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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.

Network88.4.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
88.4.0.0
Broadcast address
88.5.255.255
First usable
88.4.0.1
Last usable
88.5.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 58040000 · Integer 1476657152 to 1476788223
Reverse DNS zones
4.88.in-addr.arpa
5.88.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01011000.00000100.00000000.0000000088.4.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01011000.00000100.00000000.0000000088.4.0.0
Broadcast01011000.00000101.11111111.1111111188.5.255.255
Split into smaller subnets/24
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

88.4.0.0/15 makes 512 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
188.4.0.0/2488.4.0.1 to 88.4.0.25488.4.0.255254
288.4.1.0/2488.4.1.1 to 88.4.1.25488.4.1.255254
388.4.2.0/2488.4.2.1 to 88.4.2.25488.4.2.255254
488.4.3.0/2488.4.3.1 to 88.4.3.25488.4.3.255254
588.4.4.0/2488.4.4.1 to 88.4.4.25488.4.4.255254
688.4.5.0/2488.4.5.1 to 88.4.5.25488.4.5.255254
788.4.6.0/2488.4.6.1 to 88.4.6.25488.4.6.255254
888.4.7.0/2488.4.7.1 to 88.4.7.25488.4.7.255254
988.4.8.0/2488.4.8.1 to 88.4.8.25488.4.8.255254
1088.4.9.0/2488.4.9.1 to 88.4.9.25488.4.9.255254
1188.4.10.0/2488.4.10.1 to 88.4.10.25488.4.10.255254
1288.4.11.0/2488.4.11.1 to 88.4.11.25488.4.11.255254
1388.4.12.0/2488.4.12.1 to 88.4.12.25488.4.12.255254
1488.4.13.0/2488.4.13.1 to 88.4.13.25488.4.13.255254
1588.4.14.0/2488.4.14.1 to 88.4.14.25488.4.14.255254
1688.4.15.0/2488.4.15.1 to 88.4.15.25488.4.15.255254
1788.4.16.0/2488.4.16.1 to 88.4.16.25488.4.16.255254
1888.4.17.0/2488.4.17.1 to 88.4.17.25488.4.17.255254
1988.4.18.0/2488.4.18.1 to 88.4.18.25488.4.18.255254
2088.4.19.0/2488.4.19.1 to 88.4.19.25488.4.19.255254
2188.4.20.0/2488.4.20.1 to 88.4.20.25488.4.20.255254
2288.4.21.0/2488.4.21.1 to 88.4.21.25488.4.21.255254
2388.4.22.0/2488.4.22.1 to 88.4.22.25488.4.22.255254
2488.4.23.0/2488.4.23.1 to 88.4.23.25488.4.23.255254
2588.4.24.0/2488.4.24.1 to 88.4.24.25488.4.24.255254
2688.4.25.0/2488.4.25.1 to 88.4.25.25488.4.25.255254
2788.4.26.0/2488.4.26.1 to 88.4.26.25488.4.26.255254
2888.4.27.0/2488.4.27.1 to 88.4.27.25488.4.27.255254
2988.4.28.0/2488.4.28.1 to 88.4.28.25488.4.28.255254
3088.4.29.0/2488.4.29.1 to 88.4.29.25488.4.29.255254
3188.4.30.0/2488.4.30.1 to 88.4.30.25488.4.30.255254
3288.4.31.0/2488.4.31.1 to 88.4.31.25488.4.31.255254
3388.4.32.0/2488.4.32.1 to 88.4.32.25488.4.32.255254
