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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.

Network136.2.232.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
136.2.232.0
Broadcast address
136.2.235.255
First usable
136.2.232.1
Last usable
136.2.235.254
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
B (default /16)
As numbers
Hex 8802E800 · Integer 2281891840 to 2281892863
Reverse DNS zones
232.2.136.in-addr.arpa
233.2.136.in-addr.arpa
234.2.136.in-addr.arpa
235.2.136.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
Address10001000.00000010.11101000.00000000136.2.232.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network10001000.00000010.11101000.00000000136.2.232.0
Broadcast10001000.00000010.11101011.11111111136.2.235.255
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)

136.2.232.0/22 makes 256 subnets of /30.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1136.2.232.0/30136.2.232.1 to 136.2.232.2136.2.232.32
2136.2.232.4/30136.2.232.5 to 136.2.232.6136.2.232.72
3136.2.232.8/30136.2.232.9 to 136.2.232.10136.2.232.112
4136.2.232.12/30136.2.232.13 to 136.2.232.14136.2.232.152
5136.2.232.16/30136.2.232.17 to 136.2.232.18136.2.232.192
6136.2.232.20/30136.2.232.21 to 136.2.232.22136.2.232.232
7136.2.232.24/30136.2.232.25 to 136.2.232.26136.2.232.272
8136.2.232.28/30136.2.232.29 to 136.2.232.30136.2.232.312
9136.2.232.32/30136.2.232.33 to 136.2.232.34136.2.232.352
10136.2.232.36/30136.2.232.37 to 136.2.232.38136.2.232.392
11136.2.232.40/30136.2.232.41 to 136.2.232.42136.2.232.432
12136.2.232.44/30136.2.232.45 to 136.2.232.46136.2.232.472
13136.2.232.48/30136.2.232.49 to 136.2.232.50136.2.232.512
14136.2.232.52/30136.2.232.53 to 136.2.232.54136.2.232.552
15136.2.232.56/30136.2.232.57 to 136.2.232.58136.2.232.592
16136.2.232.60/30136.2.232.61 to 136.2.232.62136.2.232.632
17136.2.232.64/30136.2.232.65 to 136.2.232.66136.2.232.672
18136.2.232.68/30136.2.232.69 to 136.2.232.70136.2.232.712
19136.2.232.72/30136.2.232.73 to 136.2.232.74136.2.232.752
20136.2.232.76/30136.2.232.77 to 136.2.232.78136.2.232.792
21136.2.232.80/30136.2.232.81 to 136.2.232.82136.2.232.832
22136.2.232.84/30136.2.232.85 to 136.2.232.86136.2.232.872
23136.2.232.88/30136.2.232.89 to 136.2.232.90136.2.232.912
24136.2.232.92/30136.2.232.93 to 136.2.232.94136.2.232.952
25136.2.232.96/30136.2.232.97 to 136.2.232.98136.2.232.992
26136.2.232.100/30136.2.232.101 to 136.2.232.102136.2.232.1032
27136.2.232.104/30136.2.232.105 to 136.2.232.106136.2.232.1072
28136.2.232.108/30136.2.232.109 to 136.2.232.110136.2.232.1112
29136.2.232.112/30136.2.232.113 to 136.2.232.114136.2.232.1152
30136.2.232.116/30136.2.232.117 to 136.2.232.118136.2.232.1192
31136.2.232.120/30136.2.232.121 to 136.2.232.122136.2.232.1232
32136.2.232.124/30136.2.232.125 to 136.2.232.126136.2.232.1272
