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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.

Network194.2.0.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
194.2.0.0
Broadcast address
194.2.63.255
First usable
194.2.0.1
Last usable
194.2.63.254
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
C (default /24)
As numbers
Hex C2020000 · Integer 3254910976 to 3254927359
Reverse DNS zones
0.2.194.in-addr.arpa
1.2.194.in-addr.arpa
2.2.194.in-addr.arpa
3.2.194.in-addr.arpa
4.2.194.in-addr.arpa
5.2.194.in-addr.arpa
6.2.194.in-addr.arpa
7.2.194.in-addr.arpa
8.2.194.in-addr.arpa
9.2.194.in-addr.arpa
10.2.194.in-addr.arpa
11.2.194.in-addr.arpa
12.2.194.in-addr.arpa
13.2.194.in-addr.arpa
14.2.194.in-addr.arpa
15.2.194.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
Address11000010.00000010.00000000.00000000194.2.0.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network11000010.00000010.00000000.00000000194.2.0.0
Broadcast11000010.00000010.00111111.11111111194.2.63.255
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)

194.2.0.0/18 makes 4,096 subnets of /30; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1194.2.0.0/30194.2.0.1 to 194.2.0.2194.2.0.32
2194.2.0.4/30194.2.0.5 to 194.2.0.6194.2.0.72
3194.2.0.8/30194.2.0.9 to 194.2.0.10194.2.0.112
4194.2.0.12/30194.2.0.13 to 194.2.0.14194.2.0.152
5194.2.0.16/30194.2.0.17 to 194.2.0.18194.2.0.192
6194.2.0.20/30194.2.0.21 to 194.2.0.22194.2.0.232
7194.2.0.24/30194.2.0.25 to 194.2.0.26194.2.0.272
8194.2.0.28/30194.2.0.29 to 194.2.0.30194.2.0.312
9194.2.0.32/30194.2.0.33 to 194.2.0.34194.2.0.352
10194.2.0.36/30194.2.0.37 to 194.2.0.38194.2.0.392
11194.2.0.40/30194.2.0.41 to 194.2.0.42194.2.0.432
12194.2.0.44/30194.2.0.45 to 194.2.0.46194.2.0.472
13194.2.0.48/30194.2.0.49 to 194.2.0.50194.2.0.512
14194.2.0.52/30194.2.0.53 to 194.2.0.54194.2.0.552
15194.2.0.56/30194.2.0.57 to 194.2.0.58194.2.0.592
16194.2.0.60/30194.2.0.61 to 194.2.0.62194.2.0.632
17194.2.0.64/30194.2.0.65 to 194.2.0.66194.2.0.672
18194.2.0.68/30194.2.0.69 to 194.2.0.70194.2.0.712
19194.2.0.72/30194.2.0.73 to 194.2.0.74194.2.0.752
20194.2.0.76/30194.2.0.77 to 194.2.0.78194.2.0.792
21194.2.0.80/30194.2.0.81 to 194.2.0.82194.2.0.832
22194.2.0.84/30194.2.0.85 to 194.2.0.86194.2.0.872
23194.2.0.88/30194.2.0.89 to 194.2.0.90194.2.0.912
24194.2.0.92/30194.2.0.93 to 194.2.0.94194.2.0.952
25194.2.0.96/30194.2.0.97 to 194.2.0.98194.2.0.992
26194.2.0.100/30194.2.0.101 to 194.2.0.102194.2.0.1032
27194.2.0.104/30194.2.0.105 to 194.2.0.106194.2.0.1072
