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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.

Network70.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
70.0.0.0
Broadcast address
70.255.255.255
First usable
70.0.0.1
Last usable
70.255.255.254
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 46000000 · Integer 1174405120 to 1191182335
Reverse DNS zone
70.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01000110..00000000.00000000.0000000070.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01000110..00000000.00000000.0000000070.0.0.0
Broadcast01000110..11111111.11111111.1111111170.255.255.255
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)

70.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
170.0.0.0/1670.0.0.1 to 70.0.255.25470.0.255.25565,534
270.1.0.0/1670.1.0.1 to 70.1.255.25470.1.255.25565,534
370.2.0.0/1670.2.0.1 to 70.2.255.25470.2.255.25565,534
470.3.0.0/1670.3.0.1 to 70.3.255.25470.3.255.25565,534
570.4.0.0/1670.4.0.1 to 70.4.255.25470.4.255.25565,534
670.5.0.0/1670.5.0.1 to 70.5.255.25470.5.255.25565,534
770.6.0.0/1670.6.0.1 to 70.6.255.25470.6.255.25565,534
870.7.0.0/1670.7.0.1 to 70.7.255.25470.7.255.25565,534
970.8.0.0/1670.8.0.1 to 70.8.255.25470.8.255.25565,534
1070.9.0.0/1670.9.0.1 to 70.9.255.25470.9.255.25565,534
1170.10.0.0/1670.10.0.1 to 70.10.255.25470.10.255.25565,534
1270.11.0.0/1670.11.0.1 to 70.11.255.25470.11.255.25565,534
1370.12.0.0/1670.12.0.1 to 70.12.255.25470.12.255.25565,534
1470.13.0.0/1670.13.0.1 to 70.13.255.25470.13.255.25565,534
1570.14.0.0/1670.14.0.1 to 70.14.255.25470.14.255.25565,534
1670.15.0.0/1670.15.0.1 to 70.15.255.25470.15.255.25565,534
1770.16.0.0/1670.16.0.1 to 70.16.255.25470.16.255.25565,534
1870.17.0.0/1670.17.0.1 to 70.17.255.25470.17.255.25565,534
1970.18.0.0/1670.18.0.1 to 70.18.255.25470.18.255.25565,534
2070.19.0.0/1670.19.0.1 to 70.19.255.25470.19.255.25565,534
2170.20.0.0/1670.20.0.1 to 70.20.255.25470.20.255.25565,534
2270.21.0.0/1670.21.0.1 to 70.21.255.25470.21.255.25565,534
2370.22.0.0/1670.22.0.1 to 70.22.255.25470.22.255.25565,534
2470.23.0.0/1670.23.0.1 to 70.23.255.25470.23.255.25565,534
2570.24.0.0/1670.24.0.1 to 70.24.255.25470.24.255.25565,534
2670.25.0.0/1670.25.0.1 to 70.25.255.25470.25.255.25565,534
2770.26.0.0/1670.26.0.1 to 70.26.255.25470.26.255.25565,534
2870.27.0.0/1670.27.0.1 to 70.27.255.25470.27.255.25565,534
2970.28.0.0/1670.28.0.1 to 70.28.255.25470.28.255.25565,534
3070.29.0.0/1670.29.0.1 to 70.29.255.25470.29.255.25565,534
3170.30.0.0/1670.30.0.1 to 70.30.255.25470.30.255.25565,534
3270.31.0.0/1670.31.0.1 to 70.31.255.25470.31.255.25565,534
3370.32.0.0/1670.32.0.1 to 70.32.255.25470.32.255.25565,534
3470.33.0.0/1670.33.0.1 to 70.33.255.25470.33.255.25565,534
3570.34.0.0/1670.34.0.1 to 70.34.255.25470.34.255.25565,534
