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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.

Network74.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
74.0.0.0
Broadcast address
75.255.255.255
First usable
74.0.0.1
Last usable
75.255.255.254
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 4A000000 · Integer 1241513984 to 1275068415
Reverse DNS zones
74.in-addr.arpa
75.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
Address01001010.00000000.00000000.0000000074.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network01001010.00000000.00000000.0000000074.0.0.0
Broadcast01001011.11111111.11111111.1111111175.255.255.255
Split into smaller subnets/15
/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)

74.0.0.0/7 makes 256 subnets of /15.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
174.0.0.0/1574.0.0.1 to 74.1.255.25474.1.255.255131,070
274.2.0.0/1574.2.0.1 to 74.3.255.25474.3.255.255131,070
374.4.0.0/1574.4.0.1 to 74.5.255.25474.5.255.255131,070
474.6.0.0/1574.6.0.1 to 74.7.255.25474.7.255.255131,070
574.8.0.0/1574.8.0.1 to 74.9.255.25474.9.255.255131,070
674.10.0.0/1574.10.0.1 to 74.11.255.25474.11.255.255131,070
774.12.0.0/1574.12.0.1 to 74.13.255.25474.13.255.255131,070
874.14.0.0/1574.14.0.1 to 74.15.255.25474.15.255.255131,070
974.16.0.0/1574.16.0.1 to 74.17.255.25474.17.255.255131,070
1074.18.0.0/1574.18.0.1 to 74.19.255.25474.19.255.255131,070
1174.20.0.0/1574.20.0.1 to 74.21.255.25474.21.255.255131,070
1274.22.0.0/1574.22.0.1 to 74.23.255.25474.23.255.255131,070
1374.24.0.0/1574.24.0.1 to 74.25.255.25474.25.255.255131,070
1474.26.0.0/1574.26.0.1 to 74.27.255.25474.27.255.255131,070
1574.28.0.0/1574.28.0.1 to 74.29.255.25474.29.255.255131,070
1674.30.0.0/1574.30.0.1 to 74.31.255.25474.31.255.255131,070
1774.32.0.0/1574.32.0.1 to 74.33.255.25474.33.255.255131,070
1874.34.0.0/1574.34.0.1 to 74.35.255.25474.35.255.255131,070
1974.36.0.0/1574.36.0.1 to 74.37.255.25474.37.255.255131,070
2074.38.0.0/1574.38.0.1 to 74.39.255.25474.39.255.255131,070
2174.40.0.0/1574.40.0.1 to 74.41.255.25474.41.255.255131,070
2274.42.0.0/1574.42.0.1 to 74.43.255.25474.43.255.255131,070
2374.44.0.0/1574.44.0.1 to 74.45.255.25474.45.255.255131,070
2474.46.0.0/1574.46.0.1 to 74.47.255.25474.47.255.255131,070
2574.48.0.0/1574.48.0.1 to 74.49.255.25474.49.255.255131,070
2674.50.0.0/1574.50.0.1 to 74.51.255.25474.51.255.255131,070
2774.52.0.0/1574.52.0.1 to 74.53.255.25474.53.255.255131,070
2874.54.0.0/1574.54.0.1 to 74.55.255.25474.55.255.255131,070
2974.56.0.0/1574.56.0.1 to 74.57.255.25474.57.255.255131,070
3074.58.0.0/1574.58.0.1 to 74.59.255.25474.59.255.255131,070
3174.60.0.0/1574.60.0.1 to 74.61.255.25474.61.255.255131,070
3274.62.0.0/1574.62.0.1 to 74.63.255.25474.63.255.255131,070
3374.64.0.0/1574.64.0.1 to 74.65.255.25474.65.255.255131,070
3474.66.0.0/1574.66.0.1 to 74.67.255.25474.67.255.255131,070
