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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.

Network75.167.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
75.167.0.0
Broadcast address
75.167.255.255
First usable
75.167.0.1
Last usable
75.167.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
A (default /8)
As numbers
Hex 4BA70000 · Integer 1269235712 to 1269301247
Reverse DNS zone
167.75.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001011.10100111..00000000.0000000075.167.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01001011.10100111..00000000.0000000075.167.0.0
Broadcast01001011.10100111..11111111.1111111175.167.255.255
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

75.167.0.0/16 makes 256 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
175.167.0.0/2475.167.0.1 to 75.167.0.25475.167.0.255254
275.167.1.0/2475.167.1.1 to 75.167.1.25475.167.1.255254
375.167.2.0/2475.167.2.1 to 75.167.2.25475.167.2.255254
475.167.3.0/2475.167.3.1 to 75.167.3.25475.167.3.255254
575.167.4.0/2475.167.4.1 to 75.167.4.25475.167.4.255254
675.167.5.0/2475.167.5.1 to 75.167.5.25475.167.5.255254
775.167.6.0/2475.167.6.1 to 75.167.6.25475.167.6.255254
875.167.7.0/2475.167.7.1 to 75.167.7.25475.167.7.255254
975.167.8.0/2475.167.8.1 to 75.167.8.25475.167.8.255254
1075.167.9.0/2475.167.9.1 to 75.167.9.25475.167.9.255254
1175.167.10.0/2475.167.10.1 to 75.167.10.25475.167.10.255254
1275.167.11.0/2475.167.11.1 to 75.167.11.25475.167.11.255254
1375.167.12.0/2475.167.12.1 to 75.167.12.25475.167.12.255254
1475.167.13.0/2475.167.13.1 to 75.167.13.25475.167.13.255254
1575.167.14.0/2475.167.14.1 to 75.167.14.25475.167.14.255254
1675.167.15.0/2475.167.15.1 to 75.167.15.25475.167.15.255254
1775.167.16.0/2475.167.16.1 to 75.167.16.25475.167.16.255254
1875.167.17.0/2475.167.17.1 to 75.167.17.25475.167.17.255254
1975.167.18.0/2475.167.18.1 to 75.167.18.25475.167.18.255254
2075.167.19.0/2475.167.19.1 to 75.167.19.25475.167.19.255254
2175.167.20.0/2475.167.20.1 to 75.167.20.25475.167.20.255254
2275.167.21.0/2475.167.21.1 to 75.167.21.25475.167.21.255254
2375.167.22.0/2475.167.22.1 to 75.167.22.25475.167.22.255254
2475.167.23.0/2475.167.23.1 to 75.167.23.25475.167.23.255254
2575.167.24.0/2475.167.24.1 to 75.167.24.25475.167.24.255254
2675.167.25.0/2475.167.25.1 to 75.167.25.25475.167.25.255254
2775.167.26.0/2475.167.26.1 to 75.167.26.25475.167.26.255254
2875.167.27.0/2475.167.27.1 to 75.167.27.25475.167.27.255254
2975.167.28.0/2475.167.28.1 to 75.167.28.25475.167.28.255254
3075.167.29.0/2475.167.29.1 to 75.167.29.25475.167.29.255254
3175.167.30.0/2475.167.30.1 to 75.167.30.25475.167.30.255254
3275.167.31.0/2475.167.31.1 to 75.167.31.25475.167.31.255254
3375.167.32.0/2475.167.32.1 to 75.167.32.25475.167.32.255254
3475.167.33.0/2475.167.33.1 to 75.167.33.25475.167.33.255254
3575.167.34.0/2475.167.34.1 to 75.167.34.25475.167.34.255254
