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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.

Network96.3.192.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
96.3.192.0
Broadcast address
96.3.255.255
First usable
96.3.192.1
Last usable
96.3.255.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Public public
Old class
A (default /8)
As numbers
Hex 6003C000 · Integer 1610858496 to 1610874879
Reverse DNS zones
192.3.96.in-addr.arpa
193.3.96.in-addr.arpa
194.3.96.in-addr.arpa
195.3.96.in-addr.arpa
196.3.96.in-addr.arpa
197.3.96.in-addr.arpa
198.3.96.in-addr.arpa
199.3.96.in-addr.arpa
200.3.96.in-addr.arpa
201.3.96.in-addr.arpa
202.3.96.in-addr.arpa
203.3.96.in-addr.arpa
204.3.96.in-addr.arpa
205.3.96.in-addr.arpa
206.3.96.in-addr.arpa
207.3.96.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01100000.00000011.11000000.0000000096.3.192.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network01100000.00000011.11000000.0000000096.3.192.0
Broadcast01100000.00000011.11111111.1111111196.3.255.255
Split into smaller subnets/30
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

96.3.192.0/18 makes 4,096 subnets of /30; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
196.3.192.0/3096.3.192.1 to 96.3.192.296.3.192.32
296.3.192.4/3096.3.192.5 to 96.3.192.696.3.192.72
396.3.192.8/3096.3.192.9 to 96.3.192.1096.3.192.112
496.3.192.12/3096.3.192.13 to 96.3.192.1496.3.192.152
596.3.192.16/3096.3.192.17 to 96.3.192.1896.3.192.192
696.3.192.20/3096.3.192.21 to 96.3.192.2296.3.192.232
796.3.192.24/3096.3.192.25 to 96.3.192.2696.3.192.272
896.3.192.28/3096.3.192.29 to 96.3.192.3096.3.192.312
996.3.192.32/3096.3.192.33 to 96.3.192.3496.3.192.352
1096.3.192.36/3096.3.192.37 to 96.3.192.3896.3.192.392
1196.3.192.40/3096.3.192.41 to 96.3.192.4296.3.192.432
1296.3.192.44/3096.3.192.45 to 96.3.192.4696.3.192.472
1396.3.192.48/3096.3.192.49 to 96.3.192.5096.3.192.512
1496.3.192.52/3096.3.192.53 to 96.3.192.5496.3.192.552
1596.3.192.56/3096.3.192.57 to 96.3.192.5896.3.192.592
1696.3.192.60/3096.3.192.61 to 96.3.192.6296.3.192.632
1796.3.192.64/3096.3.192.65 to 96.3.192.6696.3.192.672
1896.3.192.68/3096.3.192.69 to 96.3.192.7096.3.192.712
1996.3.192.72/3096.3.192.73 to 96.3.192.7496.3.192.752
2096.3.192.76/3096.3.192.77 to 96.3.192.7896.3.192.792
2196.3.192.80/3096.3.192.81 to 96.3.192.8296.3.192.832
2296.3.192.84/3096.3.192.85 to 96.3.192.8696.3.192.872
2396.3.192.88/3096.3.192.89 to 96.3.192.9096.3.192.912
2496.3.192.92/3096.3.192.93 to 96.3.192.9496.3.192.952
2596.3.192.96/3096.3.192.97 to 96.3.192.9896.3.192.992
2696.3.192.100/3096.3.192.101 to 96.3.192.10296.3.192.1032
2796.3.192.104/3096.3.192.105 to 96.3.192.10696.3.192.1072
