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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.

Network75.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
75.0.0.0
Broadcast address
75.255.255.255
First usable
75.0.0.1
Last usable
75.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 4B000000 · Integer 1258291200 to 1275068415
Reverse DNS zone
75.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001011..00000000.00000000.0000000075.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01001011..00000000.00000000.0000000075.0.0.0
Broadcast01001011..11111111.11111111.1111111175.255.255.255
Split into smaller subnets/16
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

75.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
175.0.0.0/1675.0.0.1 to 75.0.255.25475.0.255.25565,534
275.1.0.0/1675.1.0.1 to 75.1.255.25475.1.255.25565,534
375.2.0.0/1675.2.0.1 to 75.2.255.25475.2.255.25565,534
475.3.0.0/1675.3.0.1 to 75.3.255.25475.3.255.25565,534
575.4.0.0/1675.4.0.1 to 75.4.255.25475.4.255.25565,534
675.5.0.0/1675.5.0.1 to 75.5.255.25475.5.255.25565,534
775.6.0.0/1675.6.0.1 to 75.6.255.25475.6.255.25565,534
875.7.0.0/1675.7.0.1 to 75.7.255.25475.7.255.25565,534
975.8.0.0/1675.8.0.1 to 75.8.255.25475.8.255.25565,534
1075.9.0.0/1675.9.0.1 to 75.9.255.25475.9.255.25565,534
1175.10.0.0/1675.10.0.1 to 75.10.255.25475.10.255.25565,534
1275.11.0.0/1675.11.0.1 to 75.11.255.25475.11.255.25565,534
1375.12.0.0/1675.12.0.1 to 75.12.255.25475.12.255.25565,534
1475.13.0.0/1675.13.0.1 to 75.13.255.25475.13.255.25565,534
1575.14.0.0/1675.14.0.1 to 75.14.255.25475.14.255.25565,534
1675.15.0.0/1675.15.0.1 to 75.15.255.25475.15.255.25565,534
1775.16.0.0/1675.16.0.1 to 75.16.255.25475.16.255.25565,534
1875.17.0.0/1675.17.0.1 to 75.17.255.25475.17.255.25565,534
1975.18.0.0/1675.18.0.1 to 75.18.255.25475.18.255.25565,534
2075.19.0.0/1675.19.0.1 to 75.19.255.25475.19.255.25565,534
2175.20.0.0/1675.20.0.1 to 75.20.255.25475.20.255.25565,534
2275.21.0.0/1675.21.0.1 to 75.21.255.25475.21.255.25565,534
2375.22.0.0/1675.22.0.1 to 75.22.255.25475.22.255.25565,534
2475.23.0.0/1675.23.0.1 to 75.23.255.25475.23.255.25565,534
2575.24.0.0/1675.24.0.1 to 75.24.255.25475.24.255.25565,534
2675.25.0.0/1675.25.0.1 to 75.25.255.25475.25.255.25565,534
2775.26.0.0/1675.26.0.1 to 75.26.255.25475.26.255.25565,534
2875.27.0.0/1675.27.0.1 to 75.27.255.25475.27.255.25565,534
2975.28.0.0/1675.28.0.1 to 75.28.255.25475.28.255.25565,534
3075.29.0.0/1675.29.0.1 to 75.29.255.25475.29.255.25565,534
3175.30.0.0/1675.30.0.1 to 75.30.255.25475.30.255.25565,534
3275.31.0.0/1675.31.0.1 to 75.31.255.25475.31.255.25565,534
3375.32.0.0/1675.32.0.1 to 75.32.255.25475.32.255.25565,534
3475.33.0.0/1675.33.0.1 to 75.33.255.25475.33.255.25565,534
3575.34.0.0/1675.34.0.1 to 75.34.255.25475.34.255.25565,534
