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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.

Network84.2.0.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
84.2.0.0
Broadcast address
84.2.31.255
First usable
84.2.0.1
Last usable
84.2.31.254
Usable hosts
8,190 (8,192 less the network and broadcast addresses)
Subnet mask
255.255.224.0
Wildcard mask
0.0.31.255 (Cisco ACLs, OSPF)
Prefix length
/19
Type
Public public
Old class
A (default /8)
As numbers
Hex 54020000 · Integer 1409417216 to 1409425407
Reverse DNS zones
0.2.84.in-addr.arpa
1.2.84.in-addr.arpa
2.2.84.in-addr.arpa
3.2.84.in-addr.arpa
4.2.84.in-addr.arpa
5.2.84.in-addr.arpa
6.2.84.in-addr.arpa
7.2.84.in-addr.arpa
8.2.84.in-addr.arpa
9.2.84.in-addr.arpa
10.2.84.in-addr.arpa
11.2.84.in-addr.arpa
12.2.84.in-addr.arpa
13.2.84.in-addr.arpa
14.2.84.in-addr.arpa
15.2.84.in-addr.arpa
and 16 more
/19 is not on a 8-bit boundary, so it takes 32 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010100.00000010.00000000.0000000084.2.0.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network01010100.00000010.00000000.0000000084.2.0.0
Broadcast01010100.00000010.00011111.1111111184.2.31.255
Split into smaller subnets/30
/20 (2)/21 (4)/22 (8)/23 (16)/24 (32)/25 (64)/26 (128)/27 (256)/28 (512)/29 (1,024)/30 (2,048)/31 (4,096)

84.2.0.0/19 makes 2,048 subnets of /30; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
184.2.0.0/3084.2.0.1 to 84.2.0.284.2.0.32
284.2.0.4/3084.2.0.5 to 84.2.0.684.2.0.72
384.2.0.8/3084.2.0.9 to 84.2.0.1084.2.0.112
484.2.0.12/3084.2.0.13 to 84.2.0.1484.2.0.152
584.2.0.16/3084.2.0.17 to 84.2.0.1884.2.0.192
684.2.0.20/3084.2.0.21 to 84.2.0.2284.2.0.232
784.2.0.24/3084.2.0.25 to 84.2.0.2684.2.0.272
884.2.0.28/3084.2.0.29 to 84.2.0.3084.2.0.312
984.2.0.32/3084.2.0.33 to 84.2.0.3484.2.0.352
1084.2.0.36/3084.2.0.37 to 84.2.0.3884.2.0.392
1184.2.0.40/3084.2.0.41 to 84.2.0.4284.2.0.432
1284.2.0.44/3084.2.0.45 to 84.2.0.4684.2.0.472
1384.2.0.48/3084.2.0.49 to 84.2.0.5084.2.0.512
1484.2.0.52/3084.2.0.53 to 84.2.0.5484.2.0.552
1584.2.0.56/3084.2.0.57 to 84.2.0.5884.2.0.592
1684.2.0.60/3084.2.0.61 to 84.2.0.6284.2.0.632
1784.2.0.64/3084.2.0.65 to 84.2.0.6684.2.0.672
1884.2.0.68/3084.2.0.69 to 84.2.0.7084.2.0.712
1984.2.0.72/3084.2.0.73 to 84.2.0.7484.2.0.752
2084.2.0.76/3084.2.0.77 to 84.2.0.7884.2.0.792
2184.2.0.80/3084.2.0.81 to 84.2.0.8284.2.0.832