3574.68.0.0/1574.68.0.1 to 74.69.255.25474.69.255.255131,070
3674.70.0.0/1574.70.0.1 to 74.71.255.25474.71.255.255131,070
3774.72.0.0/1574.72.0.1 to 74.73.255.25474.73.255.255131,070
3874.74.0.0/1574.74.0.1 to 74.75.255.25474.75.255.255131,070
3974.76.0.0/1574.76.0.1 to 74.77.255.25474.77.255.255131,070
4074.78.0.0/1574.78.0.1 to 74.79.255.25474.79.255.255131,070
4174.80.0.0/1574.80.0.1 to 74.81.255.25474.81.255.255131,070
4274.82.0.0/1574.82.0.1 to 74.83.255.25474.83.255.255131,070
4374.84.0.0/1574.84.0.1 to 74.85.255.25474.85.255.255131,070
4474.86.0.0/1574.86.0.1 to 74.87.255.25474.87.255.255131,070
4574.88.0.0/1574.88.0.1 to 74.89.255.25474.89.255.255131,070
4674.90.0.0/1574.90.0.1 to 74.91.255.25474.91.255.255131,070
4774.92.0.0/1574.92.0.1 to 74.93.255.25474.93.255.255131,070
4874.94.0.0/1574.94.0.1 to 74.95.255.25474.95.255.255131,070
4974.96.0.0/1574.96.0.1 to 74.97.255.25474.97.255.255131,070
5074.98.0.0/1574.98.0.1 to 74.99.255.25474.99.255.255131,070
5174.100.0.0/1574.100.0.1 to 74.101.255.25474.101.255.255131,070
5274.102.0.0/1574.102.0.1 to 74.103.255.25474.103.255.255131,070
5374.104.0.0/1574.104.0.1 to 74.105.255.25474.105.255.255131,070
5474.106.0.0/1574.106.0.1 to 74.107.255.25474.107.255.255131,070
5574.108.0.0/1574.108.0.1 to 74.109.255.25474.109.255.255131,070
5674.110.0.0/1574.110.0.1 to 74.111.255.25474.111.255.255131,070
5774.112.0.0/1574.112.0.1 to 74.113.255.25474.113.255.255131,070
5874.114.0.0/1574.114.0.1 to 74.115.255.25474.115.255.255131,070
5974.116.0.0/1574.116.0.1 to 74.117.255.25474.117.255.255131,070
6074.118.0.0/1574.118.0.1 to 74.119.255.25474.119.255.255131,070
6174.120.0.0/1574.120.0.1 to 74.121.255.25474.121.255.255131,070
6274.122.0.0/1574.122.0.1 to 74.123.255.25474.123.255.255131,070
6374.124.0.0/1574.124.0.1 to 74.125.255.25474.125.255.255131,070
6474.126.0.0/1574.126.0.1 to 74.127.255.25474.127.255.255131,070
6574.128.0.0/1574.128.0.1 to 74.129.255.25474.129.255.255131,070
6674.130.0.0/1574.130.0.1 to 74.131.255.25474.131.255.255131,070
6774.132.0.0/1574.132.0.1 to 74.133.255.25474.133.255.255131,070
6874.134.0.0/1574.134.0.1 to 74.135.255.25474.135.255.255131,070
6974.136.0.0/1574.136.0.1 to 74.137.255.25474.137.255.255131,070
7074.138.0.0/1574.138.0.1 to 74.139.255.25474.139.255.255131,070
7174.140.0.0/1574.140.0.1 to 74.141.255.25474.141.255.255131,070
7274.142.0.0/1574.142.0.1 to 74.143.255.25474.143.255.255131,070
7374.144.0.0/1574.144.0.1 to 74.145.255.25474.145.255.255131,070
7474.146.0.0/1574.146.0.1 to 74.147.255.25474.147.255.255131,070
7574.148.0.0/1574.148.0.1 to 74.149.255.25474.149.255.255131,070
7674.150.0.0/1574.150.0.1 to 74.151.255.25474.151.255.255131,070
7774.152.0.0/1574.152.0.1 to 74.153.255.25474.153.255.255131,070
7874.154.0.0/1574.154.0.1 to 74.155.255.25474.155.255.255131,070
7974.156.0.0/1574.156.0.1 to 74.157.255.25474.157.255.255131,070