3675.35.0.0/1675.35.0.1 to 75.35.255.25475.35.255.25565,534
3775.36.0.0/1675.36.0.1 to 75.36.255.25475.36.255.25565,534
3875.37.0.0/1675.37.0.1 to 75.37.255.25475.37.255.25565,534
3975.38.0.0/1675.38.0.1 to 75.38.255.25475.38.255.25565,534
4075.39.0.0/1675.39.0.1 to 75.39.255.25475.39.255.25565,534
4175.40.0.0/1675.40.0.1 to 75.40.255.25475.40.255.25565,534
4275.41.0.0/1675.41.0.1 to 75.41.255.25475.41.255.25565,534
4375.42.0.0/1675.42.0.1 to 75.42.255.25475.42.255.25565,534
4475.43.0.0/1675.43.0.1 to 75.43.255.25475.43.255.25565,534
4575.44.0.0/1675.44.0.1 to 75.44.255.25475.44.255.25565,534
4675.45.0.0/1675.45.0.1 to 75.45.255.25475.45.255.25565,534
4775.46.0.0/1675.46.0.1 to 75.46.255.25475.46.255.25565,534
4875.47.0.0/1675.47.0.1 to 75.47.255.25475.47.255.25565,534
4975.48.0.0/1675.48.0.1 to 75.48.255.25475.48.255.25565,534
5075.49.0.0/1675.49.0.1 to 75.49.255.25475.49.255.25565,534
5175.50.0.0/1675.50.0.1 to 75.50.255.25475.50.255.25565,534
5275.51.0.0/1675.51.0.1 to 75.51.255.25475.51.255.25565,534
5375.52.0.0/1675.52.0.1 to 75.52.255.25475.52.255.25565,534
5475.53.0.0/1675.53.0.1 to 75.53.255.25475.53.255.25565,534
5575.54.0.0/1675.54.0.1 to 75.54.255.25475.54.255.25565,534
5675.55.0.0/1675.55.0.1 to 75.55.255.25475.55.255.25565,534
5775.56.0.0/1675.56.0.1 to 75.56.255.25475.56.255.25565,534
5875.57.0.0/1675.57.0.1 to 75.57.255.25475.57.255.25565,534
5975.58.0.0/1675.58.0.1 to 75.58.255.25475.58.255.25565,534
6075.59.0.0/1675.59.0.1 to 75.59.255.25475.59.255.25565,534
6175.60.0.0/1675.60.0.1 to 75.60.255.25475.60.255.25565,534
6275.61.0.0/1675.61.0.1 to 75.61.255.25475.61.255.25565,534
6375.62.0.0/1675.62.0.1 to 75.62.255.25475.62.255.25565,534
6475.63.0.0/1675.63.0.1 to 75.63.255.25475.63.255.25565,534
6575.64.0.0/1675.64.0.1 to 75.64.255.25475.64.255.25565,534
6675.65.0.0/1675.65.0.1 to 75.65.255.25475.65.255.25565,534
6775.66.0.0/1675.66.0.1 to 75.66.255.25475.66.255.25565,534
6875.67.0.0/1675.67.0.1 to 75.67.255.25475.67.255.25565,534
6975.68.0.0/1675.68.0.1 to 75.68.255.25475.68.255.25565,534
7075.69.0.0/1675.69.0.1 to 75.69.255.25475.69.255.25565,534
7175.70.0.0/1675.70.0.1 to 75.70.255.25475.70.255.25565,534
7275.71.0.0/1675.71.0.1 to 75.71.255.25475.71.255.25565,534
7375.72.0.0/1675.72.0.1 to 75.72.255.25475.72.255.25565,534
7475.73.0.0/1675.73.0.1 to 75.73.255.25475.73.255.25565,534
7575.74.0.0/1675.74.0.1 to 75.74.255.25475.74.255.25565,534
7675.75.0.0/1675.75.0.1 to 75.75.255.25475.75.255.25565,534
7775.76.0.0/1675.76.0.1 to 75.76.255.25475.76.255.25565,534
7875.77.0.0/1675.77.0.1 to 75.77.255.25475.77.255.25565,534
7975.78.0.0/1675.78.0.1 to 75.78.255.25475.78.255.25565,534
8075.79.0.0/1675.79.0.1 to 75.79.255.25475.79.255.25565,534
8175.80.0.0/1675.80.0.1 to 75.80.255.25475.80.255.25565,534
8275.81.0.0/1675.81.0.1 to 75.81.255.25475.81.255.25565,534