3488.4.33.0/2488.4.33.1 to 88.4.33.25488.4.33.255254
3588.4.34.0/2488.4.34.1 to 88.4.34.25488.4.34.255254
3688.4.35.0/2488.4.35.1 to 88.4.35.25488.4.35.255254
3788.4.36.0/2488.4.36.1 to 88.4.36.25488.4.36.255254
3888.4.37.0/2488.4.37.1 to 88.4.37.25488.4.37.255254
3988.4.38.0/2488.4.38.1 to 88.4.38.25488.4.38.255254
4088.4.39.0/2488.4.39.1 to 88.4.39.25488.4.39.255254
4188.4.40.0/2488.4.40.1 to 88.4.40.25488.4.40.255254
4288.4.41.0/2488.4.41.1 to 88.4.41.25488.4.41.255254
4388.4.42.0/2488.4.42.1 to 88.4.42.25488.4.42.255254
4488.4.43.0/2488.4.43.1 to 88.4.43.25488.4.43.255254
4588.4.44.0/2488.4.44.1 to 88.4.44.25488.4.44.255254
4688.4.45.0/2488.4.45.1 to 88.4.45.25488.4.45.255254
4788.4.46.0/2488.4.46.1 to 88.4.46.25488.4.46.255254
4888.4.47.0/2488.4.47.1 to 88.4.47.25488.4.47.255254
4988.4.48.0/2488.4.48.1 to 88.4.48.25488.4.48.255254
5088.4.49.0/2488.4.49.1 to 88.4.49.25488.4.49.255254
5188.4.50.0/2488.4.50.1 to 88.4.50.25488.4.50.255254
5288.4.51.0/2488.4.51.1 to 88.4.51.25488.4.51.255254
5388.4.52.0/2488.4.52.1 to 88.4.52.25488.4.52.255254
5488.4.53.0/2488.4.53.1 to 88.4.53.25488.4.53.255254
5588.4.54.0/2488.4.54.1 to 88.4.54.25488.4.54.255254
5688.4.55.0/2488.4.55.1 to 88.4.55.25488.4.55.255254
5788.4.56.0/2488.4.56.1 to 88.4.56.25488.4.56.255254
5888.4.57.0/2488.4.57.1 to 88.4.57.25488.4.57.255254
5988.4.58.0/2488.4.58.1 to 88.4.58.25488.4.58.255254
6088.4.59.0/2488.4.59.1 to 88.4.59.25488.4.59.255254
6188.4.60.0/2488.4.60.1 to 88.4.60.25488.4.60.255254
6288.4.61.0/2488.4.61.1 to 88.4.61.25488.4.61.255254
6388.4.62.0/2488.4.62.1 to 88.4.62.25488.4.62.255254
6488.4.63.0/2488.4.63.1 to 88.4.63.25488.4.63.255254
6588.4.64.0/2488.4.64.1 to 88.4.64.25488.4.64.255254
6688.4.65.0/2488.4.65.1 to 88.4.65.25488.4.65.255254
6788.4.66.0/2488.4.66.1 to 88.4.66.25488.4.66.255254
6888.4.67.0/2488.4.67.1 to 88.4.67.25488.4.67.255254
6988.4.68.0/2488.4.68.1 to 88.4.68.25488.4.68.255254
7088.4.69.0/2488.4.69.1 to 88.4.69.25488.4.69.255254
7188.4.70.0/2488.4.70.1 to 88.4.70.25488.4.70.255254
7288.4.71.0/2488.4.71.1 to 88.4.71.25488.4.71.255254
7388.4.72.0/2488.4.72.1 to 88.4.72.25488.4.72.255254
7488.4.73.0/2488.4.73.1 to 88.4.73.25488.4.73.255254
7588.4.74.0/2488.4.74.1 to 88.4.74.25488.4.74.255254
7688.4.75.0/2488.4.75.1 to 88.4.75.25488.4.75.255254
7788.4.76.0/2488.4.76.1 to 88.4.76.25488.4.76.255254
7888.4.77.0/2488.4.77.1 to 88.4.77.25488.4.77.255254
7988.4.78.0/2488.4.78.1 to 88.4.78.25488.4.78.255254
8088.4.79.0/2488.4.79.1 to 88.4.79.25488.4.79.255254
8188.4.80.0/2488.4.80.1 to 88.4.80.25488.4.80.255254
