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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.

Network66.167.176.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
66.167.176.0
Broadcast address
66.167.179.255
First usable
66.167.176.1
Last usable
66.167.179.254
Usable hosts
1,022 (1,024 less the network and broadcast addresses)
Subnet mask
255.255.252.0
Wildcard mask
0.0.3.255 (Cisco ACLs, OSPF)
Prefix length
/22
Type
Public public
Old class
A (default /8)
As numbers
Hex 42A7B000 · Integer 1118285824 to 1118286847
Reverse DNS zones
176.167.66.in-addr.arpa
177.167.66.in-addr.arpa
178.167.66.in-addr.arpa
179.167.66.in-addr.arpa
/22 is not on a 8-bit boundary, so it takes 4 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01000010.10100111.10110000.0000000066.167.176.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network01000010.10100111.10110000.0000000066.167.176.0
Broadcast01000010.10100111.10110011.1111111166.167.179.255
Split into smaller subnets/30
/23 (2)/24 (4)/25 (8)/26 (16)/27 (32)/28 (64)/29 (128)/30 (256)/31 (512)/32 (1,024)

66.167.176.0/22 makes 256 subnets of /30.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
166.167.176.0/3066.167.176.1 to 66.167.176.266.167.176.32
266.167.176.4/3066.167.176.5 to 66.167.176.666.167.176.72
366.167.176.8/3066.167.176.9 to 66.167.176.1066.167.176.112
466.167.176.12/3066.167.176.13 to 66.167.176.1466.167.176.152
566.167.176.16/3066.167.176.17 to 66.167.176.1866.167.176.192
666.167.176.20/3066.167.176.21 to 66.167.176.2266.167.176.232
766.167.176.24/3066.167.176.25 to 66.167.176.2666.167.176.272
866.167.176.28/3066.167.176.29 to 66.167.176.3066.167.176.312
966.167.176.32/3066.167.176.33 to 66.167.176.3466.167.176.352
1066.167.176.36/3066.167.176.37 to 66.167.176.3866.167.176.392
1166.167.176.40/3066.167.176.41 to 66.167.176.4266.167.176.432
1266.167.176.44/3066.167.176.45 to 66.167.176.4666.167.176.472
1366.167.176.48/3066.167.176.49 to 66.167.176.5066.167.176.512
1466.167.176.52/3066.167.176.53 to 66.167.176.5466.167.176.552
1566.167.176.56/3066.167.176.57 to 66.167.176.5866.167.176.592
1666.167.176.60/3066.167.176.61 to 66.167.176.6266.167.176.632
1766.167.176.64/3066.167.176.65 to 66.167.176.6666.167.176.672
1866.167.176.68/3066.167.176.69 to 66.167.176.7066.167.176.712
1966.167.176.72/3066.167.176.73 to 66.167.176.7466.167.176.752
2066.167.176.76/3066.167.176.77 to 66.167.176.7866.167.176.792
2166.167.176.80/3066.167.176.81 to 66.167.176.8266.167.176.832
2266.167.176.84/3066.167.176.85 to 66.167.176.8666.167.176.872
2366.167.176.88/3066.167.176.89 to 66.167.176.9066.167.176.912
2466.167.176.92/3066.167.176.93 to 66.167.176.9466.167.176.952
2566.167.176.96/3066.167.176.97 to 66.167.176.9866.167.176.992
2666.167.176.100/3066.167.176.101 to 66.167.176.10266.167.176.1032
2766.167.176.104/3066.167.176.105 to 66.167.176.10666.167.176.1072
2866.167.176.108/3066.167.176.109 to 66.167.176.11066.167.176.1112
2966.167.176.112/3066.167.176.113 to 66.167.176.11466.167.176.1152
