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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.

Network25.64.12.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
25.64.12.0
Broadcast address
25.64.15.255
First usable
25.64.12.1
Last usable
25.64.15.254
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 19400C00 · Integer 423627776 to 423628799
Reverse DNS zones
12.64.25.in-addr.arpa
13.64.25.in-addr.arpa
14.64.25.in-addr.arpa
15.64.25.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
Address00011001.01000000.00001100.0000000025.64.12.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network00011001.01000000.00001100.0000000025.64.12.0
Broadcast00011001.01000000.00001111.1111111125.64.15.255
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)

25.64.12.0/22 makes 256 subnets of /30.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
125.64.12.0/3025.64.12.1 to 25.64.12.225.64.12.32
225.64.12.4/3025.64.12.5 to 25.64.12.625.64.12.72
325.64.12.8/3025.64.12.9 to 25.64.12.1025.64.12.112
425.64.12.12/3025.64.12.13 to 25.64.12.1425.64.12.152
525.64.12.16/3025.64.12.17 to 25.64.12.1825.64.12.192
625.64.12.20/3025.64.12.21 to 25.64.12.2225.64.12.232
725.64.12.24/3025.64.12.25 to 25.64.12.2625.64.12.272
825.64.12.28/3025.64.12.29 to 25.64.12.3025.64.12.312
925.64.12.32/3025.64.12.33 to 25.64.12.3425.64.12.352
1025.64.12.36/3025.64.12.37 to 25.64.12.3825.64.12.392
1125.64.12.40/3025.64.12.41 to 25.64.12.4225.64.12.432
1225.64.12.44/3025.64.12.45 to 25.64.12.4625.64.12.472
1325.64.12.48/3025.64.12.49 to 25.64.12.5025.64.12.512
1425.64.12.52/3025.64.12.53 to 25.64.12.5425.64.12.552
1525.64.12.56/3025.64.12.57 to 25.64.12.5825.64.12.592
1625.64.12.60/3025.64.12.61 to 25.64.12.6225.64.12.632
1725.64.12.64/3025.64.12.65 to 25.64.12.6625.64.12.672
1825.64.12.68/3025.64.12.69 to 25.64.12.7025.64.12.712
1925.64.12.72/3025.64.12.73 to 25.64.12.7425.64.12.752
2025.64.12.76/3025.64.12.77 to 25.64.12.7825.64.12.792
2125.64.12.80/3025.64.12.81 to 25.64.12.8225.64.12.832
2225.64.12.84/3025.64.12.85 to 25.64.12.8625.64.12.872
2325.64.12.88/3025.64.12.89 to 25.64.12.9025.64.12.912
2425.64.12.92/3025.64.12.93 to 25.64.12.9425.64.12.952
2525.64.12.96/3025.64.12.97 to 25.64.12.9825.64.12.992
2625.64.12.100/3025.64.12.101 to 25.64.12.10225.64.12.1032
2725.64.12.104/3025.64.12.105 to 25.64.12.10625.64.12.1072
2825.64.12.108/3025.64.12.109 to 25.64.12.11025.64.12.1112
2925.64.12.112/3025.64.12.113 to 25.64.12.11425.64.12.1152
3025.64.12.116/3025.64.12.117 to 25.64.12.11825.64.12.1192
3125.64.12.120/3025.64.12.121 to 25.64.12.12225.64.12.1232
3225.64.12.124/3025.64.12.125 to 25.64.12.12625.64.12.1272
