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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.

Network11.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
11.0.0.0
Broadcast address
11.255.255.255
First usable
11.0.0.1
Last usable
11.255.255.254
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 0B000000 · Integer 184549376 to 201326591
Reverse DNS zone
11.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00001011..00000000.00000000.0000000011.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network00001011..00000000.00000000.0000000011.0.0.0
Broadcast00001011..11111111.11111111.1111111111.255.255.255
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)

11.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
111.0.0.0/1611.0.0.1 to 11.0.255.25411.0.255.25565,534
211.1.0.0/1611.1.0.1 to 11.1.255.25411.1.255.25565,534
311.2.0.0/1611.2.0.1 to 11.2.255.25411.2.255.25565,534
411.3.0.0/1611.3.0.1 to 11.3.255.25411.3.255.25565,534
511.4.0.0/1611.4.0.1 to 11.4.255.25411.4.255.25565,534
611.5.0.0/1611.5.0.1 to 11.5.255.25411.5.255.25565,534
711.6.0.0/1611.6.0.1 to 11.6.255.25411.6.255.25565,534
811.7.0.0/1611.7.0.1 to 11.7.255.25411.7.255.25565,534
911.8.0.0/1611.8.0.1 to 11.8.255.25411.8.255.25565,534
1011.9.0.0/1611.9.0.1 to 11.9.255.25411.9.255.25565,534
1111.10.0.0/1611.10.0.1 to 11.10.255.25411.10.255.25565,534
1211.11.0.0/1611.11.0.1 to 11.11.255.25411.11.255.25565,534
1311.12.0.0/1611.12.0.1 to 11.12.255.25411.12.255.25565,534
1411.13.0.0/1611.13.0.1 to 11.13.255.25411.13.255.25565,534
1511.14.0.0/1611.14.0.1 to 11.14.255.25411.14.255.25565,534
1611.15.0.0/1611.15.0.1 to 11.15.255.25411.15.255.25565,534
1711.16.0.0/1611.16.0.1 to 11.16.255.25411.16.255.25565,534
1811.17.0.0/1611.17.0.1 to 11.17.255.25411.17.255.25565,534
1911.18.0.0/1611.18.0.1 to 11.18.255.25411.18.255.25565,534
2011.19.0.0/1611.19.0.1 to 11.19.255.25411.19.255.25565,534
2111.20.0.0/1611.20.0.1 to 11.20.255.25411.20.255.25565,534
2211.21.0.0/1611.21.0.1 to 11.21.255.25411.21.255.25565,534
2311.22.0.0/1611.22.0.1 to 11.22.255.25411.22.255.25565,534
2411.23.0.0/1611.23.0.1 to 11.23.255.25411.23.255.25565,534
2511.24.0.0/1611.24.0.1 to 11.24.255.25411.24.255.25565,534
2611.25.0.0/1611.25.0.1 to 11.25.255.25411.25.255.25565,534
2711.26.0.0/1611.26.0.1 to 11.26.255.25411.26.255.25565,534
2811.27.0.0/1611.27.0.1 to 11.27.255.25411.27.255.25565,534
2911.28.0.0/1611.28.0.1 to 11.28.255.25411.28.255.25565,534
3011.29.0.0/1611.29.0.1 to 11.29.255.25411.29.255.25565,534
3111.30.0.0/1611.30.0.1 to 11.30.255.25411.30.255.25565,534
3211.31.0.0/1611.31.0.1 to 11.31.255.25411.31.255.25565,534
3311.32.0.0/1611.32.0.1 to 11.32.255.25411.32.255.25565,534
3411.33.0.0/1611.33.0.1 to 11.33.255.25411.33.255.25565,534
3511.34.0.0/1611.34.0.1 to 11.34.255.25411.34.255.25565,534
