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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.

Network36.2.72.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
36.2.72.0
Broadcast address
36.2.75.255
First usable
36.2.72.1
Last usable
36.2.75.254
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 24024800 · Integer 604129280 to 604130303
Reverse DNS zones
72.2.36.in-addr.arpa
73.2.36.in-addr.arpa
74.2.36.in-addr.arpa
75.2.36.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
Address00100100.00000010.01001000.0000000036.2.72.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network00100100.00000010.01001000.0000000036.2.72.0
Broadcast00100100.00000010.01001011.1111111136.2.75.255
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)

36.2.72.0/22 makes 256 subnets of /30.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
136.2.72.0/3036.2.72.1 to 36.2.72.236.2.72.32
236.2.72.4/3036.2.72.5 to 36.2.72.636.2.72.72
336.2.72.8/3036.2.72.9 to 36.2.72.1036.2.72.112
436.2.72.12/3036.2.72.13 to 36.2.72.1436.2.72.152
536.2.72.16/3036.2.72.17 to 36.2.72.1836.2.72.192
636.2.72.20/3036.2.72.21 to 36.2.72.2236.2.72.232
736.2.72.24/3036.2.72.25 to 36.2.72.2636.2.72.272
836.2.72.28/3036.2.72.29 to 36.2.72.3036.2.72.312
936.2.72.32/3036.2.72.33 to 36.2.72.3436.2.72.352
1036.2.72.36/3036.2.72.37 to 36.2.72.3836.2.72.392
1136.2.72.40/3036.2.72.41 to 36.2.72.4236.2.72.432
1236.2.72.44/3036.2.72.45 to 36.2.72.4636.2.72.472
1336.2.72.48/3036.2.72.49 to 36.2.72.5036.2.72.512
1436.2.72.52/3036.2.72.53 to 36.2.72.5436.2.72.552
1536.2.72.56/3036.2.72.57 to 36.2.72.5836.2.72.592
1636.2.72.60/3036.2.72.61 to 36.2.72.6236.2.72.632
1736.2.72.64/3036.2.72.65 to 36.2.72.6636.2.72.672
1836.2.72.68/3036.2.72.69 to 36.2.72.7036.2.72.712
1936.2.72.72/3036.2.72.73 to 36.2.72.7436.2.72.752
2036.2.72.76/3036.2.72.77 to 36.2.72.7836.2.72.792
2136.2.72.80/3036.2.72.81 to 36.2.72.8236.2.72.832
2236.2.72.84/3036.2.72.85 to 36.2.72.8636.2.72.872
2336.2.72.88/3036.2.72.89 to 36.2.72.9036.2.72.912
2436.2.72.92/3036.2.72.93 to 36.2.72.9436.2.72.952
2536.2.72.96/3036.2.72.97 to 36.2.72.9836.2.72.992
2636.2.72.100/3036.2.72.101 to 36.2.72.10236.2.72.1032
2736.2.72.104/3036.2.72.105 to 36.2.72.10636.2.72.1072
2836.2.72.108/3036.2.72.109 to 36.2.72.11036.2.72.1112
2936.2.72.112/3036.2.72.113 to 36.2.72.11436.2.72.1152
3036.2.72.116/3036.2.72.117 to 36.2.72.11836.2.72.1192
3136.2.72.120/3036.2.72.121 to 36.2.72.12236.2.72.1232