3675.167.35.0/2475.167.35.1 to 75.167.35.25475.167.35.255254
3775.167.36.0/2475.167.36.1 to 75.167.36.25475.167.36.255254
3875.167.37.0/2475.167.37.1 to 75.167.37.25475.167.37.255254
3975.167.38.0/2475.167.38.1 to 75.167.38.25475.167.38.255254
4075.167.39.0/2475.167.39.1 to 75.167.39.25475.167.39.255254
4175.167.40.0/2475.167.40.1 to 75.167.40.25475.167.40.255254
4275.167.41.0/2475.167.41.1 to 75.167.41.25475.167.41.255254
4375.167.42.0/2475.167.42.1 to 75.167.42.25475.167.42.255254
4475.167.43.0/2475.167.43.1 to 75.167.43.25475.167.43.255254
4575.167.44.0/2475.167.44.1 to 75.167.44.25475.167.44.255254
4675.167.45.0/2475.167.45.1 to 75.167.45.25475.167.45.255254
4775.167.46.0/2475.167.46.1 to 75.167.46.25475.167.46.255254
4875.167.47.0/2475.167.47.1 to 75.167.47.25475.167.47.255254
4975.167.48.0/2475.167.48.1 to 75.167.48.25475.167.48.255254
5075.167.49.0/2475.167.49.1 to 75.167.49.25475.167.49.255254
5175.167.50.0/2475.167.50.1 to 75.167.50.25475.167.50.255254
5275.167.51.0/2475.167.51.1 to 75.167.51.25475.167.51.255254
5375.167.52.0/2475.167.52.1 to 75.167.52.25475.167.52.255254
5475.167.53.0/2475.167.53.1 to 75.167.53.25475.167.53.255254
5575.167.54.0/2475.167.54.1 to 75.167.54.25475.167.54.255254
5675.167.55.0/2475.167.55.1 to 75.167.55.25475.167.55.255254
5775.167.56.0/2475.167.56.1 to 75.167.56.25475.167.56.255254
5875.167.57.0/2475.167.57.1 to 75.167.57.25475.167.57.255254
5975.167.58.0/2475.167.58.1 to 75.167.58.25475.167.58.255254
6075.167.59.0/2475.167.59.1 to 75.167.59.25475.167.59.255254
6175.167.60.0/2475.167.60.1 to 75.167.60.25475.167.60.255254
6275.167.61.0/2475.167.61.1 to 75.167.61.25475.167.61.255254
6375.167.62.0/2475.167.62.1 to 75.167.62.25475.167.62.255254
6475.167.63.0/2475.167.63.1 to 75.167.63.25475.167.63.255254
6575.167.64.0/2475.167.64.1 to 75.167.64.25475.167.64.255254
6675.167.65.0/2475.167.65.1 to 75.167.65.25475.167.65.255254
6775.167.66.0/2475.167.66.1 to 75.167.66.25475.167.66.255254
6875.167.67.0/2475.167.67.1 to 75.167.67.25475.167.67.255254
6975.167.68.0/2475.167.68.1 to 75.167.68.25475.167.68.255254
7075.167.69.0/2475.167.69.1 to 75.167.69.25475.167.69.255254
7175.167.70.0/2475.167.70.1 to 75.167.70.25475.167.70.255254
7275.167.71.0/2475.167.71.1 to 75.167.71.25475.167.71.255254
7375.167.72.0/2475.167.72.1 to 75.167.72.25475.167.72.255254
7475.167.73.0/2475.167.73.1 to 75.167.73.25475.167.73.255254
7575.167.74.0/2475.167.74.1 to 75.167.74.25475.167.74.255254
7675.167.75.0/2475.167.75.1 to 75.167.75.25475.167.75.255254
7775.167.76.0/2475.167.76.1 to 75.167.76.25475.167.76.255254
7875.167.77.0/2475.167.77.1 to 75.167.77.25475.167.77.255254
7975.167.78.0/2475.167.78.1 to 75.167.78.25475.167.78.255254
8075.167.79.0/2475.167.79.1 to 75.167.79.25475.167.79.255254
8175.167.80.0/2475.167.80.1 to 75.167.80.25475.167.80.255254
8275.167.81.0/2475.167.81.1 to 75.167.81.25475.167.81.255254