3066.167.176.116/3066.167.176.117 to 66.167.176.11866.167.176.1192
3166.167.176.120/3066.167.176.121 to 66.167.176.12266.167.176.1232
3266.167.176.124/3066.167.176.125 to 66.167.176.12666.167.176.1272
3366.167.176.128/3066.167.176.129 to 66.167.176.13066.167.176.1312
3466.167.176.132/3066.167.176.133 to 66.167.176.13466.167.176.1352
3566.167.176.136/3066.167.176.137 to 66.167.176.13866.167.176.1392
3666.167.176.140/3066.167.176.141 to 66.167.176.14266.167.176.1432
3766.167.176.144/3066.167.176.145 to 66.167.176.14666.167.176.1472
3866.167.176.148/3066.167.176.149 to 66.167.176.15066.167.176.1512
3966.167.176.152/3066.167.176.153 to 66.167.176.15466.167.176.1552
4066.167.176.156/3066.167.176.157 to 66.167.176.15866.167.176.1592
4166.167.176.160/3066.167.176.161 to 66.167.176.16266.167.176.1632
4266.167.176.164/3066.167.176.165 to 66.167.176.16666.167.176.1672
4366.167.176.168/3066.167.176.169 to 66.167.176.17066.167.176.1712
4466.167.176.172/3066.167.176.173 to 66.167.176.17466.167.176.1752
4566.167.176.176/3066.167.176.177 to 66.167.176.17866.167.176.1792
4666.167.176.180/3066.167.176.181 to 66.167.176.18266.167.176.1832
4766.167.176.184/3066.167.176.185 to 66.167.176.18666.167.176.1872
4866.167.176.188/3066.167.176.189 to 66.167.176.19066.167.176.1912
4966.167.176.192/3066.167.176.193 to 66.167.176.19466.167.176.1952
5066.167.176.196/3066.167.176.197 to 66.167.176.19866.167.176.1992
5166.167.176.200/3066.167.176.201 to 66.167.176.20266.167.176.2032
5266.167.176.204/3066.167.176.205 to 66.167.176.20666.167.176.2072
5366.167.176.208/3066.167.176.209 to 66.167.176.21066.167.176.2112
5466.167.176.212/3066.167.176.213 to 66.167.176.21466.167.176.2152
5566.167.176.216/3066.167.176.217 to 66.167.176.21866.167.176.2192
5666.167.176.220/3066.167.176.221 to 66.167.176.22266.167.176.2232
5766.167.176.224/3066.167.176.225 to 66.167.176.22666.167.176.2272
5866.167.176.228/3066.167.176.229 to 66.167.176.23066.167.176.2312
5966.167.176.232/3066.167.176.233 to 66.167.176.23466.167.176.2352
6066.167.176.236/3066.167.176.237 to 66.167.176.23866.167.176.2392
6166.167.176.240/3066.167.176.241 to 66.167.176.24266.167.176.2432
6266.167.176.244/3066.167.176.245 to 66.167.176.24666.167.176.2472
6366.167.176.248/3066.167.176.249 to 66.167.176.25066.167.176.2512
6466.167.176.252/3066.167.176.253 to 66.167.176.25466.167.176.2552
6566.167.177.0/3066.167.177.1 to 66.167.177.266.167.177.32
6666.167.177.4/3066.167.177.5 to 66.167.177.666.167.177.72
6766.167.177.8/3066.167.177.9 to 66.167.177.1066.167.177.112
6866.167.177.12/3066.167.177.13 to 66.167.177.1466.167.177.152
6966.167.177.16/3066.167.177.17 to 66.167.177.1866.167.177.192
7066.167.177.20/3066.167.177.21 to 66.167.177.2266.167.177.232
7166.167.177.24/3066.167.177.25 to 66.167.177.2666.167.177.272
7266.167.177.28/3066.167.177.29 to 66.167.177.3066.167.177.312
7366.167.177.32/3066.167.177.33 to 66.167.177.3466.167.177.352
7466.167.177.36/3066.167.177.37 to 66.167.177.3866.167.177.392
7566.167.177.40/3066.167.177.41 to 66.167.177.4266.167.177.432
