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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.

Network246.3.136.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
246.3.136.0
Broadcast address
246.3.139.255
First usable
246.3.136.1
Last usable
246.3.139.254
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
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F6038800 · Integer 4127426560 to 4127427583
Reverse DNS zones
136.3.246.in-addr.arpa
137.3.246.in-addr.arpa
138.3.246.in-addr.arpa
139.3.246.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
Address11110110.00000011.10001000.00000000246.3.136.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network11110110.00000011.10001000.00000000246.3.136.0
Broadcast11110110.00000011.10001011.11111111246.3.139.255
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)

246.3.136.0/22 makes 1,024 subnets of /32; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1246.3.136.0/32246.3.136.0 to 246.3.136.0—1
2246.3.136.1/32246.3.136.1 to 246.3.136.1—1
3246.3.136.2/32246.3.136.2 to 246.3.136.2—1
4246.3.136.3/32246.3.136.3 to 246.3.136.3—1
5246.3.136.4/32246.3.136.4 to 246.3.136.4—1
6246.3.136.5/32246.3.136.5 to 246.3.136.5—1
7246.3.136.6/32246.3.136.6 to 246.3.136.6—1
8246.3.136.7/32246.3.136.7 to 246.3.136.7—1
9246.3.136.8/32246.3.136.8 to 246.3.136.8—1
10246.3.136.9/32246.3.136.9 to 246.3.136.9—1
11246.3.136.10/32246.3.136.10 to 246.3.136.10—1
12246.3.136.11/32246.3.136.11 to 246.3.136.11—1
13246.3.136.12/32246.3.136.12 to 246.3.136.12—1
14246.3.136.13/32246.3.136.13 to 246.3.136.13—1
15246.3.136.14/32246.3.136.14 to 246.3.136.14—1
16246.3.136.15/32246.3.136.15 to 246.3.136.15—1
17246.3.136.16/32246.3.136.16 to 246.3.136.16—1
18246.3.136.17/32246.3.136.17 to 246.3.136.17—1
19246.3.136.18/32246.3.136.18 to 246.3.136.18—1
20246.3.136.19/32246.3.136.19 to 246.3.136.19—1
21246.3.136.20/32246.3.136.20 to 246.3.136.20—1
22246.3.136.21/32246.3.136.21 to 246.3.136.21—1
23246.3.136.22/32246.3.136.22 to 246.3.136.22—1
24246.3.136.23/32246.3.136.23 to 246.3.136.23—1
25246.3.136.24/32246.3.136.24 to 246.3.136.24—1
26246.3.136.25/32246.3.136.25 to 246.3.136.25—1
27246.3.136.26/32246.3.136.26 to 246.3.136.26—1
28246.3.136.27/32246.3.136.27 to 246.3.136.27—1
29246.3.136.28/32246.3.136.28 to 246.3.136.28—1
30246.3.136.29/32246.3.136.29 to 246.3.136.29—1
31246.3.136.30/32246.3.136.30 to 246.3.136.30—1
32246.3.136.31/32246.3.136.31 to 246.3.136.31—1
33246.3.136.32/32246.3.136.32 to 246.3.136.32—1
34246.3.136.33/32246.3.136.33 to 246.3.136.33—1
35246.3.136.34/32246.3.136.34 to 246.3.136.34—1
36246.3.136.35/32246.3.136.35 to 246.3.136.35—1
37246.3.136.36/32246.3.136.36 to 246.3.136.36—1
38246.3.136.37/32246.3.136.37 to 246.3.136.37—1
39246.3.136.38/32246.3.136.38 to 246.3.136.38—1