3236.2.72.124/3036.2.72.125 to 36.2.72.12636.2.72.1272
3336.2.72.128/3036.2.72.129 to 36.2.72.13036.2.72.1312
3436.2.72.132/3036.2.72.133 to 36.2.72.13436.2.72.1352
3536.2.72.136/3036.2.72.137 to 36.2.72.13836.2.72.1392
3636.2.72.140/3036.2.72.141 to 36.2.72.14236.2.72.1432
3736.2.72.144/3036.2.72.145 to 36.2.72.14636.2.72.1472
3836.2.72.148/3036.2.72.149 to 36.2.72.15036.2.72.1512
3936.2.72.152/3036.2.72.153 to 36.2.72.15436.2.72.1552
4036.2.72.156/3036.2.72.157 to 36.2.72.15836.2.72.1592
4136.2.72.160/3036.2.72.161 to 36.2.72.16236.2.72.1632
4236.2.72.164/3036.2.72.165 to 36.2.72.16636.2.72.1672
4336.2.72.168/3036.2.72.169 to 36.2.72.17036.2.72.1712
4436.2.72.172/3036.2.72.173 to 36.2.72.17436.2.72.1752
4536.2.72.176/3036.2.72.177 to 36.2.72.17836.2.72.1792
4636.2.72.180/3036.2.72.181 to 36.2.72.18236.2.72.1832
4736.2.72.184/3036.2.72.185 to 36.2.72.18636.2.72.1872
4836.2.72.188/3036.2.72.189 to 36.2.72.19036.2.72.1912
4936.2.72.192/3036.2.72.193 to 36.2.72.19436.2.72.1952
5036.2.72.196/3036.2.72.197 to 36.2.72.19836.2.72.1992
5136.2.72.200/3036.2.72.201 to 36.2.72.20236.2.72.2032
5236.2.72.204/3036.2.72.205 to 36.2.72.20636.2.72.2072
5336.2.72.208/3036.2.72.209 to 36.2.72.21036.2.72.2112
5436.2.72.212/3036.2.72.213 to 36.2.72.21436.2.72.2152
5536.2.72.216/3036.2.72.217 to 36.2.72.21836.2.72.2192
5636.2.72.220/3036.2.72.221 to 36.2.72.22236.2.72.2232
5736.2.72.224/3036.2.72.225 to 36.2.72.22636.2.72.2272
5836.2.72.228/3036.2.72.229 to 36.2.72.23036.2.72.2312
5936.2.72.232/3036.2.72.233 to 36.2.72.23436.2.72.2352
6036.2.72.236/3036.2.72.237 to 36.2.72.23836.2.72.2392
6136.2.72.240/3036.2.72.241 to 36.2.72.24236.2.72.2432
6236.2.72.244/3036.2.72.245 to 36.2.72.24636.2.72.2472
6336.2.72.248/3036.2.72.249 to 36.2.72.25036.2.72.2512
6436.2.72.252/3036.2.72.253 to 36.2.72.25436.2.72.2552
6536.2.73.0/3036.2.73.1 to 36.2.73.236.2.73.32
6636.2.73.4/3036.2.73.5 to 36.2.73.636.2.73.72
6736.2.73.8/3036.2.73.9 to 36.2.73.1036.2.73.112
6836.2.73.12/3036.2.73.13 to 36.2.73.1436.2.73.152
6936.2.73.16/3036.2.73.17 to 36.2.73.1836.2.73.192
7036.2.73.20/3036.2.73.21 to 36.2.73.2236.2.73.232
7136.2.73.24/3036.2.73.25 to 36.2.73.2636.2.73.272
7236.2.73.28/3036.2.73.29 to 36.2.73.3036.2.73.312
7336.2.73.32/3036.2.73.33 to 36.2.73.3436.2.73.352
7436.2.73.36/3036.2.73.37 to 36.2.73.3836.2.73.392
7536.2.73.40/3036.2.73.41 to 36.2.73.4236.2.73.432
7636.2.73.44/3036.2.73.45 to 36.2.73.4636.2.73.472
7736.2.73.48/3036.2.73.49 to 36.2.73.5036.2.73.512