7666.167.177.44/3066.167.177.45 to 66.167.177.4666.167.177.472
7766.167.177.48/3066.167.177.49 to 66.167.177.5066.167.177.512
7866.167.177.52/3066.167.177.53 to 66.167.177.5466.167.177.552
7966.167.177.56/3066.167.177.57 to 66.167.177.5866.167.177.592
8066.167.177.60/3066.167.177.61 to 66.167.177.6266.167.177.632
8166.167.177.64/3066.167.177.65 to 66.167.177.6666.167.177.672
8266.167.177.68/3066.167.177.69 to 66.167.177.7066.167.177.712
8366.167.177.72/3066.167.177.73 to 66.167.177.7466.167.177.752
8466.167.177.76/3066.167.177.77 to 66.167.177.7866.167.177.792
8566.167.177.80/3066.167.177.81 to 66.167.177.8266.167.177.832
8666.167.177.84/3066.167.177.85 to 66.167.177.8666.167.177.872
8766.167.177.88/3066.167.177.89 to 66.167.177.9066.167.177.912
8866.167.177.92/3066.167.177.93 to 66.167.177.9466.167.177.952
8966.167.177.96/3066.167.177.97 to 66.167.177.9866.167.177.992
9066.167.177.100/3066.167.177.101 to 66.167.177.10266.167.177.1032
9166.167.177.104/3066.167.177.105 to 66.167.177.10666.167.177.1072
9266.167.177.108/3066.167.177.109 to 66.167.177.11066.167.177.1112
9366.167.177.112/3066.167.177.113 to 66.167.177.11466.167.177.1152
9466.167.177.116/3066.167.177.117 to 66.167.177.11866.167.177.1192
9566.167.177.120/3066.167.177.121 to 66.167.177.12266.167.177.1232
9666.167.177.124/3066.167.177.125 to 66.167.177.12666.167.177.1272
9766.167.177.128/3066.167.177.129 to 66.167.177.13066.167.177.1312
9866.167.177.132/3066.167.177.133 to 66.167.177.13466.167.177.1352
9966.167.177.136/3066.167.177.137 to 66.167.177.13866.167.177.1392
10066.167.177.140/3066.167.177.141 to 66.167.177.14266.167.177.1432
10166.167.177.144/3066.167.177.145 to 66.167.177.14666.167.177.1472
10266.167.177.148/3066.167.177.149 to 66.167.177.15066.167.177.1512
10366.167.177.152/3066.167.177.153 to 66.167.177.15466.167.177.1552
10466.167.177.156/3066.167.177.157 to 66.167.177.15866.167.177.1592
10566.167.177.160/3066.167.177.161 to 66.167.177.16266.167.177.1632
10666.167.177.164/3066.167.177.165 to 66.167.177.16666.167.177.1672
10766.167.177.168/3066.167.177.169 to 66.167.177.17066.167.177.1712
10866.167.177.172/3066.167.177.173 to 66.167.177.17466.167.177.1752
10966.167.177.176/3066.167.177.177 to 66.167.177.17866.167.177.1792
11066.167.177.180/3066.167.177.181 to 66.167.177.18266.167.177.1832
11166.167.177.184/3066.167.177.185 to 66.167.177.18666.167.177.1872
11266.167.177.188/3066.167.177.189 to 66.167.177.19066.167.177.1912
11366.167.177.192/3066.167.177.193 to 66.167.177.19466.167.177.1952
11466.167.177.196/3066.167.177.197 to 66.167.177.19866.167.177.1992
11566.167.177.200/3066.167.177.201 to 66.167.177.20266.167.177.2032
11666.167.177.204/3066.167.177.205 to 66.167.177.20666.167.177.2072
11766.167.177.208/3066.167.177.209 to 66.167.177.21066.167.177.2112
11866.167.177.212/3066.167.177.213 to 66.167.177.21466.167.177.2152
11966.167.177.216/3066.167.177.217 to 66.167.177.21866.167.177.2192
12066.167.177.220/3066.167.177.221 to 66.167.177.22266.167.177.2232
12166.167.177.224/3066.167.177.225 to 66.167.177.22666.167.177.2272
