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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.

Network70.131.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
70.131.0.0
Broadcast address
70.131.255.255
First usable
70.131.0.1
Last usable
70.131.255.254
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 46830000 · Integer 1182990336 to 1183055871
Reverse DNS zone
131.70.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01000110.10000011..00000000.0000000070.131.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01000110.10000011..00000000.0000000070.131.0.0
Broadcast01000110.10000011..11111111.1111111170.131.255.255
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)

70.131.0.0/16 makes 256 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
170.131.0.0/2470.131.0.1 to 70.131.0.25470.131.0.255254
270.131.1.0/2470.131.1.1 to 70.131.1.25470.131.1.255254
370.131.2.0/2470.131.2.1 to 70.131.2.25470.131.2.255254
470.131.3.0/2470.131.3.1 to 70.131.3.25470.131.3.255254
570.131.4.0/2470.131.4.1 to 70.131.4.25470.131.4.255254
670.131.5.0/2470.131.5.1 to 70.131.5.25470.131.5.255254
770.131.6.0/2470.131.6.1 to 70.131.6.25470.131.6.255254
870.131.7.0/2470.131.7.1 to 70.131.7.25470.131.7.255254
970.131.8.0/2470.131.8.1 to 70.131.8.25470.131.8.255254
1070.131.9.0/2470.131.9.1 to 70.131.9.25470.131.9.255254
1170.131.10.0/2470.131.10.1 to 70.131.10.25470.131.10.255254
1270.131.11.0/2470.131.11.1 to 70.131.11.25470.131.11.255254
1370.131.12.0/2470.131.12.1 to 70.131.12.25470.131.12.255254
1470.131.13.0/2470.131.13.1 to 70.131.13.25470.131.13.255254
1570.131.14.0/2470.131.14.1 to 70.131.14.25470.131.14.255254
1670.131.15.0/2470.131.15.1 to 70.131.15.25470.131.15.255254
1770.131.16.0/2470.131.16.1 to 70.131.16.25470.131.16.255254
1870.131.17.0/2470.131.17.1 to 70.131.17.25470.131.17.255254
1970.131.18.0/2470.131.18.1 to 70.131.18.25470.131.18.255254
2070.131.19.0/2470.131.19.1 to 70.131.19.25470.131.19.255254
2170.131.20.0/2470.131.20.1 to 70.131.20.25470.131.20.255254
2270.131.21.0/2470.131.21.1 to 70.131.21.25470.131.21.255254
2370.131.22.0/2470.131.22.1 to 70.131.22.25470.131.22.255254
2470.131.23.0/2470.131.23.1 to 70.131.23.25470.131.23.255254
2570.131.24.0/2470.131.24.1 to 70.131.24.25470.131.24.255254
2670.131.25.0/2470.131.25.1 to 70.131.25.25470.131.25.255254
2770.131.26.0/2470.131.26.1 to 70.131.26.25470.131.26.255254
2870.131.27.0/2470.131.27.1 to 70.131.27.25470.131.27.255254
2970.131.28.0/2470.131.28.1 to 70.131.28.25470.131.28.255254
3070.131.29.0/2470.131.29.1 to 70.131.29.25470.131.29.255254
3170.131.30.0/2470.131.30.1 to 70.131.30.25470.131.30.255254
3270.131.31.0/2470.131.31.1 to 70.131.31.25470.131.31.255254
3370.131.32.0/2470.131.32.1 to 70.131.32.25470.131.32.255254
3470.131.33.0/2470.131.33.1 to 70.131.33.25470.131.33.255254
3570.131.34.0/2470.131.34.1 to 70.131.34.25470.131.34.255254
