534
25334.252.0.0/1634.252.0.1 to 34.252.255.25434.252.255.25565,534
25434.253.0.0/1634.253.0.1 to 34.253.255.25434.253.255.25565,534
25534.254.0.0/1634.254.0.1 to 34.254.255.25434.254.255.25565,534
25634.255.0.0/1634.255.0.1 to 34.255.255.25434.255.255.25565,534

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.