33136.2.232.128/30136.2.232.129 to 136.2.232.130136.2.232.1312
34136.2.232.132/30136.2.232.133 to 136.2.232.134136.2.232.1352
35136.2.232.136/30136.2.232.137 to 136.2.232.138136.2.232.1392
36136.2.232.140/30136.2.232.141 to 136.2.232.142136.2.232.1432
37136.2.232.144/30136.2.232.145 to 136.2.232.146136.2.232.1472
38136.2.232.148/30136.2.232.149 to 136.2.232.150136.2.232.1512
39136.2.232.152/30136.2.232.153 to 136.2.232.154136.2.232.1552
40136.2.232.156/30136.2.232.157 to 136.2.232.158136.2.232.1592
41136.2.232.160/30136.2.232.161 to 136.2.232.162136.2.232.1632
42136.2.232.164/30136.2.232.165 to 136.2.232.166136.2.232.1672
43136.2.232.168/30136.2.232.169 to 136.2.232.170136.2.232.1712
44136.2.232.172/30136.2.232.173 to 136.2.232.174136.2.232.1752
45136.2.232.176/30136.2.232.177 to 136.2.232.178136.2.232.1792
46136.2.232.180/30136.2.232.181 to 136.2.232.182136.2.232.1832
47136.2.232.184/30136.2.232.185 to 136.2.232.186136.2.232.1872
48136.2.232.188/30136.2.232.189 to 136.2.232.190136.2.232.1912
49136.2.232.192/30136.2.232.193 to 136.2.232.194136.2.232.1952
50136.2.232.196/30136.2.232.197 to 136.2.232.198136.2.232.1992
51136.2.232.200/30136.2.232.201 to 136.2.232.202136.2.232.2032
52136.2.232.204/30136.2.232.205 to 136.2.232.206136.2.232.2072
53136.2.232.208/30136.2.232.209 to 136.2.232.210136.2.232.2112
54136.2.232.212/30136.2.232.213 to 136.2.232.214136.2.232.2152
55136.2.232.216/30136.2.232.217 to 136.2.232.218136.2.232.2192
56136.2.232.220/30136.2.232.221 to 136.2.232.222136.2.232.2232
57136.2.232.224/30136.2.232.225 to 136.2.232.226136.2.232.2272
58136.2.232.228/30136.2.232.229 to 136.2.232.230136.2.232.2312
59136.2.232.232/30136.2.232.233 to 136.2.232.234136.2.232.2352
60136.2.232.236/30136.2.232.237 to 136.2.232.238136.2.232.2392
61136.2.232.240/30136.2.232.241 to 136.2.232.242136.2.232.2432
62136.2.232.244/30136.2.232.245 to 136.2.232.246136.2.232.2472
63136.2.232.248/30136.2.232.249 to 136.2.232.250136.2.232.2512
64136.2.232.252/30136.2.232.253 to 136.2.232.254136.2.232.2552
65136.2.233.0/30136.2.233.1 to 136.2.233.2136.2.233.32
66136.2.233.4/30136.2.233.5 to 136.2.233.6136.2.233.72
67136.2.233.8/30136.2.233.9 to 136.2.233.10136.2.233.112
68136.2.233.12/30136.2.233.13 to 136.2.233.14136.2.233.152
69136.2.233.16/30136.2.233.17 to 136.2.233.18136.2.233.192
70136.2.233.20/30136.2.233.21 to 136.2.233.22136.2.233.232
71136.2.233.24/30136.2.233.25 to 136.2.233.26136.2.233.272
72136.2.233.28/30136.2.233.29 to 136.2.233.30136.2.233.312
73136.2.233.32/30136.2.233.33 to 136.2.233.34136.2.233.352
74136.2.233.36/30136.2.233.37 to 136.2.233.38136.2.233.392
75136.2.233.40/30136.2.233.41 to 136.2.233.42136.2.233.432
76136.2.233.44/30136.2.233.45 to 136.2.233.46136.2.233.472
77136.2.233.48/30136.2.233.49 to 136.2.233.50136.2.233.512