28194.2.0.108/30194.2.0.109 to 194.2.0.110194.2.0.1112
29194.2.0.112/30194.2.0.113 to 194.2.0.114194.2.0.1152
30194.2.0.116/30194.2.0.117 to 194.2.0.118194.2.0.1192
31194.2.0.120/30194.2.0.121 to 194.2.0.122194.2.0.1232
32194.2.0.124/30194.2.0.125 to 194.2.0.126194.2.0.1272
33194.2.0.128/30194.2.0.129 to 194.2.0.130194.2.0.1312
34194.2.0.132/30194.2.0.133 to 194.2.0.134194.2.0.1352
35194.2.0.136/30194.2.0.137 to 194.2.0.138194.2.0.1392
36194.2.0.140/30194.2.0.141 to 194.2.0.142194.2.0.1432
37194.2.0.144/30194.2.0.145 to 194.2.0.146194.2.0.1472
38194.2.0.148/30194.2.0.149 to 194.2.0.150194.2.0.1512
39194.2.0.152/30194.2.0.153 to 194.2.0.154194.2.0.1552
40194.2.0.156/30194.2.0.157 to 194.2.0.158194.2.0.1592
41194.2.0.160/30194.2.0.161 to 194.2.0.162194.2.0.1632
42194.2.0.164/30194.2.0.165 to 194.2.0.166194.2.0.1672
43194.2.0.168/30194.2.0.169 to 194.2.0.170194.2.0.1712
44194.2.0.172/30194.2.0.173 to 194.2.0.174194.2.0.1752
45194.2.0.176/30194.2.0.177 to 194.2.0.178194.2.0.1792
46194.2.0.180/30194.2.0.181 to 194.2.0.182194.2.0.1832
47194.2.0.184/30194.2.0.185 to 194.2.0.186194.2.0.1872
48194.2.0.188/30194.2.0.189 to 194.2.0.190194.2.0.1912
49194.2.0.192/30194.2.0.193 to 194.2.0.194194.2.0.1952
50194.2.0.196/30194.2.0.197 to 194.2.0.198194.2.0.1992
51194.2.0.200/30194.2.0.201 to 194.2.0.202194.2.0.2032
52194.2.0.204/30194.2.0.205 to 194.2.0.206194.2.0.2072
53194.2.0.208/30194.2.0.209 to 194.2.0.210194.2.0.2112
54194.2.0.212/30194.2.0.213 to 194.2.0.214194.2.0.2152
55194.2.0.216/30194.2.0.217 to 194.2.0.218194.2.0.2192
56194.2.0.220/30194.2.0.221 to 194.2.0.222194.2.0.2232
57194.2.0.224/30194.2.0.225 to 194.2.0.226194.2.0.2272
58194.2.0.228/30194.2.0.229 to 194.2.0.230194.2.0.2312
59194.2.0.232/30194.2.0.233 to 194.2.0.234194.2.0.2352
60194.2.0.236/30194.2.0.237 to 194.2.0.238194.2.0.2392
61194.2.0.240/30194.2.0.241 to 194.2.0.242194.2.0.2432
62194.2.0.244/30194.2.0.245 to 194.2.0.246194.2.0.2472
63194.2.0.248/30194.2.0.249 to 194.2.0.250194.2.0.2512
64194.2.0.252/30194.2.0.253 to 194.2.0.254194.2.0.2552
65194.2.1.0/30194.2.1.1 to 194.2.1.2194.2.1.32
66194.2.1.4/30194.2.1.5 to 194.2.1.6194.2.1.72
67194.2.1.8/30194.2.1.9 to 194.2.1.10194.2.1.112
68194.2.1.12/30194.2.1.13 to 194.2.1.14194.2.1.152
69194.2.1.16/30194.2.1.17 to 194.2.1.18194.2.1.192
70194.2.1.20/30194.2.1.21 to 194.2.1.22194.2.1.232
71194.2.1.24/30194.2.1.25 to 194.2.1.26194.2.1.272
72194.2.1.28/30194.2.1.29 to 194.2.1.30194.2.1.312
73194.2.1.32/30194.2.1.33 to 194.2.1.34194.2.1.352