40246.3.136.39/32246.3.136.39 to 246.3.136.39—1
41246.3.136.40/32246.3.136.40 to 246.3.136.40—1
42246.3.136.41/32246.3.136.41 to 246.3.136.41—1
43246.3.136.42/32246.3.136.42 to 246.3.136.42—1
44246.3.136.43/32246.3.136.43 to 246.3.136.43—1
45246.3.136.44/32246.3.136.44 to 246.3.136.44—1
46246.3.136.45/32246.3.136.45 to 246.3.136.45—1
47246.3.136.46/32246.3.136.46 to 246.3.136.46—1
48246.3.136.47/32246.3.136.47 to 246.3.136.47—1
49246.3.136.48/32246.3.136.48 to 246.3.136.48—1
50246.3.136.49/32246.3.136.49 to 246.3.136.49—1
51246.3.136.50/32246.3.136.50 to 246.3.136.50—1
52246.3.136.51/32246.3.136.51 to 246.3.136.51—1
53246.3.136.52/32246.3.136.52 to 246.3.136.52—1
54246.3.136.53/32246.3.136.53 to 246.3.136.53—1
55246.3.136.54/32246.3.136.54 to 246.3.136.54—1
56246.3.136.55/32246.3.136.55 to 246.3.136.55—1
57246.3.136.56/32246.3.136.56 to 246.3.136.56—1
58246.3.136.57/32246.3.136.57 to 246.3.136.57—1
59246.3.136.58/32246.3.136.58 to 246.3.136.58—1
60246.3.136.59/32246.3.136.59 to 246.3.136.59—1
61246.3.136.60/32246.3.136.60 to 246.3.136.60—1
62246.3.136.61/32246.3.136.61 to 246.3.136.61—1
63246.3.136.62/32246.3.136.62 to 246.3.136.62—1
64246.3.136.63/32246.3.136.63 to 246.3.136.63—1
65246.3.136.64/32246.3.136.64 to 246.3.136.64—1
66246.3.136.65/32246.3.136.65 to 246.3.136.65—1
67246.3.136.66/32246.3.136.66 to 246.3.136.66—1
68246.3.136.67/32246.3.136.67 to 246.3.136.67—1
69246.3.136.68/32246.3.136.68 to 246.3.136.68—1
70246.3.136.69/32246.3.136.69 to 246.3.136.69—1
71246.3.136.70/32246.3.136.70 to 246.3.136.70—1
72246.3.136.71/32246.3.136.71 to 246.3.136.71—1
73246.3.136.72/32246.3.136.72 to 246.3.136.72—1
74246.3.136.73/32246.3.136.73 to 246.3.136.73—1
75246.3.136.74/32246.3.136.74 to 246.3.136.74—1
76246.3.136.75/32246.3.136.75 to 246.3.136.75—1
77246.3.136.76/32246.3.136.76 to 246.3.136.76—1
78246.3.136.77/32246.3.136.77 to 246.3.136.77—1
79246.3.136.78/32246.3.136.78 to 246.3.136.78—1
80246.3.136.79/32246.3.136.79 to 246.3.136.79—1
81246.3.136.80/32246.3.136.80 to 246.3.136.80—1
82246.3.136.81/32246.3.136.81 to 246.3.136.81—1
83246.3.136.82/32246.3.136.82 to 246.3.136.82—1
84246.3.136.83/32246.3.136.83 to 246.3.136.83—1
85246.3.136.84/32246.3.136.84 to 246.3.136.84—1
86246.3.136.85/32246.3.136.85 to 246.3.136.85—1
87246.3.136.86/32246.3.136.86 to 246.3.136.86—1
88246.3.136.87/32246.3.136.87 to 246.3.136.87—1
89246.3.136.88/32246.3.136.88 to 246.3.136.88—1
90246.3.136.89/32246.3.136.89 to 246.3.136.89—1
91246.3.136.90/32246.3.136.90 to 246.3.136.90—1
92246.3.136.91/32246.3.136.91 to 246.3.136.91—1
93246.3.136.92/32246.3.136.92 to 246.3.136.92—1
94246.3.136.93/32246.3.136.93 to 246.3.136.93—1
95246.3.136.94/32246.3.136.94 to 246.3.136.94—1
96246.3.136.95/32246.3.136.95 to 246.3.136.95—1
97246.3.136.96/32246.3.136.96 to 246.3.136.96—1