8375.167.82.0/2475.167.82.1 to 75.167.82.25475.167.82.255254
8475.167.83.0/2475.167.83.1 to 75.167.83.25475.167.83.255254
8575.167.84.0/2475.167.84.1 to 75.167.84.25475.167.84.255254
8675.167.85.0/2475.167.85.1 to 75.167.85.25475.167.85.255254
8775.167.86.0/2475.167.86.1 to 75.167.86.25475.167.86.255254
8875.167.87.0/2475.167.87.1 to 75.167.87.25475.167.87.255254
8975.167.88.0/2475.167.88.1 to 75.167.88.25475.167.88.255254
9075.167.89.0/2475.167.89.1 to 75.167.89.25475.167.89.255254
9175.167.90.0/2475.167.90.1 to 75.167.90.25475.167.90.255254
9275.167.91.0/2475.167.91.1 to 75.167.91.25475.167.91.255254
9375.167.92.0/2475.167.92.1 to 75.167.92.25475.167.92.255254
9475.167.93.0/2475.167.93.1 to 75.167.93.25475.167.93.255254
9575.167.94.0/2475.167.94.1 to 75.167.94.25475.167.94.255254
9675.167.95.0/2475.167.95.1 to 75.167.95.25475.167.95.255254
9775.167.96.0/2475.167.96.1 to 75.167.96.25475.167.96.255254
9875.167.97.0/2475.167.97.1 to 75.167.97.25475.167.97.255254
9975.167.98.0/2475.167.98.1 to 75.167.98.25475.167.98.255254
10075.167.99.0/2475.167.99.1 to 75.167.99.25475.167.99.255254
10175.167.100.0/2475.167.100.1 to 75.167.100.25475.167.100.255254
10275.167.101.0/2475.167.101.1 to 75.167.101.25475.167.101.255254
10375.167.102.0/2475.167.102.1 to 75.167.102.25475.167.102.255254
10475.167.103.0/2475.167.103.1 to 75.167.103.25475.167.103.255254
10575.167.104.0/2475.167.104.1 to 75.167.104.25475.167.104.255254
10675.167.105.0/2475.167.105.1 to 75.167.105.25475.167.105.255254
10775.167.106.0/2475.167.106.1 to 75.167.106.25475.167.106.255254
10875.167.107.0/2475.167.107.1 to 75.167.107.25475.167.107.255254
10975.167.108.0/2475.167.108.1 to 75.167.108.25475.167.108.255254
11075.167.109.0/2475.167.109.1 to 75.167.109.25475.167.109.255254
11175.167.110.0/2475.167.110.1 to 75.167.110.25475.167.110.255254
11275.167.111.0/2475.167.111.1 to 75.167.111.25475.167.111.255254
11375.167.112.0/2475.167.112.1 to 75.167.112.25475.167.112.255254
11475.167.113.0/2475.167.113.1 to 75.167.113.25475.167.113.255254
11575.167.114.0/2475.167.114.1 to 75.167.114.25475.167.114.255254
11675.167.115.0/2475.167.115.1 to 75.167.115.25475.167.115.255254
11775.167.116.0/2475.167.116.1 to 75.167.116.25475.167.116.255254
11875.167.117.0/2475.167.117.1 to 75.167.117.25475.167.117.255254
11975.167.118.0/2475.167.118.1 to 75.167.118.25475.167.118.255254
12075.167.119.0/2475.167.119.1 to 75.167.119.25475.167.119.255254
12175.167.120.0/2475.167.120.1 to 75.167.120.25475.167.120.255254
12275.167.121.0/2475.167.121.1 to 75.167.121.25475.167.121.255254
12375.167.122.0/2475.167.122.1 to 75.167.122.25475.167.122.255254
12475.167.123.0/2475.167.123.1 to 75.167.123.25475.167.123.255254
12575.167.124.0/2475.167.124.1 to 75.167.124.25475.167.124.255254
12675.167.125.0/2475.167.125.1 to 75.167.125.25475.167.125.255254