8288.4.81.0/2488.4.81.1 to 88.4.81.25488.4.81.255254
8388.4.82.0/2488.4.82.1 to 88.4.82.25488.4.82.255254
8488.4.83.0/2488.4.83.1 to 88.4.83.25488.4.83.255254
8588.4.84.0/2488.4.84.1 to 88.4.84.25488.4.84.255254
8688.4.85.0/2488.4.85.1 to 88.4.85.25488.4.85.255254
8788.4.86.0/2488.4.86.1 to 88.4.86.25488.4.86.255254
8888.4.87.0/2488.4.87.1 to 88.4.87.25488.4.87.255254
8988.4.88.0/2488.4.88.1 to 88.4.88.25488.4.88.255254
9088.4.89.0/2488.4.89.1 to 88.4.89.25488.4.89.255254
9188.4.90.0/2488.4.90.1 to 88.4.90.25488.4.90.255254
9288.4.91.0/2488.4.91.1 to 88.4.91.25488.4.91.255254
9388.4.92.0/2488.4.92.1 to 88.4.92.25488.4.92.255254
9488.4.93.0/2488.4.93.1 to 88.4.93.25488.4.93.255254
9588.4.94.0/2488.4.94.1 to 88.4.94.25488.4.94.255254
9688.4.95.0/2488.4.95.1 to 88.4.95.25488.4.95.255254
9788.4.96.0/2488.4.96.1 to 88.4.96.25488.4.96.255254
9888.4.97.0/2488.4.97.1 to 88.4.97.25488.4.97.255254
9988.4.98.0/2488.4.98.1 to 88.4.98.25488.4.98.255254
10088.4.99.0/2488.4.99.1 to 88.4.99.25488.4.99.255254
10188.4.100.0/2488.4.100.1 to 88.4.100.25488.4.100.255254
10288.4.101.0/2488.4.101.1 to 88.4.101.25488.4.101.255254
10388.4.102.0/2488.4.102.1 to 88.4.102.25488.4.102.255254
10488.4.103.0/2488.4.103.1 to 88.4.103.25488.4.103.255254
10588.4.104.0/2488.4.104.1 to 88.4.104.25488.4.104.255254
10688.4.105.0/2488.4.105.1 to 88.4.105.25488.4.105.255254
10788.4.106.0/2488.4.106.1 to 88.4.106.25488.4.106.255254
10888.4.107.0/2488.4.107.1 to 88.4.107.25488.4.107.255254
10988.4.108.0/2488.4.108.1 to 88.4.108.25488.4.108.255254
11088.4.109.0/2488.4.109.1 to 88.4.109.25488.4.109.255254
11188.4.110.0/2488.4.110.1 to 88.4.110.25488.4.110.255254
11288.4.111.0/2488.4.111.1 to 88.4.111.25488.4.111.255254
11388.4.112.0/2488.4.112.1 to 88.4.112.25488.4.112.255254
11488.4.113.0/2488.4.113.1 to 88.4.113.25488.4.113.255254
11588.4.114.0/2488.4.114.1 to 88.4.114.25488.4.114.255254
11688.4.115.0/2488.4.115.1 to 88.4.115.25488.4.115.255254
11788.4.116.0/2488.4.116.1 to 88.4.116.25488.4.116.255254
11888.4.117.0/2488.4.117.1 to 88.4.117.25488.4.117.255254
11988.4.118.0/2488.4.118.1 to 88.4.118.25488.4.118.255254
12088.4.119.0/2488.4.119.1 to 88.4.119.25488.4.119.255254
12188.4.120.0/2488.4.120.1 to 88.4.120.25488.4.120.255254
12288.4.121.0/2488.4.121.1 to 88.4.121.25488.4.121.255254
12388.4.122.0/2488.4.122.1 to 88.4.122.25488.4.122.255254
12488.4.123.0/2488.4.123.1 to 88.4.123.25488.4.123.255254
12588.4.124.0/2488.4.124.1 to 88.4.124.25488.4.124.255254
12688.4.125.0/2488.4.125.1 to 88.4.125.25488.4.125.255254