3325.64.12.128/3025.64.12.129 to 25.64.12.13025.64.12.1312
3425.64.12.132/3025.64.12.133 to 25.64.12.13425.64.12.1352
3525.64.12.136/3025.64.12.137 to 25.64.12.13825.64.12.1392
3625.64.12.140/3025.64.12.141 to 25.64.12.14225.64.12.1432
3725.64.12.144/3025.64.12.145 to 25.64.12.14625.64.12.1472
3825.64.12.148/3025.64.12.149 to 25.64.12.15025.64.12.1512
3925.64.12.152/3025.64.12.153 to 25.64.12.15425.64.12.1552
4025.64.12.156/3025.64.12.157 to 25.64.12.15825.64.12.1592
4125.64.12.160/3025.64.12.161 to 25.64.12.16225.64.12.1632
4225.64.12.164/3025.64.12.165 to 25.64.12.16625.64.12.1672
4325.64.12.168/3025.64.12.169 to 25.64.12.17025.64.12.1712
4425.64.12.172/3025.64.12.173 to 25.64.12.17425.64.12.1752
4525.64.12.176/3025.64.12.177 to 25.64.12.17825.64.12.1792
4625.64.12.180/3025.64.12.181 to 25.64.12.18225.64.12.1832
4725.64.12.184/3025.64.12.185 to 25.64.12.18625.64.12.1872
4825.64.12.188/3025.64.12.189 to 25.64.12.19025.64.12.1912
4925.64.12.192/3025.64.12.193 to 25.64.12.19425.64.12.1952
5025.64.12.196/3025.64.12.197 to 25.64.12.19825.64.12.1992
5125.64.12.200/3025.64.12.201 to 25.64.12.20225.64.12.2032
5225.64.12.204/3025.64.12.205 to 25.64.12.20625.64.12.2072
5325.64.12.208/3025.64.12.209 to 25.64.12.21025.64.12.2112
5425.64.12.212/3025.64.12.213 to 25.64.12.21425.64.12.2152
5525.64.12.216/3025.64.12.217 to 25.64.12.21825.64.12.2192
5625.64.12.220/3025.64.12.221 to 25.64.12.22225.64.12.2232
5725.64.12.224/3025.64.12.225 to 25.64.12.22625.64.12.2272
5825.64.12.228/3025.64.12.229 to 25.64.12.23025.64.12.2312
5925.64.12.232/3025.64.12.233 to 25.64.12.23425.64.12.2352
6025.64.12.236/3025.64.12.237 to 25.64.12.23825.64.12.2392
6125.64.12.240/3025.64.12.241 to 25.64.12.24225.64.12.2432
6225.64.12.244/3025.64.12.245 to 25.64.12.24625.64.12.2472
6325.64.12.248/3025.64.12.249 to 25.64.12.25025.64.12.2512
6425.64.12.252/3025.64.12.253 to 25.64.12.25425.64.12.2552
6525.64.13.0/3025.64.13.1 to 25.64.13.225.64.13.32
6625.64.13.4/3025.64.13.5 to 25.64.13.625.64.13.72
6725.64.13.8/3025.64.13.9 to 25.64.13.1025.64.13.112
6825.64.13.12/3025.64.13.13 to 25.64.13.1425.64.13.152
6925.64.13.16/3025.64.13.17 to 25.64.13.1825.64.13.192
7025.64.13.20/3025.64.13.21 to 25.64.13.2225.64.13.232
7125.64.13.24/3025.64.13.25 to 25.64.13.2625.64.13.272
7225.64.13.28/3025.64.13.29 to 25.64.13.3025.64.13.312
7325.64.13.32/3025.64.13.33 to 25.64.13.3425.64.13.352
7425.64.13.36/3025.64.13.37 to 25.64.13.3825.64.13.392
7525.64.13.40/3025.64.13.41 to 25.64.13.4225.64.13.432
7625.64.13.44/3025.64.13.45 to 25.64.13.4625.64.13.472
7725.64.13.48/3025.64.13.49 to 25.64.13.5025.64.13.512