74194.2.1.36/30194.2.1.37 to 194.2.1.38194.2.1.392
75194.2.1.40/30194.2.1.41 to 194.2.1.42194.2.1.432
76194.2.1.44/30194.2.1.45 to 194.2.1.46194.2.1.472
77194.2.1.48/30194.2.1.49 to 194.2.1.50194.2.1.512
78194.2.1.52/30194.2.1.53 to 194.2.1.54194.2.1.552
79194.2.1.56/30194.2.1.57 to 194.2.1.58194.2.1.592
80194.2.1.60/30194.2.1.61 to 194.2.1.62194.2.1.632
81194.2.1.64/30194.2.1.65 to 194.2.1.66194.2.1.672
82194.2.1.68/30194.2.1.69 to 194.2.1.70194.2.1.712
83194.2.1.72/30194.2.1.73 to 194.2.1.74194.2.1.752
84194.2.1.76/30194.2.1.77 to 194.2.1.78194.2.1.792
85194.2.1.80/30194.2.1.81 to 194.2.1.82194.2.1.832
86194.2.1.84/30194.2.1.85 to 194.2.1.86194.2.1.872
87194.2.1.88/30194.2.1.89 to 194.2.1.90194.2.1.912
88194.2.1.92/30194.2.1.93 to 194.2.1.94194.2.1.952
89194.2.1.96/30194.2.1.97 to 194.2.1.98194.2.1.992
90194.2.1.100/30194.2.1.101 to 194.2.1.102194.2.1.1032
91194.2.1.104/30194.2.1.105 to 194.2.1.106194.2.1.1072
92194.2.1.108/30194.2.1.109 to 194.2.1.110194.2.1.1112
93194.2.1.112/30194.2.1.113 to 194.2.1.114194.2.1.1152
94194.2.1.116/30194.2.1.117 to 194.2.1.118194.2.1.1192
95194.2.1.120/30194.2.1.121 to 194.2.1.122194.2.1.1232
96194.2.1.124/30194.2.1.125 to 194.2.1.126194.2.1.1272
97194.2.1.128/30194.2.1.129 to 194.2.1.130194.2.1.1312
98194.2.1.132/30194.2.1.133 to 194.2.1.134194.2.1.1352
99194.2.1.136/30194.2.1.137 to 194.2.1.138194.2.1.1392
100194.2.1.140/30194.2.1.141 to 194.2.1.142194.2.1.1432
101194.2.1.144/30194.2.1.145 to 194.2.1.146194.2.1.1472
102194.2.1.148/30194.2.1.149 to 194.2.1.150194.2.1.1512
103194.2.1.152/30194.2.1.153 to 194.2.1.154194.2.1.1552
104194.2.1.156/30194.2.1.157 to 194.2.1.158194.2.1.1592
105194.2.1.160/30194.2.1.161 to 194.2.1.162194.2.1.1632
106194.2.1.164/30194.2.1.165 to 194.2.1.166194.2.1.1672
107194.2.1.168/30194.2.1.169 to 194.2.1.170194.2.1.1712
108194.2.1.172/30194.2.1.173 to 194.2.1.174194.2.1.1752
109194.2.1.176/30194.2.1.177 to 194.2.1.178194.2.1.1792
110194.2.1.180/30194.2.1.181 to 194.2.1.182194.2.1.1832
111194.2.1.184/30194.2.1.185 to 194.2.1.186194.2.1.1872
112194.2.1.188/30194.2.1.189 to 194.2.1.190194.2.1.1912
113194.2.1.192/30194.2.1.193 to 194.2.1.194194.2.1.1952
114194.2.1.196/30194.2.1.197 to 194.2.1.198194.2.1.1992
115194.2.1.200/30194.2.1.201 to 194.2.1.202194.2.1.2032
116194.2.1.204/30194.2.1.205 to 194.2.1.206194.2.1.2072
117194.2.1.208/30194.2.1.209 to 194.2.1.210194.2.1.2112
118194.2.1.212/30194.2.1.213 to 194.2.1.214194.2.1.2152
119194.2.1.216/30194.2.1.217 to 194.2.1.218194.2.1.2192