12788.4.126.0/2488.4.126.1 to 88.4.126.25488.4.126.255254
12888.4.127.0/2488.4.127.1 to 88.4.127.25488.4.127.255254
12988.4.128.0/2488.4.128.1 to 88.4.128.25488.4.128.255254
13088.4.129.0/2488.4.129.1 to 88.4.129.25488.4.129.255254
13188.4.130.0/2488.4.130.1 to 88.4.130.25488.4.130.255254
13288.4.131.0/2488.4.131.1 to 88.4.131.25488.4.131.255254
13388.4.132.0/2488.4.132.1 to 88.4.132.25488.4.132.255254
13488.4.133.0/2488.4.133.1 to 88.4.133.25488.4.133.255254
13588.4.134.0/2488.4.134.1 to 88.4.134.25488.4.134.255254
13688.4.135.0/2488.4.135.1 to 88.4.135.25488.4.135.255254
13788.4.136.0/2488.4.136.1 to 88.4.136.25488.4.136.255254
13888.4.137.0/2488.4.137.1 to 88.4.137.25488.4.137.255254
13988.4.138.0/2488.4.138.1 to 88.4.138.25488.4.138.255254
14088.4.139.0/2488.4.139.1 to 88.4.139.25488.4.139.255254
14188.4.140.0/2488.4.140.1 to 88.4.140.25488.4.140.255254
14288.4.141.0/2488.4.141.1 to 88.4.141.25488.4.141.255254
14388.4.142.0/2488.4.142.1 to 88.4.142.25488.4.142.255254
14488.4.143.0/2488.4.143.1 to 88.4.143.25488.4.143.255254
14588.4.144.0/2488.4.144.1 to 88.4.144.25488.4.144.255254
14688.4.145.0/2488.4.145.1 to 88.4.145.25488.4.145.255254
14788.4.146.0/2488.4.146.1 to 88.4.146.25488.4.146.255254
14888.4.147.0/2488.4.147.1 to 88.4.147.25488.4.147.255254
14988.4.148.0/2488.4.148.1 to 88.4.148.25488.4.148.255254
15088.4.149.0/2488.4.149.1 to 88.4.149.25488.4.149.255254
15188.4.150.0/2488.4.150.1 to 88.4.150.25488.4.150.255254
15288.4.151.0/2488.4.151.1 to 88.4.151.25488.4.151.255254
15388.4.152.0/2488.4.152.1 to 88.4.152.25488.4.152.255254
15488.4.153.0/2488.4.153.1 to 88.4.153.25488.4.153.255254
15588.4.154.0/2488.4.154.1 to 88.4.154.25488.4.154.255254
15688.4.155.0/2488.4.155.1 to 88.4.155.25488.4.155.255254
15788.4.156.0/2488.4.156.1 to 88.4.156.25488.4.156.255254
15888.4.157.0/2488.4.157.1 to 88.4.157.25488.4.157.255254
15988.4.158.0/2488.4.158.1 to 88.4.158.25488.4.158.255254
16088.4.159.0/2488.4.159.1 to 88.4.159.25488.4.159.255254
16188.4.160.0/2488.4.160.1 to 88.4.160.25488.4.160.255254
16288.4.161.0/2488.4.161.1 to 88.4.161.25488.4.161.255254
16388.4.162.0/2488.4.162.1 to 88.4.162.25488.4.162.255254
16488.4.163.0/2488.4.163.1 to 88.4.163.25488.4.163.255254
16588.4.164.0/2488.4.164.1 to 88.4.164.25488.4.164.255254
16688.4.165.0/2488.4.165.1 to 88.4.165.25488.4.165.255254
16788.4.166.0/2488.4.166.1 to 88.4.166.25488.4.166.255254
16888.4.167.0/2488.4.167.1 to 88.4.167.25488.4.167.255254
16988.4.168.0/2488.4.168.1 to 88.4.168.25488.4.168.255254
17088.4.169.0/2488.4.169.1 to 88.4.169.25488.4.169.255254
