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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.

Network235.2.192.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
235.2.192.0
Broadcast address
235.2.195.255
First usable
235.2.192.1
Last usable
235.2.195.254
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
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex EB02C000 · Integer 3942825984 to 3942827007
Reverse DNS zones
192.2.235.in-addr.arpa
193.2.235.in-addr.arpa
194.2.235.in-addr.arpa
195.2.235.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
Address11101011.00000010.11000000.00000000235.2.192.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network11101011.00000010.11000000.00000000235.2.192.0
Broadcast11101011.00000010.11000011.11111111235.2.195.255
Split into smaller subnets/32
/23 (2)/24 (4)/25 (8)/26 (16)/27 (32)/28 (64)/29 (128)/30 (256)/31 (512)/32 (1,024)

235.2.192.0/22 makes 1,024 subnets of /32; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1235.2.192.0/32235.2.192.0 to 235.2.192.0—1
2235.2.192.1/32235.2.192.1 to 235.2.192.1—1
3235.2.192.2/32235.2.192.2 to 235.2.192.2—1
4235.2.192.3/32235.2.192.3 to 235.2.192.3—1
5235.2.192.4/32235.2.192.4 to 235.2.192.4—1
6235.2.192.5/32235.2.192.5 to 235.2.192.5—1
7235.2.192.6/32235.2.192.6 to 235.2.192.6—1
8235.2.192.7/32235.2.192.7 to 235.2.192.7—1
9235.2.192.8/32235.2.192.8 to 235.2.192.8—1
10235.2.192.9/32235.2.192.9 to 235.2.192.9—1
11235.2.192.10/32235.2.192.10 to 235.2.192.10—1
12235.2.192.11/32235.2.192.11 to 235.2.192.11—1
13235.2.192.12/32235.2.192.12 to 235.2.192.12—1
14235.2.192.13/32235.2.192.13 to 235.2.192.13—1
15235.2.192.14/32235.2.192.14 to 235.2.192.14—1
16235.2.192.15/32235.2.192.15 to 235.2.192.15—1
17235.2.192.16/32235.2.192.16 to 235.2.192.16—1
18235.2.192.17/32235.2.192.17 to 235.2.192.17—1
19235.2.192.18/32235.2.192.18 to 235.2.192.18—1
20235.2.192.19/32235.2.192.19 to 235.2.192.19—1
21235.2.192.20/32235.2.192.20 to 235.2.192.20—1
22235.2.192.21/32235.2.192.21 to 235.2.192.21—1
23235.2.192.22/32235.2.192.22 to 235.2.192.22—1
24235.2.192.23/32235.2.192.23 to 235.2.192.23—1
25235.2.192.24/32235.2.192.24 to 235.2.192.24—1
26235.2.192.25/32235.2.192.25 to 235.2.192.25—1
27235.2.192.26/32235.2.192.26 to 235.2.192.26—1
28235.2.192.27/32235.2.192.27 to 235.2.192.27—1
29235.2.192.28/32235.2.192.28 to 235.2.192.28—1
30235.2.192.29/32235.2.192.29 to 235.2.192.29—1
31235.2.192.30/32235.2.192.30 to 235.2.192.30—1
32235.2.192.31/32235.2.192.31 to 235.2.192.31—1
33235.2.192.32/32235.2.192.32 to 235.2.192.32—1
34235.2.192.33/32235.2.192.33 to 235.2.192.33—1
35235.2.192.34/32235.2.192.34 to 235.2.192.34—1
36235.2.192.35/32235.2.192.35 to 235.2.192.35—1
37235.2.192.36/32235.2.192.36 to 235.2.192.36—1
38235.2.192.37/32235.2.192.37 to 235.2.192.37—1