3611.35.0.0/1611.35.0.1 to 11.35.255.25411.35.255.25565,534
3711.36.0.0/1611.36.0.1 to 11.36.255.25411.36.255.25565,534
3811.37.0.0/1611.37.0.1 to 11.37.255.25411.37.255.25565,534
3911.38.0.0/1611.38.0.1 to 11.38.255.25411.38.255.25565,534
4011.39.0.0/1611.39.0.1 to 11.39.255.25411.39.255.25565,534
4111.40.0.0/1611.40.0.1 to 11.40.255.25411.40.255.25565,534
4211.41.0.0/1611.41.0.1 to 11.41.255.25411.41.255.25565,534
4311.42.0.0/1611.42.0.1 to 11.42.255.25411.42.255.25565,534
4411.43.0.0/1611.43.0.1 to 11.43.255.25411.43.255.25565,534
4511.44.0.0/1611.44.0.1 to 11.44.255.25411.44.255.25565,534
4611.45.0.0/1611.45.0.1 to 11.45.255.25411.45.255.25565,534
4711.46.0.0/1611.46.0.1 to 11.46.255.25411.46.255.25565,534
4811.47.0.0/1611.47.0.1 to 11.47.255.25411.47.255.25565,534
4911.48.0.0/1611.48.0.1 to 11.48.255.25411.48.255.25565,534
5011.49.0.0/1611.49.0.1 to 11.49.255.25411.49.255.25565,534
5111.50.0.0/1611.50.0.1 to 11.50.255.25411.50.255.25565,534
5211.51.0.0/1611.51.0.1 to 11.51.255.25411.51.255.25565,534
5311.52.0.0/1611.52.0.1 to 11.52.255.25411.52.255.25565,534
5411.53.0.0/1611.53.0.1 to 11.53.255.25411.53.255.25565,534
5511.54.0.0/1611.54.0.1 to 11.54.255.25411.54.255.25565,534
5611.55.0.0/1611.55.0.1 to 11.55.255.25411.55.255.25565,534
5711.56.0.0/1611.56.0.1 to 11.56.255.25411.56.255.25565,534
5811.57.0.0/1611.57.0.1 to 11.57.255.25411.57.255.25565,534
5911.58.0.0/1611.58.0.1 to 11.58.255.25411.58.255.25565,534
6011.59.0.0/1611.59.0.1 to 11.59.255.25411.59.255.25565,534
6111.60.0.0/1611.60.0.1 to 11.60.255.25411.60.255.25565,534
6211.61.0.0/1611.61.0.1 to 11.61.255.25411.61.255.25565,534
6311.62.0.0/1611.62.0.1 to 11.62.255.25411.62.255.25565,534
6411.63.0.0/1611.63.0.1 to 11.63.255.25411.63.255.25565,534
6511.64.0.0/1611.64.0.1 to 11.64.255.25411.64.255.25565,534
6611.65.0.0/1611.65.0.1 to 11.65.255.25411.65.255.25565,534
6711.66.0.0/1611.66.0.1 to 11.66.255.25411.66.255.25565,534
6811.67.0.0/1611.67.0.1 to 11.67.255.25411.67.255.25565,534
6911.68.0.0/1611.68.0.1 to 11.68.255.25411.68.255.25565,534
7011.69.0.0/1611.69.0.1 to 11.69.255.25411.69.255.25565,534
7111.70.0.0/1611.70.0.1 to 11.70.255.25411.70.255.25565,534
7211.71.0.0/1611.71.0.1 to 11.71.255.25411.71.255.25565,534
7311.72.0.0/1611.72.0.1 to 11.72.255.25411.72.255.25565,534
7411.73.0.0/1611.73.0.1 to 11.73.255.25411.73.255.25565,534
7511.74.0.0/1611.74.0.1 to 11.74.255.25411.74.255.25565,534
7611.75.0.0/1611.75.0.1 to 11.75.255.25411.75.255.25565,534
7711.76.0.0/1611.76.0.1 to 11.76.255.25411.76.255.25565,534
7811.77.0.0/1611.77.0.1 to 11.77.255.25411.77.255.25565,534
7911.78.0.0/1611.78.0.1 to 11.78.255.25411.78.255.25565,534
8011.79.0.0/1611.79.0.1 to 11.79.255.25411.79.255.25565,534
8111.80.0.0/1611.80.0.1 to 11.80.255.25411.80.255.25565,534
8211.81.0.0/1611.81.0.1 to 11.81.255.25411.81.255.25565,534