2896.3.192.108/3096.3.192.109 to 96.3.192.11096.3.192.1112
2996.3.192.112/3096.3.192.113 to 96.3.192.11496.3.192.1152
3096.3.192.116/3096.3.192.117 to 96.3.192.11896.3.192.1192
3196.3.192.120/3096.3.192.121 to 96.3.192.12296.3.192.1232
3296.3.192.124/3096.3.192.125 to 96.3.192.12696.3.192.1272
3396.3.192.128/3096.3.192.129 to 96.3.192.13096.3.192.1312
3496.3.192.132/3096.3.192.133 to 96.3.192.13496.3.192.1352
3596.3.192.136/3096.3.192.137 to 96.3.192.13896.3.192.1392
3696.3.192.140/3096.3.192.141 to 96.3.192.14296.3.192.1432
3796.3.192.144/3096.3.192.145 to 96.3.192.14696.3.192.1472
3896.3.192.148/3096.3.192.149 to 96.3.192.15096.3.192.1512
3996.3.192.152/3096.3.192.153 to 96.3.192.15496.3.192.1552
4096.3.192.156/3096.3.192.157 to 96.3.192.15896.3.192.1592
4196.3.192.160/3096.3.192.161 to 96.3.192.16296.3.192.1632
4296.3.192.164/3096.3.192.165 to 96.3.192.16696.3.192.1672
4396.3.192.168/3096.3.192.169 to 96.3.192.17096.3.192.1712
4496.3.192.172/3096.3.192.173 to 96.3.192.17496.3.192.1752
4596.3.192.176/3096.3.192.177 to 96.3.192.17896.3.192.1792
4696.3.192.180/3096.3.192.181 to 96.3.192.18296.3.192.1832
4796.3.192.184/3096.3.192.185 to 96.3.192.18696.3.192.1872
4896.3.192.188/3096.3.192.189 to 96.3.192.19096.3.192.1912
4996.3.192.192/3096.3.192.193 to 96.3.192.19496.3.192.1952
5096.3.192.196/3096.3.192.197 to 96.3.192.19896.3.192.1992
5196.3.192.200/3096.3.192.201 to 96.3.192.20296.3.192.2032
5296.3.192.204/3096.3.192.205 to 96.3.192.20696.3.192.2072
5396.3.192.208/3096.3.192.209 to 96.3.192.21096.3.192.2112
5496.3.192.212/3096.3.192.213 to 96.3.192.21496.3.192.2152
5596.3.192.216/3096.3.192.217 to 96.3.192.21896.3.192.2192
5696.3.192.220/3096.3.192.221 to 96.3.192.22296.3.192.2232
5796.3.192.224/3096.3.192.225 to 96.3.192.22696.3.192.2272
5896.3.192.228/3096.3.192.229 to 96.3.192.23096.3.192.2312
5996.3.192.232/3096.3.192.233 to 96.3.192.23496.3.192.2352
6096.3.192.236/3096.3.192.237 to 96.3.192.23896.3.192.2392
6196.3.192.240/3096.3.192.241 to 96.3.192.24296.3.192.2432
6296.3.192.244/3096.3.192.245 to 96.3.192.24696.3.192.2472
6396.3.192.248/3096.3.192.249 to 96.3.192.25096.3.192.2512
6496.3.192.252/3096.3.192.253 to 96.3.192.25496.3.192.2552
6596.3.193.0/3096.3.193.1 to 96.3.193.296.3.193.32
6696.3.193.4/3096.3.193.5 to 96.3.193.696.3.193.72
6796.3.193.8/3096.3.193.9 to 96.3.193.1096.3.193.112
6896.3.193.12/3096.3.193.13 to 96.3.193.1496.3.193.152
6996.3.193.16/3096.3.193.17 to 96.3.193.1896.3.193.192
7096.3.193.20/3096.3.193.21 to 96.3.193.2296.3.193.232
7196.3.193.24/3096.3.193.25 to 96.3.193.2696.3.193.272
7296.3.193.28/3096.3.193.29 to 96.3.193.3096.3.193.312
7396.3.193.32/3096.3.193.33 to 96.3.193.3496.3.193.352