39235.2.192.38/32235.2.192.38 to 235.2.192.38—1
40235.2.192.39/32235.2.192.39 to 235.2.192.39—1
41235.2.192.40/32235.2.192.40 to 235.2.192.40—1
42235.2.192.41/32235.2.192.41 to 235.2.192.41—1
43235.2.192.42/32235.2.192.42 to 235.2.192.42—1
44235.2.192.43/32235.2.192.43 to 235.2.192.43—1
45235.2.192.44/32235.2.192.44 to 235.2.192.44—1
46235.2.192.45/32235.2.192.45 to 235.2.192.45—1
47235.2.192.46/32235.2.192.46 to 235.2.192.46—1
48235.2.192.47/32235.2.192.47 to 235.2.192.47—1
49235.2.192.48/32235.2.192.48 to 235.2.192.48—1
50235.2.192.49/32235.2.192.49 to 235.2.192.49—1
51235.2.192.50/32235.2.192.50 to 235.2.192.50—1
52235.2.192.51/32235.2.192.51 to 235.2.192.51—1
53235.2.192.52/32235.2.192.52 to 235.2.192.52—1
54235.2.192.53/32235.2.192.53 to 235.2.192.53—1
55235.2.192.54/32235.2.192.54 to 235.2.192.54—1
56235.2.192.55/32235.2.192.55 to 235.2.192.55—1
57235.2.192.56/32235.2.192.56 to 235.2.192.56—1
58235.2.192.57/32235.2.192.57 to 235.2.192.57—1
59235.2.192.58/32235.2.192.58 to 235.2.192.58—1
60235.2.192.59/32235.2.192.59 to 235.2.192.59—1
61235.2.192.60/32235.2.192.60 to 235.2.192.60—1
62235.2.192.61/32235.2.192.61 to 235.2.192.61—1
63235.2.192.62/32235.2.192.62 to 235.2.192.62—1
64235.2.192.63/32235.2.192.63 to 235.2.192.63—1
65235.2.192.64/32235.2.192.64 to 235.2.192.64—1
66235.2.192.65/32235.2.192.65 to 235.2.192.65—1
67235.2.192.66/32235.2.192.66 to 235.2.192.66—1
68235.2.192.67/32235.2.192.67 to 235.2.192.67—1
69235.2.192.68/32235.2.192.68 to 235.2.192.68—1
70235.2.192.69/32235.2.192.69 to 235.2.192.69—1
71235.2.192.70/32235.2.192.70 to 235.2.192.70—1
72235.2.192.71/32235.2.192.71 to 235.2.192.71—1
73235.2.192.72/32235.2.192.72 to 235.2.192.72—1
74235.2.192.73/32235.2.192.73 to 235.2.192.73—1
75235.2.192.74/32235.2.192.74 to 235.2.192.74—1
76235.2.192.75/32235.2.192.75 to 235.2.192.75—1
77235.2.192.76/32235.2.192.76 to 235.2.192.76—1
78235.2.192.77/32235.2.192.77 to 235.2.192.77—1
79235.2.192.78/32235.2.192.78 to 235.2.192.78—1
80235.2.192.79/32235.2.192.79 to 235.2.192.79—1
81235.2.192.80/32235.2.192.80 to 235.2.192.80—1
82235.2.192.81/32235.2.192.81 to 235.2.192.81—1
83235.2.192.82/32235.2.192.82 to 235.2.192.82—1
84235.2.192.83/32235.2.192.83 to 235.2.192.83—1
85235.2.192.84/32235.2.192.84 to 235.2.192.84—1
86235.2.192.85/32235.2.192.85 to 235.2.192.85—1
87235.2.192.86/32235.2.192.86 to 235.2.192.86—1
88235.2.192.87/32235.2.192.87 to 235.2.192.87—1
89235.2.192.88/32235.2.192.88 to 235.2.192.88—1
90235.2.192.89/32235.2.192.89 to 235.2.192.89—1
91235.2.192.90/32235.2.192.90 to 235.2.192.90—1
92235.2.192.91/32235.2.192.91 to 235.2.192.91—1
93235.2.192.92/32235.2.192.92 to 235.2.192.92—1
94235.2.192.93/32235.2.192.93 to 235.2.192.93—1
95235.2.192.94/32235.2.192.94 to 235.2.192.94—1
96235.2.192.95/32235.2.192.95 to 235.2.192.95—1