3670.35.0.0/1670.35.0.1 to 70.35.255.25470.35.255.25565,534
3770.36.0.0/1670.36.0.1 to 70.36.255.25470.36.255.25565,534
3870.37.0.0/1670.37.0.1 to 70.37.255.25470.37.255.25565,534
3970.38.0.0/1670.38.0.1 to 70.38.255.25470.38.255.25565,534
4070.39.0.0/1670.39.0.1 to 70.39.255.25470.39.255.25565,534
4170.40.0.0/1670.40.0.1 to 70.40.255.25470.40.255.25565,534
4270.41.0.0/1670.41.0.1 to 70.41.255.25470.41.255.25565,534
4370.42.0.0/1670.42.0.1 to 70.42.255.25470.42.255.25565,534
4470.43.0.0/1670.43.0.1 to 70.43.255.25470.43.255.25565,534
4570.44.0.0/1670.44.0.1 to 70.44.255.25470.44.255.25565,534
4670.45.0.0/1670.45.0.1 to 70.45.255.25470.45.255.25565,534
4770.46.0.0/1670.46.0.1 to 70.46.255.25470.46.255.25565,534
4870.47.0.0/1670.47.0.1 to 70.47.255.25470.47.255.25565,534
4970.48.0.0/1670.48.0.1 to 70.48.255.25470.48.255.25565,534
5070.49.0.0/1670.49.0.1 to 70.49.255.25470.49.255.25565,534
5170.50.0.0/1670.50.0.1 to 70.50.255.25470.50.255.25565,534
5270.51.0.0/1670.51.0.1 to 70.51.255.25470.51.255.25565,534
5370.52.0.0/1670.52.0.1 to 70.52.255.25470.52.255.25565,534
5470.53.0.0/1670.53.0.1 to 70.53.255.25470.53.255.25565,534
5570.54.0.0/1670.54.0.1 to 70.54.255.25470.54.255.25565,534
5670.55.0.0/1670.55.0.1 to 70.55.255.25470.55.255.25565,534
5770.56.0.0/1670.56.0.1 to 70.56.255.25470.56.255.25565,534
5870.57.0.0/1670.57.0.1 to 70.57.255.25470.57.255.25565,534
5970.58.0.0/1670.58.0.1 to 70.58.255.25470.58.255.25565,534
6070.59.0.0/1670.59.0.1 to 70.59.255.25470.59.255.25565,534
6170.60.0.0/1670.60.0.1 to 70.60.255.25470.60.255.25565,534
6270.61.0.0/1670.61.0.1 to 70.61.255.25470.61.255.25565,534
6370.62.0.0/1670.62.0.1 to 70.62.255.25470.62.255.25565,534
6470.63.0.0/1670.63.0.1 to 70.63.255.25470.63.255.25565,534
6570.64.0.0/1670.64.0.1 to 70.64.255.25470.64.255.25565,534
6670.65.0.0/1670.65.0.1 to 70.65.255.25470.65.255.25565,534
6770.66.0.0/1670.66.0.1 to 70.66.255.25470.66.255.25565,534
6870.67.0.0/1670.67.0.1 to 70.67.255.25470.67.255.25565,534
6970.68.0.0/1670.68.0.1 to 70.68.255.25470.68.255.25565,534
7070.69.0.0/1670.69.0.1 to 70.69.255.25470.69.255.25565,534
7170.70.0.0/1670.70.0.1 to 70.70.255.25470.70.255.25565,534
7270.71.0.0/1670.71.0.1 to 70.71.255.25470.71.255.25565,534
7370.72.0.0/1670.72.0.1 to 70.72.255.25470.72.255.25565,534
7470.73.0.0/1670.73.0.1 to 70.73.255.25470.73.255.25565,534
7570.74.0.0/1670.74.0.1 to 70.74.255.25470.74.255.25565,534
7670.75.0.0/1670.75.0.1 to 70.75.255.25470.75.255.25565,534
7770.76.0.0/1670.76.0.1 to 70.76.255.25470.76.255.25565,534
7870.77.0.0/1670.77.0.1 to 70.77.255.25470.77.255.25565,534
7970.78.0.0/1670.78.0.1 to 70.78.255.25470.78.255.25565,534
8070.79.0.0/1670.79.0.1 to 70.79.255.25470.79.255.25565,534
8170.80.0.0/1670.80.0.1 to 70.80.255.25470.80.255.25565,534
8270.81.0.0/1670.81.0.1 to 70.81.255.25470.81.255.25565,534