120194.2.1.220/30194.2.1.221 to 194.2.1.222194.2.1.2232
121194.2.1.224/30194.2.1.225 to 194.2.1.226194.2.1.2272
122194.2.1.228/30194.2.1.229 to 194.2.1.230194.2.1.2312
123194.2.1.232/30194.2.1.233 to 194.2.1.234194.2.1.2352
124194.2.1.236/30194.2.1.237 to 194.2.1.238194.2.1.2392
125194.2.1.240/30194.2.1.241 to 194.2.1.242194.2.1.2432
126194.2.1.244/30194.2.1.245 to 194.2.1.246194.2.1.2472
127194.2.1.248/30194.2.1.249 to 194.2.1.250194.2.1.2512
128194.2.1.252/30194.2.1.253 to 194.2.1.254194.2.1.2552
129194.2.2.0/30194.2.2.1 to 194.2.2.2194.2.2.32
130194.2.2.4/30194.2.2.5 to 194.2.2.6194.2.2.72
131194.2.2.8/30194.2.2.9 to 194.2.2.10194.2.2.112
132194.2.2.12/30194.2.2.13 to 194.2.2.14194.2.2.152
133194.2.2.16/30194.2.2.17 to 194.2.2.18194.2.2.192
134194.2.2.20/30194.2.2.21 to 194.2.2.22194.2.2.232
135194.2.2.24/30194.2.2.25 to 194.2.2.26194.2.2.272
136194.2.2.28/30194.2.2.29 to 194.2.2.30194.2.2.312
137194.2.2.32/30194.2.2.33 to 194.2.2.34194.2.2.352
138194.2.2.36/30194.2.2.37 to 194.2.2.38194.2.2.392
139194.2.2.40/30194.2.2.41 to 194.2.2.42194.2.2.432
140194.2.2.44/30194.2.2.45 to 194.2.2.46194.2.2.472
141194.2.2.48/30194.2.2.49 to 194.2.2.50194.2.2.512
142194.2.2.52/30194.2.2.53 to 194.2.2.54194.2.2.552
143194.2.2.56/30194.2.2.57 to 194.2.2.58194.2.2.592
144194.2.2.60/30194.2.2.61 to 194.2.2.62194.2.2.632
145194.2.2.64/30194.2.2.65 to 194.2.2.66194.2.2.672
146194.2.2.68/30194.2.2.69 to 194.2.2.70194.2.2.712
147194.2.2.72/30194.2.2.73 to 194.2.2.74194.2.2.752
148194.2.2.76/30194.2.2.77 to 194.2.2.78194.2.2.792
149194.2.2.80/30194.2.2.81 to 194.2.2.82194.2.2.832
150194.2.2.84/30194.2.2.85 to 194.2.2.86194.2.2.872
151194.2.2.88/30194.2.2.89 to 194.2.2.90194.2.2.912
152194.2.2.92/30194.2.2.93 to 194.2.2.94194.2.2.952
153194.2.2.96/30194.2.2.97 to 194.2.2.98194.2.2.992
154194.2.2.100/30194.2.2.101 to 194.2.2.102194.2.2.1032
155194.2.2.104/30194.2.2.105 to 194.2.2.106194.2.2.1072
156194.2.2.108/30194.2.2.109 to 194.2.2.110194.2.2.1112
157194.2.2.112/30194.2.2.113 to 194.2.2.114194.2.2.1152
158194.2.2.116/30194.2.2.117 to 194.2.2.118194.2.2.1192
159194.2.2.120/30194.2.2.121 to 194.2.2.122194.2.2.1232
160194.2.2.124/30194.2.2.125 to 194.2.2.126194.2.2.1272
161194.2.2.128/30194.2.2.129 to 194.2.2.130194.2.2.1312
162194.2.2.132/30194.2.2.133 to 194.2.2.134194.2.2.1352
163194.2.2.136/30194.2.2.137 to 194.2.2.138194.2.2.1392
164194.2.2.140/30194.2.2.141 to 194.2.2.142194.2.2.1432
165194.2.2.144/30194.2.2.145 to 194.2.2.146194.2.2.1472
166194.2.2.148/30194.2.2.149 to 194.2.2.150194.2.2.1512