3670.131.35.0/2470.131.35.1 to 70.131.35.25470.131.35.255254
3770.131.36.0/2470.131.36.1 to 70.131.36.25470.131.36.255254
3870.131.37.0/2470.131.37.1 to 70.131.37.25470.131.37.255254
3970.131.38.0/2470.131.38.1 to 70.131.38.25470.131.38.255254
4070.131.39.0/2470.131.39.1 to 70.131.39.25470.131.39.255254
4170.131.40.0/2470.131.40.1 to 70.131.40.25470.131.40.255254
4270.131.41.0/2470.131.41.1 to 70.131.41.25470.131.41.255254
4370.131.42.0/2470.131.42.1 to 70.131.42.25470.131.42.255254
4470.131.43.0/2470.131.43.1 to 70.131.43.25470.131.43.255254
4570.131.44.0/2470.131.44.1 to 70.131.44.25470.131.44.255254
4670.131.45.0/2470.131.45.1 to 70.131.45.25470.131.45.255254
4770.131.46.0/2470.131.46.1 to 70.131.46.25470.131.46.255254
4870.131.47.0/2470.131.47.1 to 70.131.47.25470.131.47.255254
4970.131.48.0/2470.131.48.1 to 70.131.48.25470.131.48.255254
5070.131.49.0/2470.131.49.1 to 70.131.49.25470.131.49.255254
5170.131.50.0/2470.131.50.1 to 70.131.50.25470.131.50.255254
5270.131.51.0/2470.131.51.1 to 70.131.51.25470.131.51.255254
5370.131.52.0/2470.131.52.1 to 70.131.52.25470.131.52.255254
5470.131.53.0/2470.131.53.1 to 70.131.53.25470.131.53.255254
5570.131.54.0/2470.131.54.1 to 70.131.54.25470.131.54.255254
5670.131.55.0/2470.131.55.1 to 70.131.55.25470.131.55.255254
5770.131.56.0/2470.131.56.1 to 70.131.56.25470.131.56.255254
5870.131.57.0/2470.131.57.1 to 70.131.57.25470.131.57.255254
5970.131.58.0/2470.131.58.1 to 70.131.58.25470.131.58.255254
6070.131.59.0/2470.131.59.1 to 70.131.59.25470.131.59.255254
6170.131.60.0/2470.131.60.1 to 70.131.60.25470.131.60.255254
6270.131.61.0/2470.131.61.1 to 70.131.61.25470.131.61.255254
6370.131.62.0/2470.131.62.1 to 70.131.62.25470.131.62.255254
6470.131.63.0/2470.131.63.1 to 70.131.63.25470.131.63.255254
6570.131.64.0/2470.131.64.1 to 70.131.64.25470.131.64.255254
6670.131.65.0/2470.131.65.1 to 70.131.65.25470.131.65.255254
6770.131.66.0/2470.131.66.1 to 70.131.66.25470.131.66.255254
6870.131.67.0/2470.131.67.1 to 70.131.67.25470.131.67.255254
6970.131.68.0/2470.131.68.1 to 70.131.68.25470.131.68.255254
7070.131.69.0/2470.131.69.1 to 70.131.69.25470.131.69.255254
7170.131.70.0/2470.131.70.1 to 70.131.70.25470.131.70.255254
7270.131.71.0/2470.131.71.1 to 70.131.71.25470.131.71.255254
7370.131.72.0/2470.131.72.1 to 70.131.72.25470.131.72.255254
7470.131.73.0/2470.131.73.1 to 70.131.73.25470.131.73.255254
7570.131.74.0/2470.131.74.1 to 70.131.74.25470.131.74.255254
7670.131.75.0/2470.131.75.1 to 70.131.75.25470.131.75.255254
7770.131.76.0/2470.131.76.1 to 70.131.76.25470.131.76.255254
7870.131.77.0/2470.131.77.1 to 70.131.77.25470.131.77.255254
7970.131.78.0/2470.131.78.1 to 70.131.78.25470.131.78.255254
8070.131.79.0/2470.131.79.1 to 70.131.79.25470.131.79.255254
8170.131.80.0/2470.131.80.1 to 70.131.80.25470.131.80.255254
8270.131.81.0/2470.131.81.1 to 70.131.81.25470.131.81.255254