7496.3.193.36/3096.3.193.37 to 96.3.193.3896.3.193.392
7596.3.193.40/3096.3.193.41 to 96.3.193.4296.3.193.432
7696.3.193.44/3096.3.193.45 to 96.3.193.4696.3.193.472
7796.3.193.48/3096.3.193.49 to 96.3.193.5096.3.193.512
7896.3.193.52/3096.3.193.53 to 96.3.193.5496.3.193.552
7996.3.193.56/3096.3.193.57 to 96.3.193.5896.3.193.592
8096.3.193.60/3096.3.193.61 to 96.3.193.6296.3.193.632
8196.3.193.64/3096.3.193.65 to 96.3.193.6696.3.193.672
8296.3.193.68/3096.3.193.69 to 96.3.193.7096.3.193.712
8396.3.193.72/3096.3.193.73 to 96.3.193.7496.3.193.752
8496.3.193.76/3096.3.193.77 to 96.3.193.7896.3.193.792
8596.3.193.80/3096.3.193.81 to 96.3.193.8296.3.193.832
8696.3.193.84/3096.3.193.85 to 96.3.193.8696.3.193.872
8796.3.193.88/3096.3.193.89 to 96.3.193.9096.3.193.912
8896.3.193.92/3096.3.193.93 to 96.3.193.9496.3.193.952
8996.3.193.96/3096.3.193.97 to 96.3.193.9896.3.193.992
9096.3.193.100/3096.3.193.101 to 96.3.193.10296.3.193.1032
9196.3.193.104/3096.3.193.105 to 96.3.193.10696.3.193.1072
9296.3.193.108/3096.3.193.109 to 96.3.193.11096.3.193.1112
9396.3.193.112/3096.3.193.113 to 96.3.193.11496.3.193.1152
9496.3.193.116/3096.3.193.117 to 96.3.193.11896.3.193.1192
9596.3.193.120/3096.3.193.121 to 96.3.193.12296.3.193.1232
9696.3.193.124/3096.3.193.125 to 96.3.193.12696.3.193.1272
9796.3.193.128/3096.3.193.129 to 96.3.193.13096.3.193.1312
9896.3.193.132/3096.3.193.133 to 96.3.193.13496.3.193.1352
9996.3.193.136/3096.3.193.137 to 96.3.193.13896.3.193.1392
10096.3.193.140/3096.3.193.141 to 96.3.193.14296.3.193.1432
10196.3.193.144/3096.3.193.145 to 96.3.193.14696.3.193.1472
10296.3.193.148/3096.3.193.149 to 96.3.193.15096.3.193.1512
10396.3.193.152/3096.3.193.153 to 96.3.193.15496.3.193.1552
10496.3.193.156/3096.3.193.157 to 96.3.193.15896.3.193.1592
10596.3.193.160/3096.3.193.161 to 96.3.193.16296.3.193.1632
10696.3.193.164/3096.3.193.165 to 96.3.193.16696.3.193.1672
10796.3.193.168/3096.3.193.169 to 96.3.193.17096.3.193.1712
10896.3.193.172/3096.3.193.173 to 96.3.193.17496.3.193.1752
10996.3.193.176/3096.3.193.177 to 96.3.193.17896.3.193.1792
11096.3.193.180/3096.3.193.181 to 96.3.193.18296.3.193.1832
11196.3.193.184/3096.3.193.185 to 96.3.193.18696.3.193.1872
11296.3.193.188/3096.3.193.189 to 96.3.193.19096.3.193.1912
11396.3.193.192/3096.3.193.193 to 96.3.193.19496.3.193.1952
11496.3.193.196/3096.3.193.197 to 96.3.193.19896.3.193.1992
11596.3.193.200/3096.3.193.201 to 96.3.193.20296.3.193.2032
11696.3.193.204/3096.3.193.205 to 96.3.193.20696.3.193.2072
11796.3.193.208/3096.3.193.209 to 96.3.193.21096.3.193.2112
11896.3.193.212/3096.3.193.213 to 96.3.193.21496.3.193.2152
11996.3.193.216/3096.3.193.217 to 96.3.193.21896.3.193.2192