7825.64.13.52/3025.64.13.53 to 25.64.13.5425.64.13.552
7925.64.13.56/3025.64.13.57 to 25.64.13.5825.64.13.592
8025.64.13.60/3025.64.13.61 to 25.64.13.6225.64.13.632
8125.64.13.64/3025.64.13.65 to 25.64.13.6625.64.13.672
8225.64.13.68/3025.64.13.69 to 25.64.13.7025.64.13.712
8325.64.13.72/3025.64.13.73 to 25.64.13.7425.64.13.752
8425.64.13.76/3025.64.13.77 to 25.64.13.7825.64.13.792
8525.64.13.80/3025.64.13.81 to 25.64.13.8225.64.13.832
8625.64.13.84/3025.64.13.85 to 25.64.13.8625.64.13.872
8725.64.13.88/3025.64.13.89 to 25.64.13.9025.64.13.912
8825.64.13.92/3025.64.13.93 to 25.64.13.9425.64.13.952
8925.64.13.96/3025.64.13.97 to 25.64.13.9825.64.13.992
9025.64.13.100/3025.64.13.101 to 25.64.13.10225.64.13.1032
9125.64.13.104/3025.64.13.105 to 25.64.13.10625.64.13.1072
9225.64.13.108/3025.64.13.109 to 25.64.13.11025.64.13.1112
9325.64.13.112/3025.64.13.113 to 25.64.13.11425.64.13.1152
9425.64.13.116/3025.64.13.117 to 25.64.13.11825.64.13.1192
9525.64.13.120/3025.64.13.121 to 25.64.13.12225.64.13.1232
9625.64.13.124/3025.64.13.125 to 25.64.13.12625.64.13.1272
9725.64.13.128/3025.64.13.129 to 25.64.13.13025.64.13.1312
9825.64.13.132/3025.64.13.133 to 25.64.13.13425.64.13.1352
9925.64.13.136/3025.64.13.137 to 25.64.13.13825.64.13.1392
10025.64.13.140/3025.64.13.141 to 25.64.13.14225.64.13.1432
10125.64.13.144/3025.64.13.145 to 25.64.13.14625.64.13.1472
10225.64.13.148/3025.64.13.149 to 25.64.13.15025.64.13.1512
10325.64.13.152/3025.64.13.153 to 25.64.13.15425.64.13.1552
10425.64.13.156/3025.64.13.157 to 25.64.13.15825.64.13.1592
10525.64.13.160/3025.64.13.161 to 25.64.13.16225.64.13.1632
10625.64.13.164/3025.64.13.165 to 25.64.13.16625.64.13.1672
10725.64.13.168/3025.64.13.169 to 25.64.13.17025.64.13.1712
10825.64.13.172/3025.64.13.173 to 25.64.13.17425.64.13.1752
10925.64.13.176/3025.64.13.177 to 25.64.13.17825.64.13.1792
11025.64.13.180/3025.64.13.181 to 25.64.13.18225.64.13.1832
11125.64.13.184/3025.64.13.185 to 25.64.13.18625.64.13.1872
11225.64.13.188/3025.64.13.189 to 25.64.13.19025.64.13.1912
11325.64.13.192/3025.64.13.193 to 25.64.13.19425.64.13.1952
11425.64.13.196/3025.64.13.197 to 25.64.13.19825.64.13.1992
11525.64.13.200/3025.64.13.201 to 25.64.13.20225.64.13.2032
11625.64.13.204/3025.64.13.205 to 25.64.13.20625.64.13.2072
11725.64.13.208/3025.64.13.209 to 25.64.13.21025.64.13.2112
11825.64.13.212/3025.64.13.213 to 25.64.13.21425.64.13.2152
11925.64.13.216/3025.64.13.217 to 25.64.13.21825.64.13.2192
12025.64.13.220/3025.64.13.221 to 25.64.13.22225.64.13.2232
12125.64.13.224/3025.64.13.225 to 25.64.13.22625.64.13.2272
12225.64.13.228/3025.64.13.229 to 25.64.13.23025.64.13.2312