8375.82.0.0/1675.82.0.1 to 75.82.255.25475.82.255.25565,534
8475.83.0.0/1675.83.0.1 to 75.83.255.25475.83.255.25565,534
8575.84.0.0/1675.84.0.1 to 75.84.255.25475.84.255.25565,534
8675.85.0.0/1675.85.0.1 to 75.85.255.25475.85.255.25565,534
8775.86.0.0/1675.86.0.1 to 75.86.255.25475.86.255.25565,534
8875.87.0.0/1675.87.0.1 to 75.87.255.25475.87.255.25565,534
8975.88.0.0/1675.88.0.1 to 75.88.255.25475.88.255.25565,534
9075.89.0.0/1675.89.0.1 to 75.89.255.25475.89.255.25565,534
9175.90.0.0/1675.90.0.1 to 75.90.255.25475.90.255.25565,534
9275.91.0.0/1675.91.0.1 to 75.91.255.25475.91.255.25565,534
9375.92.0.0/1675.92.0.1 to 75.92.255.25475.92.255.25565,534
9475.93.0.0/1675.93.0.1 to 75.93.255.25475.93.255.25565,534
9575.94.0.0/1675.94.0.1 to 75.94.255.25475.94.255.25565,534
9675.95.0.0/1675.95.0.1 to 75.95.255.25475.95.255.25565,534
9775.96.0.0/1675.96.0.1 to 75.96.255.25475.96.255.25565,534
9875.97.0.0/1675.97.0.1 to 75.97.255.25475.97.255.25565,534
9975.98.0.0/1675.98.0.1 to 75.98.255.25475.98.255.25565,534
10075.99.0.0/1675.99.0.1 to 75.99.255.25475.99.255.25565,534
10175.100.0.0/1675.100.0.1 to 75.100.255.25475.100.255.25565,534
10275.101.0.0/1675.101.0.1 to 75.101.255.25475.101.255.25565,534
10375.102.0.0/1675.102.0.1 to 75.102.255.25475.102.255.25565,534
10475.103.0.0/1675.103.0.1 to 75.103.255.25475.103.255.25565,534
10575.104.0.0/1675.104.0.1 to 75.104.255.25475.104.255.25565,534
10675.105.0.0/1675.105.0.1 to 75.105.255.25475.105.255.25565,534
10775.106.0.0/1675.106.0.1 to 75.106.255.25475.106.255.25565,534
10875.107.0.0/1675.107.0.1 to 75.107.255.25475.107.255.25565,534
10975.108.0.0/1675.108.0.1 to 75.108.255.25475.108.255.25565,534
11075.109.0.0/1675.109.0.1 to 75.109.255.25475.109.255.25565,534
11175.110.0.0/1675.110.0.1 to 75.110.255.25475.110.255.25565,534
11275.111.0.0/1675.111.0.1 to 75.111.255.25475.111.255.25565,534
11375.112.0.0/1675.112.0.1 to 75.112.255.25475.112.255.25565,534
11475.113.0.0/1675.113.0.1 to 75.113.255.25475.113.255.25565,534
11575.114.0.0/1675.114.0.1 to 75.114.255.25475.114.255.25565,534
11675.115.0.0/1675.115.0.1 to 75.115.255.25475.115.255.25565,534
11775.116.0.0/1675.116.0.1 to 75.116.255.25475.116.255.25565,534
11875.117.0.0/1675.117.0.1 to 75.117.255.25475.117.255.25565,534
11975.118.0.0/1675.118.0.1 to 75.118.255.25475.118.255.25565,534
12075.119.0.0/1675.119.0.1 to 75.119.255.25475.119.255.25565,534
12175.120.0.0/1675.120.0.1 to 75.120.255.25475.120.255.25565,534
12275.121.0.0/1675.121.0.1 to 75.121.255.25475.121.255.25565,534
12375.122.0.0/1675.122.0.1 to 75.122.255.25475.122.255.25565,534
12475.123.0.0/1675.123.0.1 to 75.123.255.25475.123.255.25565,534
12575.124.0.0/1675.124.0.1 to 75.124.255.25475.124.255.25565,534
12675.125.0.0/1675.125.0.1 to 75.125.255.25475.125.255.25565,534
12775.126.0.0/1675.126.0.1 to 75.126.255.25475.126.255.25565,534