78136.2.233.52/30136.2.233.53 to 136.2.233.54136.2.233.552
79136.2.233.56/30136.2.233.57 to 136.2.233.58136.2.233.592
80136.2.233.60/30136.2.233.61 to 136.2.233.62136.2.233.632
81136.2.233.64/30136.2.233.65 to 136.2.233.66136.2.233.672
82136.2.233.68/30136.2.233.69 to 136.2.233.70136.2.233.712
83136.2.233.72/30136.2.233.73 to 136.2.233.74136.2.233.752
84136.2.233.76/30136.2.233.77 to 136.2.233.78136.2.233.792
85136.2.233.80/30136.2.233.81 to 136.2.233.82136.2.233.832
86136.2.233.84/30136.2.233.85 to 136.2.233.86136.2.233.872
87136.2.233.88/30136.2.233.89 to 136.2.233.90136.2.233.912
88136.2.233.92/30136.2.233.93 to 136.2.233.94136.2.233.952
89136.2.233.96/30136.2.233.97 to 136.2.233.98136.2.233.992
90136.2.233.100/30136.2.233.101 to 136.2.233.102136.2.233.1032
91136.2.233.104/30136.2.233.105 to 136.2.233.106136.2.233.1072
92136.2.233.108/30136.2.233.109 to 136.2.233.110136.2.233.1112
93136.2.233.112/30136.2.233.113 to 136.2.233.114136.2.233.1152
94136.2.233.116/30136.2.233.117 to 136.2.233.118136.2.233.1192
95136.2.233.120/30136.2.233.121 to 136.2.233.122136.2.233.1232
96136.2.233.124/30136.2.233.125 to 136.2.233.126136.2.233.1272
97136.2.233.128/30136.2.233.129 to 136.2.233.130136.2.233.1312
98136.2.233.132/30136.2.233.133 to 136.2.233.134136.2.233.1352
99136.2.233.136/30136.2.233.137 to 136.2.233.138136.2.233.1392
100136.2.233.140/30136.2.233.141 to 136.2.233.142136.2.233.1432
101136.2.233.144/30136.2.233.145 to 136.2.233.146136.2.233.1472
102136.2.233.148/30136.2.233.149 to 136.2.233.150136.2.233.1512
103136.2.233.152/30136.2.233.153 to 136.2.233.154136.2.233.1552
104136.2.233.156/30136.2.233.157 to 136.2.233.158136.2.233.1592
105136.2.233.160/30136.2.233.161 to 136.2.233.162136.2.233.1632
106136.2.233.164/30136.2.233.165 to 136.2.233.166136.2.233.1672
107136.2.233.168/30136.2.233.169 to 136.2.233.170136.2.233.1712
108136.2.233.172/30136.2.233.173 to 136.2.233.174136.2.233.1752
109136.2.233.176/30136.2.233.177 to 136.2.233.178136.2.233.1792
110136.2.233.180/30136.2.233.181 to 136.2.233.182136.2.233.1832
111136.2.233.184/30136.2.233.185 to 136.2.233.186136.2.233.1872
112136.2.233.188/30136.2.233.189 to 136.2.233.190136.2.233.1912
113136.2.233.192/30136.2.233.193 to 136.2.233.194136.2.233.1952
114136.2.233.196/30136.2.233.197 to 136.2.233.198136.2.233.1992
115136.2.233.200/30136.2.233.201 to 136.2.233.202136.2.233.2032
116136.2.233.204/30136.2.233.205 to 136.2.233.206136.2.233.2072
117136.2.233.208/30136.2.233.209 to 136.2.233.210136.2.233.2112
118136.2.233.212/30136.2.233.213 to 136.2.233.214136.2.233.2152
119136.2.233.216/30136.2.233.217 to 136.2.233.218136.2.233.2192
120136.2.233.220/30136.2.233.221 to 136.2.233.222136.2.233.2232
121136.2.233.224/30136.2.233.225 to 136.2.233.226136.2.233.2272
122136.2.233.228/30136.2.233.229 to 136.2.233.230136.2.233.2312