8370.82.0.0/1670.82.0.1 to 70.82.255.25470.82.255.25565,534
8470.83.0.0/1670.83.0.1 to 70.83.255.25470.83.255.25565,534
8570.84.0.0/1670.84.0.1 to 70.84.255.25470.84.255.25565,534
8670.85.0.0/1670.85.0.1 to 70.85.255.25470.85.255.25565,534
8770.86.0.0/1670.86.0.1 to 70.86.255.25470.86.255.25565,534
8870.87.0.0/1670.87.0.1 to 70.87.255.25470.87.255.25565,534
8970.88.0.0/1670.88.0.1 to 70.88.255.25470.88.255.25565,534
9070.89.0.0/1670.89.0.1 to 70.89.255.25470.89.255.25565,534
9170.90.0.0/1670.90.0.1 to 70.90.255.25470.90.255.25565,534
9270.91.0.0/1670.91.0.1 to 70.91.255.25470.91.255.25565,534
9370.92.0.0/1670.92.0.1 to 70.92.255.25470.92.255.25565,534
9470.93.0.0/1670.93.0.1 to 70.93.255.25470.93.255.25565,534
9570.94.0.0/1670.94.0.1 to 70.94.255.25470.94.255.25565,534
9670.95.0.0/1670.95.0.1 to 70.95.255.25470.95.255.25565,534
9770.96.0.0/1670.96.0.1 to 70.96.255.25470.96.255.25565,534
9870.97.0.0/1670.97.0.1 to 70.97.255.25470.97.255.25565,534
9970.98.0.0/1670.98.0.1 to 70.98.255.25470.98.255.25565,534
10070.99.0.0/1670.99.0.1 to 70.99.255.25470.99.255.25565,534
10170.100.0.0/1670.100.0.1 to 70.100.255.25470.100.255.25565,534
10270.101.0.0/1670.101.0.1 to 70.101.255.25470.101.255.25565,534
10370.102.0.0/1670.102.0.1 to 70.102.255.25470.102.255.25565,534
10470.103.0.0/1670.103.0.1 to 70.103.255.25470.103.255.25565,534
10570.104.0.0/1670.104.0.1 to 70.104.255.25470.104.255.25565,534
10670.105.0.0/1670.105.0.1 to 70.105.255.25470.105.255.25565,534
10770.106.0.0/1670.106.0.1 to 70.106.255.25470.106.255.25565,534
10870.107.0.0/1670.107.0.1 to 70.107.255.25470.107.255.25565,534
10970.108.0.0/1670.108.0.1 to 70.108.255.25470.108.255.25565,534
11070.109.0.0/1670.109.0.1 to 70.109.255.25470.109.255.25565,534
11170.110.0.0/1670.110.0.1 to 70.110.255.25470.110.255.25565,534
11270.111.0.0/1670.111.0.1 to 70.111.255.25470.111.255.25565,534
11370.112.0.0/1670.112.0.1 to 70.112.255.25470.112.255.25565,534
11470.113.0.0/1670.113.0.1 to 70.113.255.25470.113.255.25565,534
11570.114.0.0/1670.114.0.1 to 70.114.255.25470.114.255.25565,534
11670.115.0.0/1670.115.0.1 to 70.115.255.25470.115.255.25565,534
11770.116.0.0/1670.116.0.1 to 70.116.255.25470.116.255.25565,534
11870.117.0.0/1670.117.0.1 to 70.117.255.25470.117.255.25565,534
11970.118.0.0/1670.118.0.1 to 70.118.255.25470.118.255.25565,534
12070.119.0.0/1670.119.0.1 to 70.119.255.25470.119.255.25565,534
12170.120.0.0/1670.120.0.1 to 70.120.255.25470.120.255.25565,534
12270.121.0.0/1670.121.0.1 to 70.121.255.25470.121.255.25565,534
12370.122.0.0/1670.122.0.1 to 70.122.255.25470.122.255.25565,534
12470.123.0.0/1670.123.0.1 to 70.123.255.25470.123.255.25565,534
12570.124.0.0/1670.124.0.1 to 70.124.255.25470.124.255.25565,534
12670.125.0.0/1670.125.0.1 to 70.125.255.25470.125.255.25565,534
12770.126.0.0/1670.126.0.1 to 70.126.255.25470.126.255.25565,534