12325.64.13.232/3025.64.13.233 to 25.64.13.23425.64.13.2352
12425.64.13.236/3025.64.13.237 to 25.64.13.23825.64.13.2392
12525.64.13.240/3025.64.13.241 to 25.64.13.24225.64.13.2432
12625.64.13.244/3025.64.13.245 to 25.64.13.24625.64.13.2472
12725.64.13.248/3025.64.13.249 to 25.64.13.25025.64.13.2512
12825.64.13.252/3025.64.13.253 to 25.64.13.25425.64.13.2552
12925.64.14.0/3025.64.14.1 to 25.64.14.225.64.14.32
13025.64.14.4/3025.64.14.5 to 25.64.14.625.64.14.72
13125.64.14.8/3025.64.14.9 to 25.64.14.1025.64.14.112
13225.64.14.12/3025.64.14.13 to 25.64.14.1425.64.14.152
13325.64.14.16/3025.64.14.17 to 25.64.14.1825.64.14.192
13425.64.14.20/3025.64.14.21 to 25.64.14.2225.64.14.232
13525.64.14.24/3025.64.14.25 to 25.64.14.2625.64.14.272
13625.64.14.28/3025.64.14.29 to 25.64.14.3025.64.14.312
13725.64.14.32/3025.64.14.33 to 25.64.14.3425.64.14.352
13825.64.14.36/3025.64.14.37 to 25.64.14.3825.64.14.392
13925.64.14.40/3025.64.14.41 to 25.64.14.4225.64.14.432
14025.64.14.44/3025.64.14.45 to 25.64.14.4625.64.14.472
14125.64.14.48/3025.64.14.49 to 25.64.14.5025.64.14.512
14225.64.14.52/3025.64.14.53 to 25.64.14.5425.64.14.552
14325.64.14.56/3025.64.14.57 to 25.64.14.5825.64.14.592
14425.64.14.60/3025.64.14.61 to 25.64.14.6225.64.14.632
14525.64.14.64/3025.64.14.65 to 25.64.14.6625.64.14.672
14625.64.14.68/3025.64.14.69 to 25.64.14.7025.64.14.712
14725.64.14.72/3025.64.14.73 to 25.64.14.7425.64.14.752
14825.64.14.76/3025.64.14.77 to 25.64.14.7825.64.14.792
14925.64.14.80/3025.64.14.81 to 25.64.14.8225.64.14.832
15025.64.14.84/3025.64.14.85 to 25.64.14.8625.64.14.872
15125.64.14.88/3025.64.14.89 to 25.64.14.9025.64.14.912
15225.64.14.92/3025.64.14.93 to 25.64.14.9425.64.14.952
15325.64.14.96/3025.64.14.97 to 25.64.14.9825.64.14.992
15425.64.14.100/3025.64.14.101 to 25.64.14.10225.64.14.1032
15525.64.14.104/3025.64.14.105 to 25.64.14.10625.64.14.1072
15625.64.14.108/3025.64.14.109 to 25.64.14.11025.64.14.1112
15725.64.14.112/3025.64.14.113 to 25.64.14.11425.64.14.1152
15825.64.14.116/3025.64.14.117 to 25.64.14.11825.64.14.1192
15925.64.14.120/3025.64.14.121 to 25.64.14.12225.64.14.1232
16025.64.14.124/3025.64.14.125 to 25.64.14.12625.64.14.1272
16125.64.14.128/3025.64.14.129 to 25.64.14.13025.64.14.1312
16225.64.14.132/3025.64.14.133 to 25.64.14.13425.64.14.1352
16325.64.14.136/3025.64.14.137 to 25.64.14.13825.64.14.1392
16425.64.14.140/3025.64.14.141 to 25.64.14.14225.64.14.1432
16525.64.14.144/3025.64.14.145 to 25.64.14.14625.64.14.1472
16625.64.14.148/3025.64.14.149 to 25.64.14.15025.64.14.1512
16725.64.14.152/3025.64.14.153 to 25.64.14.15425.64.14.1552
16825.64.14.156/3025.64.14.157 to 25.64.14.15825.64.14.1592