7836.2.73.52/3036.2.73.53 to 36.2.73.5436.2.73.552
7936.2.73.56/3036.2.73.57 to 36.2.73.5836.2.73.592
8036.2.73.60/3036.2.73.61 to 36.2.73.6236.2.73.632
8136.2.73.64/3036.2.73.65 to 36.2.73.6636.2.73.672
8236.2.73.68/3036.2.73.69 to 36.2.73.7036.2.73.712
8336.2.73.72/3036.2.73.73 to 36.2.73.7436.2.73.752
8436.2.73.76/3036.2.73.77 to 36.2.73.7836.2.73.792
8536.2.73.80/3036.2.73.81 to 36.2.73.8236.2.73.832
8636.2.73.84/3036.2.73.85 to 36.2.73.8636.2.73.872
8736.2.73.88/3036.2.73.89 to 36.2.73.9036.2.73.912
8836.2.73.92/3036.2.73.93 to 36.2.73.9436.2.73.952
8936.2.73.96/3036.2.73.97 to 36.2.73.9836.2.73.992
9036.2.73.100/3036.2.73.101 to 36.2.73.10236.2.73.1032
9136.2.73.104/3036.2.73.105 to 36.2.73.10636.2.73.1072
9236.2.73.108/3036.2.73.109 to 36.2.73.11036.2.73.1112
9336.2.73.112/3036.2.73.113 to 36.2.73.11436.2.73.1152
9436.2.73.116/3036.2.73.117 to 36.2.73.11836.2.73.1192
9536.2.73.120/3036.2.73.121 to 36.2.73.12236.2.73.1232
9636.2.73.124/3036.2.73.125 to 36.2.73.12636.2.73.1272
9736.2.73.128/3036.2.73.129 to 36.2.73.13036.2.73.1312
9836.2.73.132/3036.2.73.133 to 36.2.73.13436.2.73.1352
9936.2.73.136/3036.2.73.137 to 36.2.73.13836.2.73.1392
10036.2.73.140/3036.2.73.141 to 36.2.73.14236.2.73.1432
10136.2.73.144/3036.2.73.145 to 36.2.73.14636.2.73.1472
10236.2.73.148/3036.2.73.149 to 36.2.73.15036.2.73.1512
10336.2.73.152/3036.2.73.153 to 36.2.73.15436.2.73.1552
10436.2.73.156/3036.2.73.157 to 36.2.73.15836.2.73.1592
10536.2.73.160/3036.2.73.161 to 36.2.73.16236.2.73.1632
10636.2.73.164/3036.2.73.165 to 36.2.73.16636.2.73.1672
10736.2.73.168/3036.2.73.169 to 36.2.73.17036.2.73.1712
10836.2.73.172/3036.2.73.173 to 36.2.73.17436.2.73.1752
10936.2.73.176/3036.2.73.177 to 36.2.73.17836.2.73.1792
11036.2.73.180/3036.2.73.181 to 36.2.73.18236.2.73.1832
11136.2.73.184/3036.2.73.185 to 36.2.73.18636.2.73.1872
11236.2.73.188/3036.2.73.189 to 36.2.73.19036.2.73.1912
11336.2.73.192/3036.2.73.193 to 36.2.73.19436.2.73.1952
11436.2.73.196/3036.2.73.197 to 36.2.73.19836.2.73.1992
11536.2.73.200/3036.2.73.201 to 36.2.73.20236.2.73.2032
11636.2.73.204/3036.2.73.205 to 36.2.73.20636.2.73.2072
11736.2.73.208/3036.2.73.209 to 36.2.73.21036.2.73.2112
11836.2.73.212/3036.2.73.213 to 36.2.73.21436.2.73.2152
11936.2.73.216/3036.2.73.217 to 36.2.73.21836.2.73.2192
12036.2.73.220/3036.2.73.221 to 36.2.73.22236.2.73.2232
12136.2.73.224/3036.2.73.225 to 36.2.73.22636.2.73.2272
12236.2.73.228/3036.2.73.229 to 36.2.73.23036.2.73.2312