2284.2.0.84/3084.2.0.85 to 84.2.0.8684.2.0.872
2384.2.0.88/3084.2.0.89 to 84.2.0.9084.2.0.912
2484.2.0.92/3084.2.0.93 to 84.2.0.9484.2.0.952
2584.2.0.96/3084.2.0.97 to 84.2.0.9884.2.0.992
2684.2.0.100/3084.2.0.101 to 84.2.0.10284.2.0.1032
2784.2.0.104/3084.2.0.105 to 84.2.0.10684.2.0.1072
2884.2.0.108/3084.2.0.109 to 84.2.0.11084.2.0.1112
2984.2.0.112/3084.2.0.113 to 84.2.0.11484.2.0.1152
3084.2.0.116/3084.2.0.117 to 84.2.0.11884.2.0.1192
3184.2.0.120/3084.2.0.121 to 84.2.0.12284.2.0.1232
3284.2.0.124/3084.2.0.125 to 84.2.0.12684.2.0.1272
3384.2.0.128/3084.2.0.129 to 84.2.0.13084.2.0.1312
3484.2.0.132/3084.2.0.133 to 84.2.0.13484.2.0.1352
3584.2.0.136/3084.2.0.137 to 84.2.0.13884.2.0.1392
3684.2.0.140/3084.2.0.141 to 84.2.0.14284.2.0.1432
3784.2.0.144/3084.2.0.145 to 84.2.0.14684.2.0.1472
3884.2.0.148/3084.2.0.149 to 84.2.0.15084.2.0.1512
3984.2.0.152/3084.2.0.153 to 84.2.0.15484.2.0.1552
4084.2.0.156/3084.2.0.157 to 84.2.0.15884.2.0.1592
4184.2.0.160/3084.2.0.161 to 84.2.0.16284.2.0.1632
4284.2.0.164/3084.2.0.165 to 84.2.0.16684.2.0.1672
4384.2.0.168/3084.2.0.169 to 84.2.0.17084.2.0.1712
4484.2.0.172/3084.2.0.173 to 84.2.0.17484.2.0.1752
4584.2.0.176/3084.2.0.177 to 84.2.0.17884.2.0.1792
4684.2.0.180/3084.2.0.181 to 84.2.0.18284.2.0.1832
4784.2.0.184/3084.2.0.185 to 84.2.0.18684.2.0.1872
4884.2.0.188/3084.2.0.189 to 84.2.0.19084.2.0.1912
4984.2.0.192/3084.2.0.193 to 84.2.0.19484.2.0.1952
5084.2.0.196/3084.2.0.197 to 84.2.0.19884.2.0.1992
5184.2.0.200/3084.2.0.201 to 84.2.0.20284.2.0.2032
5284.2.0.204/3084.2.0.205 to 84.2.0.20684.2.0.2072
5384.2.0.208/3084.2.0.209 to 84.2.0.21084.2.0.2112
5484.2.0.212/3084.2.0.213 to 84.2.0.21484.2.0.2152
5584.2.0.216/3084.2.0.217 to 84.2.0.21884.2.0.2192
5684.2.0.220/3084.2.0.221 to 84.2.0.22284.2.0.2232
5784.2.0.224/3084.2.0.225 to 84.2.0.22684.2.0.2272
5884.2.0.228/3084.2.0.229 to 84.2.0.23084.2.0.2312
5984.2.0.232/3084.2.0.233 to 84.2.0.23484.2.0.2352
6084.2.0.236/3084.2.0.237 to 84.2.0.23884.2.0.2392
6184.2.0.240/3084.2.0.241 to 84.2.0.24284.2.0.2432
6284.2.0.244/3084.2.0.245 to 84.2.0.24684.2.0.2472
6384.2.0.248/3084.2.0.249 to 84.2.0.25084.2.0.2512
6484.2.0.252/3084.2.0.253 to 84.2.0.25484.2.0.2552
6584.2.1.0/3084.2.1.1 to 84.2.1.284.2.1.32
6684.2.1.4/3084.2.1.5 to 84.2.1.684.2.1.72
6784.2.1.8/3084.2.1.9 to 84.2.1.1084.2.1.112
6884.2.1.12/3084.2.1.13 to 84.2.1.1484.2.1.152