12875.127.0.0/1675.127.0.1 to 75.127.255.25475.127.255.25565,534
12975.128.0.0/1675.128.0.1 to 75.128.255.25475.128.255.25565,534
13075.129.0.0/1675.129.0.1 to 75.129.255.25475.129.255.25565,534
13175.130.0.0/1675.130.0.1 to 75.130.255.25475.130.255.25565,534
13275.131.0.0/1675.131.0.1 to 75.131.255.25475.131.255.25565,534
13375.132.0.0/1675.132.0.1 to 75.132.255.25475.132.255.25565,534
13475.133.0.0/1675.133.0.1 to 75.133.255.25475.133.255.25565,534
13575.134.0.0/1675.134.0.1 to 75.134.255.25475.134.255.25565,534
13675.135.0.0/1675.135.0.1 to 75.135.255.25475.135.255.25565,534
13775.136.0.0/1675.136.0.1 to 75.136.255.25475.136.255.25565,534
13875.137.0.0/1675.137.0.1 to 75.137.255.25475.137.255.25565,534
13975.138.0.0/1675.138.0.1 to 75.138.255.25475.138.255.25565,534
14075.139.0.0/1675.139.0.1 to 75.139.255.25475.139.255.25565,534
14175.140.0.0/1675.140.0.1 to 75.140.255.25475.140.255.25565,534
14275.141.0.0/1675.141.0.1 to 75.141.255.25475.141.255.25565,534
14375.142.0.0/1675.142.0.1 to 75.142.255.25475.142.255.25565,534
14475.143.0.0/1675.143.0.1 to 75.143.255.25475.143.255.25565,534
14575.144.0.0/1675.144.0.1 to 75.144.255.25475.144.255.25565,534
14675.145.0.0/1675.145.0.1 to 75.145.255.25475.145.255.25565,534
14775.146.0.0/1675.146.0.1 to 75.146.255.25475.146.255.25565,534
14875.147.0.0/1675.147.0.1 to 75.147.255.25475.147.255.25565,534
14975.148.0.0/1675.148.0.1 to 75.148.255.25475.148.255.25565,534
15075.149.0.0/1675.149.0.1 to 75.149.255.25475.149.255.25565,534
15175.150.0.0/1675.150.0.1 to 75.150.255.25475.150.255.25565,534
15275.151.0.0/1675.151.0.1 to 75.151.255.25475.151.255.25565,534
15375.152.0.0/1675.152.0.1 to 75.152.255.25475.152.255.25565,534
15475.153.0.0/1675.153.0.1 to 75.153.255.25475.153.255.25565,534
15575.154.0.0/1675.154.0.1 to 75.154.255.25475.154.255.25565,534
15675.155.0.0/1675.155.0.1 to 75.155.255.25475.155.255.25565,534
15775.156.0.0/1675.156.0.1 to 75.156.255.25475.156.255.25565,534
15875.157.0.0/1675.157.0.1 to 75.157.255.25475.157.255.25565,534
15975.158.0.0/1675.158.0.1 to 75.158.255.25475.158.255.25565,534
16075.159.0.0/1675.159.0.1 to 75.159.255.25475.159.255.25565,534
16175.160.0.0/1675.160.0.1 to 75.160.255.25475.160.255.25565,534
16275.161.0.0/1675.161.0.1 to 75.161.255.25475.161.255.25565,534
16375.162.0.0/1675.162.0.1 to 75.162.255.25475.162.255.25565,534
16475.163.0.0/1675.163.0.1 to 75.163.255.25475.163.255.25565,534
16575.164.0.0/1675.164.0.1 to 75.164.255.25475.164.255.25565,534
16675.165.0.0/1675.165.0.1 to 75.165.255.25475.165.255.25565,534
16775.166.0.0/1675.166.0.1 to 75.166.255.25475.166.255.25565,534
16875.167.0.0/1675.167.0.1 to 75.167.255.25475.167.255.25565,534
16975.168.0.0/1675.168.0.1 to 75.168.255.25475.168.255.25565,534
17075.169.0.0/1675.169.0.1 to 75.169.255.25475.169.255.25565,534