8074.158.0.0/1574.158.0.1 to 74.159.255.25474.159.255.255131,070
8174.160.0.0/1574.160.0.1 to 74.161.255.25474.161.255.255131,070
8274.162.0.0/1574.162.0.1 to 74.163.255.25474.163.255.255131,070
8374.164.0.0/1574.164.0.1 to 74.165.255.25474.165.255.255131,070
8474.166.0.0/1574.166.0.1 to 74.167.255.25474.167.255.255131,070
8574.168.0.0/1574.168.0.1 to 74.169.255.25474.169.255.255131,070
8674.170.0.0/1574.170.0.1 to 74.171.255.25474.171.255.255131,070
8774.172.0.0/1574.172.0.1 to 74.173.255.25474.173.255.255131,070
8874.174.0.0/1574.174.0.1 to 74.175.255.25474.175.255.255131,070
8974.176.0.0/1574.176.0.1 to 74.177.255.25474.177.255.255131,070
9074.178.0.0/1574.178.0.1 to 74.179.255.25474.179.255.255131,070
9174.180.0.0/1574.180.0.1 to 74.181.255.25474.181.255.255131,070
9274.182.0.0/1574.182.0.1 to 74.183.255.25474.183.255.255131,070
9374.184.0.0/1574.184.0.1 to 74.185.255.25474.185.255.255131,070
9474.186.0.0/1574.186.0.1 to 74.187.255.25474.187.255.255131,070
9574.188.0.0/1574.188.0.1 to 74.189.255.25474.189.255.255131,070
9674.190.0.0/1574.190.0.1 to 74.191.255.25474.191.255.255131,070
9774.192.0.0/1574.192.0.1 to 74.193.255.25474.193.255.255131,070
9874.194.0.0/1574.194.0.1 to 74.195.255.25474.195.255.255131,070
9974.196.0.0/1574.196.0.1 to 74.197.255.25474.197.255.255131,070
10074.198.0.0/1574.198.0.1 to 74.199.255.25474.199.255.255131,070
10174.200.0.0/1574.200.0.1 to 74.201.255.25474.201.255.255131,070
10274.202.0.0/1574.202.0.1 to 74.203.255.25474.203.255.255131,070
10374.204.0.0/1574.204.0.1 to 74.205.255.25474.205.255.255131,070
10474.206.0.0/1574.206.0.1 to 74.207.255.25474.207.255.255131,070
10574.208.0.0/1574.208.0.1 to 74.209.255.25474.209.255.255131,070
10674.210.0.0/1574.210.0.1 to 74.211.255.25474.211.255.255131,070
10774.212.0.0/1574.212.0.1 to 74.213.255.25474.213.255.255131,070
10874.214.0.0/1574.214.0.1 to 74.215.255.25474.215.255.255131,070
10974.216.0.0/1574.216.0.1 to 74.217.255.25474.217.255.255131,070
11074.218.0.0/1574.218.0.1 to 74.219.255.25474.219.255.255131,070
11174.220.0.0/1574.220.0.1 to 74.221.255.25474.221.255.255131,070
11274.222.0.0/1574.222.0.1 to 74.223.255.25474.223.255.255131,070
11374.224.0.0/1574.224.0.1 to 74.225.255.25474.225.255.255131,070
11474.226.0.0/1574.226.0.1 to 74.227.255.25474.227.255.255131,070
11574.228.0.0/1574.228.0.1 to 74.229.255.25474.229.255.255131,070
11674.230.0.0/1574.230.0.1 to 74.231.255.25474.231.255.255131,070
11774.232.0.0/1574.232.0.1 to 74.233.255.25474.233.255.255131,070
11874.234.0.0/1574.234.0.1 to 74.235.255.25474.235.255.255131,070
11974.236.0.0/1574.236.0.1 to 74.237.255.25474.237.255.255131,070
12074.238.0.0/1574.238.0.1 to 74.239.255.25474.239.255.255131,070
12174.240.0.0/1574.240.0.1 to 74.241.255.25474.241.255.255131,070
12274.242.0.0/1574.242.0.1 to 74.243.255.25474.243.255.255131,070
12374.244.0.0/1574.244.0.1 to 74.245.255.25474.245.255.255131,070