12096.3.193.220/3096.3.193.221 to 96.3.193.22296.3.193.2232
12196.3.193.224/3096.3.193.225 to 96.3.193.22696.3.193.2272
12296.3.193.228/3096.3.193.229 to 96.3.193.23096.3.193.2312
12396.3.193.232/3096.3.193.233 to 96.3.193.23496.3.193.2352
12496.3.193.236/3096.3.193.237 to 96.3.193.23896.3.193.2392
12596.3.193.240/3096.3.193.241 to 96.3.193.24296.3.193.2432
12696.3.193.244/3096.3.193.245 to 96.3.193.24696.3.193.2472
12796.3.193.248/3096.3.193.249 to 96.3.193.25096.3.193.2512
12896.3.193.252/3096.3.193.253 to 96.3.193.25496.3.193.2552
12996.3.194.0/3096.3.194.1 to 96.3.194.296.3.194.32
13096.3.194.4/3096.3.194.5 to 96.3.194.696.3.194.72
13196.3.194.8/3096.3.194.9 to 96.3.194.1096.3.194.112
13296.3.194.12/3096.3.194.13 to 96.3.194.1496.3.194.152
13396.3.194.16/3096.3.194.17 to 96.3.194.1896.3.194.192
13496.3.194.20/3096.3.194.21 to 96.3.194.2296.3.194.232
13596.3.194.24/3096.3.194.25 to 96.3.194.2696.3.194.272
13696.3.194.28/3096.3.194.29 to 96.3.194.3096.3.194.312
13796.3.194.32/3096.3.194.33 to 96.3.194.3496.3.194.352
13896.3.194.36/3096.3.194.37 to 96.3.194.3896.3.194.392
13996.3.194.40/3096.3.194.41 to 96.3.194.4296.3.194.432
14096.3.194.44/3096.3.194.45 to 96.3.194.4696.3.194.472
14196.3.194.48/3096.3.194.49 to 96.3.194.5096.3.194.512
14296.3.194.52/3096.3.194.53 to 96.3.194.5496.3.194.552
14396.3.194.56/3096.3.194.57 to 96.3.194.5896.3.194.592
14496.3.194.60/3096.3.194.61 to 96.3.194.6296.3.194.632
14596.3.194.64/3096.3.194.65 to 96.3.194.6696.3.194.672
14696.3.194.68/3096.3.194.69 to 96.3.194.7096.3.194.712
14796.3.194.72/3096.3.194.73 to 96.3.194.7496.3.194.752
14896.3.194.76/3096.3.194.77 to 96.3.194.7896.3.194.792
14996.3.194.80/3096.3.194.81 to 96.3.194.8296.3.194.832
15096.3.194.84/3096.3.194.85 to 96.3.194.8696.3.194.872
15196.3.194.88/3096.3.194.89 to 96.3.194.9096.3.194.912
15296.3.194.92/3096.3.194.93 to 96.3.194.9496.3.194.952
15396.3.194.96/3096.3.194.97 to 96.3.194.9896.3.194.992
15496.3.194.100/3096.3.194.101 to 96.3.194.10296.3.194.1032
15596.3.194.104/3096.3.194.105 to 96.3.194.10696.3.194.1072
15696.3.194.108/3096.3.194.109 to 96.3.194.11096.3.194.1112
15796.3.194.112/3096.3.194.113 to 96.3.194.11496.3.194.1152
15896.3.194.116/3096.3.194.117 to 96.3.194.11896.3.194.1192
15996.3.194.120/3096.3.194.121 to 96.3.194.12296.3.194.1232
16096.3.194.124/3096.3.194.125 to 96.3.194.12696.3.194.1272
16196.3.194.128/3096.3.194.129 to 96.3.194.13096.3.194.1312
16296.3.194.132/3096.3.194.133 to 96.3.194.13496.3.194.1352
16396.3.194.136/3096.3.194.137 to 96.3.194.13896.3.194.1392
16496.3.194.140/3096.3.194.141 to 96.3.194.14296.3.194.1432
16596.3.194.144/3096.3.194.145 to 96.3.194.14696.3.194.1472
16696.3.194.148/3096.3.194.149 to 96.3.194.15096.3.194.1512