12775.167.126.0/2475.167.126.1 to 75.167.126.25475.167.126.255254
12875.167.127.0/2475.167.127.1 to 75.167.127.25475.167.127.255254
12975.167.128.0/2475.167.128.1 to 75.167.128.25475.167.128.255254
13075.167.129.0/2475.167.129.1 to 75.167.129.25475.167.129.255254
13175.167.130.0/2475.167.130.1 to 75.167.130.25475.167.130.255254
13275.167.131.0/2475.167.131.1 to 75.167.131.25475.167.131.255254
13375.167.132.0/2475.167.132.1 to 75.167.132.25475.167.132.255254
13475.167.133.0/2475.167.133.1 to 75.167.133.25475.167.133.255254
13575.167.134.0/2475.167.134.1 to 75.167.134.25475.167.134.255254
13675.167.135.0/2475.167.135.1 to 75.167.135.25475.167.135.255254
13775.167.136.0/2475.167.136.1 to 75.167.136.25475.167.136.255254
13875.167.137.0/2475.167.137.1 to 75.167.137.25475.167.137.255254
13975.167.138.0/2475.167.138.1 to 75.167.138.25475.167.138.255254
14075.167.139.0/2475.167.139.1 to 75.167.139.25475.167.139.255254
14175.167.140.0/2475.167.140.1 to 75.167.140.25475.167.140.255254
14275.167.141.0/2475.167.141.1 to 75.167.141.25475.167.141.255254
14375.167.142.0/2475.167.142.1 to 75.167.142.25475.167.142.255254
14475.167.143.0/2475.167.143.1 to 75.167.143.25475.167.143.255254
14575.167.144.0/2475.167.144.1 to 75.167.144.25475.167.144.255254
14675.167.145.0/2475.167.145.1 to 75.167.145.25475.167.145.255254
14775.167.146.0/2475.167.146.1 to 75.167.146.25475.167.146.255254
14875.167.147.0/2475.167.147.1 to 75.167.147.25475.167.147.255254
14975.167.148.0/2475.167.148.1 to 75.167.148.25475.167.148.255254
15075.167.149.0/2475.167.149.1 to 75.167.149.25475.167.149.255254
15175.167.150.0/2475.167.150.1 to 75.167.150.25475.167.150.255254
15275.167.151.0/2475.167.151.1 to 75.167.151.25475.167.151.255254
15375.167.152.0/2475.167.152.1 to 75.167.152.25475.167.152.255254
15475.167.153.0/2475.167.153.1 to 75.167.153.25475.167.153.255254
15575.167.154.0/2475.167.154.1 to 75.167.154.25475.167.154.255254
15675.167.155.0/2475.167.155.1 to 75.167.155.25475.167.155.255254
15775.167.156.0/2475.167.156.1 to 75.167.156.25475.167.156.255254
15875.167.157.0/2475.167.157.1 to 75.167.157.25475.167.157.255254
15975.167.158.0/2475.167.158.1 to 75.167.158.25475.167.158.255254
16075.167.159.0/2475.167.159.1 to 75.167.159.25475.167.159.255254
16175.167.160.0/2475.167.160.1 to 75.167.160.25475.167.160.255254
16275.167.161.0/2475.167.161.1 to 75.167.161.25475.167.161.255254
16375.167.162.0/2475.167.162.1 to 75.167.162.25475.167.162.255254
16475.167.163.0/2475.167.163.1 to 75.167.163.25475.167.163.255254
16575.167.164.0/2475.167.164.1 to 75.167.164.25475.167.164.255254
16675.167.165.0/2475.167.165.1 to 75.167.165.25475.167.165.255254
16775.167.166.0/2475.167.166.1 to 75.167.166.25475.167.166.255254
16875.167.167.0/2475.167.167.1 to 75.167.167.25475.167.167.255254
16975.167.168.0/2475.167.168.1 to 75.167.168.25475.167.168.255254
17075.167.169.0/2475.167.169.1 to 75.167.169.25475.167.169.255254