12266.167.177.228/3066.167.177.229 to 66.167.177.23066.167.177.2312
12366.167.177.232/3066.167.177.233 to 66.167.177.23466.167.177.2352
12466.167.177.236/3066.167.177.237 to 66.167.177.23866.167.177.2392
12566.167.177.240/3066.167.177.241 to 66.167.177.24266.167.177.2432
12666.167.177.244/3066.167.177.245 to 66.167.177.24666.167.177.2472
12766.167.177.248/3066.167.177.249 to 66.167.177.25066.167.177.2512
12866.167.177.252/3066.167.177.253 to 66.167.177.25466.167.177.2552
12966.167.178.0/3066.167.178.1 to 66.167.178.266.167.178.32
13066.167.178.4/3066.167.178.5 to 66.167.178.666.167.178.72
13166.167.178.8/3066.167.178.9 to 66.167.178.1066.167.178.112
13266.167.178.12/3066.167.178.13 to 66.167.178.1466.167.178.152
13366.167.178.16/3066.167.178.17 to 66.167.178.1866.167.178.192
13466.167.178.20/3066.167.178.21 to 66.167.178.2266.167.178.232
13566.167.178.24/3066.167.178.25 to 66.167.178.2666.167.178.272
13666.167.178.28/3066.167.178.29 to 66.167.178.3066.167.178.312
13766.167.178.32/3066.167.178.33 to 66.167.178.3466.167.178.352
13866.167.178.36/3066.167.178.37 to 66.167.178.3866.167.178.392
13966.167.178.40/3066.167.178.41 to 66.167.178.4266.167.178.432
14066.167.178.44/3066.167.178.45 to 66.167.178.4666.167.178.472
14166.167.178.48/3066.167.178.49 to 66.167.178.5066.167.178.512
14266.167.178.52/3066.167.178.53 to 66.167.178.5466.167.178.552
14366.167.178.56/3066.167.178.57 to 66.167.178.5866.167.178.592
14466.167.178.60/3066.167.178.61 to 66.167.178.6266.167.178.632
14566.167.178.64/3066.167.178.65 to 66.167.178.6666.167.178.672
14666.167.178.68/3066.167.178.69 to 66.167.178.7066.167.178.712
14766.167.178.72/3066.167.178.73 to 66.167.178.7466.167.178.752
14866.167.178.76/3066.167.178.77 to 66.167.178.7866.167.178.792
14966.167.178.80/3066.167.178.81 to 66.167.178.8266.167.178.832
15066.167.178.84/3066.167.178.85 to 66.167.178.8666.167.178.872
15166.167.178.88/3066.167.178.89 to 66.167.178.9066.167.178.912
15266.167.178.92/3066.167.178.93 to 66.167.178.9466.167.178.952
15366.167.178.96/3066.167.178.97 to 66.167.178.9866.167.178.992
15466.167.178.100/3066.167.178.101 to 66.167.178.10266.167.178.1032
15566.167.178.104/3066.167.178.105 to 66.167.178.10666.167.178.1072
15666.167.178.108/3066.167.178.109 to 66.167.178.11066.167.178.1112
15766.167.178.112/3066.167.178.113 to 66.167.178.11466.167.178.1152
15866.167.178.116/3066.167.178.117 to 66.167.178.11866.167.178.1192
15966.167.178.120/3066.167.178.121 to 66.167.178.12266.167.178.1232
16066.167.178.124/3066.167.178.125 to 66.167.178.12666.167.178.1272
16166.167.178.128/3066.167.178.129 to 66.167.178.13066.167.178.1312
16266.167.178.132/3066.167.178.133 to 66.167.178.13466.167.178.1352
16366.167.178.136/3066.167.178.137 to 66.167.178.13866.167.178.1392
16466.167.178.140/3066.167.178.141 to 66.167.178.14266.167.178.1432
16566.167.178.144/3066.167.178.145 to 66.167.178.14666.167.178.1472
16666.167.178.148/3066.167.178.149 to 66.167.178.15066.167.178.1512
16766.167.178.152/3066.167.178.153 to 66.167.178.15466.167.178.1552
