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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.

Network152.2.112.0/20
Usable hosts4,094
Subnet mask255.255.240.0
Addresses4,096
Network address
152.2.112.0
Broadcast address
152.2.127.255
First usable
152.2.112.1
Last usable
152.2.127.254
Usable hosts
4,094 (4,096 less the network and broadcast addresses)
Subnet mask
255.255.240.0
Wildcard mask
0.0.15.255 (Cisco ACLs, OSPF)
Prefix length
/20
Type
Public public
Old class
B (default /16)
As numbers
Hex 98027000 · Integer 2550296576 to 2550300671
Reverse DNS zones
112.2.152.in-addr.arpa
113.2.152.in-addr.arpa
114.2.152.in-addr.arpa
115.2.152.in-addr.arpa
116.2.152.in-addr.arpa
117.2.152.in-addr.arpa
118.2.152.in-addr.arpa
119.2.152.in-addr.arpa
120.2.152.in-addr.arpa
121.2.152.in-addr.arpa
122.2.152.in-addr.arpa
123.2.152.in-addr.arpa
124.2.152.in-addr.arpa
125.2.152.in-addr.arpa
126.2.152.in-addr.arpa
127.2.152.in-addr.arpa
/20 is not on a 8-bit boundary, so it takes 16 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011000.00000010.01110000.00000000152.2.112.0
Subnet mask11111111.11111111.11110000.00000000255.255.240.0
Network10011000.00000010.01110000.00000000152.2.112.0
Broadcast10011000.00000010.01111111.11111111152.2.127.255
Split into smaller subnets/32
/21 (2)/22 (4)/23 (8)/24 (16)/25 (32)/26 (64)/27 (128)/28 (256)/29 (512)/30 (1,024)/31 (2,048)/32 (4,096)

152.2.112.0/20 makes 4,096 subnets of /32; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1152.2.112.0/32152.2.112.0 to 152.2.112.0—1
2152.2.112.1/32152.2.112.1 to 152.2.112.1—1
3152.2.112.2/32152.2.112.2 to 152.2.112.2—1
4152.2.112.3/32152.2.112.3 to 152.2.112.3—1
5152.2.112.4/32152.2.112.4 to 152.2.112.4—1
6152.2.112.5/32152.2.112.5 to 152.2.112.5—1
7152.2.112.6/32152.2.112.6 to 152.2.112.6—1
8152.2.112.7/32152.2.112.7 to 152.2.112.7—1
9152.2.112.8/32152.2.112.8 to 152.2.112.8—1
10152.2.112.9/32152.2.112.9 to 152.2.112.9—1
11152.2.112.10/32152.2.112.10 to 152.2.112.10—1
12152.2.112.11/32152.2.112.11 to 152.2.112.11—1
13152.2.112.12/32152.2.112.12 to 152.2.112.12—1
14152.2.112.13/32152.2.112.13 to 152.2.112.13—1
15152.2.112.14/32152.2.112.14 to 152.2.112.14—1
16152.2.112.15/32152.2.112.15 to 152.2.112.15—1
17152.2.112.16/32152.2.112.16 to 152.2.112.16—1
18152.2.112.17/32152.2.112.17 to 152.2.112.17—1
19152.2.112.18/32152.2.112.18 to 152.2.112.18—1
20152.2.112.19/32152.2.112.19 to 152.2.112.19—1
21152.2.112.20/32152.2.112.20 to 152.2.112.20—1
22152.2.112.21/32152.2.112.21 to 152.2.112.21—1
23152.2.112.22/32152.2.112.22 to 152.2.112.22—1
24152.2.112.23/32152.2.112.23 to 152.2.112.23—1
25152.2.112.24/32152.2.112.24 to 152.2.112.24—1
26152.2.112.25/32152.2.112.25 to 152.2.112.25—1
27152.2.112.26/32152.2.112.26 to 152.2.112.26—1
28152.2.112.27/32152.2.112.27 to 152.2.112.27—1
29152.2.112.28/32152.2.112.28 to 152.2.112.28—1
30152.2.112.29/32152.2.112.29 to 152.2.112.29—1