17188.4.170.0/2488.4.170.1 to 88.4.170.25488.4.170.255254
17288.4.171.0/2488.4.171.1 to 88.4.171.25488.4.171.255254
17388.4.172.0/2488.4.172.1 to 88.4.172.25488.4.172.255254
17488.4.173.0/2488.4.173.1 to 88.4.173.25488.4.173.255254
17588.4.174.0/2488.4.174.1 to 88.4.174.25488.4.174.255254
17688.4.175.0/2488.4.175.1 to 88.4.175.25488.4.175.255254
17788.4.176.0/2488.4.176.1 to 88.4.176.25488.4.176.255254
17888.4.177.0/2488.4.177.1 to 88.4.177.25488.4.177.255254
17988.4.178.0/2488.4.178.1 to 88.4.178.25488.4.178.255254
18088.4.179.0/2488.4.179.1 to 88.4.179.25488.4.179.255254
18188.4.180.0/2488.4.180.1 to 88.4.180.25488.4.180.255254
18288.4.181.0/2488.4.181.1 to 88.4.181.25488.4.181.255254
18388.4.182.0/2488.4.182.1 to 88.4.182.25488.4.182.255254
18488.4.183.0/2488.4.183.1 to 88.4.183.25488.4.183.255254
18588.4.184.0/2488.4.184.1 to 88.4.184.25488.4.184.255254
18688.4.185.0/2488.4.185.1 to 88.4.185.25488.4.185.255254
18788.4.186.0/2488.4.186.1 to 88.4.186.25488.4.186.255254
18888.4.187.0/2488.4.187.1 to 88.4.187.25488.4.187.255254
18988.4.188.0/2488.4.188.1 to 88.4.188.25488.4.188.255254
19088.4.189.0/2488.4.189.1 to 88.4.189.25488.4.189.255254
19188.4.190.0/2488.4.190.1 to 88.4.190.25488.4.190.255254
19288.4.191.0/2488.4.191.1 to 88.4.191.25488.4.191.255254
19388.4.192.0/2488.4.192.1 to 88.4.192.25488.4.192.255254
19488.4.193.0/2488.4.193.1 to 88.4.193.25488.4.193.255254
19588.4.194.0/2488.4.194.1 to 88.4.194.25488.4.194.255254
19688.4.195.0/2488.4.195.1 to 88.4.195.25488.4.195.255254
19788.4.196.0/2488.4.196.1 to 88.4.196.25488.4.196.255254
19888.4.197.0/2488.4.197.1 to 88.4.197.25488.4.197.255254
19988.4.198.0/2488.4.198.1 to 88.4.198.25488.4.198.255254
20088.4.199.0/2488.4.199.1 to 88.4.199.25488.4.199.255254
20188.4.200.0/2488.4.200.1 to 88.4.200.25488.4.200.255254
20288.4.201.0/2488.4.201.1 to 88.4.201.25488.4.201.255254
20388.4.202.0/2488.4.202.1 to 88.4.202.25488.4.202.255254
20488.4.203.0/2488.4.203.1 to 88.4.203.25488.4.203.255254
20588.4.204.0/2488.4.204.1 to 88.4.204.25488.4.204.255254
20688.4.205.0/2488.4.205.1 to 88.4.205.25488.4.205.255254
20788.4.206.0/2488.4.206.1 to 88.4.206.25488.4.206.255254
20888.4.207.0/2488.4.207.1 to 88.4.207.25488.4.207.255254
20988.4.208.0/2488.4.208.1 to 88.4.208.25488.4.208.255254
21088.4.209.0/2488.4.209.1 to 88.4.209.25488.4.209.255254
21188.4.210.0/2488.4.210.1 to 88.4.210.25488.4.210.255254
21288.4.211.0/2488.4.211.1 to 88.4.211.25488.4.211.255254
21388.4.212.0/2488.4.212.1 to 88.4.212.25488.4.212.255254