12474.246.0.0/1574.246.0.1 to 74.247.255.25474.247.255.255131,070
12574.248.0.0/1574.248.0.1 to 74.249.255.25474.249.255.255131,070
12674.250.0.0/1574.250.0.1 to 74.251.255.25474.251.255.255131,070
12774.252.0.0/1574.252.0.1 to 74.253.255.25474.253.255.255131,070
12874.254.0.0/1574.254.0.1 to 74.255.255.25474.255.255.255131,070
12975.0.0.0/1575.0.0.1 to 75.1.255.25475.1.255.255131,070
13075.2.0.0/1575.2.0.1 to 75.3.255.25475.3.255.255131,070
13175.4.0.0/1575.4.0.1 to 75.5.255.25475.5.255.255131,070
13275.6.0.0/1575.6.0.1 to 75.7.255.25475.7.255.255131,070
13375.8.0.0/1575.8.0.1 to 75.9.255.25475.9.255.255131,070
13475.10.0.0/1575.10.0.1 to 75.11.255.25475.11.255.255131,070
13575.12.0.0/1575.12.0.1 to 75.13.255.25475.13.255.255131,070
13675.14.0.0/1575.14.0.1 to 75.15.255.25475.15.255.255131,070
13775.16.0.0/1575.16.0.1 to 75.17.255.25475.17.255.255131,070
13875.18.0.0/1575.18.0.1 to 75.19.255.25475.19.255.255131,070
13975.20.0.0/1575.20.0.1 to 75.21.255.25475.21.255.255131,070
14075.22.0.0/1575.22.0.1 to 75.23.255.25475.23.255.255131,070
14175.24.0.0/1575.24.0.1 to 75.25.255.25475.25.255.255131,070
14275.26.0.0/1575.26.0.1 to 75.27.255.25475.27.255.255131,070
14375.28.0.0/1575.28.0.1 to 75.29.255.25475.29.255.255131,070
14475.30.0.0/1575.30.0.1 to 75.31.255.25475.31.255.255131,070
14575.32.0.0/1575.32.0.1 to 75.33.255.25475.33.255.255131,070
14675.34.0.0/1575.34.0.1 to 75.35.255.25475.35.255.255131,070
14775.36.0.0/1575.36.0.1 to 75.37.255.25475.37.255.255131,070
14875.38.0.0/1575.38.0.1 to 75.39.255.25475.39.255.255131,070
14975.40.0.0/1575.40.0.1 to 75.41.255.25475.41.255.255131,070
15075.42.0.0/1575.42.0.1 to 75.43.255.25475.43.255.255131,070
15175.44.0.0/1575.44.0.1 to 75.45.255.25475.45.255.255131,070
15275.46.0.0/1575.46.0.1 to 75.47.255.25475.47.255.255131,070
15375.48.0.0/1575.48.0.1 to 75.49.255.25475.49.255.255131,070
15475.50.0.0/1575.50.0.1 to 75.51.255.25475.51.255.255131,070
15575.52.0.0/1575.52.0.1 to 75.53.255.25475.53.255.255131,070
15675.54.0.0/1575.54.0.1 to 75.55.255.25475.55.255.255131,070
15775.56.0.0/1575.56.0.1 to 75.57.255.25475.57.255.255131,070
15875.58.0.0/1575.58.0.1 to 75.59.255.25475.59.255.255131,070
15975.60.0.0/1575.60.0.1 to 75.61.255.25475.61.255.255131,070
16075.62.0.0/1575.62.0.1 to 75.63.255.25475.63.255.255131,070
16175.64.0.0/1575.64.0.1 to 75.65.255.25475.65.255.255131,070
16275.66.0.0/1575.66.0.1 to 75.67.255.25475.67.255.255131,070
16375.68.0.0/1575.68.0.1 to 75.69.255.25475.69.255.255131,070
16475.70.0.0/1575.70.0.1 to 75.71.255.25475.71.255.255131,070
16575.72.0.0/1575.72.0.1 to 75.73.255.25475.73.255.255131,070
16675.74.0.0/1575.74.0.1 to 75.75.255.25475.75.255.255131,070
16775.76.0.0/1575.76.0.1 to 75.77.255.25475.77.255.255131,070
16875.78.0.0/1575.78.0.1 to 75.79.255.25475.79.255.255131,070
16975.80.0.0/1575.80.0.1 to 75.81.255.25475.81.255.255131,070