167194.2.2.152/30194.2.2.153 to 194.2.2.154194.2.2.1552
168194.2.2.156/30194.2.2.157 to 194.2.2.158194.2.2.1592
169194.2.2.160/30194.2.2.161 to 194.2.2.162194.2.2.1632
170194.2.2.164/30194.2.2.165 to 194.2.2.166194.2.2.1672
171194.2.2.168/30194.2.2.169 to 194.2.2.170194.2.2.1712
172194.2.2.172/30194.2.2.173 to 194.2.2.174194.2.2.1752
173194.2.2.176/30194.2.2.177 to 194.2.2.178194.2.2.1792
174194.2.2.180/30194.2.2.181 to 194.2.2.182194.2.2.1832
175194.2.2.184/30194.2.2.185 to 194.2.2.186194.2.2.1872
176194.2.2.188/30194.2.2.189 to 194.2.2.190194.2.2.1912
177194.2.2.192/30194.2.2.193 to 194.2.2.194194.2.2.1952
178194.2.2.196/30194.2.2.197 to 194.2.2.198194.2.2.1992
179194.2.2.200/30194.2.2.201 to 194.2.2.202194.2.2.2032
180194.2.2.204/30194.2.2.205 to 194.2.2.206194.2.2.2072
181194.2.2.208/30194.2.2.209 to 194.2.2.210194.2.2.2112
182194.2.2.212/30194.2.2.213 to 194.2.2.214194.2.2.2152
183194.2.2.216/30194.2.2.217 to 194.2.2.218194.2.2.2192
184194.2.2.220/30194.2.2.221 to 194.2.2.222194.2.2.2232
185194.2.2.224/30194.2.2.225 to 194.2.2.226194.2.2.2272
186194.2.2.228/30194.2.2.229 to 194.2.2.230194.2.2.2312
187194.2.2.232/30194.2.2.233 to 194.2.2.234194.2.2.2352
188194.2.2.236/30194.2.2.237 to 194.2.2.238194.2.2.2392
189194.2.2.240/30194.2.2.241 to 194.2.2.242194.2.2.2432
190194.2.2.244/30194.2.2.245 to 194.2.2.246194.2.2.2472
191194.2.2.248/30194.2.2.249 to 194.2.2.250194.2.2.2512
192194.2.2.252/30194.2.2.253 to 194.2.2.254194.2.2.2552
193194.2.3.0/30194.2.3.1 to 194.2.3.2194.2.3.32
194194.2.3.4/30194.2.3.5 to 194.2.3.6194.2.3.72
195194.2.3.8/30194.2.3.9 to 194.2.3.10194.2.3.112
196194.2.3.12/30194.2.3.13 to 194.2.3.14194.2.3.152
197194.2.3.16/30194.2.3.17 to 194.2.3.18194.2.3.192
198194.2.3.20/30194.2.3.21 to 194.2.3.22194.2.3.232
199194.2.3.24/30194.2.3.25 to 194.2.3.26194.2.3.272
200194.2.3.28/30194.2.3.29 to 194.2.3.30194.2.3.312
201194.2.3.32/30194.2.3.33 to 194.2.3.34194.2.3.352
202194.2.3.36/30194.2.3.37 to 194.2.3.38194.2.3.392
203194.2.3.40/30194.2.3.41 to 194.2.3.42194.2.3.432
204194.2.3.44/30194.2.3.45 to 194.2.3.46194.2.3.472
205194.2.3.48/30194.2.3.49 to 194.2.3.50194.2.3.512
206194.2.3.52/30194.2.3.53 to 194.2.3.54194.2.3.552
207194.2.3.56/30194.2.3.57 to 194.2.3.58194.2.3.592
208194.2.3.60/30194.2.3.61 to 194.2.3.62194.2.3.632
209194.2.3.64/30194.2.3.65 to 194.2.3.66194.2.3.672
210194.2.3.68/30194.2.3.69 to 194.2.3.70194.2.3.712
211194.2.3.72/30194.2.3.73 to 194.2.3.74194.2.3.752
212194.2.3.76/30194.2.3.77 to 194.2.3.78194.2.3.792