8370.131.82.0/2470.131.82.1 to 70.131.82.25470.131.82.255254
8470.131.83.0/2470.131.83.1 to 70.131.83.25470.131.83.255254
8570.131.84.0/2470.131.84.1 to 70.131.84.25470.131.84.255254
8670.131.85.0/2470.131.85.1 to 70.131.85.25470.131.85.255254
8770.131.86.0/2470.131.86.1 to 70.131.86.25470.131.86.255254
8870.131.87.0/2470.131.87.1 to 70.131.87.25470.131.87.255254
8970.131.88.0/2470.131.88.1 to 70.131.88.25470.131.88.255254
9070.131.89.0/2470.131.89.1 to 70.131.89.25470.131.89.255254
9170.131.90.0/2470.131.90.1 to 70.131.90.25470.131.90.255254
9270.131.91.0/2470.131.91.1 to 70.131.91.25470.131.91.255254
9370.131.92.0/2470.131.92.1 to 70.131.92.25470.131.92.255254
9470.131.93.0/2470.131.93.1 to 70.131.93.25470.131.93.255254
9570.131.94.0/2470.131.94.1 to 70.131.94.25470.131.94.255254
9670.131.95.0/2470.131.95.1 to 70.131.95.25470.131.95.255254
9770.131.96.0/2470.131.96.1 to 70.131.96.25470.131.96.255254
9870.131.97.0/2470.131.97.1 to 70.131.97.25470.131.97.255254
9970.131.98.0/2470.131.98.1 to 70.131.98.25470.131.98.255254
10070.131.99.0/2470.131.99.1 to 70.131.99.25470.131.99.255254
10170.131.100.0/2470.131.100.1 to 70.131.100.25470.131.100.255254
10270.131.101.0/2470.131.101.1 to 70.131.101.25470.131.101.255254
10370.131.102.0/2470.131.102.1 to 70.131.102.25470.131.102.255254
10470.131.103.0/2470.131.103.1 to 70.131.103.25470.131.103.255254
10570.131.104.0/2470.131.104.1 to 70.131.104.25470.131.104.255254
10670.131.105.0/2470.131.105.1 to 70.131.105.25470.131.105.255254
10770.131.106.0/2470.131.106.1 to 70.131.106.25470.131.106.255254
10870.131.107.0/2470.131.107.1 to 70.131.107.25470.131.107.255254
10970.131.108.0/2470.131.108.1 to 70.131.108.25470.131.108.255254
11070.131.109.0/2470.131.109.1 to 70.131.109.25470.131.109.255254
11170.131.110.0/2470.131.110.1 to 70.131.110.25470.131.110.255254
11270.131.111.0/2470.131.111.1 to 70.131.111.25470.131.111.255254
11370.131.112.0/2470.131.112.1 to 70.131.112.25470.131.112.255254
11470.131.113.0/2470.131.113.1 to 70.131.113.25470.131.113.255254
11570.131.114.0/2470.131.114.1 to 70.131.114.25470.131.114.255254
11670.131.115.0/2470.131.115.1 to 70.131.115.25470.131.115.255254
11770.131.116.0/2470.131.116.1 to 70.131.116.25470.131.116.255254
11870.131.117.0/2470.131.117.1 to 70.131.117.25470.131.117.255254
11970.131.118.0/2470.131.118.1 to 70.131.118.25470.131.118.255254
12070.131.119.0/2470.131.119.1 to 70.131.119.25470.131.119.255254
12170.131.120.0/2470.131.120.1 to 70.131.120.25470.131.120.255254
12270.131.121.0/2470.131.121.1 to 70.131.121.25470.131.121.255254
12370.131.122.0/2470.131.122.1 to 70.131.122.25470.131.122.255254
12470.131.123.0/2470.131.123.1 to 70.131.123.25470.131.123.255254
12570.131.124.0/2470.131.124.1 to 70.131.124.25470.131.124.255254
12670.131.125.0/2470.131.125.1 to 70.131.125.25470.131.125.255254
12770.131.126.0/2470.131.126.1 to 70.131.126.25470.131.126.255254