8311.82.0.0/1611.82.0.1 to 11.82.255.25411.82.255.25565,534
8411.83.0.0/1611.83.0.1 to 11.83.255.25411.83.255.25565,534
8511.84.0.0/1611.84.0.1 to 11.84.255.25411.84.255.25565,534
8611.85.0.0/1611.85.0.1 to 11.85.255.25411.85.255.25565,534
8711.86.0.0/1611.86.0.1 to 11.86.255.25411.86.255.25565,534
8811.87.0.0/1611.87.0.1 to 11.87.255.25411.87.255.25565,534
8911.88.0.0/1611.88.0.1 to 11.88.255.25411.88.255.25565,534
9011.89.0.0/1611.89.0.1 to 11.89.255.25411.89.255.25565,534
9111.90.0.0/1611.90.0.1 to 11.90.255.25411.90.255.25565,534
9211.91.0.0/1611.91.0.1 to 11.91.255.25411.91.255.25565,534
9311.92.0.0/1611.92.0.1 to 11.92.255.25411.92.255.25565,534
9411.93.0.0/1611.93.0.1 to 11.93.255.25411.93.255.25565,534
9511.94.0.0/1611.94.0.1 to 11.94.255.25411.94.255.25565,534
9611.95.0.0/1611.95.0.1 to 11.95.255.25411.95.255.25565,534
9711.96.0.0/1611.96.0.1 to 11.96.255.25411.96.255.25565,534
9811.97.0.0/1611.97.0.1 to 11.97.255.25411.97.255.25565,534
9911.98.0.0/1611.98.0.1 to 11.98.255.25411.98.255.25565,534
10011.99.0.0/1611.99.0.1 to 11.99.255.25411.99.255.25565,534
10111.100.0.0/1611.100.0.1 to 11.100.255.25411.100.255.25565,534
10211.101.0.0/1611.101.0.1 to 11.101.255.25411.101.255.25565,534
10311.102.0.0/1611.102.0.1 to 11.102.255.25411.102.255.25565,534
10411.103.0.0/1611.103.0.1 to 11.103.255.25411.103.255.25565,534
10511.104.0.0/1611.104.0.1 to 11.104.255.25411.104.255.25565,534
10611.105.0.0/1611.105.0.1 to 11.105.255.25411.105.255.25565,534
10711.106.0.0/1611.106.0.1 to 11.106.255.25411.106.255.25565,534
10811.107.0.0/1611.107.0.1 to 11.107.255.25411.107.255.25565,534
10911.108.0.0/1611.108.0.1 to 11.108.255.25411.108.255.25565,534
11011.109.0.0/1611.109.0.1 to 11.109.255.25411.109.255.25565,534
11111.110.0.0/1611.110.0.1 to 11.110.255.25411.110.255.25565,534
11211.111.0.0/1611.111.0.1 to 11.111.255.25411.111.255.25565,534
11311.112.0.0/1611.112.0.1 to 11.112.255.25411.112.255.25565,534
11411.113.0.0/1611.113.0.1 to 11.113.255.25411.113.255.25565,534
11511.114.0.0/1611.114.0.1 to 11.114.255.25411.114.255.25565,534
11611.115.0.0/1611.115.0.1 to 11.115.255.25411.115.255.25565,534
11711.116.0.0/1611.116.0.1 to 11.116.255.25411.116.255.25565,534
11811.117.0.0/1611.117.0.1 to 11.117.255.25411.117.255.25565,534
11911.118.0.0/1611.118.0.1 to 11.118.255.25411.118.255.25565,534
12011.119.0.0/1611.119.0.1 to 11.119.255.25411.119.255.25565,534
12111.120.0.0/1611.120.0.1 to 11.120.255.25411.120.255.25565,534
12211.121.0.0/1611.121.0.1 to 11.121.255.25411.121.255.25565,534
12311.122.0.0/1611.122.0.1 to 11.122.255.25411.122.255.25565,534
12411.123.0.0/1611.123.0.1 to 11.123.255.25411.123.255.25565,534
12511.124.0.0/1611.124.0.1 to 11.124.255.25411.124.255.25565,534
12611.125.0.0/1611.125.0.1 to 11.125.255.25411.125.255.25565,534
12711.126.0.0/1611.126.0.1 to 11.126.255.25411.126.255.25565,534