12336.2.73.232/3036.2.73.233 to 36.2.73.23436.2.73.2352
12436.2.73.236/3036.2.73.237 to 36.2.73.23836.2.73.2392
12536.2.73.240/3036.2.73.241 to 36.2.73.24236.2.73.2432
12636.2.73.244/3036.2.73.245 to 36.2.73.24636.2.73.2472
12736.2.73.248/3036.2.73.249 to 36.2.73.25036.2.73.2512
12836.2.73.252/3036.2.73.253 to 36.2.73.25436.2.73.2552
12936.2.74.0/3036.2.74.1 to 36.2.74.236.2.74.32
13036.2.74.4/3036.2.74.5 to 36.2.74.636.2.74.72
13136.2.74.8/3036.2.74.9 to 36.2.74.1036.2.74.112
13236.2.74.12/3036.2.74.13 to 36.2.74.1436.2.74.152
13336.2.74.16/3036.2.74.17 to 36.2.74.1836.2.74.192
13436.2.74.20/3036.2.74.21 to 36.2.74.2236.2.74.232
13536.2.74.24/3036.2.74.25 to 36.2.74.2636.2.74.272
13636.2.74.28/3036.2.74.29 to 36.2.74.3036.2.74.312
13736.2.74.32/3036.2.74.33 to 36.2.74.3436.2.74.352
13836.2.74.36/3036.2.74.37 to 36.2.74.3836.2.74.392
13936.2.74.40/3036.2.74.41 to 36.2.74.4236.2.74.432
14036.2.74.44/3036.2.74.45 to 36.2.74.4636.2.74.472
14136.2.74.48/3036.2.74.49 to 36.2.74.5036.2.74.512
14236.2.74.52/3036.2.74.53 to 36.2.74.5436.2.74.552
14336.2.74.56/3036.2.74.57 to 36.2.74.5836.2.74.592
14436.2.74.60/3036.2.74.61 to 36.2.74.6236.2.74.632
14536.2.74.64/3036.2.74.65 to 36.2.74.6636.2.74.672
14636.2.74.68/3036.2.74.69 to 36.2.74.7036.2.74.712
14736.2.74.72/3036.2.74.73 to 36.2.74.7436.2.74.752
14836.2.74.76/3036.2.74.77 to 36.2.74.7836.2.74.792
14936.2.74.80/3036.2.74.81 to 36.2.74.8236.2.74.832
15036.2.74.84/3036.2.74.85 to 36.2.74.8636.2.74.872
15136.2.74.88/3036.2.74.89 to 36.2.74.9036.2.74.912
15236.2.74.92/3036.2.74.93 to 36.2.74.9436.2.74.952
15336.2.74.96/3036.2.74.97 to 36.2.74.9836.2.74.992
15436.2.74.100/3036.2.74.101 to 36.2.74.10236.2.74.1032
15536.2.74.104/3036.2.74.105 to 36.2.74.10636.2.74.1072
15636.2.74.108/3036.2.74.109 to 36.2.74.11036.2.74.1112
15736.2.74.112/3036.2.74.113 to 36.2.74.11436.2.74.1152
15836.2.74.116/3036.2.74.117 to 36.2.74.11836.2.74.1192
15936.2.74.120/3036.2.74.121 to 36.2.74.12236.2.74.1232
16036.2.74.124/3036.2.74.125 to 36.2.74.12636.2.74.1272
16136.2.74.128/3036.2.74.129 to 36.2.74.13036.2.74.1312
16236.2.74.132/3036.2.74.133 to 36.2.74.13436.2.74.1352
16336.2.74.136/3036.2.74.137 to 36.2.74.13836.2.74.1392
16436.2.74.140/3036.2.74.141 to 36.2.74.14236.2.74.1432
16536.2.74.144/3036.2.74.145 to 36.2.74.14636.2.74.1472
16636.2.74.148/3036.2.74.149 to 36.2.74.15036.2.74.1512
16736.2.74.152/3036.2.74.153 to 36.2.74.15436.2.74.1552