31152.2.112.30/32152.2.112.30 to 152.2.112.30—1
32152.2.112.31/32152.2.112.31 to 152.2.112.31—1
33152.2.112.32/32152.2.112.32 to 152.2.112.32—1
34152.2.112.33/32152.2.112.33 to 152.2.112.33—1
35152.2.112.34/32152.2.112.34 to 152.2.112.34—1
36152.2.112.35/32152.2.112.35 to 152.2.112.35—1
37152.2.112.36/32152.2.112.36 to 152.2.112.36—1
38152.2.112.37/32152.2.112.37 to 152.2.112.37—1
39152.2.112.38/32152.2.112.38 to 152.2.112.38—1
40152.2.112.39/32152.2.112.39 to 152.2.112.39—1
41152.2.112.40/32152.2.112.40 to 152.2.112.40—1
42152.2.112.41/32152.2.112.41 to 152.2.112.41—1
43152.2.112.42/32152.2.112.42 to 152.2.112.42—1
44152.2.112.43/32152.2.112.43 to 152.2.112.43—1
45152.2.112.44/32152.2.112.44 to 152.2.112.44—1
46152.2.112.45/32152.2.112.45 to 152.2.112.45—1
47152.2.112.46/32152.2.112.46 to 152.2.112.46—1
48152.2.112.47/32152.2.112.47 to 152.2.112.47—1
49152.2.112.48/32152.2.112.48 to 152.2.112.48—1
50152.2.112.49/32152.2.112.49 to 152.2.112.49—1
51152.2.112.50/32152.2.112.50 to 152.2.112.50—1
52152.2.112.51/32152.2.112.51 to 152.2.112.51—1
53152.2.112.52/32152.2.112.52 to 152.2.112.52—1
54152.2.112.53/32152.2.112.53 to 152.2.112.53—1
55152.2.112.54/32152.2.112.54 to 152.2.112.54—1
56152.2.112.55/32152.2.112.55 to 152.2.112.55—1
57152.2.112.56/32152.2.112.56 to 152.2.112.56—1
58152.2.112.57/32152.2.112.57 to 152.2.112.57—1
59152.2.112.58/32152.2.112.58 to 152.2.112.58—1
60152.2.112.59/32152.2.112.59 to 152.2.112.59—1
61152.2.112.60/32152.2.112.60 to 152.2.112.60—1
62152.2.112.61/32152.2.112.61 to 152.2.112.61—1
63152.2.112.62/32152.2.112.62 to 152.2.112.62—1
64152.2.112.63/32152.2.112.63 to 152.2.112.63—1
65152.2.112.64/32152.2.112.64 to 152.2.112.64—1
66152.2.112.65/32152.2.112.65 to 152.2.112.65—1
67152.2.112.66/32152.2.112.66 to 152.2.112.66—1
68152.2.112.67/32152.2.112.67 to 152.2.112.67—1
69152.2.112.68/32152.2.112.68 to 152.2.112.68—1
70152.2.112.69/32152.2.112.69 to 152.2.112.69—1
71152.2.112.70/32152.2.112.70 to 152.2.112.70—1
72152.2.112.71/32152.2.112.71 to 152.2.112.71—1
73152.2.112.72/32152.2.112.72 to 152.2.112.72—1
74152.2.112.73/32152.2.112.73 to 152.2.112.73—1
75152.2.112.74/32152.2.112.74 to 152.2.112.74—1
76152.2.112.75/32152.2.112.75 to 152.2.112.75—1
77152.2.112.76/32152.2.112.76 to 152.2.112.76—1
78152.2.112.77/32152.2.112.77 to 152.2.112.77—1
79152.2.112.78/32152.2.112.78 to 152.2.112.78—1
80152.2.112.79/32152.2.112.79 to 152.2.112.79—1
81152.2.112.80/32152.2.112.80 to 152.2.112.80—1
82152.2.112.81/32152.2.112.81 to 152.2.112.81—1
83152.2.112.82/32152.2.112.82 to 152.2.112.82—1
84152.2.112.83/32152.2.112.83 to 152.2.112.83—1
85152.2.112.84/32152.2.112.84 to 152.2.112.84—1
86152.2.112.85/32152.2.112.85 to 152.2.112.85—1
87152.2.112.86/32152.2.112.86 to 152.2.112.86—1
88152.2.112.87/32152.2.112.87 to 152.2.112.87—1
89152.2.112.88/32152.2.112.88 to 152.2.112.88—1
90152.2.112.89/32152.2.112.89 to 152.2.112.89—1