12811.127.0.0/1611.127.0.1 to 11.127.255.25411.127.255.25565,534
12911.128.0.0/1611.128.0.1 to 11.128.255.25411.128.255.25565,534
13011.129.0.0/1611.129.0.1 to 11.129.255.25411.129.255.25565,534
13111.130.0.0/1611.130.0.1 to 11.130.255.25411.130.255.25565,534
13211.131.0.0/1611.131.0.1 to 11.131.255.25411.131.255.25565,534
13311.132.0.0/1611.132.0.1 to 11.132.255.25411.132.255.25565,534
13411.133.0.0/1611.133.0.1 to 11.133.255.25411.133.255.25565,534
13511.134.0.0/1611.134.0.1 to 11.134.255.25411.134.255.25565,534
13611.135.0.0/1611.135.0.1 to 11.135.255.25411.135.255.25565,534
13711.136.0.0/1611.136.0.1 to 11.136.255.25411.136.255.25565,534
13811.137.0.0/1611.137.0.1 to 11.137.255.25411.137.255.25565,534
13911.138.0.0/1611.138.0.1 to 11.138.255.25411.138.255.25565,534
14011.139.0.0/1611.139.0.1 to 11.139.255.25411.139.255.25565,534
14111.140.0.0/1611.140.0.1 to 11.140.255.25411.140.255.25565,534
14211.141.0.0/1611.141.0.1 to 11.141.255.25411.141.255.25565,534
14311.142.0.0/1611.142.0.1 to 11.142.255.25411.142.255.25565,534
14411.143.0.0/1611.143.0.1 to 11.143.255.25411.143.255.25565,534
14511.144.0.0/1611.144.0.1 to 11.144.255.25411.144.255.25565,534
14611.145.0.0/1611.145.0.1 to 11.145.255.25411.145.255.25565,534
14711.146.0.0/1611.146.0.1 to 11.146.255.25411.146.255.25565,534
14811.147.0.0/1611.147.0.1 to 11.147.255.25411.147.255.25565,534
14911.148.0.0/1611.148.0.1 to 11.148.255.25411.148.255.25565,534
15011.149.0.0/1611.149.0.1 to 11.149.255.25411.149.255.25565,534
15111.150.0.0/1611.150.0.1 to 11.150.255.25411.150.255.25565,534
15211.151.0.0/1611.151.0.1 to 11.151.255.25411.151.255.25565,534
15311.152.0.0/1611.152.0.1 to 11.152.255.25411.152.255.25565,534
15411.153.0.0/1611.153.0.1 to 11.153.255.25411.153.255.25565,534
15511.154.0.0/1611.154.0.1 to 11.154.255.25411.154.255.25565,534
15611.155.0.0/1611.155.0.1 to 11.155.255.25411.155.255.25565,534
15711.156.0.0/1611.156.0.1 to 11.156.255.25411.156.255.25565,534
15811.157.0.0/1611.157.0.1 to 11.157.255.25411.157.255.25565,534
15911.158.0.0/1611.158.0.1 to 11.158.255.25411.158.255.25565,534
16011.159.0.0/1611.159.0.1 to 11.159.255.25411.159.255.25565,534
16111.160.0.0/1611.160.0.1 to 11.160.255.25411.160.255.25565,534
16211.161.0.0/1611.161.0.1 to 11.161.255.25411.161.255.25565,534
16311.162.0.0/1611.162.0.1 to 11.162.255.25411.162.255.25565,534
16411.163.0.0/1611.163.0.1 to 11.163.255.25411.163.255.25565,534
16511.164.0.0/1611.164.0.1 to 11.164.255.25411.164.255.25565,534
16611.165.0.0/1611.165.0.1 to 11.165.255.25411.165.255.25565,534
16711.166.0.0/1611.166.0.1 to 11.166.255.25411.166.255.25565,534
16811.167.0.0/1611.167.0.1 to 11.167.255.25411.167.255.25565,534
16911.168.0.0/1611.168.0.1 to 11.168.255.25411.168.255.25565,534
17011.169.0.0/1611.169.0.1 to 11.169.255.25411.169.255.25565,534