97235.2.192.96/32235.2.192.96 to 235.2.192.96—1
98235.2.192.97/32235.2.192.97 to 235.2.192.97—1
99235.2.192.98/32235.2.192.98 to 235.2.192.98—1
100235.2.192.99/32235.2.192.99 to 235.2.192.99—1
101235.2.192.100/32235.2.192.100 to 235.2.192.100—1
102235.2.192.101/32235.2.192.101 to 235.2.192.101—1
103235.2.192.102/32235.2.192.102 to 235.2.192.102—1
104235.2.192.103/32235.2.192.103 to 235.2.192.103—1
105235.2.192.104/32235.2.192.104 to 235.2.192.104—1
106235.2.192.105/32235.2.192.105 to 235.2.192.105—1
107235.2.192.106/32235.2.192.106 to 235.2.192.106—1
108235.2.192.107/32235.2.192.107 to 235.2.192.107—1
109235.2.192.108/32235.2.192.108 to 235.2.192.108—1
110235.2.192.109/32235.2.192.109 to 235.2.192.109—1
111235.2.192.110/32235.2.192.110 to 235.2.192.110—1
112235.2.192.111/32235.2.192.111 to 235.2.192.111—1
113235.2.192.112/32235.2.192.112 to 235.2.192.112—1
114235.2.192.113/32235.2.192.113 to 235.2.192.113—1
115235.2.192.114/32235.2.192.114 to 235.2.192.114—1
116235.2.192.115/32235.2.192.115 to 235.2.192.115—1
117235.2.192.116/32235.2.192.116 to 235.2.192.116—1
118235.2.192.117/32235.2.192.117 to 235.2.192.117—1
119235.2.192.118/32235.2.192.118 to 235.2.192.118—1
120235.2.192.119/32235.2.192.119 to 235.2.192.119—1
121235.2.192.120/32235.2.192.120 to 235.2.192.120—1
122235.2.192.121/32235.2.192.121 to 235.2.192.121—1
123235.2.192.122/32235.2.192.122 to 235.2.192.122—1
124235.2.192.123/32235.2.192.123 to 235.2.192.123—1
125235.2.192.124/32235.2.192.124 to 235.2.192.124—1
126235.2.192.125/32235.2.192.125 to 235.2.192.125—1
127235.2.192.126/32235.2.192.126 to 235.2.192.126—1
128235.2.192.127/32235.2.192.127 to 235.2.192.127—1
129235.2.192.128/32235.2.192.128 to 235.2.192.128—1
130235.2.192.129/32235.2.192.129 to 235.2.192.129—1
131235.2.192.130/32235.2.192.130 to 235.2.192.130—1
132235.2.192.131/32235.2.192.131 to 235.2.192.131—1
133235.2.192.132/32235.2.192.132 to 235.2.192.132—1
134235.2.192.133/32235.2.192.133 to 235.2.192.133—1
135235.2.192.134/32235.2.192.134 to 235.2.192.134—1
136235.2.192.135/32235.2.192.135 to 235.2.192.135—1
137235.2.192.136/32235.2.192.136 to 235.2.192.136—1
138235.2.192.137/32235.2.192.137 to 235.2.192.137—1
139235.2.192.138/32235.2.192.138 to 235.2.192.138—1
140235.2.192.139/32235.2.192.139 to 235.2.192.139—1
141235.2.192.140/32235.2.192.140 to 235.2.192.140—1
142235.2.192.141/32235.2.192.141 to 235.2.192.141—1
143235.2.192.142/32235.2.192.142 to 235.2.192.142—1
144235.2.192.143/32235.2.192.143 to 235.2.192.143—1
145235.2.192.144/32235.2.192.144 to 235.2.192.144—1
146235.2.192.145/32235.2.192.145 to 235.2.192.145—1
147235.2.192.146/32235.2.192.146 to 235.2.192.146—1
148235.2.192.147/32235.2.192.147 to 235.2.192.147—1
149235.2.192.148/32235.2.192.148 to 235.2.192.148—1
150235.2.192.149/32235.2.192.149 to 235.2.192.149—1