213194.2.3.80/30194.2.3.81 to 194.2.3.82194.2.3.832
214194.2.3.84/30194.2.3.85 to 194.2.3.86194.2.3.872
215194.2.3.88/30194.2.3.89 to 194.2.3.90194.2.3.912
216194.2.3.92/30194.2.3.93 to 194.2.3.94194.2.3.952
217194.2.3.96/30194.2.3.97 to 194.2.3.98194.2.3.992
218194.2.3.100/30194.2.3.101 to 194.2.3.102194.2.3.1032
219194.2.3.104/30194.2.3.105 to 194.2.3.106194.2.3.1072
220194.2.3.108/30194.2.3.109 to 194.2.3.110194.2.3.1112
221194.2.3.112/30194.2.3.113 to 194.2.3.114194.2.3.1152
222194.2.3.116/30194.2.3.117 to 194.2.3.118194.2.3.1192
223194.2.3.120/30194.2.3.121 to 194.2.3.122194.2.3.1232
224194.2.3.124/30194.2.3.125 to 194.2.3.126194.2.3.1272
225194.2.3.128/30194.2.3.129 to 194.2.3.130194.2.3.1312
226194.2.3.132/30194.2.3.133 to 194.2.3.134194.2.3.1352
227194.2.3.136/30194.2.3.137 to 194.2.3.138194.2.3.1392
228194.2.3.140/30194.2.3.141 to 194.2.3.142194.2.3.1432
229194.2.3.144/30194.2.3.145 to 194.2.3.146194.2.3.1472
230194.2.3.148/30194.2.3.149 to 194.2.3.150194.2.3.1512
231194.2.3.152/30194.2.3.153 to 194.2.3.154194.2.3.1552
232194.2.3.156/30194.2.3.157 to 194.2.3.158194.2.3.1592
233194.2.3.160/30194.2.3.161 to 194.2.3.162194.2.3.1632
234194.2.3.164/30194.2.3.165 to 194.2.3.166194.2.3.1672
235194.2.3.168/30194.2.3.169 to 194.2.3.170194.2.3.1712
236194.2.3.172/30194.2.3.173 to 194.2.3.174194.2.3.1752
237194.2.3.176/30194.2.3.177 to 194.2.3.178194.2.3.1792
238194.2.3.180/30194.2.3.181 to 194.2.3.182194.2.3.1832
239194.2.3.184/30194.2.3.185 to 194.2.3.186194.2.3.1872
240194.2.3.188/30194.2.3.189 to 194.2.3.190194.2.3.1912
241194.2.3.192/30194.2.3.193 to 194.2.3.194194.2.3.1952
242194.2.3.196/30194.2.3.197 to 194.2.3.198194.2.3.1992
243194.2.3.200/30194.2.3.201 to 194.2.3.202194.2.3.2032
244194.2.3.204/30194.2.3.205 to 194.2.3.206194.2.3.2072
245194.2.3.208/30194.2.3.209 to 194.2.3.210194.2.3.2112
246194.2.3.212/30194.2.3.213 to 194.2.3.214194.2.3.2152
247194.2.3.216/30194.2.3.217 to 194.2.3.218194.2.3.2192
248194.2.3.220/30194.2.3.221 to 194.2.3.222194.2.3.2232
249194.2.3.224/30194.2.3.225 to 194.2.3.226194.2.3.2272
250194.2.3.228/30194.2.3.229 to 194.2.3.230194.2.3.2312
251194.2.3.232/30194.2.3.233 to 194.2.3.234194.2.3.2352
252194.2.3.236/30194.2.3.237 to 194.2.3.238194.2.3.2392
253194.2.3.240/30194.2.3.241 to 194.2.3.242194.2.3.2432
254194.2.3.244/30194.2.3.245 to 194.2.3.246194.2.3.2472
255194.2.3.248/30194.2.3.249 to 194.2.3.250194.2.3.2512
256194.2.3.252/30194.2.3.253 to 194.2.3.254194.2.3.2552

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.