91152.2.112.90/32152.2.112.90 to 152.2.112.90—1
92152.2.112.91/32152.2.112.91 to 152.2.112.91—1
93152.2.112.92/32152.2.112.92 to 152.2.112.92—1
94152.2.112.93/32152.2.112.93 to 152.2.112.93—1
95152.2.112.94/32152.2.112.94 to 152.2.112.94—1
96152.2.112.95/32152.2.112.95 to 152.2.112.95—1
97152.2.112.96/32152.2.112.96 to 152.2.112.96—1
98152.2.112.97/32152.2.112.97 to 152.2.112.97—1
99152.2.112.98/32152.2.112.98 to 152.2.112.98—1
100152.2.112.99/32152.2.112.99 to 152.2.112.99—1
101152.2.112.100/32152.2.112.100 to 152.2.112.100—1
102152.2.112.101/32152.2.112.101 to 152.2.112.101—1
103152.2.112.102/32152.2.112.102 to 152.2.112.102—1
104152.2.112.103/32152.2.112.103 to 152.2.112.103—1
105152.2.112.104/32152.2.112.104 to 152.2.112.104—1
106152.2.112.105/32152.2.112.105 to 152.2.112.105—1
107152.2.112.106/32152.2.112.106 to 152.2.112.106—1
108152.2.112.107/32152.2.112.107 to 152.2.112.107—1
109152.2.112.108/32152.2.112.108 to 152.2.112.108—1
110152.2.112.109/32152.2.112.109 to 152.2.112.109—1
111152.2.112.110/32152.2.112.110 to 152.2.112.110—1
112152.2.112.111/32152.2.112.111 to 152.2.112.111—1
113152.2.112.112/32152.2.112.112 to 152.2.112.112—1
114152.2.112.113/32152.2.112.113 to 152.2.112.113—1
115152.2.112.114/32152.2.112.114 to 152.2.112.114—1
116152.2.112.115/32152.2.112.115 to 152.2.112.115—1
117152.2.112.116/32152.2.112.116 to 152.2.112.116—1
118152.2.112.117/32152.2.112.117 to 152.2.112.117—1
119152.2.112.118/32152.2.112.118 to 152.2.112.118—1
120152.2.112.119/32152.2.112.119 to 152.2.112.119—1
121152.2.112.120/32152.2.112.120 to 152.2.112.120—1
122152.2.112.121/32152.2.112.121 to 152.2.112.121—1
123152.2.112.122/32152.2.112.122 to 152.2.112.122—1
124152.2.112.123/32152.2.112.123 to 152.2.112.123—1
125152.2.112.124/32152.2.112.124 to 152.2.112.124—1
126152.2.112.125/32152.2.112.125 to 152.2.112.125—1
127152.2.112.126/32152.2.112.126 to 152.2.112.126—1
128152.2.112.127/32152.2.112.127 to 152.2.112.127—1
129152.2.112.128/32152.2.112.128 to 152.2.112.128—1
130152.2.112.129/32152.2.112.129 to 152.2.112.129—1
131152.2.112.130/32152.2.112.130 to 152.2.112.130—1
132152.2.112.131/32152.2.112.131 to 152.2.112.131—1
133152.2.112.132/32152.2.112.132 to 152.2.112.132—1
134152.2.112.133/32152.2.112.133 to 152.2.112.133—1
135152.2.112.134/32152.2.112.134 to 152.2.112.134—1
136152.2.112.135/32152.2.112.135 to 152.2.112.135—1
137152.2.112.136/32152.2.112.136 to 152.2.112.136—1
138152.2.112.137/32152.2.112.137 to 152.2.112.137—1
139152.2.112.138/32152.2.112.138 to 152.2.112.138—1
140152.2.112.139/32152.2.112.139 to 152.2.112.139—1
141152.2.112.140/32152.2.112.140 to 152.2.112.140—1
142152.2.112.141/32152.2.112.141 to 152.2.112.141—1
143152.2.112.142/32152.2.112.142 to 152.2.112.142—1
144152.2.112.143/32152.2.112.143 to 152.2.112.143—1
145152.2.112.144/32152.2.112.144 to 152.2.112.144—1
146152.2.112.145/32152.2.112.145 to 152.2.112.145—1