151235.2.192.150/32235.2.192.150 to 235.2.192.150—1
152235.2.192.151/32235.2.192.151 to 235.2.192.151—1
153235.2.192.152/32235.2.192.152 to 235.2.192.152—1
154235.2.192.153/32235.2.192.153 to 235.2.192.153—1
155235.2.192.154/32235.2.192.154 to 235.2.192.154—1
156235.2.192.155/32235.2.192.155 to 235.2.192.155—1
157235.2.192.156/32235.2.192.156 to 235.2.192.156—1
158235.2.192.157/32235.2.192.157 to 235.2.192.157—1
159235.2.192.158/32235.2.192.158 to 235.2.192.158—1
160235.2.192.159/32235.2.192.159 to 235.2.192.159—1
161235.2.192.160/32235.2.192.160 to 235.2.192.160—1
162235.2.192.161/32235.2.192.161 to 235.2.192.161—1
163235.2.192.162/32235.2.192.162 to 235.2.192.162—1
164235.2.192.163/32235.2.192.163 to 235.2.192.163—1
165235.2.192.164/32235.2.192.164 to 235.2.192.164—1
166235.2.192.165/32235.2.192.165 to 235.2.192.165—1
167235.2.192.166/32235.2.192.166 to 235.2.192.166—1
168235.2.192.167/32235.2.192.167 to 235.2.192.167—1
169235.2.192.168/32235.2.192.168 to 235.2.192.168—1
170235.2.192.169/32235.2.192.169 to 235.2.192.169—1
171235.2.192.170/32235.2.192.170 to 235.2.192.170—1
172235.2.192.171/32235.2.192.171 to 235.2.192.171—1
173235.2.192.172/32235.2.192.172 to 235.2.192.172—1
174235.2.192.173/32235.2.192.173 to 235.2.192.173—1
175235.2.192.174/32235.2.192.174 to 235.2.192.174—1
176235.2.192.175/32235.2.192.175 to 235.2.192.175—1
177235.2.192.176/32235.2.192.176 to 235.2.192.176—1
178235.2.192.177/32235.2.192.177 to 235.2.192.177—1
179235.2.192.178/32235.2.192.178 to 235.2.192.178—1
180235.2.192.179/32235.2.192.179 to 235.2.192.179—1
181235.2.192.180/32235.2.192.180 to 235.2.192.180—1
182235.2.192.181/32235.2.192.181 to 235.2.192.181—1
183235.2.192.182/32235.2.192.182 to 235.2.192.182—1
184235.2.192.183/32235.2.192.183 to 235.2.192.183—1
185235.2.192.184/32235.2.192.184 to 235.2.192.184—1
186235.2.192.185/32235.2.192.185 to 235.2.192.185—1
187235.2.192.186/32235.2.192.186 to 235.2.192.186—1
188235.2.192.187/32235.2.192.187 to 235.2.192.187—1
189235.2.192.188/32235.2.192.188 to 235.2.192.188—1
190235.2.192.189/32235.2.192.189 to 235.2.192.189—1
191235.2.192.190/32235.2.192.190 to 235.2.192.190—1
192235.2.192.191/32235.2.192.191 to 235.2.192.191—1
193235.2.192.192/32235.2.192.192 to 235.2.192.192—1
194235.2.192.193/32235.2.192.193 to 235.2.192.193—1
195235.2.192.194/32235.2.192.194 to 235.2.192.194—1
196235.2.192.195/32235.2.192.195 to 235.2.192.195—1
197235.2.192.196/32235.2.192.196 to 235.2.192.196—1
198235.2.192.197/32235.2.192.197 to 235.2.192.197—1
199235.2.192.198/32235.2.192.198 to 235.2.192.198—1
200235.2.192.199/32235.2.192.199 to 235.2.192.199—1
201235.2.192.200/32235.2.192.200 to 235.2.192.200—1
202235.2.192.201/32235.2.192.201 to 235.2.192.201—1
203235.2.192.202/32235.2.192.202 to 235.2.192.202—1