17075.82.0.0/1575.82.0.1 to 75.83.255.25475.83.255.255131,070
17175.84.0.0/1575.84.0.1 to 75.85.255.25475.85.255.255131,070
17275.86.0.0/1575.86.0.1 to 75.87.255.25475.87.255.255131,070
17375.88.0.0/1575.88.0.1 to 75.89.255.25475.89.255.255131,070
17475.90.0.0/1575.90.0.1 to 75.91.255.25475.91.255.255131,070
17575.92.0.0/1575.92.0.1 to 75.93.255.25475.93.255.255131,070
17675.94.0.0/1575.94.0.1 to 75.95.255.25475.95.255.255131,070
17775.96.0.0/1575.96.0.1 to 75.97.255.25475.97.255.255131,070
17875.98.0.0/1575.98.0.1 to 75.99.255.25475.99.255.255131,070
17975.100.0.0/1575.100.0.1 to 75.101.255.25475.101.255.255131,070
18075.102.0.0/1575.102.0.1 to 75.103.255.25475.103.255.255131,070
18175.104.0.0/1575.104.0.1 to 75.105.255.25475.105.255.255131,070
18275.106.0.0/1575.106.0.1 to 75.107.255.25475.107.255.255131,070
18375.108.0.0/1575.108.0.1 to 75.109.255.25475.109.255.255131,070
18475.110.0.0/1575.110.0.1 to 75.111.255.25475.111.255.255131,070
18575.112.0.0/1575.112.0.1 to 75.113.255.25475.113.255.255131,070
18675.114.0.0/1575.114.0.1 to 75.115.255.25475.115.255.255131,070
18775.116.0.0/1575.116.0.1 to 75.117.255.25475.117.255.255131,070
18875.118.0.0/1575.118.0.1 to 75.119.255.25475.119.255.255131,070
18975.120.0.0/1575.120.0.1 to 75.121.255.25475.121.255.255131,070
19075.122.0.0/1575.122.0.1 to 75.123.255.25475.123.255.255131,070
19175.124.0.0/1575.124.0.1 to 75.125.255.25475.125.255.255131,070
19275.126.0.0/1575.126.0.1 to 75.127.255.25475.127.255.255131,070
19375.128.0.0/1575.128.0.1 to 75.129.255.25475.129.255.255131,070
19475.130.0.0/1575.130.0.1 to 75.131.255.25475.131.255.255131,070
19575.132.0.0/1575.132.0.1 to 75.133.255.25475.133.255.255131,070
19675.134.0.0/1575.134.0.1 to 75.135.255.25475.135.255.255131,070
19775.136.0.0/1575.136.0.1 to 75.137.255.25475.137.255.255131,070
19875.138.0.0/1575.138.0.1 to 75.139.255.25475.139.255.255131,070
19975.140.0.0/1575.140.0.1 to 75.141.255.25475.141.255.255131,070
20075.142.0.0/1575.142.0.1 to 75.143.255.25475.143.255.255131,070
20175.144.0.0/1575.144.0.1 to 75.145.255.25475.145.255.255131,070
20275.146.0.0/1575.146.0.1 to 75.147.255.25475.147.255.255131,070
20375.148.0.0/1575.148.0.1 to 75.149.255.25475.149.255.255131,070
20475.150.0.0/1575.150.0.1 to 75.151.255.25475.151.255.255131,070
20575.152.0.0/1575.152.0.1 to 75.153.255.25475.153.255.255131,070
20675.154.0.0/1575.154.0.1 to 75.155.255.25475.155.255.255131,070
20775.156.0.0/1575.156.0.1 to 75.157.255.25475.157.255.255131,070
20875.158.0.0/1575.158.0.1 to 75.159.255.25475.159.255.255131,070
20975.160.0.0/1575.160.0.1 to 75.161.255.25475.161.255.255131,070
21075.162.0.0/1575.162.0.1 to 75.163.255.25475.163.255.255131,070
21175.164.0.0/1575.164.0.1 to 75.165.255.25475.165.255.255131,070
21275.166.0.0/1575.166.0.1 to 75.167.255.25475.167.255.255131,070
21375.168.0.0/1575.168.0.1 to 75.169.255.25475.169.255.255131,070