6984.2.1.16/3084.2.1.17 to 84.2.1.1884.2.1.192
7084.2.1.20/3084.2.1.21 to 84.2.1.2284.2.1.232
7184.2.1.24/3084.2.1.25 to 84.2.1.2684.2.1.272
7284.2.1.28/3084.2.1.29 to 84.2.1.3084.2.1.312
7384.2.1.32/3084.2.1.33 to 84.2.1.3484.2.1.352
7484.2.1.36/3084.2.1.37 to 84.2.1.3884.2.1.392
7584.2.1.40/3084.2.1.41 to 84.2.1.4284.2.1.432
7684.2.1.44/3084.2.1.45 to 84.2.1.4684.2.1.472
7784.2.1.48/3084.2.1.49 to 84.2.1.5084.2.1.512
7884.2.1.52/3084.2.1.53 to 84.2.1.5484.2.1.552
7984.2.1.56/3084.2.1.57 to 84.2.1.5884.2.1.592
8084.2.1.60/3084.2.1.61 to 84.2.1.6284.2.1.632
8184.2.1.64/3084.2.1.65 to 84.2.1.6684.2.1.672
8284.2.1.68/3084.2.1.69 to 84.2.1.7084.2.1.712
8384.2.1.72/3084.2.1.73 to 84.2.1.7484.2.1.752
8484.2.1.76/3084.2.1.77 to 84.2.1.7884.2.1.792
8584.2.1.80/3084.2.1.81 to 84.2.1.8284.2.1.832
8684.2.1.84/3084.2.1.85 to 84.2.1.8684.2.1.872
8784.2.1.88/3084.2.1.89 to 84.2.1.9084.2.1.912
8884.2.1.92/3084.2.1.93 to 84.2.1.9484.2.1.952
8984.2.1.96/3084.2.1.97 to 84.2.1.9884.2.1.992
9084.2.1.100/3084.2.1.101 to 84.2.1.10284.2.1.1032
9184.2.1.104/3084.2.1.105 to 84.2.1.10684.2.1.1072
9284.2.1.108/3084.2.1.109 to 84.2.1.11084.2.1.1112
9384.2.1.112/3084.2.1.113 to 84.2.1.11484.2.1.1152
9484.2.1.116/3084.2.1.117 to 84.2.1.11884.2.1.1192
9584.2.1.120/3084.2.1.121 to 84.2.1.12284.2.1.1232
9684.2.1.124/3084.2.1.125 to 84.2.1.12684.2.1.1272
9784.2.1.128/3084.2.1.129 to 84.2.1.13084.2.1.1312
9884.2.1.132/3084.2.1.133 to 84.2.1.13484.2.1.1352
9984.2.1.136/3084.2.1.137 to 84.2.1.13884.2.1.1392
10084.2.1.140/3084.2.1.141 to 84.2.1.14284.2.1.1432
10184.2.1.144/3084.2.1.145 to 84.2.1.14684.2.1.1472
10284.2.1.148/3084.2.1.149 to 84.2.1.15084.2.1.1512
10384.2.1.152/3084.2.1.153 to 84.2.1.15484.2.1.1552
10484.2.1.156/3084.2.1.157 to 84.2.1.15884.2.1.1592
10584.2.1.160/3084.2.1.161 to 84.2.1.16284.2.1.1632
10684.2.1.164/3084.2.1.165 to 84.2.1.16684.2.1.1672
10784.2.1.168/3084.2.1.169 to 84.2.1.17084.2.1.1712
10884.2.1.172/3084.2.1.173 to 84.2.1.17484.2.1.1752
10984.2.1.176/3084.2.1.177 to 84.2.1.17884.2.1.1792
11084.2.1.180/3084.2.1.181 to 84.2.1.18284.2.1.1832
11184.2.1.184/3084.2.1.185 to 84.2.1.18684.2.1.1872
11284.2.1.188/3084.2.1.189 to 84.2.1.19084.2.1.1912
11384.2.1.192/3084.2.1.193 to 84.2.1.19484.2.1.1952
11484.2.1.196/3084.2.1.197 to 84.2.1.19884.2.1.1992
11584.2.1.200/3084.2.1.201 to 84.2.1.20284.2.1.2032
11684.2.1.204/3084.2.1.205 to 84.2.1.20684.2.1.2072