204235.2.192.203/32235.2.192.203 to 235.2.192.203—1
205235.2.192.204/32235.2.192.204 to 235.2.192.204—1
206235.2.192.205/32235.2.192.205 to 235.2.192.205—1
207235.2.192.206/32235.2.192.206 to 235.2.192.206—1
208235.2.192.207/32235.2.192.207 to 235.2.192.207—1
209235.2.192.208/32235.2.192.208 to 235.2.192.208—1
210235.2.192.209/32235.2.192.209 to 235.2.192.209—1
211235.2.192.210/32235.2.192.210 to 235.2.192.210—1
212235.2.192.211/32235.2.192.211 to 235.2.192.211—1
213235.2.192.212/32235.2.192.212 to 235.2.192.212—1
214235.2.192.213/32235.2.192.213 to 235.2.192.213—1
215235.2.192.214/32235.2.192.214 to 235.2.192.214—1
216235.2.192.215/32235.2.192.215 to 235.2.192.215—1
217235.2.192.216/32235.2.192.216 to 235.2.192.216—1
218235.2.192.217/32235.2.192.217 to 235.2.192.217—1
219235.2.192.218/32235.2.192.218 to 235.2.192.218—1
220235.2.192.219/32235.2.192.219 to 235.2.192.219—1
221235.2.192.220/32235.2.192.220 to 235.2.192.220—1
222235.2.192.221/32235.2.192.221 to 235.2.192.221—1
223235.2.192.222/32235.2.192.222 to 235.2.192.222—1
224235.2.192.223/32235.2.192.223 to 235.2.192.223—1
225235.2.192.224/32235.2.192.224 to 235.2.192.224—1
226235.2.192.225/32235.2.192.225 to 235.2.192.225—1
227235.2.192.226/32235.2.192.226 to 235.2.192.226—1
228235.2.192.227/32235.2.192.227 to 235.2.192.227—1
229235.2.192.228/32235.2.192.228 to 235.2.192.228—1
230235.2.192.229/32235.2.192.229 to 235.2.192.229—1
231235.2.192.230/32235.2.192.230 to 235.2.192.230—1
232235.2.192.231/32235.2.192.231 to 235.2.192.231—1
233235.2.192.232/32235.2.192.232 to 235.2.192.232—1
234235.2.192.233/32235.2.192.233 to 235.2.192.233—1
235235.2.192.234/32235.2.192.234 to 235.2.192.234—1
236235.2.192.235/32235.2.192.235 to 235.2.192.235—1
237235.2.192.236/32235.2.192.236 to 235.2.192.236—1
238235.2.192.237/32235.2.192.237 to 235.2.192.237—1
239235.2.192.238/32235.2.192.238 to 235.2.192.238—1
240235.2.192.239/32235.2.192.239 to 235.2.192.239—1
241235.2.192.240/32235.2.192.240 to 235.2.192.240—1
242235.2.192.241/32235.2.192.241 to 235.2.192.241—1
243235.2.192.242/32235.2.192.242 to 235.2.192.242—1
244235.2.192.243/32235.2.192.243 to 235.2.192.243—1
245235.2.192.244/32235.2.192.244 to 235.2.192.244—1
246235.2.192.245/32235.2.192.245 to 235.2.192.245—1
247235.2.192.246/32235.2.192.246 to 235.2.192.246—1
248235.2.192.247/32235.2.192.247 to 235.2.192.247—1
249235.2.192.248/32235.2.192.248 to 235.2.192.248—1
250235.2.192.249/32235.2.192.249 to 235.2.192.249—1
251235.2.192.250/32235.2.192.250 to 235.2.192.250—1
252235.2.192.251/32235.2.192.251 to 235.2.192.251—1
253235.2.192.252/32235.2.192.252 to 235.2.192.252—1
254235.2.192.253/32235.2.192.253 to 235.2.192.253—1
255235.2.192.254/32235.2.192.254 to 235.2.192.254—1
256235.2.192.255/32235.2.192.255 to 235.2.192.255—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.