21475.170.0.0/1575.170.0.1 to 75.171.255.25475.171.255.255131,070
21575.172.0.0/1575.172.0.1 to 75.173.255.25475.173.255.255131,070
21675.174.0.0/1575.174.0.1 to 75.175.255.25475.175.255.255131,070
21775.176.0.0/1575.176.0.1 to 75.177.255.25475.177.255.255131,070
21875.178.0.0/1575.178.0.1 to 75.179.255.25475.179.255.255131,070
21975.180.0.0/1575.180.0.1 to 75.181.255.25475.181.255.255131,070
22075.182.0.0/1575.182.0.1 to 75.183.255.25475.183.255.255131,070
22175.184.0.0/1575.184.0.1 to 75.185.255.25475.185.255.255131,070
22275.186.0.0/1575.186.0.1 to 75.187.255.25475.187.255.255131,070
22375.188.0.0/1575.188.0.1 to 75.189.255.25475.189.255.255131,070
22475.190.0.0/1575.190.0.1 to 75.191.255.25475.191.255.255131,070
22575.192.0.0/1575.192.0.1 to 75.193.255.25475.193.255.255131,070
22675.194.0.0/1575.194.0.1 to 75.195.255.25475.195.255.255131,070
22775.196.0.0/1575.196.0.1 to 75.197.255.25475.197.255.255131,070
22875.198.0.0/1575.198.0.1 to 75.199.255.25475.199.255.255131,070
22975.200.0.0/1575.200.0.1 to 75.201.255.25475.201.255.255131,070
23075.202.0.0/1575.202.0.1 to 75.203.255.25475.203.255.255131,070
23175.204.0.0/1575.204.0.1 to 75.205.255.25475.205.255.255131,070
23275.206.0.0/1575.206.0.1 to 75.207.255.25475.207.255.255131,070
23375.208.0.0/1575.208.0.1 to 75.209.255.25475.209.255.255131,070
23475.210.0.0/1575.210.0.1 to 75.211.255.25475.211.255.255131,070
23575.212.0.0/1575.212.0.1 to 75.213.255.25475.213.255.255131,070
23675.214.0.0/1575.214.0.1 to 75.215.255.25475.215.255.255131,070
23775.216.0.0/1575.216.0.1 to 75.217.255.25475.217.255.255131,070
23875.218.0.0/1575.218.0.1 to 75.219.255.25475.219.255.255131,070
23975.220.0.0/1575.220.0.1 to 75.221.255.25475.221.255.255131,070
24075.222.0.0/1575.222.0.1 to 75.223.255.25475.223.255.255131,070
24175.224.0.0/1575.224.0.1 to 75.225.255.25475.225.255.255131,070
24275.226.0.0/1575.226.0.1 to 75.227.255.25475.227.255.255131,070
24375.228.0.0/1575.228.0.1 to 75.229.255.25475.229.255.255131,070
24475.230.0.0/1575.230.0.1 to 75.231.255.25475.231.255.255131,070
24575.232.0.0/1575.232.0.1 to 75.233.255.25475.233.255.255131,070
24675.234.0.0/1575.234.0.1 to 75.235.255.25475.235.255.255131,070
24775.236.0.0/1575.236.0.1 to 75.237.255.25475.237.255.255131,070
24875.238.0.0/1575.238.0.1 to 75.239.255.25475.239.255.255131,070
24975.240.0.0/1575.240.0.1 to 75.241.255.25475.241.255.255131,070
25075.242.0.0/1575.242.0.1 to 75.243.255.25475.243.255.255131,070
25175.244.0.0/1575.244.0.1 to 75.245.255.25475.245.255.255131,070
25275.246.0.0/1575.246.0.1 to 75.247.255.25475.247.255.255131,070
25375.248.0.0/1575.248.0.1 to 75.249.255.25475.249.255.255131,070
25475.250.0.0/1575.250.0.1 to 75.251.255.25475.251.255.255131,070
25575.252.0.0/1575.252.0.1 to 75.253.255.25475.253.255.255131,070
25675.254.0.0/1575.254.0.1 to 75.255.255.25475.255.255.255131,070

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.