17175.167.170.0/2475.167.170.1 to 75.167.170.25475.167.170.255254
17275.167.171.0/2475.167.171.1 to 75.167.171.25475.167.171.255254
17375.167.172.0/2475.167.172.1 to 75.167.172.25475.167.172.255254
17475.167.173.0/2475.167.173.1 to 75.167.173.25475.167.173.255254
17575.167.174.0/2475.167.174.1 to 75.167.174.25475.167.174.255254
17675.167.175.0/2475.167.175.1 to 75.167.175.25475.167.175.255254
17775.167.176.0/2475.167.176.1 to 75.167.176.25475.167.176.255254
17875.167.177.0/2475.167.177.1 to 75.167.177.25475.167.177.255254
17975.167.178.0/2475.167.178.1 to 75.167.178.25475.167.178.255254
18075.167.179.0/2475.167.179.1 to 75.167.179.25475.167.179.255254
18175.167.180.0/2475.167.180.1 to 75.167.180.25475.167.180.255254
18275.167.181.0/2475.167.181.1 to 75.167.181.25475.167.181.255254
18375.167.182.0/2475.167.182.1 to 75.167.182.25475.167.182.255254
18475.167.183.0/2475.167.183.1 to 75.167.183.25475.167.183.255254
18575.167.184.0/2475.167.184.1 to 75.167.184.25475.167.184.255254
18675.167.185.0/2475.167.185.1 to 75.167.185.25475.167.185.255254
18775.167.186.0/2475.167.186.1 to 75.167.186.25475.167.186.255254
18875.167.187.0/2475.167.187.1 to 75.167.187.25475.167.187.255254
18975.167.188.0/2475.167.188.1 to 75.167.188.25475.167.188.255254
19075.167.189.0/2475.167.189.1 to 75.167.189.25475.167.189.255254
19175.167.190.0/2475.167.190.1 to 75.167.190.25475.167.190.255254
19275.167.191.0/2475.167.191.1 to 75.167.191.25475.167.191.255254
19375.167.192.0/2475.167.192.1 to 75.167.192.25475.167.192.255254
19475.167.193.0/2475.167.193.1 to 75.167.193.25475.167.193.255254
19575.167.194.0/2475.167.194.1 to 75.167.194.25475.167.194.255254
19675.167.195.0/2475.167.195.1 to 75.167.195.25475.167.195.255254
19775.167.196.0/2475.167.196.1 to 75.167.196.25475.167.196.255254
19875.167.197.0/2475.167.197.1 to 75.167.197.25475.167.197.255254
19975.167.198.0/2475.167.198.1 to 75.167.198.25475.167.198.255254
20075.167.199.0/2475.167.199.1 to 75.167.199.25475.167.199.255254
20175.167.200.0/2475.167.200.1 to 75.167.200.25475.167.200.255254
20275.167.201.0/2475.167.201.1 to 75.167.201.25475.167.201.255254
20375.167.202.0/2475.167.202.1 to 75.167.202.25475.167.202.255254
20475.167.203.0/2475.167.203.1 to 75.167.203.25475.167.203.255254
20575.167.204.0/2475.167.204.1 to 75.167.204.25475.167.204.255254
20675.167.205.0/2475.167.205.1 to 75.167.205.25475.167.205.255254
20775.167.206.0/2475.167.206.1 to 75.167.206.25475.167.206.255254
20875.167.207.0/2475.167.207.1 to 75.167.207.25475.167.207.255254
20975.167.208.0/2475.167.208.1 to 75.167.208.25475.167.208.255254
21075.167.209.0/2475.167.209.1 to 75.167.209.25475.167.209.255254
21175.167.210.0/2475.167.210.1 to 75.167.210.25475.167.210.255254
21275.167.211.0/2475.167.211.1 to 75.167.211.25475.167.211.255254
21375.167.212.0/2475.167.212.1 to 75.167.212.25475.167.212.255254