17175.170.0.0/1675.170.0.1 to 75.170.255.25475.170.255.25565,534
17275.171.0.0/1675.171.0.1 to 75.171.255.25475.171.255.25565,534
17375.172.0.0/1675.172.0.1 to 75.172.255.25475.172.255.25565,534
17475.173.0.0/1675.173.0.1 to 75.173.255.25475.173.255.25565,534
17575.174.0.0/1675.174.0.1 to 75.174.255.25475.174.255.25565,534
17675.175.0.0/1675.175.0.1 to 75.175.255.25475.175.255.25565,534
17775.176.0.0/1675.176.0.1 to 75.176.255.25475.176.255.25565,534
17875.177.0.0/1675.177.0.1 to 75.177.255.25475.177.255.25565,534
17975.178.0.0/1675.178.0.1 to 75.178.255.25475.178.255.25565,534
18075.179.0.0/1675.179.0.1 to 75.179.255.25475.179.255.25565,534
18175.180.0.0/1675.180.0.1 to 75.180.255.25475.180.255.25565,534
18275.181.0.0/1675.181.0.1 to 75.181.255.25475.181.255.25565,534
18375.182.0.0/1675.182.0.1 to 75.182.255.25475.182.255.25565,534
18475.183.0.0/1675.183.0.1 to 75.183.255.25475.183.255.25565,534
18575.184.0.0/1675.184.0.1 to 75.184.255.25475.184.255.25565,534
18675.185.0.0/1675.185.0.1 to 75.185.255.25475.185.255.25565,534
18775.186.0.0/1675.186.0.1 to 75.186.255.25475.186.255.25565,534
18875.187.0.0/1675.187.0.1 to 75.187.255.25475.187.255.25565,534
18975.188.0.0/1675.188.0.1 to 75.188.255.25475.188.255.25565,534
19075.189.0.0/1675.189.0.1 to 75.189.255.25475.189.255.25565,534
19175.190.0.0/1675.190.0.1 to 75.190.255.25475.190.255.25565,534
19275.191.0.0/1675.191.0.1 to 75.191.255.25475.191.255.25565,534
19375.192.0.0/1675.192.0.1 to 75.192.255.25475.192.255.25565,534
19475.193.0.0/1675.193.0.1 to 75.193.255.25475.193.255.25565,534
19575.194.0.0/1675.194.0.1 to 75.194.255.25475.194.255.25565,534
19675.195.0.0/1675.195.0.1 to 75.195.255.25475.195.255.25565,534
19775.196.0.0/1675.196.0.1 to 75.196.255.25475.196.255.25565,534
19875.197.0.0/1675.197.0.1 to 75.197.255.25475.197.255.25565,534
19975.198.0.0/1675.198.0.1 to 75.198.255.25475.198.255.25565,534
20075.199.0.0/1675.199.0.1 to 75.199.255.25475.199.255.25565,534
20175.200.0.0/1675.200.0.1 to 75.200.255.25475.200.255.25565,534
20275.201.0.0/1675.201.0.1 to 75.201.255.25475.201.255.25565,534
20375.202.0.0/1675.202.0.1 to 75.202.255.25475.202.255.25565,534
20475.203.0.0/1675.203.0.1 to 75.203.255.25475.203.255.25565,534
20575.204.0.0/1675.204.0.1 to 75.204.255.25475.204.255.25565,534
20675.205.0.0/1675.205.0.1 to 75.205.255.25475.205.255.25565,534
20775.206.0.0/1675.206.0.1 to 75.206.255.25475.206.255.25565,534
20875.207.0.0/1675.207.0.1 to 75.207.255.25475.207.255.25565,534
20975.208.0.0/1675.208.0.1 to 75.208.255.25475.208.255.25565,534
21075.209.0.0/1675.209.0.1 to 75.209.255.25475.209.255.25565,534
21175.210.0.0/1675.210.0.1 to 75.210.255.25475.210.255.25565,534
21275.211.0.0/1675.211.0.1 to 75.211.255.25475.211.255.25565,534
21375.212.0.0/1675.212.0.1 to 75.212.255.25475.212.255.25565,534