147152.2.112.146/32152.2.112.146 to 152.2.112.146—1
148152.2.112.147/32152.2.112.147 to 152.2.112.147—1
149152.2.112.148/32152.2.112.148 to 152.2.112.148—1
150152.2.112.149/32152.2.112.149 to 152.2.112.149—1
151152.2.112.150/32152.2.112.150 to 152.2.112.150—1
152152.2.112.151/32152.2.112.151 to 152.2.112.151—1
153152.2.112.152/32152.2.112.152 to 152.2.112.152—1
154152.2.112.153/32152.2.112.153 to 152.2.112.153—1
155152.2.112.154/32152.2.112.154 to 152.2.112.154—1
156152.2.112.155/32152.2.112.155 to 152.2.112.155—1
157152.2.112.156/32152.2.112.156 to 152.2.112.156—1
158152.2.112.157/32152.2.112.157 to 152.2.112.157—1
159152.2.112.158/32152.2.112.158 to 152.2.112.158—1
160152.2.112.159/32152.2.112.159 to 152.2.112.159—1
161152.2.112.160/32152.2.112.160 to 152.2.112.160—1
162152.2.112.161/32152.2.112.161 to 152.2.112.161—1
163152.2.112.162/32152.2.112.162 to 152.2.112.162—1
164152.2.112.163/32152.2.112.163 to 152.2.112.163—1
165152.2.112.164/32152.2.112.164 to 152.2.112.164—1
166152.2.112.165/32152.2.112.165 to 152.2.112.165—1
167152.2.112.166/32152.2.112.166 to 152.2.112.166—1
168152.2.112.167/32152.2.112.167 to 152.2.112.167—1
169152.2.112.168/32152.2.112.168 to 152.2.112.168—1
170152.2.112.169/32152.2.112.169 to 152.2.112.169—1
171152.2.112.170/32152.2.112.170 to 152.2.112.170—1
172152.2.112.171/32152.2.112.171 to 152.2.112.171—1
173152.2.112.172/32152.2.112.172 to 152.2.112.172—1
174152.2.112.173/32152.2.112.173 to 152.2.112.173—1
175152.2.112.174/32152.2.112.174 to 152.2.112.174—1
176152.2.112.175/32152.2.112.175 to 152.2.112.175—1
177152.2.112.176/32152.2.112.176 to 152.2.112.176—1
178152.2.112.177/32152.2.112.177 to 152.2.112.177—1
179152.2.112.178/32152.2.112.178 to 152.2.112.178—1
180152.2.112.179/32152.2.112.179 to 152.2.112.179—1
181152.2.112.180/32152.2.112.180 to 152.2.112.180—1
182152.2.112.181/32152.2.112.181 to 152.2.112.181—1
183152.2.112.182/32152.2.112.182 to 152.2.112.182—1
184152.2.112.183/32152.2.112.183 to 152.2.112.183—1
185152.2.112.184/32152.2.112.184 to 152.2.112.184—1
186152.2.112.185/32152.2.112.185 to 152.2.112.185—1
187152.2.112.186/32152.2.112.186 to 152.2.112.186—1
188152.2.112.187/32152.2.112.187 to 152.2.112.187—1
189152.2.112.188/32152.2.112.188 to 152.2.112.188—1
190152.2.112.189/32152.2.112.189 to 152.2.112.189—1
191152.2.112.190/32152.2.112.190 to 152.2.112.190—1
192152.2.112.191/32152.2.112.191 to 152.2.112.191—1
193152.2.112.192/32152.2.112.192 to 152.2.112.192—1
194152.2.112.193/32152.2.112.193 to 152.2.112.193—1
195152.2.112.194/32152.2.112.194 to 152.2.112.194—1
196152.2.112.195/32152.2.112.195 to 152.2.112.195—1
197152.2.112.196/32152.2.112.196 to 152.2.112.196—1
198152.2.112.197/32152.2.112.197 to 152.2.112.197—1
199152.2.112.198/32152.2.112.198 to 152.2.112.198—1
200152.2.112.199/32152.2.112.199 to 152.2.112.199—1
201152.2.112.200/32152.2.112.200 to 152.2.112.200—1
202152.2.112.201/32152.2.112.201 to 152.2.112.201—1