12870.127.0.0/1670.127.0.1 to 70.127.255.25470.127.255.25565,534
12970.128.0.0/1670.128.0.1 to 70.128.255.25470.128.255.25565,534
13070.129.0.0/1670.129.0.1 to 70.129.255.25470.129.255.25565,534
13170.130.0.0/1670.130.0.1 to 70.130.255.25470.130.255.25565,534
13270.131.0.0/1670.131.0.1 to 70.131.255.25470.131.255.25565,534
13370.132.0.0/1670.132.0.1 to 70.132.255.25470.132.255.25565,534
13470.133.0.0/1670.133.0.1 to 70.133.255.25470.133.255.25565,534
13570.134.0.0/1670.134.0.1 to 70.134.255.25470.134.255.25565,534
13670.135.0.0/1670.135.0.1 to 70.135.255.25470.135.255.25565,534
13770.136.0.0/1670.136.0.1 to 70.136.255.25470.136.255.25565,534
13870.137.0.0/1670.137.0.1 to 70.137.255.25470.137.255.25565,534
13970.138.0.0/1670.138.0.1 to 70.138.255.25470.138.255.25565,534
14070.139.0.0/1670.139.0.1 to 70.139.255.25470.139.255.25565,534
14170.140.0.0/1670.140.0.1 to 70.140.255.25470.140.255.25565,534
14270.141.0.0/1670.141.0.1 to 70.141.255.25470.141.255.25565,534
14370.142.0.0/1670.142.0.1 to 70.142.255.25470.142.255.25565,534
14470.143.0.0/1670.143.0.1 to 70.143.255.25470.143.255.25565,534
14570.144.0.0/1670.144.0.1 to 70.144.255.25470.144.255.25565,534
14670.145.0.0/1670.145.0.1 to 70.145.255.25470.145.255.25565,534
14770.146.0.0/1670.146.0.1 to 70.146.255.25470.146.255.25565,534
14870.147.0.0/1670.147.0.1 to 70.147.255.25470.147.255.25565,534
14970.148.0.0/1670.148.0.1 to 70.148.255.25470.148.255.25565,534
15070.149.0.0/1670.149.0.1 to 70.149.255.25470.149.255.25565,534
15170.150.0.0/1670.150.0.1 to 70.150.255.25470.150.255.25565,534
15270.151.0.0/1670.151.0.1 to 70.151.255.25470.151.255.25565,534
15370.152.0.0/1670.152.0.1 to 70.152.255.25470.152.255.25565,534
15470.153.0.0/1670.153.0.1 to 70.153.255.25470.153.255.25565,534
15570.154.0.0/1670.154.0.1 to 70.154.255.25470.154.255.25565,534
15670.155.0.0/1670.155.0.1 to 70.155.255.25470.155.255.25565,534
15770.156.0.0/1670.156.0.1 to 70.156.255.25470.156.255.25565,534
15870.157.0.0/1670.157.0.1 to 70.157.255.25470.157.255.25565,534
15970.158.0.0/1670.158.0.1 to 70.158.255.25470.158.255.25565,534
16070.159.0.0/1670.159.0.1 to 70.159.255.25470.159.255.25565,534
16170.160.0.0/1670.160.0.1 to 70.160.255.25470.160.255.25565,534
16270.161.0.0/1670.161.0.1 to 70.161.255.25470.161.255.25565,534
16370.162.0.0/1670.162.0.1 to 70.162.255.25470.162.255.25565,534
16470.163.0.0/1670.163.0.1 to 70.163.255.25470.163.255.25565,534
16570.164.0.0/1670.164.0.1 to 70.164.255.25470.164.255.25565,534
16670.165.0.0/1670.165.0.1 to 70.165.255.25470.165.255.25565,534
16770.166.0.0/1670.166.0.1 to 70.166.255.25470.166.255.25565,534
16870.167.0.0/1670.167.0.1 to 70.167.255.25470.167.255.25565,534
16970.168.0.0/1670.168.0.1 to 70.168.255.25470.168.255.25565,534
17070.169.0.0/1670.169.0.1 to 70.169.255.25470.169.255.25565,534