123136.2.233.232/30136.2.233.233 to 136.2.233.234136.2.233.2352
124136.2.233.236/30136.2.233.237 to 136.2.233.238136.2.233.2392
125136.2.233.240/30136.2.233.241 to 136.2.233.242136.2.233.2432
126136.2.233.244/30136.2.233.245 to 136.2.233.246136.2.233.2472
127136.2.233.248/30136.2.233.249 to 136.2.233.250136.2.233.2512
128136.2.233.252/30136.2.233.253 to 136.2.233.254136.2.233.2552
129136.2.234.0/30136.2.234.1 to 136.2.234.2136.2.234.32
130136.2.234.4/30136.2.234.5 to 136.2.234.6136.2.234.72
131136.2.234.8/30136.2.234.9 to 136.2.234.10136.2.234.112
132136.2.234.12/30136.2.234.13 to 136.2.234.14136.2.234.152
133136.2.234.16/30136.2.234.17 to 136.2.234.18136.2.234.192
134136.2.234.20/30136.2.234.21 to 136.2.234.22136.2.234.232
135136.2.234.24/30136.2.234.25 to 136.2.234.26136.2.234.272
136136.2.234.28/30136.2.234.29 to 136.2.234.30136.2.234.312
137136.2.234.32/30136.2.234.33 to 136.2.234.34136.2.234.352
138136.2.234.36/30136.2.234.37 to 136.2.234.38136.2.234.392
139136.2.234.40/30136.2.234.41 to 136.2.234.42136.2.234.432
140136.2.234.44/30136.2.234.45 to 136.2.234.46136.2.234.472
141136.2.234.48/30136.2.234.49 to 136.2.234.50136.2.234.512
142136.2.234.52/30136.2.234.53 to 136.2.234.54136.2.234.552
143136.2.234.56/30136.2.234.57 to 136.2.234.58136.2.234.592
144136.2.234.60/30136.2.234.61 to 136.2.234.62136.2.234.632
145136.2.234.64/30136.2.234.65 to 136.2.234.66136.2.234.672
146136.2.234.68/30136.2.234.69 to 136.2.234.70136.2.234.712
147136.2.234.72/30136.2.234.73 to 136.2.234.74136.2.234.752
148136.2.234.76/30136.2.234.77 to 136.2.234.78136.2.234.792
149136.2.234.80/30136.2.234.81 to 136.2.234.82136.2.234.832
150136.2.234.84/30136.2.234.85 to 136.2.234.86136.2.234.872
151136.2.234.88/30136.2.234.89 to 136.2.234.90136.2.234.912
152136.2.234.92/30136.2.234.93 to 136.2.234.94136.2.234.952
153136.2.234.96/30136.2.234.97 to 136.2.234.98136.2.234.992
154136.2.234.100/30136.2.234.101 to 136.2.234.102136.2.234.1032
155136.2.234.104/30136.2.234.105 to 136.2.234.106136.2.234.1072
156136.2.234.108/30136.2.234.109 to 136.2.234.110136.2.234.1112
157136.2.234.112/30136.2.234.113 to 136.2.234.114136.2.234.1152
158136.2.234.116/30136.2.234.117 to 136.2.234.118136.2.234.1192
159136.2.234.120/30136.2.234.121 to 136.2.234.122136.2.234.1232
160136.2.234.124/30136.2.234.125 to 136.2.234.126136.2.234.1272
161136.2.234.128/30136.2.234.129 to 136.2.234.130136.2.234.1312
162136.2.234.132/30136.2.234.133 to 136.2.234.134136.2.234.1352
163136.2.234.136/30136.2.234.137 to 136.2.234.138136.2.234.1392
164136.2.234.140/30136.2.234.141 to 136.2.234.142136.2.234.1432
165136.2.234.144/30136.2.234.145 to 136.2.234.146136.2.234.1472
166136.2.234.148/30136.2.234.149 to 136.2.234.150136.2.234.1512
167136.2.234.152/30136.2.234.153 to 136.2.234.154136.2.234.1552
168136.2.234.156/30136.2.234.157 to 136.2.234.158136.2.234.1592