21475.213.0.0/1675.213.0.1 to 75.213.255.25475.213.255.25565,534
21575.214.0.0/1675.214.0.1 to 75.214.255.25475.214.255.25565,534
21675.215.0.0/1675.215.0.1 to 75.215.255.25475.215.255.25565,534
21775.216.0.0/1675.216.0.1 to 75.216.255.25475.216.255.25565,534
21875.217.0.0/1675.217.0.1 to 75.217.255.25475.217.255.25565,534
21975.218.0.0/1675.218.0.1 to 75.218.255.25475.218.255.25565,534
22075.219.0.0/1675.219.0.1 to 75.219.255.25475.219.255.25565,534
22175.220.0.0/1675.220.0.1 to 75.220.255.25475.220.255.25565,534
22275.221.0.0/1675.221.0.1 to 75.221.255.25475.221.255.25565,534
22375.222.0.0/1675.222.0.1 to 75.222.255.25475.222.255.25565,534
22475.223.0.0/1675.223.0.1 to 75.223.255.25475.223.255.25565,534
22575.224.0.0/1675.224.0.1 to 75.224.255.25475.224.255.25565,534
22675.225.0.0/1675.225.0.1 to 75.225.255.25475.225.255.25565,534
22775.226.0.0/1675.226.0.1 to 75.226.255.25475.226.255.25565,534
22875.227.0.0/1675.227.0.1 to 75.227.255.25475.227.255.25565,534
22975.228.0.0/1675.228.0.1 to 75.228.255.25475.228.255.25565,534
23075.229.0.0/1675.229.0.1 to 75.229.255.25475.229.255.25565,534
23175.230.0.0/1675.230.0.1 to 75.230.255.25475.230.255.25565,534
23275.231.0.0/1675.231.0.1 to 75.231.255.25475.231.255.25565,534
23375.232.0.0/1675.232.0.1 to 75.232.255.25475.232.255.25565,534
23475.233.0.0/1675.233.0.1 to 75.233.255.25475.233.255.25565,534
23575.234.0.0/1675.234.0.1 to 75.234.255.25475.234.255.25565,534
23675.235.0.0/1675.235.0.1 to 75.235.255.25475.235.255.25565,534
23775.236.0.0/1675.236.0.1 to 75.236.255.25475.236.255.25565,534
23875.237.0.0/1675.237.0.1 to 75.237.255.25475.237.255.25565,534
23975.238.0.0/1675.238.0.1 to 75.238.255.25475.238.255.25565,534
24075.239.0.0/1675.239.0.1 to 75.239.255.25475.239.255.25565,534
24175.240.0.0/1675.240.0.1 to 75.240.255.25475.240.255.25565,534
24275.241.0.0/1675.241.0.1 to 75.241.255.25475.241.255.25565,534
24375.242.0.0/1675.242.0.1 to 75.242.255.25475.242.255.25565,534
24475.243.0.0/1675.243.0.1 to 75.243.255.25475.243.255.25565,534
24575.244.0.0/1675.244.0.1 to 75.244.255.25475.244.255.25565,534
24675.245.0.0/1675.245.0.1 to 75.245.255.25475.245.255.25565,534
24775.246.0.0/1675.246.0.1 to 75.246.255.25475.246.255.25565,534
24875.247.0.0/1675.247.0.1 to 75.247.255.25475.247.255.25565,534
24975.248.0.0/1675.248.0.1 to 75.248.255.25475.248.255.25565,534
25075.249.0.0/1675.249.0.1 to 75.249.255.25475.249.255.25565,534
25175.250.0.0/1675.250.0.1 to 75.250.255.25475.250.255.25565,534
25275.251.0.0/1675.251.0.1 to 75.251.255.25475.251.255.25565,534
25375.252.0.0/1675.252.0.1 to 75.252.255.25475.252.255.25565,534
25475.253.0.0/1675.253.0.1 to 75.253.255.25475.253.255.25565,534
25575.254.0.0/1675.254.0.1 to 75.254.255.25475.254.255.25565,534
25675.255.0.0/1675.255.0.1 to 75.255.255.25475.255.255.25565,534

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.