11784.2.1.208/3084.2.1.209 to 84.2.1.21084.2.1.2112
11884.2.1.212/3084.2.1.213 to 84.2.1.21484.2.1.2152
11984.2.1.216/3084.2.1.217 to 84.2.1.21884.2.1.2192
12084.2.1.220/3084.2.1.221 to 84.2.1.22284.2.1.2232
12184.2.1.224/3084.2.1.225 to 84.2.1.22684.2.1.2272
12284.2.1.228/3084.2.1.229 to 84.2.1.23084.2.1.2312
12384.2.1.232/3084.2.1.233 to 84.2.1.23484.2.1.2352
12484.2.1.236/3084.2.1.237 to 84.2.1.23884.2.1.2392
12584.2.1.240/3084.2.1.241 to 84.2.1.24284.2.1.2432
12684.2.1.244/3084.2.1.245 to 84.2.1.24684.2.1.2472
12784.2.1.248/3084.2.1.249 to 84.2.1.25084.2.1.2512
12884.2.1.252/3084.2.1.253 to 84.2.1.25484.2.1.2552
12984.2.2.0/3084.2.2.1 to 84.2.2.284.2.2.32
13084.2.2.4/3084.2.2.5 to 84.2.2.684.2.2.72
13184.2.2.8/3084.2.2.9 to 84.2.2.1084.2.2.112
13284.2.2.12/3084.2.2.13 to 84.2.2.1484.2.2.152
13384.2.2.16/3084.2.2.17 to 84.2.2.1884.2.2.192
13484.2.2.20/3084.2.2.21 to 84.2.2.2284.2.2.232
13584.2.2.24/3084.2.2.25 to 84.2.2.2684.2.2.272
13684.2.2.28/3084.2.2.29 to 84.2.2.3084.2.2.312
13784.2.2.32/3084.2.2.33 to 84.2.2.3484.2.2.352
13884.2.2.36/3084.2.2.37 to 84.2.2.3884.2.2.392
13984.2.2.40/3084.2.2.41 to 84.2.2.4284.2.2.432
14084.2.2.44/3084.2.2.45 to 84.2.2.4684.2.2.472
14184.2.2.48/3084.2.2.49 to 84.2.2.5084.2.2.512
14284.2.2.52/3084.2.2.53 to 84.2.2.5484.2.2.552
14384.2.2.56/3084.2.2.57 to 84.2.2.5884.2.2.592
14484.2.2.60/3084.2.2.61 to 84.2.2.6284.2.2.632
14584.2.2.64/3084.2.2.65 to 84.2.2.6684.2.2.672
14684.2.2.68/3084.2.2.69 to 84.2.2.7084.2.2.712
14784.2.2.72/3084.2.2.73 to 84.2.2.7484.2.2.752
14884.2.2.76/3084.2.2.77 to 84.2.2.7884.2.2.792
14984.2.2.80/3084.2.2.81 to 84.2.2.8284.2.2.832
15084.2.2.84/3084.2.2.85 to 84.2.2.8684.2.2.872
15184.2.2.88/3084.2.2.89 to 84.2.2.9084.2.2.912
15284.2.2.92/3084.2.2.93 to 84.2.2.9484.2.2.952
15384.2.2.96/3084.2.2.97 to 84.2.2.9884.2.2.992
15484.2.2.100/3084.2.2.101 to 84.2.2.10284.2.2.1032
15584.2.2.104/3084.2.2.105 to 84.2.2.10684.2.2.1072
15684.2.2.108/3084.2.2.109 to 84.2.2.11084.2.2.1112
15784.2.2.112/3084.2.2.113 to 84.2.2.11484.2.2.1152
15884.2.2.116/3084.2.2.117 to 84.2.2.11884.2.2.1192
15984.2.2.120/3084.2.2.121 to 84.2.2.12284.2.2.1232
16084.2.2.124/3084.2.2.125 to 84.2.2.12684.2.2.1272
16184.2.2.128/3084.2.2.129 to 84.2.2.13084.2.2.1312
16284.2.2.132/3084.2.2.133 to 84.2.2.13484.2.2.1352
16384.2.2.136/3084.2.2.137 to 84.2.2.13884.2.2.1392
16484.2.2.140/3084.2.2.141 to 84.2.2.14284.2.2.1432