16866.167.178.156/3066.167.178.157 to 66.167.178.15866.167.178.1592
16966.167.178.160/3066.167.178.161 to 66.167.178.16266.167.178.1632
17066.167.178.164/3066.167.178.165 to 66.167.178.16666.167.178.1672
17166.167.178.168/3066.167.178.169 to 66.167.178.17066.167.178.1712
17266.167.178.172/3066.167.178.173 to 66.167.178.17466.167.178.1752
17366.167.178.176/3066.167.178.177 to 66.167.178.17866.167.178.1792
17466.167.178.180/3066.167.178.181 to 66.167.178.18266.167.178.1832
17566.167.178.184/3066.167.178.185 to 66.167.178.18666.167.178.1872
17666.167.178.188/3066.167.178.189 to 66.167.178.19066.167.178.1912
17766.167.178.192/3066.167.178.193 to 66.167.178.19466.167.178.1952
17866.167.178.196/3066.167.178.197 to 66.167.178.19866.167.178.1992
17966.167.178.200/3066.167.178.201 to 66.167.178.20266.167.178.2032
18066.167.178.204/3066.167.178.205 to 66.167.178.20666.167.178.2072
18166.167.178.208/3066.167.178.209 to 66.167.178.21066.167.178.2112
18266.167.178.212/3066.167.178.213 to 66.167.178.21466.167.178.2152
18366.167.178.216/3066.167.178.217 to 66.167.178.21866.167.178.2192
18466.167.178.220/3066.167.178.221 to 66.167.178.22266.167.178.2232
18566.167.178.224/3066.167.178.225 to 66.167.178.22666.167.178.2272
18666.167.178.228/3066.167.178.229 to 66.167.178.23066.167.178.2312
18766.167.178.232/3066.167.178.233 to 66.167.178.23466.167.178.2352
18866.167.178.236/3066.167.178.237 to 66.167.178.23866.167.178.2392
18966.167.178.240/3066.167.178.241 to 66.167.178.24266.167.178.2432
19066.167.178.244/3066.167.178.245 to 66.167.178.24666.167.178.2472
19166.167.178.248/3066.167.178.249 to 66.167.178.25066.167.178.2512
19266.167.178.252/3066.167.178.253 to 66.167.178.25466.167.178.2552
19366.167.179.0/3066.167.179.1 to 66.167.179.266.167.179.32
19466.167.179.4/3066.167.179.5 to 66.167.179.666.167.179.72
19566.167.179.8/3066.167.179.9 to 66.167.179.1066.167.179.112
19666.167.179.12/3066.167.179.13 to 66.167.179.1466.167.179.152
19766.167.179.16/3066.167.179.17 to 66.167.179.1866.167.179.192
19866.167.179.20/3066.167.179.21 to 66.167.179.2266.167.179.232
19966.167.179.24/3066.167.179.25 to 66.167.179.2666.167.179.272
20066.167.179.28/3066.167.179.29 to 66.167.179.3066.167.179.312
20166.167.179.32/3066.167.179.33 to 66.167.179.3466.167.179.352
20266.167.179.36/3066.167.179.37 to 66.167.179.3866.167.179.392
20366.167.179.40/3066.167.179.41 to 66.167.179.4266.167.179.432
20466.167.179.44/3066.167.179.45 to 66.167.179.4666.167.179.472
20566.167.179.48/3066.167.179.49 to 66.167.179.5066.167.179.512
20666.167.179.52/3066.167.179.53 to 66.167.179.5466.167.179.552
20766.167.179.56/3066.167.179.57 to 66.167.179.5866.167.179.592
20866.167.179.60/3066.167.179.61 to 66.167.179.6266.167.179.632
20966.167.179.64/3066.167.179.65 to 66.167.179.6666.167.179.672
21066.167.179.68/3066.167.179.69 to 66.167.179.7066.167.179.712
21166.167.179.72/3066.167.179.73 to 66.167.179.7466.167.179.752
21266.167.179.76/3066.167.179.77 to 66.167.179.7866.167.179.792