16796.3.194.152/3096.3.194.153 to 96.3.194.15496.3.194.1552
16896.3.194.156/3096.3.194.157 to 96.3.194.15896.3.194.1592
16996.3.194.160/3096.3.194.161 to 96.3.194.16296.3.194.1632
17096.3.194.164/3096.3.194.165 to 96.3.194.16696.3.194.1672
17196.3.194.168/3096.3.194.169 to 96.3.194.17096.3.194.1712
17296.3.194.172/3096.3.194.173 to 96.3.194.17496.3.194.1752
17396.3.194.176/3096.3.194.177 to 96.3.194.17896.3.194.1792
17496.3.194.180/3096.3.194.181 to 96.3.194.18296.3.194.1832
17596.3.194.184/3096.3.194.185 to 96.3.194.18696.3.194.1872
17696.3.194.188/3096.3.194.189 to 96.3.194.19096.3.194.1912
17796.3.194.192/3096.3.194.193 to 96.3.194.19496.3.194.1952
17896.3.194.196/3096.3.194.197 to 96.3.194.19896.3.194.1992
17996.3.194.200/3096.3.194.201 to 96.3.194.20296.3.194.2032
18096.3.194.204/3096.3.194.205 to 96.3.194.20696.3.194.2072
18196.3.194.208/3096.3.194.209 to 96.3.194.21096.3.194.2112
18296.3.194.212/3096.3.194.213 to 96.3.194.21496.3.194.2152
18396.3.194.216/3096.3.194.217 to 96.3.194.21896.3.194.2192
18496.3.194.220/3096.3.194.221 to 96.3.194.22296.3.194.2232
18596.3.194.224/3096.3.194.225 to 96.3.194.22696.3.194.2272
18696.3.194.228/3096.3.194.229 to 96.3.194.23096.3.194.2312
18796.3.194.232/3096.3.194.233 to 96.3.194.23496.3.194.2352
18896.3.194.236/3096.3.194.237 to 96.3.194.23896.3.194.2392
18996.3.194.240/3096.3.194.241 to 96.3.194.24296.3.194.2432
19096.3.194.244/3096.3.194.245 to 96.3.194.24696.3.194.2472
19196.3.194.248/3096.3.194.249 to 96.3.194.25096.3.194.2512
19296.3.194.252/3096.3.194.253 to 96.3.194.25496.3.194.2552
19396.3.195.0/3096.3.195.1 to 96.3.195.296.3.195.32
19496.3.195.4/3096.3.195.5 to 96.3.195.696.3.195.72
19596.3.195.8/3096.3.195.9 to 96.3.195.1096.3.195.112
19696.3.195.12/3096.3.195.13 to 96.3.195.1496.3.195.152
19796.3.195.16/3096.3.195.17 to 96.3.195.1896.3.195.192
19896.3.195.20/3096.3.195.21 to 96.3.195.2296.3.195.232
19996.3.195.24/3096.3.195.25 to 96.3.195.2696.3.195.272
20096.3.195.28/3096.3.195.29 to 96.3.195.3096.3.195.312
20196.3.195.32/3096.3.195.33 to 96.3.195.3496.3.195.352
20296.3.195.36/3096.3.195.37 to 96.3.195.3896.3.195.392
20396.3.195.40/3096.3.195.41 to 96.3.195.4296.3.195.432
20496.3.195.44/3096.3.195.45 to 96.3.195.4696.3.195.472
20596.3.195.48/3096.3.195.49 to 96.3.195.5096.3.195.512
20696.3.195.52/3096.3.195.53 to 96.3.195.5496.3.195.552
20796.3.195.56/3096.3.195.57 to 96.3.195.5896.3.195.592
20896.3.195.60/3096.3.195.61 to 96.3.195.6296.3.195.632
20996.3.195.64/3096.3.195.65 to 96.3.195.6696.3.195.672
21096.3.195.68/3096.3.195.69 to 96.3.195.7096.3.195.712
21196.3.195.72/3096.3.195.73 to 96.3.195.7496.3.195.752
21296.3.195.76/3096.3.195.77 to 96.3.195.7896.3.195.792