17170.170.0.0/1670.170.0.1 to 70.170.255.25470.170.255.25565,534
17270.171.0.0/1670.171.0.1 to 70.171.255.25470.171.255.25565,534
17370.172.0.0/1670.172.0.1 to 70.172.255.25470.172.255.25565,534
17470.173.0.0/1670.173.0.1 to 70.173.255.25470.173.255.25565,534
17570.174.0.0/1670.174.0.1 to 70.174.255.25470.174.255.25565,534
17670.175.0.0/1670.175.0.1 to 70.175.255.25470.175.255.25565,534
17770.176.0.0/1670.176.0.1 to 70.176.255.25470.176.255.25565,534
17870.177.0.0/1670.177.0.1 to 70.177.255.25470.177.255.25565,534
17970.178.0.0/1670.178.0.1 to 70.178.255.25470.178.255.25565,534
18070.179.0.0/1670.179.0.1 to 70.179.255.25470.179.255.25565,534
18170.180.0.0/1670.180.0.1 to 70.180.255.25470.180.255.25565,534
18270.181.0.0/1670.181.0.1 to 70.181.255.25470.181.255.25565,534
18370.182.0.0/1670.182.0.1 to 70.182.255.25470.182.255.25565,534
18470.183.0.0/1670.183.0.1 to 70.183.255.25470.183.255.25565,534
18570.184.0.0/1670.184.0.1 to 70.184.255.25470.184.255.25565,534
18670.185.0.0/1670.185.0.1 to 70.185.255.25470.185.255.25565,534
18770.186.0.0/1670.186.0.1 to 70.186.255.25470.186.255.25565,534
18870.187.0.0/1670.187.0.1 to 70.187.255.25470.187.255.25565,534
18970.188.0.0/1670.188.0.1 to 70.188.255.25470.188.255.25565,534
19070.189.0.0/1670.189.0.1 to 70.189.255.25470.189.255.25565,534
19170.190.0.0/1670.190.0.1 to 70.190.255.25470.190.255.25565,534
19270.191.0.0/1670.191.0.1 to 70.191.255.25470.191.255.25565,534
19370.192.0.0/1670.192.0.1 to 70.192.255.25470.192.255.25565,534
19470.193.0.0/1670.193.0.1 to 70.193.255.25470.193.255.25565,534
19570.194.0.0/1670.194.0.1 to 70.194.255.25470.194.255.25565,534
19670.195.0.0/1670.195.0.1 to 70.195.255.25470.195.255.25565,534
19770.196.0.0/1670.196.0.1 to 70.196.255.25470.196.255.25565,534
19870.197.0.0/1670.197.0.1 to 70.197.255.25470.197.255.25565,534
19970.198.0.0/1670.198.0.1 to 70.198.255.25470.198.255.25565,534
20070.199.0.0/1670.199.0.1 to 70.199.255.25470.199.255.25565,534
20170.200.0.0/1670.200.0.1 to 70.200.255.25470.200.255.25565,534
20270.201.0.0/1670.201.0.1 to 70.201.255.25470.201.255.25565,534
20370.202.0.0/1670.202.0.1 to 70.202.255.25470.202.255.25565,534
20470.203.0.0/1670.203.0.1 to 70.203.255.25470.203.255.25565,534
20570.204.0.0/1670.204.0.1 to 70.204.255.25470.204.255.25565,534
20670.205.0.0/1670.205.0.1 to 70.205.255.25470.205.255.25565,534
20770.206.0.0/1670.206.0.1 to 70.206.255.25470.206.255.25565,534
20870.207.0.0/1670.207.0.1 to 70.207.255.25470.207.255.25565,534
20970.208.0.0/1670.208.0.1 to 70.208.255.25470.208.255.25565,534
21070.209.0.0/1670.209.0.1 to 70.209.255.25470.209.255.25565,534
21170.210.0.0/1670.210.0.1 to 70.210.255.25470.210.255.25565,534
21270.211.0.0/1670.211.0.1 to 70.211.255.25470.211.255.25565,534
21370.212.0.0/1670.212.0.1 to 70.212.255.25470.212.255.25565,534
21470.213.0.0/1670.213.0.1 to 70.213.255.25470.213.255.25565,534