16925.64.14.160/3025.64.14.161 to 25.64.14.16225.64.14.1632
17025.64.14.164/3025.64.14.165 to 25.64.14.16625.64.14.1672
17125.64.14.168/3025.64.14.169 to 25.64.14.17025.64.14.1712
17225.64.14.172/3025.64.14.173 to 25.64.14.17425.64.14.1752
17325.64.14.176/3025.64.14.177 to 25.64.14.17825.64.14.1792
17425.64.14.180/3025.64.14.181 to 25.64.14.18225.64.14.1832
17525.64.14.184/3025.64.14.185 to 25.64.14.18625.64.14.1872
17625.64.14.188/3025.64.14.189 to 25.64.14.19025.64.14.1912
17725.64.14.192/3025.64.14.193 to 25.64.14.19425.64.14.1952
17825.64.14.196/3025.64.14.197 to 25.64.14.19825.64.14.1992
17925.64.14.200/3025.64.14.201 to 25.64.14.20225.64.14.2032
18025.64.14.204/3025.64.14.205 to 25.64.14.20625.64.14.2072
18125.64.14.208/3025.64.14.209 to 25.64.14.21025.64.14.2112
18225.64.14.212/3025.64.14.213 to 25.64.14.21425.64.14.2152
18325.64.14.216/3025.64.14.217 to 25.64.14.21825.64.14.2192
18425.64.14.220/3025.64.14.221 to 25.64.14.22225.64.14.2232
18525.64.14.224/3025.64.14.225 to 25.64.14.22625.64.14.2272
18625.64.14.228/3025.64.14.229 to 25.64.14.23025.64.14.2312
18725.64.14.232/3025.64.14.233 to 25.64.14.23425.64.14.2352
18825.64.14.236/3025.64.14.237 to 25.64.14.23825.64.14.2392
18925.64.14.240/3025.64.14.241 to 25.64.14.24225.64.14.2432
19025.64.14.244/3025.64.14.245 to 25.64.14.24625.64.14.2472
19125.64.14.248/3025.64.14.249 to 25.64.14.25025.64.14.2512
19225.64.14.252/3025.64.14.253 to 25.64.14.25425.64.14.2552
19325.64.15.0/3025.64.15.1 to 25.64.15.225.64.15.32
19425.64.15.4/3025.64.15.5 to 25.64.15.625.64.15.72
19525.64.15.8/3025.64.15.9 to 25.64.15.1025.64.15.112
19625.64.15.12/3025.64.15.13 to 25.64.15.1425.64.15.152
19725.64.15.16/3025.64.15.17 to 25.64.15.1825.64.15.192
19825.64.15.20/3025.64.15.21 to 25.64.15.2225.64.15.232
19925.64.15.24/3025.64.15.25 to 25.64.15.2625.64.15.272
20025.64.15.28/3025.64.15.29 to 25.64.15.3025.64.15.312
20125.64.15.32/3025.64.15.33 to 25.64.15.3425.64.15.352
20225.64.15.36/3025.64.15.37 to 25.64.15.3825.64.15.392
20325.64.15.40/3025.64.15.41 to 25.64.15.4225.64.15.432
20425.64.15.44/3025.64.15.45 to 25.64.15.4625.64.15.472
20525.64.15.48/3025.64.15.49 to 25.64.15.5025.64.15.512
20625.64.15.52/3025.64.15.53 to 25.64.15.5425.64.15.552
20725.64.15.56/3025.64.15.57 to 25.64.15.5825.64.15.592
20825.64.15.60/3025.64.15.61 to 25.64.15.6225.64.15.632
20925.64.15.64/3025.64.15.65 to 25.64.15.6625.64.15.672
21025.64.15.68/3025.64.15.69 to 25.64.15.7025.64.15.712
21125.64.15.72/3025.64.15.73 to 25.64.15.7425.64.15.752
21225.64.15.76/3025.64.15.77 to 25.64.15.7825.64.15.792
21325.64.15.80/3025.64.15.81 to 25.64.15.8225.64.15.832