21396.3.195.80/3096.3.195.81 to 96.3.195.8296.3.195.832
21496.3.195.84/3096.3.195.85 to 96.3.195.8696.3.195.872
21596.3.195.88/3096.3.195.89 to 96.3.195.9096.3.195.912
21696.3.195.92/3096.3.195.93 to 96.3.195.9496.3.195.952
21796.3.195.96/3096.3.195.97 to 96.3.195.9896.3.195.992
21896.3.195.100/3096.3.195.101 to 96.3.195.10296.3.195.1032
21996.3.195.104/3096.3.195.105 to 96.3.195.10696.3.195.1072
22096.3.195.108/3096.3.195.109 to 96.3.195.11096.3.195.1112
22196.3.195.112/3096.3.195.113 to 96.3.195.11496.3.195.1152
22296.3.195.116/3096.3.195.117 to 96.3.195.11896.3.195.1192
22396.3.195.120/3096.3.195.121 to 96.3.195.12296.3.195.1232
22496.3.195.124/3096.3.195.125 to 96.3.195.12696.3.195.1272
22596.3.195.128/3096.3.195.129 to 96.3.195.13096.3.195.1312
22696.3.195.132/3096.3.195.133 to 96.3.195.13496.3.195.1352
22796.3.195.136/3096.3.195.137 to 96.3.195.13896.3.195.1392
22896.3.195.140/3096.3.195.141 to 96.3.195.14296.3.195.1432
22996.3.195.144/3096.3.195.145 to 96.3.195.14696.3.195.1472
23096.3.195.148/3096.3.195.149 to 96.3.195.15096.3.195.1512
23196.3.195.152/3096.3.195.153 to 96.3.195.15496.3.195.1552
23296.3.195.156/3096.3.195.157 to 96.3.195.15896.3.195.1592
23396.3.195.160/3096.3.195.161 to 96.3.195.16296.3.195.1632
23496.3.195.164/3096.3.195.165 to 96.3.195.16696.3.195.1672
23596.3.195.168/3096.3.195.169 to 96.3.195.17096.3.195.1712
23696.3.195.172/3096.3.195.173 to 96.3.195.17496.3.195.1752
23796.3.195.176/3096.3.195.177 to 96.3.195.17896.3.195.1792
23896.3.195.180/3096.3.195.181 to 96.3.195.18296.3.195.1832
23996.3.195.184/3096.3.195.185 to 96.3.195.18696.3.195.1872
24096.3.195.188/3096.3.195.189 to 96.3.195.19096.3.195.1912
24196.3.195.192/3096.3.195.193 to 96.3.195.19496.3.195.1952
24296.3.195.196/3096.3.195.197 to 96.3.195.19896.3.195.1992
24396.3.195.200/3096.3.195.201 to 96.3.195.20296.3.195.2032
24496.3.195.204/3096.3.195.205 to 96.3.195.20696.3.195.2072
24596.3.195.208/3096.3.195.209 to 96.3.195.21096.3.195.2112
24696.3.195.212/3096.3.195.213 to 96.3.195.21496.3.195.2152
24796.3.195.216/3096.3.195.217 to 96.3.195.21896.3.195.2192
24896.3.195.220/3096.3.195.221 to 96.3.195.22296.3.195.2232
24996.3.195.224/3096.3.195.225 to 96.3.195.22696.3.195.2272
25096.3.195.228/3096.3.195.229 to 96.3.195.23096.3.195.2312
25196.3.195.232/3096.3.195.233 to 96.3.195.23496.3.195.2352
25296.3.195.236/3096.3.195.237 to 96.3.195.23896.3.195.2392
25396.3.195.240/3096.3.195.241 to 96.3.195.24296.3.195.2432
25496.3.195.244/3096.3.195.245 to 96.3.195.24696.3.195.2472
25596.3.195.248/3096.3.195.249 to 96.3.195.25096.3.195.2512
25696.3.195.252/3096.3.195.253 to 96.3.195.25496.3.195.2552

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.