16584.2.2.144/3084.2.2.145 to 84.2.2.14684.2.2.1472
16684.2.2.148/3084.2.2.149 to 84.2.2.15084.2.2.1512
16784.2.2.152/3084.2.2.153 to 84.2.2.15484.2.2.1552
16884.2.2.156/3084.2.2.157 to 84.2.2.15884.2.2.1592
16984.2.2.160/3084.2.2.161 to 84.2.2.16284.2.2.1632
17084.2.2.164/3084.2.2.165 to 84.2.2.16684.2.2.1672
17184.2.2.168/3084.2.2.169 to 84.2.2.17084.2.2.1712
17284.2.2.172/3084.2.2.173 to 84.2.2.17484.2.2.1752
17384.2.2.176/3084.2.2.177 to 84.2.2.17884.2.2.1792
17484.2.2.180/3084.2.2.181 to 84.2.2.18284.2.2.1832
17584.2.2.184/3084.2.2.185 to 84.2.2.18684.2.2.1872
17684.2.2.188/3084.2.2.189 to 84.2.2.19084.2.2.1912
17784.2.2.192/3084.2.2.193 to 84.2.2.19484.2.2.1952
17884.2.2.196/3084.2.2.197 to 84.2.2.19884.2.2.1992
17984.2.2.200/3084.2.2.201 to 84.2.2.20284.2.2.2032
18084.2.2.204/3084.2.2.205 to 84.2.2.20684.2.2.2072
18184.2.2.208/3084.2.2.209 to 84.2.2.21084.2.2.2112
18284.2.2.212/3084.2.2.213 to 84.2.2.21484.2.2.2152
18384.2.2.216/3084.2.2.217 to 84.2.2.21884.2.2.2192
18484.2.2.220/3084.2.2.221 to 84.2.2.22284.2.2.2232
18584.2.2.224/3084.2.2.225 to 84.2.2.22684.2.2.2272
18684.2.2.228/3084.2.2.229 to 84.2.2.23084.2.2.2312
18784.2.2.232/3084.2.2.233 to 84.2.2.23484.2.2.2352
18884.2.2.236/3084.2.2.237 to 84.2.2.23884.2.2.2392
18984.2.2.240/3084.2.2.241 to 84.2.2.24284.2.2.2432
19084.2.2.244/3084.2.2.245 to 84.2.2.24684.2.2.2472
19184.2.2.248/3084.2.2.249 to 84.2.2.25084.2.2.2512
19284.2.2.252/3084.2.2.253 to 84.2.2.25484.2.2.2552
19384.2.3.0/3084.2.3.1 to 84.2.3.284.2.3.32
19484.2.3.4/3084.2.3.5 to 84.2.3.684.2.3.72
19584.2.3.8/3084.2.3.9 to 84.2.3.1084.2.3.112
19684.2.3.12/3084.2.3.13 to 84.2.3.1484.2.3.152
19784.2.3.16/3084.2.3.17 to 84.2.3.1884.2.3.192
19884.2.3.20/3084.2.3.21 to 84.2.3.2284.2.3.232
19984.2.3.24/3084.2.3.25 to 84.2.3.2684.2.3.272
20084.2.3.28/3084.2.3.29 to 84.2.3.3084.2.3.312
20184.2.3.32/3084.2.3.33 to 84.2.3.3484.2.3.352
20284.2.3.36/3084.2.3.37 to 84.2.3.3884.2.3.392
20384.2.3.40/3084.2.3.41 to 84.2.3.4284.2.3.432
20484.2.3.44/3084.2.3.45 to 84.2.3.4684.2.3.472
20584.2.3.48/3084.2.3.49 to 84.2.3.5084.2.3.512
20684.2.3.52/3084.2.3.53 to 84.2.3.5484.2.3.552
20784.2.3.56/3084.2.3.57 to 84.2.3.5884.2.3.592
20884.2.3.60/3084.2.3.61 to 84.2.3.6284.2.3.632
20984.2.3.64/3084.2.3.65 to 84.2.3.6684.2.3.672
21084.2.3.68/3084.2.3.69 to 84.2.3.7084.2.3.712
21184.2.3.72/3084.2.3.73 to 84.2.3.7484.2.3.752