21570.214.0.0/1670.214.0.1 to 70.214.255.25470.214.255.25565,534
21670.215.0.0/1670.215.0.1 to 70.215.255.25470.215.255.25565,534
21770.216.0.0/1670.216.0.1 to 70.216.255.25470.216.255.25565,534
21870.217.0.0/1670.217.0.1 to 70.217.255.25470.217.255.25565,534
21970.218.0.0/1670.218.0.1 to 70.218.255.25470.218.255.25565,534
22070.219.0.0/1670.219.0.1 to 70.219.255.25470.219.255.25565,534
22170.220.0.0/1670.220.0.1 to 70.220.255.25470.220.255.25565,534
22270.221.0.0/1670.221.0.1 to 70.221.255.25470.221.255.25565,534
22370.222.0.0/1670.222.0.1 to 70.222.255.25470.222.255.25565,534
22470.223.0.0/1670.223.0.1 to 70.223.255.25470.223.255.25565,534
22570.224.0.0/1670.224.0.1 to 70.224.255.25470.224.255.25565,534
22670.225.0.0/1670.225.0.1 to 70.225.255.25470.225.255.25565,534
22770.226.0.0/1670.226.0.1 to 70.226.255.25470.226.255.25565,534
22870.227.0.0/1670.227.0.1 to 70.227.255.25470.227.255.25565,534
22970.228.0.0/1670.228.0.1 to 70.228.255.25470.228.255.25565,534
23070.229.0.0/1670.229.0.1 to 70.229.255.25470.229.255.25565,534
23170.230.0.0/1670.230.0.1 to 70.230.255.25470.230.255.25565,534
23270.231.0.0/1670.231.0.1 to 70.231.255.25470.231.255.25565,534
23370.232.0.0/1670.232.0.1 to 70.232.255.25470.232.255.25565,534
23470.233.0.0/1670.233.0.1 to 70.233.255.25470.233.255.25565,534
23570.234.0.0/1670.234.0.1 to 70.234.255.25470.234.255.25565,534
23670.235.0.0/1670.235.0.1 to 70.235.255.25470.235.255.25565,534
23770.236.0.0/1670.236.0.1 to 70.236.255.25470.236.255.25565,534
23870.237.0.0/1670.237.0.1 to 70.237.255.25470.237.255.25565,534
23970.238.0.0/1670.238.0.1 to 70.238.255.25470.238.255.25565,534
24070.239.0.0/1670.239.0.1 to 70.239.255.25470.239.255.25565,534
24170.240.0.0/1670.240.0.1 to 70.240.255.25470.240.255.25565,534
24270.241.0.0/1670.241.0.1 to 70.241.255.25470.241.255.25565,534
24370.242.0.0/1670.242.0.1 to 70.242.255.25470.242.255.25565,534
24470.243.0.0/1670.243.0.1 to 70.243.255.25470.243.255.25565,534
24570.244.0.0/1670.244.0.1 to 70.244.255.25470.244.255.25565,534
24670.245.0.0/1670.245.0.1 to 70.245.255.25470.245.255.25565,534
24770.246.0.0/1670.246.0.1 to 70.246.255.25470.246.255.25565,534
24870.247.0.0/1670.247.0.1 to 70.247.255.25470.247.255.25565,534
24970.248.0.0/1670.248.0.1 to 70.248.255.25470.248.255.25565,534
25070.249.0.0/1670.249.0.1 to 70.249.255.25470.249.255.25565,534
25170.250.0.0/1670.250.0.1 to 70.250.255.25470.250.255.25565,534
25270.251.0.0/1670.251.0.1 to 70.251.255.25470.251.255.25565,534
25370.252.0.0/1670.252.0.1 to 70.252.255.25470.252.255.25565,534
25470.253.0.0/1670.253.0.1 to 70.253.255.25470.253.255.25565,534
25570.254.0.0/1670.254.0.1 to 70.254.255.25470.254.255.25565,534
25670.255.0.0/1670.255.0.1 to 70.255.255.25470.255.255.25565,534

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.