16836.2.74.156/3036.2.74.157 to 36.2.74.15836.2.74.1592
16936.2.74.160/3036.2.74.161 to 36.2.74.16236.2.74.1632
17036.2.74.164/3036.2.74.165 to 36.2.74.16636.2.74.1672
17136.2.74.168/3036.2.74.169 to 36.2.74.17036.2.74.1712
17236.2.74.172/3036.2.74.173 to 36.2.74.17436.2.74.1752
17336.2.74.176/3036.2.74.177 to 36.2.74.17836.2.74.1792
17436.2.74.180/3036.2.74.181 to 36.2.74.18236.2.74.1832
17536.2.74.184/3036.2.74.185 to 36.2.74.18636.2.74.1872
17636.2.74.188/3036.2.74.189 to 36.2.74.19036.2.74.1912
17736.2.74.192/3036.2.74.193 to 36.2.74.19436.2.74.1952
17836.2.74.196/3036.2.74.197 to 36.2.74.19836.2.74.1992
17936.2.74.200/3036.2.74.201 to 36.2.74.20236.2.74.2032
18036.2.74.204/3036.2.74.205 to 36.2.74.20636.2.74.2072
18136.2.74.208/3036.2.74.209 to 36.2.74.21036.2.74.2112
18236.2.74.212/3036.2.74.213 to 36.2.74.21436.2.74.2152
18336.2.74.216/3036.2.74.217 to 36.2.74.21836.2.74.2192
18436.2.74.220/3036.2.74.221 to 36.2.74.22236.2.74.2232
18536.2.74.224/3036.2.74.225 to 36.2.74.22636.2.74.2272
18636.2.74.228/3036.2.74.229 to 36.2.74.23036.2.74.2312
18736.2.74.232/3036.2.74.233 to 36.2.74.23436.2.74.2352
18836.2.74.236/3036.2.74.237 to 36.2.74.23836.2.74.2392
18936.2.74.240/3036.2.74.241 to 36.2.74.24236.2.74.2432
19036.2.74.244/3036.2.74.245 to 36.2.74.24636.2.74.2472
19136.2.74.248/3036.2.74.249 to 36.2.74.25036.2.74.2512
19236.2.74.252/3036.2.74.253 to 36.2.74.25436.2.74.2552
19336.2.75.0/3036.2.75.1 to 36.2.75.236.2.75.32
19436.2.75.4/3036.2.75.5 to 36.2.75.636.2.75.72
19536.2.75.8/3036.2.75.9 to 36.2.75.1036.2.75.112
19636.2.75.12/3036.2.75.13 to 36.2.75.1436.2.75.152
19736.2.75.16/3036.2.75.17 to 36.2.75.1836.2.75.192
19836.2.75.20/3036.2.75.21 to 36.2.75.2236.2.75.232
19936.2.75.24/3036.2.75.25 to 36.2.75.2636.2.75.272
20036.2.75.28/3036.2.75.29 to 36.2.75.3036.2.75.312
20136.2.75.32/3036.2.75.33 to 36.2.75.3436.2.75.352
20236.2.75.36/3036.2.75.37 to 36.2.75.3836.2.75.392
20336.2.75.40/3036.2.75.41 to 36.2.75.4236.2.75.432
20436.2.75.44/3036.2.75.45 to 36.2.75.4636.2.75.472
20536.2.75.48/3036.2.75.49 to 36.2.75.5036.2.75.512
20636.2.75.52/3036.2.75.53 to 36.2.75.5436.2.75.552
20736.2.75.56/3036.2.75.57 to 36.2.75.5836.2.75.592
20836.2.75.60/3036.2.75.61 to 36.2.75.6236.2.75.632
20936.2.75.64/3036.2.75.65 to 36.2.75.6636.2.75.672
21036.2.75.68/3036.2.75.69 to 36.2.75.7036.2.75.712
21136.2.75.72/3036.2.75.73 to 36.2.75.7436.2.75.752
21236.2.75.76/3036.2.75.77 to 36.2.75.7836.2.75.792
21336.2.75.80/3036.2.75.81 to 36.2.75.8236.2.75.832