21425.64.15.84/3025.64.15.85 to 25.64.15.8625.64.15.872
21525.64.15.88/3025.64.15.89 to 25.64.15.9025.64.15.912
21625.64.15.92/3025.64.15.93 to 25.64.15.9425.64.15.952
21725.64.15.96/3025.64.15.97 to 25.64.15.9825.64.15.992
21825.64.15.100/3025.64.15.101 to 25.64.15.10225.64.15.1032
21925.64.15.104/3025.64.15.105 to 25.64.15.10625.64.15.1072
22025.64.15.108/3025.64.15.109 to 25.64.15.11025.64.15.1112
22125.64.15.112/3025.64.15.113 to 25.64.15.11425.64.15.1152
22225.64.15.116/3025.64.15.117 to 25.64.15.11825.64.15.1192
22325.64.15.120/3025.64.15.121 to 25.64.15.12225.64.15.1232
22425.64.15.124/3025.64.15.125 to 25.64.15.12625.64.15.1272
22525.64.15.128/3025.64.15.129 to 25.64.15.13025.64.15.1312
22625.64.15.132/3025.64.15.133 to 25.64.15.13425.64.15.1352
22725.64.15.136/3025.64.15.137 to 25.64.15.13825.64.15.1392
22825.64.15.140/3025.64.15.141 to 25.64.15.14225.64.15.1432
22925.64.15.144/3025.64.15.145 to 25.64.15.14625.64.15.1472
23025.64.15.148/3025.64.15.149 to 25.64.15.15025.64.15.1512
23125.64.15.152/3025.64.15.153 to 25.64.15.15425.64.15.1552
23225.64.15.156/3025.64.15.157 to 25.64.15.15825.64.15.1592
23325.64.15.160/3025.64.15.161 to 25.64.15.16225.64.15.1632
23425.64.15.164/3025.64.15.165 to 25.64.15.16625.64.15.1672
23525.64.15.168/3025.64.15.169 to 25.64.15.17025.64.15.1712
23625.64.15.172/3025.64.15.173 to 25.64.15.17425.64.15.1752
23725.64.15.176/3025.64.15.177 to 25.64.15.17825.64.15.1792
23825.64.15.180/3025.64.15.181 to 25.64.15.18225.64.15.1832
23925.64.15.184/3025.64.15.185 to 25.64.15.18625.64.15.1872
24025.64.15.188/3025.64.15.189 to 25.64.15.19025.64.15.1912
24125.64.15.192/3025.64.15.193 to 25.64.15.19425.64.15.1952
24225.64.15.196/3025.64.15.197 to 25.64.15.19825.64.15.1992
24325.64.15.200/3025.64.15.201 to 25.64.15.20225.64.15.2032
24425.64.15.204/3025.64.15.205 to 25.64.15.20625.64.15.2072
24525.64.15.208/3025.64.15.209 to 25.64.15.21025.64.15.2112
24625.64.15.212/3025.64.15.213 to 25.64.15.21425.64.15.2152
24725.64.15.216/3025.64.15.217 to 25.64.15.21825.64.15.2192
24825.64.15.220/3025.64.15.221 to 25.64.15.22225.64.15.2232
24925.64.15.224/3025.64.15.225 to 25.64.15.22625.64.15.2272
25025.64.15.228/3025.64.15.229 to 25.64.15.23025.64.15.2312
25125.64.15.232/3025.64.15.233 to 25.64.15.23425.64.15.2352
25225.64.15.236/3025.64.15.237 to 25.64.15.23825.64.15.2392
25325.64.15.240/3025.64.15.241 to 25.64.15.24225.64.15.2432
25425.64.15.244/3025.64.15.245 to 25.64.15.24625.64.15.2472
25525.64.15.248/3025.64.15.249 to 25.64.15.25025.64.15.2512
25625.64.15.252/3025.64.15.253 to 25.64.15.25425.64.15.2552

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.