17111.170.0.0/1611.170.0.1 to 11.170.255.25411.170.255.25565,534
17211.171.0.0/1611.171.0.1 to 11.171.255.25411.171.255.25565,534
17311.172.0.0/1611.172.0.1 to 11.172.255.25411.172.255.25565,534
17411.173.0.0/1611.173.0.1 to 11.173.255.25411.173.255.25565,534
17511.174.0.0/1611.174.0.1 to 11.174.255.25411.174.255.25565,534
17611.175.0.0/1611.175.0.1 to 11.175.255.25411.175.255.25565,534
17711.176.0.0/1611.176.0.1 to 11.176.255.25411.176.255.25565,534
17811.177.0.0/1611.177.0.1 to 11.177.255.25411.177.255.25565,534
17911.178.0.0/1611.178.0.1 to 11.178.255.25411.178.255.25565,534
18011.179.0.0/1611.179.0.1 to 11.179.255.25411.179.255.25565,534
18111.180.0.0/1611.180.0.1 to 11.180.255.25411.180.255.25565,534
18211.181.0.0/1611.181.0.1 to 11.181.255.25411.181.255.25565,534
18311.182.0.0/1611.182.0.1 to 11.182.255.25411.182.255.25565,534
18411.183.0.0/1611.183.0.1 to 11.183.255.25411.183.255.25565,534
18511.184.0.0/1611.184.0.1 to 11.184.255.25411.184.255.25565,534
18611.185.0.0/1611.185.0.1 to 11.185.255.25411.185.255.25565,534
18711.186.0.0/1611.186.0.1 to 11.186.255.25411.186.255.25565,534
18811.187.0.0/1611.187.0.1 to 11.187.255.25411.187.255.25565,534
18911.188.0.0/1611.188.0.1 to 11.188.255.25411.188.255.25565,534
19011.189.0.0/1611.189.0.1 to 11.189.255.25411.189.255.25565,534
19111.190.0.0/1611.190.0.1 to 11.190.255.25411.190.255.25565,534
19211.191.0.0/1611.191.0.1 to 11.191.255.25411.191.255.25565,534
19311.192.0.0/1611.192.0.1 to 11.192.255.25411.192.255.25565,534
19411.193.0.0/1611.193.0.1 to 11.193.255.25411.193.255.25565,534
19511.194.0.0/1611.194.0.1 to 11.194.255.25411.194.255.25565,534
19611.195.0.0/1611.195.0.1 to 11.195.255.25411.195.255.25565,534
19711.196.0.0/1611.196.0.1 to 11.196.255.25411.196.255.25565,534
19811.197.0.0/1611.197.0.1 to 11.197.255.25411.197.255.25565,534
19911.198.0.0/1611.198.0.1 to 11.198.255.25411.198.255.25565,534
20011.199.0.0/1611.199.0.1 to 11.199.255.25411.199.255.25565,534
20111.200.0.0/1611.200.0.1 to 11.200.255.25411.200.255.25565,534
20211.201.0.0/1611.201.0.1 to 11.201.255.25411.201.255.25565,534
20311.202.0.0/1611.202.0.1 to 11.202.255.25411.202.255.25565,534
20411.203.0.0/1611.203.0.1 to 11.203.255.25411.203.255.25565,534
20511.204.0.0/1611.204.0.1 to 11.204.255.25411.204.255.25565,534
20611.205.0.0/1611.205.0.1 to 11.205.255.25411.205.255.25565,534
20711.206.0.0/1611.206.0.1 to 11.206.255.25411.206.255.25565,534
20811.207.0.0/1611.207.0.1 to 11.207.255.25411.207.255.25565,534
20911.208.0.0/1611.208.0.1 to 11.208.255.25411.208.255.25565,534
21011.209.0.0/1611.209.0.1 to 11.209.255.25411.209.255.25565,534
21111.210.0.0/1611.210.0.1 to 11.210.255.25411.210.255.25565,534
21211.211.0.0/1611.211.0.1 to 11.211.255.25411.211.255.25565,534
21311.212.0.0/1611.212.0.1 to 11.212.255.25411.212.255.25565,534
21411.213.0.0/1611.213.0.1 to 11.213.255.25411.213.255.25565,534