21436.2.75.84/3036.2.75.85 to 36.2.75.8636.2.75.872
21536.2.75.88/3036.2.75.89 to 36.2.75.9036.2.75.912
21636.2.75.92/3036.2.75.93 to 36.2.75.9436.2.75.952
21736.2.75.96/3036.2.75.97 to 36.2.75.9836.2.75.992
21836.2.75.100/3036.2.75.101 to 36.2.75.10236.2.75.1032
21936.2.75.104/3036.2.75.105 to 36.2.75.10636.2.75.1072
22036.2.75.108/3036.2.75.109 to 36.2.75.11036.2.75.1112
22136.2.75.112/3036.2.75.113 to 36.2.75.11436.2.75.1152
22236.2.75.116/3036.2.75.117 to 36.2.75.11836.2.75.1192
22336.2.75.120/3036.2.75.121 to 36.2.75.12236.2.75.1232
22436.2.75.124/3036.2.75.125 to 36.2.75.12636.2.75.1272
22536.2.75.128/3036.2.75.129 to 36.2.75.13036.2.75.1312
22636.2.75.132/3036.2.75.133 to 36.2.75.13436.2.75.1352
22736.2.75.136/3036.2.75.137 to 36.2.75.13836.2.75.1392
22836.2.75.140/3036.2.75.141 to 36.2.75.14236.2.75.1432
22936.2.75.144/3036.2.75.145 to 36.2.75.14636.2.75.1472
23036.2.75.148/3036.2.75.149 to 36.2.75.15036.2.75.1512
23136.2.75.152/3036.2.75.153 to 36.2.75.15436.2.75.1552
23236.2.75.156/3036.2.75.157 to 36.2.75.15836.2.75.1592
23336.2.75.160/3036.2.75.161 to 36.2.75.16236.2.75.1632
23436.2.75.164/3036.2.75.165 to 36.2.75.16636.2.75.1672
23536.2.75.168/3036.2.75.169 to 36.2.75.17036.2.75.1712
23636.2.75.172/3036.2.75.173 to 36.2.75.17436.2.75.1752
23736.2.75.176/3036.2.75.177 to 36.2.75.17836.2.75.1792
23836.2.75.180/3036.2.75.181 to 36.2.75.18236.2.75.1832
23936.2.75.184/3036.2.75.185 to 36.2.75.18636.2.75.1872
24036.2.75.188/3036.2.75.189 to 36.2.75.19036.2.75.1912
24136.2.75.192/3036.2.75.193 to 36.2.75.19436.2.75.1952
24236.2.75.196/3036.2.75.197 to 36.2.75.19836.2.75.1992
24336.2.75.200/3036.2.75.201 to 36.2.75.20236.2.75.2032
24436.2.75.204/3036.2.75.205 to 36.2.75.20636.2.75.2072
24536.2.75.208/3036.2.75.209 to 36.2.75.21036.2.75.2112
24636.2.75.212/3036.2.75.213 to 36.2.75.21436.2.75.2152
24736.2.75.216/3036.2.75.217 to 36.2.75.21836.2.75.2192
24836.2.75.220/3036.2.75.221 to 36.2.75.22236.2.75.2232
24936.2.75.224/3036.2.75.225 to 36.2.75.22636.2.75.2272
25036.2.75.228/3036.2.75.229 to 36.2.75.23036.2.75.2312
25136.2.75.232/3036.2.75.233 to 36.2.75.23436.2.75.2352
25236.2.75.236/3036.2.75.237 to 36.2.75.23836.2.75.2392
25336.2.75.240/3036.2.75.241 to 36.2.75.24236.2.75.2432
25436.2.75.244/3036.2.75.245 to 36.2.75.24636.2.75.2472
25536.2.75.248/3036.2.75.249 to 36.2.75.25036.2.75.2512
25636.2.75.252/3036.2.75.253 to 36.2.75.25436.2.75.2552

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.