203152.2.112.202/32152.2.112.202 to 152.2.112.202—1
204152.2.112.203/32152.2.112.203 to 152.2.112.203—1
205152.2.112.204/32152.2.112.204 to 152.2.112.204—1
206152.2.112.205/32152.2.112.205 to 152.2.112.205—1
207152.2.112.206/32152.2.112.206 to 152.2.112.206—1
208152.2.112.207/32152.2.112.207 to 152.2.112.207—1
209152.2.112.208/32152.2.112.208 to 152.2.112.208—1
210152.2.112.209/32152.2.112.209 to 152.2.112.209—1
211152.2.112.210/32152.2.112.210 to 152.2.112.210—1
212152.2.112.211/32152.2.112.211 to 152.2.112.211—1
213152.2.112.212/32152.2.112.212 to 152.2.112.212—1
214152.2.112.213/32152.2.112.213 to 152.2.112.213—1
215152.2.112.214/32152.2.112.214 to 152.2.112.214—1
216152.2.112.215/32152.2.112.215 to 152.2.112.215—1
217152.2.112.216/32152.2.112.216 to 152.2.112.216—1
218152.2.112.217/32152.2.112.217 to 152.2.112.217—1
219152.2.112.218/32152.2.112.218 to 152.2.112.218—1
220152.2.112.219/32152.2.112.219 to 152.2.112.219—1
221152.2.112.220/32152.2.112.220 to 152.2.112.220—1
222152.2.112.221/32152.2.112.221 to 152.2.112.221—1
223152.2.112.222/32152.2.112.222 to 152.2.112.222—1
224152.2.112.223/32152.2.112.223 to 152.2.112.223—1
225152.2.112.224/32152.2.112.224 to 152.2.112.224—1
226152.2.112.225/32152.2.112.225 to 152.2.112.225—1
227152.2.112.226/32152.2.112.226 to 152.2.112.226—1
228152.2.112.227/32152.2.112.227 to 152.2.112.227—1
229152.2.112.228/32152.2.112.228 to 152.2.112.228—1
230152.2.112.229/32152.2.112.229 to 152.2.112.229—1
231152.2.112.230/32152.2.112.230 to 152.2.112.230—1
232152.2.112.231/32152.2.112.231 to 152.2.112.231—1
233152.2.112.232/32152.2.112.232 to 152.2.112.232—1
234152.2.112.233/32152.2.112.233 to 152.2.112.233—1
235152.2.112.234/32152.2.112.234 to 152.2.112.234—1
236152.2.112.235/32152.2.112.235 to 152.2.112.235—1
237152.2.112.236/32152.2.112.236 to 152.2.112.236—1
238152.2.112.237/32152.2.112.237 to 152.2.112.237—1
239152.2.112.238/32152.2.112.238 to 152.2.112.238—1
240152.2.112.239/32152.2.112.239 to 152.2.112.239—1
241152.2.112.240/32152.2.112.240 to 152.2.112.240—1
242152.2.112.241/32152.2.112.241 to 152.2.112.241—1
243152.2.112.242/32152.2.112.242 to 152.2.112.242—1
244152.2.112.243/32152.2.112.243 to 152.2.112.243—1
245152.2.112.244/32152.2.112.244 to 152.2.112.244—1
246152.2.112.245/32152.2.112.245 to 152.2.112.245—1
247152.2.112.246/32152.2.112.246 to 152.2.112.246—1
248152.2.112.247/32152.2.112.247 to 152.2.112.247—1
249152.2.112.248/32152.2.112.248 to 152.2.112.248—1
250152.2.112.249/32152.2.112.249 to 152.2.112.249—1
251152.2.112.250/32152.2.112.250 to 152.2.112.250—1
252152.2.112.251/32152.2.112.251 to 152.2.112.251—1
253152.2.112.252/32152.2.112.252 to 152.2.112.252—1
254152.2.112.253/32152.2.112.253 to 152.2.112.253—1
255152.2.112.254/32152.2.112.254 to 152.2.112.254—1
256152.2.112.255/32152.2.112.255 to 152.2.112.255—1

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.