12870.131.127.0/2470.131.127.1 to 70.131.127.25470.131.127.255254
12970.131.128.0/2470.131.128.1 to 70.131.128.25470.131.128.255254
13070.131.129.0/2470.131.129.1 to 70.131.129.25470.131.129.255254
13170.131.130.0/2470.131.130.1 to 70.131.130.25470.131.130.255254
13270.131.131.0/2470.131.131.1 to 70.131.131.25470.131.131.255254
13370.131.132.0/2470.131.132.1 to 70.131.132.25470.131.132.255254
13470.131.133.0/2470.131.133.1 to 70.131.133.25470.131.133.255254
13570.131.134.0/2470.131.134.1 to 70.131.134.25470.131.134.255254
13670.131.135.0/2470.131.135.1 to 70.131.135.25470.131.135.255254
13770.131.136.0/2470.131.136.1 to 70.131.136.25470.131.136.255254
13870.131.137.0/2470.131.137.1 to 70.131.137.25470.131.137.255254
13970.131.138.0/2470.131.138.1 to 70.131.138.25470.131.138.255254
14070.131.139.0/2470.131.139.1 to 70.131.139.25470.131.139.255254
14170.131.140.0/2470.131.140.1 to 70.131.140.25470.131.140.255254
14270.131.141.0/2470.131.141.1 to 70.131.141.25470.131.141.255254
14370.131.142.0/2470.131.142.1 to 70.131.142.25470.131.142.255254
14470.131.143.0/2470.131.143.1 to 70.131.143.25470.131.143.255254
14570.131.144.0/2470.131.144.1 to 70.131.144.25470.131.144.255254
14670.131.145.0/2470.131.145.1 to 70.131.145.25470.131.145.255254
14770.131.146.0/2470.131.146.1 to 70.131.146.25470.131.146.255254
14870.131.147.0/2470.131.147.1 to 70.131.147.25470.131.147.255254
14970.131.148.0/2470.131.148.1 to 70.131.148.25470.131.148.255254
15070.131.149.0/2470.131.149.1 to 70.131.149.25470.131.149.255254
15170.131.150.0/2470.131.150.1 to 70.131.150.25470.131.150.255254
15270.131.151.0/2470.131.151.1 to 70.131.151.25470.131.151.255254
15370.131.152.0/2470.131.152.1 to 70.131.152.25470.131.152.255254
15470.131.153.0/2470.131.153.1 to 70.131.153.25470.131.153.255254
15570.131.154.0/2470.131.154.1 to 70.131.154.25470.131.154.255254
15670.131.155.0/2470.131.155.1 to 70.131.155.25470.131.155.255254
15770.131.156.0/2470.131.156.1 to 70.131.156.25470.131.156.255254
15870.131.157.0/2470.131.157.1 to 70.131.157.25470.131.157.255254
15970.131.158.0/2470.131.158.1 to 70.131.158.25470.131.158.255254
16070.131.159.0/2470.131.159.1 to 70.131.159.25470.131.159.255254
16170.131.160.0/2470.131.160.1 to 70.131.160.25470.131.160.255254
16270.131.161.0/2470.131.161.1 to 70.131.161.25470.131.161.255254
16370.131.162.0/2470.131.162.1 to 70.131.162.25470.131.162.255254
16470.131.163.0/2470.131.163.1 to 70.131.163.25470.131.163.255254
16570.131.164.0/2470.131.164.1 to 70.131.164.25470.131.164.255254
16670.131.165.0/2470.131.165.1 to 70.131.165.25470.131.165.255254
16770.131.166.0/2470.131.166.1 to 70.131.166.25470.131.166.255254
16870.131.167.0/2470.131.167.1 to 70.131.167.25470.131.167.255254
16970.131.168.0/2470.131.168.1 to 70.131.168.25470.131.168.255254
17070.131.169.0/2470.131.169.1 to 70.131.169.25470.131.169.255254