21284.2.3.76/3084.2.3.77 to 84.2.3.7884.2.3.792
21384.2.3.80/3084.2.3.81 to 84.2.3.8284.2.3.832
21484.2.3.84/3084.2.3.85 to 84.2.3.8684.2.3.872
21584.2.3.88/3084.2.3.89 to 84.2.3.9084.2.3.912
21684.2.3.92/3084.2.3.93 to 84.2.3.9484.2.3.952
21784.2.3.96/3084.2.3.97 to 84.2.3.9884.2.3.992
21884.2.3.100/3084.2.3.101 to 84.2.3.10284.2.3.1032
21984.2.3.104/3084.2.3.105 to 84.2.3.10684.2.3.1072
22084.2.3.108/3084.2.3.109 to 84.2.3.11084.2.3.1112
22184.2.3.112/3084.2.3.113 to 84.2.3.11484.2.3.1152
22284.2.3.116/3084.2.3.117 to 84.2.3.11884.2.3.1192
22384.2.3.120/3084.2.3.121 to 84.2.3.12284.2.3.1232
22484.2.3.124/3084.2.3.125 to 84.2.3.12684.2.3.1272
22584.2.3.128/3084.2.3.129 to 84.2.3.13084.2.3.1312
22684.2.3.132/3084.2.3.133 to 84.2.3.13484.2.3.1352
22784.2.3.136/3084.2.3.137 to 84.2.3.13884.2.3.1392
22884.2.3.140/3084.2.3.141 to 84.2.3.14284.2.3.1432
22984.2.3.144/3084.2.3.145 to 84.2.3.14684.2.3.1472
23084.2.3.148/3084.2.3.149 to 84.2.3.15084.2.3.1512
23184.2.3.152/3084.2.3.153 to 84.2.3.15484.2.3.1552
23284.2.3.156/3084.2.3.157 to 84.2.3.15884.2.3.1592
23384.2.3.160/3084.2.3.161 to 84.2.3.16284.2.3.1632
23484.2.3.164/3084.2.3.165 to 84.2.3.16684.2.3.1672
23584.2.3.168/3084.2.3.169 to 84.2.3.17084.2.3.1712
23684.2.3.172/3084.2.3.173 to 84.2.3.17484.2.3.1752
23784.2.3.176/3084.2.3.177 to 84.2.3.17884.2.3.1792
23884.2.3.180/3084.2.3.181 to 84.2.3.18284.2.3.1832
23984.2.3.184/3084.2.3.185 to 84.2.3.18684.2.3.1872
24084.2.3.188/3084.2.3.189 to 84.2.3.19084.2.3.1912
24184.2.3.192/3084.2.3.193 to 84.2.3.19484.2.3.1952
24284.2.3.196/3084.2.3.197 to 84.2.3.19884.2.3.1992
24384.2.3.200/3084.2.3.201 to 84.2.3.20284.2.3.2032
24484.2.3.204/3084.2.3.205 to 84.2.3.20684.2.3.2072
24584.2.3.208/3084.2.3.209 to 84.2.3.21084.2.3.2112
24684.2.3.212/3084.2.3.213 to 84.2.3.21484.2.3.2152
24784.2.3.216/3084.2.3.217 to 84.2.3.21884.2.3.2192
24884.2.3.220/3084.2.3.221 to 84.2.3.22284.2.3.2232
24984.2.3.224/3084.2.3.225 to 84.2.3.22684.2.3.2272
25084.2.3.228/3084.2.3.229 to 84.2.3.23084.2.3.2312
25184.2.3.232/3084.2.3.233 to 84.2.3.23484.2.3.2352
25284.2.3.236/3084.2.3.237 to 84.2.3.23884.2.3.2392
25384.2.3.240/3084.2.3.241 to 84.2.3.24284.2.3.2432
25484.2.3.244/3084.2.3.245 to 84.2.3.24684.2.3.2472
25584.2.3.248/3084.2.3.249 to 84.2.3.25084.2.3.2512
25684.2.3.252/3084.2.3.253 to 84.2.3.25484.2.3.2552

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.