169136.2.234.160/30136.2.234.161 to 136.2.234.162136.2.234.1632
170136.2.234.164/30136.2.234.165 to 136.2.234.166136.2.234.1672
171136.2.234.168/30136.2.234.169 to 136.2.234.170136.2.234.1712
172136.2.234.172/30136.2.234.173 to 136.2.234.174136.2.234.1752
173136.2.234.176/30136.2.234.177 to 136.2.234.178136.2.234.1792
174136.2.234.180/30136.2.234.181 to 136.2.234.182136.2.234.1832
175136.2.234.184/30136.2.234.185 to 136.2.234.186136.2.234.1872
176136.2.234.188/30136.2.234.189 to 136.2.234.190136.2.234.1912
177136.2.234.192/30136.2.234.193 to 136.2.234.194136.2.234.1952
178136.2.234.196/30136.2.234.197 to 136.2.234.198136.2.234.1992
179136.2.234.200/30136.2.234.201 to 136.2.234.202136.2.234.2032
180136.2.234.204/30136.2.234.205 to 136.2.234.206136.2.234.2072
181136.2.234.208/30136.2.234.209 to 136.2.234.210136.2.234.2112
182136.2.234.212/30136.2.234.213 to 136.2.234.214136.2.234.2152
183136.2.234.216/30136.2.234.217 to 136.2.234.218136.2.234.2192
184136.2.234.220/30136.2.234.221 to 136.2.234.222136.2.234.2232
185136.2.234.224/30136.2.234.225 to 136.2.234.226136.2.234.2272
186136.2.234.228/30136.2.234.229 to 136.2.234.230136.2.234.2312
187136.2.234.232/30136.2.234.233 to 136.2.234.234136.2.234.2352
188136.2.234.236/30136.2.234.237 to 136.2.234.238136.2.234.2392
189136.2.234.240/30136.2.234.241 to 136.2.234.242136.2.234.2432
190136.2.234.244/30136.2.234.245 to 136.2.234.246136.2.234.2472
191136.2.234.248/30136.2.234.249 to 136.2.234.250136.2.234.2512
192136.2.234.252/30136.2.234.253 to 136.2.234.254136.2.234.2552
193136.2.235.0/30136.2.235.1 to 136.2.235.2136.2.235.32
194136.2.235.4/30136.2.235.5 to 136.2.235.6136.2.235.72
195136.2.235.8/30136.2.235.9 to 136.2.235.10136.2.235.112
196136.2.235.12/30136.2.235.13 to 136.2.235.14136.2.235.152
197136.2.235.16/30136.2.235.17 to 136.2.235.18136.2.235.192
198136.2.235.20/30136.2.235.21 to 136.2.235.22136.2.235.232
199136.2.235.24/30136.2.235.25 to 136.2.235.26136.2.235.272
200136.2.235.28/30136.2.235.29 to 136.2.235.30136.2.235.312
201136.2.235.32/30136.2.235.33 to 136.2.235.34136.2.235.352
202136.2.235.36/30136.2.235.37 to 136.2.235.38136.2.235.392
203136.2.235.40/30136.2.235.41 to 136.2.235.42136.2.235.432
204136.2.235.44/30136.2.235.45 to 136.2.235.46136.2.235.472
205136.2.235.48/30136.2.235.49 to 136.2.235.50136.2.235.512
206136.2.235.52/30136.2.235.53 to 136.2.235.54136.2.235.552
207136.2.235.56/30136.2.235.57 to 136.2.235.58136.2.235.592
208136.2.235.60/30136.2.235.61 to 136.2.235.62136.2.235.632
209136.2.235.64/30136.2.235.65 to 136.2.235.66136.2.235.672
210136.2.235.68/30136.2.235.69 to 136.2.235.70136.2.235.712
211136.2.235.72/30136.2.235.73 to 136.2.235.74136.2.235.752
212136.2.235.76/30136.2.235.77 to 136.2.235.78136.2.235.792
213136.2.235.80/30136.2.235.81 to 136.2.235.82136.2.235.832