17170.131.170.0/2470.131.170.1 to 70.131.170.25470.131.170.255254
17270.131.171.0/2470.131.171.1 to 70.131.171.25470.131.171.255254
17370.131.172.0/2470.131.172.1 to 70.131.172.25470.131.172.255254
17470.131.173.0/2470.131.173.1 to 70.131.173.25470.131.173.255254
17570.131.174.0/2470.131.174.1 to 70.131.174.25470.131.174.255254
17670.131.175.0/2470.131.175.1 to 70.131.175.25470.131.175.255254
17770.131.176.0/2470.131.176.1 to 70.131.176.25470.131.176.255254
17870.131.177.0/2470.131.177.1 to 70.131.177.25470.131.177.255254
17970.131.178.0/2470.131.178.1 to 70.131.178.25470.131.178.255254
18070.131.179.0/2470.131.179.1 to 70.131.179.25470.131.179.255254
18170.131.180.0/2470.131.180.1 to 70.131.180.25470.131.180.255254
18270.131.181.0/2470.131.181.1 to 70.131.181.25470.131.181.255254
18370.131.182.0/2470.131.182.1 to 70.131.182.25470.131.182.255254
18470.131.183.0/2470.131.183.1 to 70.131.183.25470.131.183.255254
18570.131.184.0/2470.131.184.1 to 70.131.184.25470.131.184.255254
18670.131.185.0/2470.131.185.1 to 70.131.185.25470.131.185.255254
18770.131.186.0/2470.131.186.1 to 70.131.186.25470.131.186.255254
18870.131.187.0/2470.131.187.1 to 70.131.187.25470.131.187.255254
18970.131.188.0/2470.131.188.1 to 70.131.188.25470.131.188.255254
19070.131.189.0/2470.131.189.1 to 70.131.189.25470.131.189.255254
19170.131.190.0/2470.131.190.1 to 70.131.190.25470.131.190.255254
19270.131.191.0/2470.131.191.1 to 70.131.191.25470.131.191.255254
19370.131.192.0/2470.131.192.1 to 70.131.192.25470.131.192.255254
19470.131.193.0/2470.131.193.1 to 70.131.193.25470.131.193.255254
19570.131.194.0/2470.131.194.1 to 70.131.194.25470.131.194.255254
19670.131.195.0/2470.131.195.1 to 70.131.195.25470.131.195.255254
19770.131.196.0/2470.131.196.1 to 70.131.196.25470.131.196.255254
19870.131.197.0/2470.131.197.1 to 70.131.197.25470.131.197.255254
19970.131.198.0/2470.131.198.1 to 70.131.198.25470.131.198.255254
20070.131.199.0/2470.131.199.1 to 70.131.199.25470.131.199.255254
20170.131.200.0/2470.131.200.1 to 70.131.200.25470.131.200.255254
20270.131.201.0/2470.131.201.1 to 70.131.201.25470.131.201.255254
20370.131.202.0/2470.131.202.1 to 70.131.202.25470.131.202.255254
20470.131.203.0/2470.131.203.1 to 70.131.203.25470.131.203.255254
20570.131.204.0/2470.131.204.1 to 70.131.204.25470.131.204.255254
20670.131.205.0/2470.131.205.1 to 70.131.205.25470.131.205.255254
20770.131.206.0/2470.131.206.1 to 70.131.206.25470.131.206.255254
20870.131.207.0/2470.131.207.1 to 70.131.207.25470.131.207.255254
20970.131.208.0/2470.131.208.1 to 70.131.208.25470.131.208.255254
21070.131.209.0/2470.131.209.1 to 70.131.209.25470.131.209.255254
21170.131.210.0/2470.131.210.1 to 70.131.210.25470.131.210.255254
21270.131.211.0/2470.131.211.1 to 70.131.211.25470.131.211.255254
21370.131.212.0/2470.131.212.1 to 70.131.212.25470.131.212.255254