21366.167.179.80/3066.167.179.81 to 66.167.179.8266.167.179.832
21466.167.179.84/3066.167.179.85 to 66.167.179.8666.167.179.872
21566.167.179.88/3066.167.179.89 to 66.167.179.9066.167.179.912
21666.167.179.92/3066.167.179.93 to 66.167.179.9466.167.179.952
21766.167.179.96/3066.167.179.97 to 66.167.179.9866.167.179.992
21866.167.179.100/3066.167.179.101 to 66.167.179.10266.167.179.1032
21966.167.179.104/3066.167.179.105 to 66.167.179.10666.167.179.1072
22066.167.179.108/3066.167.179.109 to 66.167.179.11066.167.179.1112
22166.167.179.112/3066.167.179.113 to 66.167.179.11466.167.179.1152
22266.167.179.116/3066.167.179.117 to 66.167.179.11866.167.179.1192
22366.167.179.120/3066.167.179.121 to 66.167.179.12266.167.179.1232
22466.167.179.124/3066.167.179.125 to 66.167.179.12666.167.179.1272
22566.167.179.128/3066.167.179.129 to 66.167.179.13066.167.179.1312
22666.167.179.132/3066.167.179.133 to 66.167.179.13466.167.179.1352
22766.167.179.136/3066.167.179.137 to 66.167.179.13866.167.179.1392
22866.167.179.140/3066.167.179.141 to 66.167.179.14266.167.179.1432
22966.167.179.144/3066.167.179.145 to 66.167.179.14666.167.179.1472
23066.167.179.148/3066.167.179.149 to 66.167.179.15066.167.179.1512
23166.167.179.152/3066.167.179.153 to 66.167.179.15466.167.179.1552
23266.167.179.156/3066.167.179.157 to 66.167.179.15866.167.179.1592
23366.167.179.160/3066.167.179.161 to 66.167.179.16266.167.179.1632
23466.167.179.164/3066.167.179.165 to 66.167.179.16666.167.179.1672
23566.167.179.168/3066.167.179.169 to 66.167.179.17066.167.179.1712
23666.167.179.172/3066.167.179.173 to 66.167.179.17466.167.179.1752
23766.167.179.176/3066.167.179.177 to 66.167.179.17866.167.179.1792
23866.167.179.180/3066.167.179.181 to 66.167.179.18266.167.179.1832
23966.167.179.184/3066.167.179.185 to 66.167.179.18666.167.179.1872
24066.167.179.188/3066.167.179.189 to 66.167.179.19066.167.179.1912
24166.167.179.192/3066.167.179.193 to 66.167.179.19466.167.179.1952
24266.167.179.196/3066.167.179.197 to 66.167.179.19866.167.179.1992
24366.167.179.200/3066.167.179.201 to 66.167.179.20266.167.179.2032
24466.167.179.204/3066.167.179.205 to 66.167.179.20666.167.179.2072
24566.167.179.208/3066.167.179.209 to 66.167.179.21066.167.179.2112
24666.167.179.212/3066.167.179.213 to 66.167.179.21466.167.179.2152
24766.167.179.216/3066.167.179.217 to 66.167.179.21866.167.179.2192
24866.167.179.220/3066.167.179.221 to 66.167.179.22266.167.179.2232
24966.167.179.224/3066.167.179.225 to 66.167.179.22666.167.179.2272
25066.167.179.228/3066.167.179.229 to 66.167.179.23066.167.179.2312
25166.167.179.232/3066.167.179.233 to 66.167.179.23466.167.179.2352
25266.167.179.236/3066.167.179.237 to 66.167.179.23866.167.179.2392
25366.167.179.240/3066.167.179.241 to 66.167.179.24266.167.179.2432
25466.167.179.244/3066.167.179.245 to 66.167.179.24666.167.179.2472
25566.167.179.248/3066.167.179.249 to 66.167.179.25066.167.179.2512
25666.167.179.252/3066.167.179.253 to 66.167.179.25466.167.179.2552

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.