214136.2.235.84/30136.2.235.85 to 136.2.235.86136.2.235.872
215136.2.235.88/30136.2.235.89 to 136.2.235.90136.2.235.912
216136.2.235.92/30136.2.235.93 to 136.2.235.94136.2.235.952
217136.2.235.96/30136.2.235.97 to 136.2.235.98136.2.235.992
218136.2.235.100/30136.2.235.101 to 136.2.235.102136.2.235.1032
219136.2.235.104/30136.2.235.105 to 136.2.235.106136.2.235.1072
220136.2.235.108/30136.2.235.109 to 136.2.235.110136.2.235.1112
221136.2.235.112/30136.2.235.113 to 136.2.235.114136.2.235.1152
222136.2.235.116/30136.2.235.117 to 136.2.235.118136.2.235.1192
223136.2.235.120/30136.2.235.121 to 136.2.235.122136.2.235.1232
224136.2.235.124/30136.2.235.125 to 136.2.235.126136.2.235.1272
225136.2.235.128/30136.2.235.129 to 136.2.235.130136.2.235.1312
226136.2.235.132/30136.2.235.133 to 136.2.235.134136.2.235.1352
227136.2.235.136/30136.2.235.137 to 136.2.235.138136.2.235.1392
228136.2.235.140/30136.2.235.141 to 136.2.235.142136.2.235.1432
229136.2.235.144/30136.2.235.145 to 136.2.235.146136.2.235.1472
230136.2.235.148/30136.2.235.149 to 136.2.235.150136.2.235.1512
231136.2.235.152/30136.2.235.153 to 136.2.235.154136.2.235.1552
232136.2.235.156/30136.2.235.157 to 136.2.235.158136.2.235.1592
233136.2.235.160/30136.2.235.161 to 136.2.235.162136.2.235.1632
234136.2.235.164/30136.2.235.165 to 136.2.235.166136.2.235.1672
235136.2.235.168/30136.2.235.169 to 136.2.235.170136.2.235.1712
236136.2.235.172/30136.2.235.173 to 136.2.235.174136.2.235.1752
237136.2.235.176/30136.2.235.177 to 136.2.235.178136.2.235.1792
238136.2.235.180/30136.2.235.181 to 136.2.235.182136.2.235.1832
239136.2.235.184/30136.2.235.185 to 136.2.235.186136.2.235.1872
240136.2.235.188/30136.2.235.189 to 136.2.235.190136.2.235.1912
241136.2.235.192/30136.2.235.193 to 136.2.235.194136.2.235.1952
242136.2.235.196/30136.2.235.197 to 136.2.235.198136.2.235.1992
243136.2.235.200/30136.2.235.201 to 136.2.235.202136.2.235.2032
244136.2.235.204/30136.2.235.205 to 136.2.235.206136.2.235.2072
245136.2.235.208/30136.2.235.209 to 136.2.235.210136.2.235.2112
246136.2.235.212/30136.2.235.213 to 136.2.235.214136.2.235.2152
247136.2.235.216/30136.2.235.217 to 136.2.235.218136.2.235.2192
248136.2.235.220/30136.2.235.221 to 136.2.235.222136.2.235.2232
249136.2.235.224/30136.2.235.225 to 136.2.235.226136.2.235.2272
250136.2.235.228/30136.2.235.229 to 136.2.235.230136.2.235.2312
251136.2.235.232/30136.2.235.233 to 136.2.235.234136.2.235.2352
252136.2.235.236/30136.2.235.237 to 136.2.235.238136.2.235.2392
253136.2.235.240/30136.2.235.241 to 136.2.235.242136.2.235.2432
254136.2.235.244/30136.2.235.245 to 136.2.235.246136.2.235.2472
255136.2.235.248/30136.2.235.249 to 136.2.235.250136.2.235.2512
256136.2.235.252/30136.2.235.253 to 136.2.235.254136.2.235.2552

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.