21511.214.0.0/1611.214.0.1 to 11.214.255.25411.214.255.25565,534
21611.215.0.0/1611.215.0.1 to 11.215.255.25411.215.255.25565,534
21711.216.0.0/1611.216.0.1 to 11.216.255.25411.216.255.25565,534
21811.217.0.0/1611.217.0.1 to 11.217.255.25411.217.255.25565,534
21911.218.0.0/1611.218.0.1 to 11.218.255.25411.218.255.25565,534
22011.219.0.0/1611.219.0.1 to 11.219.255.25411.219.255.25565,534
22111.220.0.0/1611.220.0.1 to 11.220.255.25411.220.255.25565,534
22211.221.0.0/1611.221.0.1 to 11.221.255.25411.221.255.25565,534
22311.222.0.0/1611.222.0.1 to 11.222.255.25411.222.255.25565,534
22411.223.0.0/1611.223.0.1 to 11.223.255.25411.223.255.25565,534
22511.224.0.0/1611.224.0.1 to 11.224.255.25411.224.255.25565,534
22611.225.0.0/1611.225.0.1 to 11.225.255.25411.225.255.25565,534
22711.226.0.0/1611.226.0.1 to 11.226.255.25411.226.255.25565,534
22811.227.0.0/1611.227.0.1 to 11.227.255.25411.227.255.25565,534
22911.228.0.0/1611.228.0.1 to 11.228.255.25411.228.255.25565,534
23011.229.0.0/1611.229.0.1 to 11.229.255.25411.229.255.25565,534
23111.230.0.0/1611.230.0.1 to 11.230.255.25411.230.255.25565,534
23211.231.0.0/1611.231.0.1 to 11.231.255.25411.231.255.25565,534
23311.232.0.0/1611.232.0.1 to 11.232.255.25411.232.255.25565,534
23411.233.0.0/1611.233.0.1 to 11.233.255.25411.233.255.25565,534
23511.234.0.0/1611.234.0.1 to 11.234.255.25411.234.255.25565,534
23611.235.0.0/1611.235.0.1 to 11.235.255.25411.235.255.25565,534
23711.236.0.0/1611.236.0.1 to 11.236.255.25411.236.255.25565,534
23811.237.0.0/1611.237.0.1 to 11.237.255.25411.237.255.25565,534
23911.238.0.0/1611.238.0.1 to 11.238.255.25411.238.255.25565,534
24011.239.0.0/1611.239.0.1 to 11.239.255.25411.239.255.25565,534
24111.240.0.0/1611.240.0.1 to 11.240.255.25411.240.255.25565,534
24211.241.0.0/1611.241.0.1 to 11.241.255.25411.241.255.25565,534
24311.242.0.0/1611.242.0.1 to 11.242.255.25411.242.255.25565,534
24411.243.0.0/1611.243.0.1 to 11.243.255.25411.243.255.25565,534
24511.244.0.0/1611.244.0.1 to 11.244.255.25411.244.255.25565,534
24611.245.0.0/1611.245.0.1 to 11.245.255.25411.245.255.25565,534
24711.246.0.0/1611.246.0.1 to 11.246.255.25411.246.255.25565,534
24811.247.0.0/1611.247.0.1 to 11.247.255.25411.247.255.25565,534
24911.248.0.0/1611.248.0.1 to 11.248.255.25411.248.255.25565,534
25011.249.0.0/1611.249.0.1 to 11.249.255.25411.249.255.25565,534
25111.250.0.0/1611.250.0.1 to 11.250.255.25411.250.255.25565,534
25211.251.0.0/1611.251.0.1 to 11.251.255.25411.251.255.25565,534
25311.252.0.0/1611.252.0.1 to 11.252.255.25411.252.255.25565,534
25411.253.0.0/1611.253.0.1 to 11.253.255.25411.253.255.25565,534
25511.254.0.0/1611.254.0.1 to 11.254.255.25411.254.255.25565,534
25611.255.0.0/1611.255.0.1 to 11.255.255.25411.255.255.25565,534

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.