98246.3.136.97/32246.3.136.97 to 246.3.136.97—1
99246.3.136.98/32246.3.136.98 to 246.3.136.98—1
100246.3.136.99/32246.3.136.99 to 246.3.136.99—1
101246.3.136.100/32246.3.136.100 to 246.3.136.100—1
102246.3.136.101/32246.3.136.101 to 246.3.136.101—1
103246.3.136.102/32246.3.136.102 to 246.3.136.102—1
104246.3.136.103/32246.3.136.103 to 246.3.136.103—1
105246.3.136.104/32246.3.136.104 to 246.3.136.104—1
106246.3.136.105/32246.3.136.105 to 246.3.136.105—1
107246.3.136.106/32246.3.136.106 to 246.3.136.106—1
108246.3.136.107/32246.3.136.107 to 246.3.136.107—1
109246.3.136.108/32246.3.136.108 to 246.3.136.108—1
110246.3.136.109/32246.3.136.109 to 246.3.136.109—1
111246.3.136.110/32246.3.136.110 to 246.3.136.110—1
112246.3.136.111/32246.3.136.111 to 246.3.136.111—1
113246.3.136.112/32246.3.136.112 to 246.3.136.112—1
114246.3.136.113/32246.3.136.113 to 246.3.136.113—1
115246.3.136.114/32246.3.136.114 to 246.3.136.114—1
116246.3.136.115/32246.3.136.115 to 246.3.136.115—1
117246.3.136.116/32246.3.136.116 to 246.3.136.116—1
118246.3.136.117/32246.3.136.117 to 246.3.136.117—1
119246.3.136.118/32246.3.136.118 to 246.3.136.118—1
120246.3.136.119/32246.3.136.119 to 246.3.136.119—1
121246.3.136.120/32246.3.136.120 to 246.3.136.120—1
122246.3.136.121/32246.3.136.121 to 246.3.136.121—1
123246.3.136.122/32246.3.136.122 to 246.3.136.122—1
124246.3.136.123/32246.3.136.123 to 246.3.136.123—1
125246.3.136.124/32246.3.136.124 to 246.3.136.124—1
126246.3.136.125/32246.3.136.125 to 246.3.136.125—1
127246.3.136.126/32246.3.136.126 to 246.3.136.126—1
128246.3.136.127/32246.3.136.127 to 246.3.136.127—1
129246.3.136.128/32246.3.136.128 to 246.3.136.128—1
130246.3.136.129/32246.3.136.129 to 246.3.136.129—1
131246.3.136.130/32246.3.136.130 to 246.3.136.130—1
132246.3.136.131/32246.3.136.131 to 246.3.136.131—1
133246.3.136.132/32246.3.136.132 to 246.3.136.132—1
134246.3.136.133/32246.3.136.133 to 246.3.136.133—1
135246.3.136.134/32246.3.136.134 to 246.3.136.134—1
136246.3.136.135/32246.3.136.135 to 246.3.136.135—1
137246.3.136.136/32246.3.136.136 to 246.3.136.136—1
138246.3.136.137/32246.3.136.137 to 246.3.136.137—1
139246.3.136.138/32246.3.136.138 to 246.3.136.138—1
140246.3.136.139/32246.3.136.139 to 246.3.136.139—1
141246.3.136.140/32246.3.136.140 to 246.3.136.140—1
142246.3.136.141/32246.3.136.141 to 246.3.136.141—1
143246.3.136.142/32246.3.136.142 to 246.3.136.142—1
144246.3.136.143/32246.3.136.143 to 246.3.136.143—1
145246.3.136.144/32246.3.136.144 to 246.3.136.144—1
146246.3.136.145/32246.3.136.145 to 246.3.136.145—1
147246.3.136.146/32246.3.136.146 to 246.3.136.146—1
148246.3.136.147/32246.3.136.147 to 246.3.136.147—1
149246.3.136.148/32246.3.136.148 to 246.3.136.148—1
150246.3.136.149/32246.3.136.149 to 246.3.136.149—1