21475.167.213.0/2475.167.213.1 to 75.167.213.25475.167.213.255254
21575.167.214.0/2475.167.214.1 to 75.167.214.25475.167.214.255254
21675.167.215.0/2475.167.215.1 to 75.167.215.25475.167.215.255254
21775.167.216.0/2475.167.216.1 to 75.167.216.25475.167.216.255254
21875.167.217.0/2475.167.217.1 to 75.167.217.25475.167.217.255254
21975.167.218.0/2475.167.218.1 to 75.167.218.25475.167.218.255254
22075.167.219.0/2475.167.219.1 to 75.167.219.25475.167.219.255254
22175.167.220.0/2475.167.220.1 to 75.167.220.25475.167.220.255254
22275.167.221.0/2475.167.221.1 to 75.167.221.25475.167.221.255254
22375.167.222.0/2475.167.222.1 to 75.167.222.25475.167.222.255254
22475.167.223.0/2475.167.223.1 to 75.167.223.25475.167.223.255254
22575.167.224.0/2475.167.224.1 to 75.167.224.25475.167.224.255254
22675.167.225.0/2475.167.225.1 to 75.167.225.25475.167.225.255254
22775.167.226.0/2475.167.226.1 to 75.167.226.25475.167.226.255254
22875.167.227.0/2475.167.227.1 to 75.167.227.25475.167.227.255254
22975.167.228.0/2475.167.228.1 to 75.167.228.25475.167.228.255254
23075.167.229.0/2475.167.229.1 to 75.167.229.25475.167.229.255254
23175.167.230.0/2475.167.230.1 to 75.167.230.25475.167.230.255254
23275.167.231.0/2475.167.231.1 to 75.167.231.25475.167.231.255254
23375.167.232.0/2475.167.232.1 to 75.167.232.25475.167.232.255254
23475.167.233.0/2475.167.233.1 to 75.167.233.25475.167.233.255254
23575.167.234.0/2475.167.234.1 to 75.167.234.25475.167.234.255254
23675.167.235.0/2475.167.235.1 to 75.167.235.25475.167.235.255254
23775.167.236.0/2475.167.236.1 to 75.167.236.25475.167.236.255254
23875.167.237.0/2475.167.237.1 to 75.167.237.25475.167.237.255254
23975.167.238.0/2475.167.238.1 to 75.167.238.25475.167.238.255254
24075.167.239.0/2475.167.239.1 to 75.167.239.25475.167.239.255254
24175.167.240.0/2475.167.240.1 to 75.167.240.25475.167.240.255254
24275.167.241.0/2475.167.241.1 to 75.167.241.25475.167.241.255254
24375.167.242.0/2475.167.242.1 to 75.167.242.25475.167.242.255254
24475.167.243.0/2475.167.243.1 to 75.167.243.25475.167.243.255254
24575.167.244.0/2475.167.244.1 to 75.167.244.25475.167.244.255254
24675.167.245.0/2475.167.245.1 to 75.167.245.25475.167.245.255254
24775.167.246.0/2475.167.246.1 to 75.167.246.25475.167.246.255254
24875.167.247.0/2475.167.247.1 to 75.167.247.25475.167.247.255254
24975.167.248.0/2475.167.248.1 to 75.167.248.25475.167.248.255254
25075.167.249.0/2475.167.249.1 to 75.167.249.25475.167.249.255254
25175.167.250.0/2475.167.250.1 to 75.167.250.25475.167.250.255254
25275.167.251.0/2475.167.251.1 to 75.167.251.25475.167.251.255254
25375.167.252.0/2475.167.252.1 to 75.167.252.25475.167.252.255254
25475.167.253.0/2475.167.253.1 to 75.167.253.25475.167.253.255254
25575.167.254.0/2475.167.254.1 to 75.167.254.25475.167.254.255254
25675.167.255.0/2475.167.255.1 to 75.167.255.25475.167.255.255254

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.