21470.131.213.0/2470.131.213.1 to 70.131.213.25470.131.213.255254
21570.131.214.0/2470.131.214.1 to 70.131.214.25470.131.214.255254
21670.131.215.0/2470.131.215.1 to 70.131.215.25470.131.215.255254
21770.131.216.0/2470.131.216.1 to 70.131.216.25470.131.216.255254
21870.131.217.0/2470.131.217.1 to 70.131.217.25470.131.217.255254
21970.131.218.0/2470.131.218.1 to 70.131.218.25470.131.218.255254
22070.131.219.0/2470.131.219.1 to 70.131.219.25470.131.219.255254
22170.131.220.0/2470.131.220.1 to 70.131.220.25470.131.220.255254
22270.131.221.0/2470.131.221.1 to 70.131.221.25470.131.221.255254
22370.131.222.0/2470.131.222.1 to 70.131.222.25470.131.222.255254
22470.131.223.0/2470.131.223.1 to 70.131.223.25470.131.223.255254
22570.131.224.0/2470.131.224.1 to 70.131.224.25470.131.224.255254
22670.131.225.0/2470.131.225.1 to 70.131.225.25470.131.225.255254
22770.131.226.0/2470.131.226.1 to 70.131.226.25470.131.226.255254
22870.131.227.0/2470.131.227.1 to 70.131.227.25470.131.227.255254
22970.131.228.0/2470.131.228.1 to 70.131.228.25470.131.228.255254
23070.131.229.0/2470.131.229.1 to 70.131.229.25470.131.229.255254
23170.131.230.0/2470.131.230.1 to 70.131.230.25470.131.230.255254
23270.131.231.0/2470.131.231.1 to 70.131.231.25470.131.231.255254
23370.131.232.0/2470.131.232.1 to 70.131.232.25470.131.232.255254
23470.131.233.0/2470.131.233.1 to 70.131.233.25470.131.233.255254
23570.131.234.0/2470.131.234.1 to 70.131.234.25470.131.234.255254
23670.131.235.0/2470.131.235.1 to 70.131.235.25470.131.235.255254
23770.131.236.0/2470.131.236.1 to 70.131.236.25470.131.236.255254
23870.131.237.0/2470.131.237.1 to 70.131.237.25470.131.237.255254
23970.131.238.0/2470.131.238.1 to 70.131.238.25470.131.238.255254
24070.131.239.0/2470.131.239.1 to 70.131.239.25470.131.239.255254
24170.131.240.0/2470.131.240.1 to 70.131.240.25470.131.240.255254
24270.131.241.0/2470.131.241.1 to 70.131.241.25470.131.241.255254
24370.131.242.0/2470.131.242.1 to 70.131.242.25470.131.242.255254
24470.131.243.0/2470.131.243.1 to 70.131.243.25470.131.243.255254
24570.131.244.0/2470.131.244.1 to 70.131.244.25470.131.244.255254
24670.131.245.0/2470.131.245.1 to 70.131.245.25470.131.245.255254
24770.131.246.0/2470.131.246.1 to 70.131.246.25470.131.246.255254
24870.131.247.0/2470.131.247.1 to 70.131.247.25470.131.247.255254
24970.131.248.0/2470.131.248.1 to 70.131.248.25470.131.248.255254
25070.131.249.0/2470.131.249.1 to 70.131.249.25470.131.249.255254
25170.131.250.0/2470.131.250.1 to 70.131.250.25470.131.250.255254
25270.131.251.0/2470.131.251.1 to 70.131.251.25470.131.251.255254
25370.131.252.0/2470.131.252.1 to 70.131.252.25470.131.252.255254
25470.131.253.0/2470.131.253.1 to 70.131.253.25470.131.253.255254
25570.131.254.0/2470.131.254.1 to 70.131.254.25470.131.254.255254
25670.131.255.0/2470.131.255.1 to 70.131.255.25470.131.255.255254

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.