21488.4.213.0/2488.4.213.1 to 88.4.213.25488.4.213.255254
21588.4.214.0/2488.4.214.1 to 88.4.214.25488.4.214.255254
21688.4.215.0/2488.4.215.1 to 88.4.215.25488.4.215.255254
21788.4.216.0/2488.4.216.1 to 88.4.216.25488.4.216.255254
21888.4.217.0/2488.4.217.1 to 88.4.217.25488.4.217.255254
21988.4.218.0/2488.4.218.1 to 88.4.218.25488.4.218.255254
22088.4.219.0/2488.4.219.1 to 88.4.219.25488.4.219.255254
22188.4.220.0/2488.4.220.1 to 88.4.220.25488.4.220.255254
22288.4.221.0/2488.4.221.1 to 88.4.221.25488.4.221.255254
22388.4.222.0/2488.4.222.1 to 88.4.222.25488.4.222.255254
22488.4.223.0/2488.4.223.1 to 88.4.223.25488.4.223.255254
22588.4.224.0/2488.4.224.1 to 88.4.224.25488.4.224.255254
22688.4.225.0/2488.4.225.1 to 88.4.225.25488.4.225.255254
22788.4.226.0/2488.4.226.1 to 88.4.226.25488.4.226.255254
22888.4.227.0/2488.4.227.1 to 88.4.227.25488.4.227.255254
22988.4.228.0/2488.4.228.1 to 88.4.228.25488.4.228.255254
23088.4.229.0/2488.4.229.1 to 88.4.229.25488.4.229.255254
23188.4.230.0/2488.4.230.1 to 88.4.230.25488.4.230.255254
23288.4.231.0/2488.4.231.1 to 88.4.231.25488.4.231.255254
23388.4.232.0/2488.4.232.1 to 88.4.232.25488.4.232.255254
23488.4.233.0/2488.4.233.1 to 88.4.233.25488.4.233.255254
23588.4.234.0/2488.4.234.1 to 88.4.234.25488.4.234.255254
23688.4.235.0/2488.4.235.1 to 88.4.235.25488.4.235.255254
23788.4.236.0/2488.4.236.1 to 88.4.236.25488.4.236.255254
23888.4.237.0/2488.4.237.1 to 88.4.237.25488.4.237.255254
23988.4.238.0/2488.4.238.1 to 88.4.238.25488.4.238.255254
24088.4.239.0/2488.4.239.1 to 88.4.239.25488.4.239.255254
24188.4.240.0/2488.4.240.1 to 88.4.240.25488.4.240.255254
24288.4.241.0/2488.4.241.1 to 88.4.241.25488.4.241.255254
24388.4.242.0/2488.4.242.1 to 88.4.242.25488.4.242.255254
24488.4.243.0/2488.4.243.1 to 88.4.243.25488.4.243.255254
24588.4.244.0/2488.4.244.1 to 88.4.244.25488.4.244.255254
24688.4.245.0/2488.4.245.1 to 88.4.245.25488.4.245.255254
24788.4.246.0/2488.4.246.1 to 88.4.246.25488.4.246.255254
24888.4.247.0/2488.4.247.1 to 88.4.247.25488.4.247.255254
24988.4.248.0/2488.4.248.1 to 88.4.248.25488.4.248.255254
25088.4.249.0/2488.4.249.1 to 88.4.249.25488.4.249.255254
25188.4.250.0/2488.4.250.1 to 88.4.250.25488.4.250.255254
25288.4.251.0/2488.4.251.1 to 88.4.251.25488.4.251.255254
25388.4.252.0/2488.4.252.1 to 88.4.252.25488.4.252.255254
25488.4.253.0/2488.4.253.1 to 88.4.253.25488.4.253.255254
25588.4.254.0/2488.4.254.1 to 88.4.254.25488.4.254.255254
25688.4.255.0/2488.4.255.1 to 88.4.255.25488.4.255.255254

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.