151246.3.136.150/32246.3.136.150 to 246.3.136.150—1
152246.3.136.151/32246.3.136.151 to 246.3.136.151—1
153246.3.136.152/32246.3.136.152 to 246.3.136.152—1
154246.3.136.153/32246.3.136.153 to 246.3.136.153—1
155246.3.136.154/32246.3.136.154 to 246.3.136.154—1
156246.3.136.155/32246.3.136.155 to 246.3.136.155—1
157246.3.136.156/32246.3.136.156 to 246.3.136.156—1
158246.3.136.157/32246.3.136.157 to 246.3.136.157—1
159246.3.136.158/32246.3.136.158 to 246.3.136.158—1
160246.3.136.159/32246.3.136.159 to 246.3.136.159—1
161246.3.136.160/32246.3.136.160 to 246.3.136.160—1
162246.3.136.161/32246.3.136.161 to 246.3.136.161—1
163246.3.136.162/32246.3.136.162 to 246.3.136.162—1
164246.3.136.163/32246.3.136.163 to 246.3.136.163—1
165246.3.136.164/32246.3.136.164 to 246.3.136.164—1
166246.3.136.165/32246.3.136.165 to 246.3.136.165—1
167246.3.136.166/32246.3.136.166 to 246.3.136.166—1
168246.3.136.167/32246.3.136.167 to 246.3.136.167—1
169246.3.136.168/32246.3.136.168 to 246.3.136.168—1
170246.3.136.169/32246.3.136.169 to 246.3.136.169—1
171246.3.136.170/32246.3.136.170 to 246.3.136.170—1
172246.3.136.171/32246.3.136.171 to 246.3.136.171—1
173246.3.136.172/32246.3.136.172 to 246.3.136.172—1
174246.3.136.173/32246.3.136.173 to 246.3.136.173—1
175246.3.136.174/32246.3.136.174 to 246.3.136.174—1
176246.3.136.175/32246.3.136.175 to 246.3.136.175—1
177246.3.136.176/32246.3.136.176 to 246.3.136.176—1
178246.3.136.177/32246.3.136.177 to 246.3.136.177—1
179246.3.136.178/32246.3.136.178 to 246.3.136.178—1
180246.3.136.179/32246.3.136.179 to 246.3.136.179—1
181246.3.136.180/32246.3.136.180 to 246.3.136.180—1
182246.3.136.181/32246.3.136.181 to 246.3.136.181—1
183246.3.136.182/32246.3.136.182 to 246.3.136.182—1
184246.3.136.183/32246.3.136.183 to 246.3.136.183—1
185246.3.136.184/32246.3.136.184 to 246.3.136.184—1
186246.3.136.185/32246.3.136.185 to 246.3.136.185—1
187246.3.136.186/32246.3.136.186 to 246.3.136.186—1
188246.3.136.187/32246.3.136.187 to 246.3.136.187—1
189246.3.136.188/32246.3.136.188 to 246.3.136.188—1
190246.3.136.189/32246.3.136.189 to 246.3.136.189—1
191246.3.136.190/32246.3.136.190 to 246.3.136.190—1
192246.3.136.191/32246.3.136.191 to 246.3.136.191—1
193246.3.136.192/32246.3.136.192 to 246.3.136.192—1
194246.3.136.193/32246.3.136.193 to 246.3.136.193—1
195246.3.136.194/32246.3.136.194 to 246.3.136.194—1
196246.3.136.195/32246.3.136.195 to 246.3.136.195—1
197246.3.136.196/32246.3.136.196 to 246.3.136.196—1
198246.3.136.197/32246.3.136.197 to 246.3.136.197—1
199246.3.136.198/32246.3.136.198 to 246.3.136.198—1
200246.3.136.199/32246.3.136.199 to 246.3.136.199—1
201246.3.136.200/32246.3.136.200 to 246.3.136.200—1
202246.3.136.201/32246.3.136.201 to 246.3.136.201—1
203246.3.136.202/32246.3.136.202 to 246.3.136.202—1
204246.3.136.203/32246.3.136.203 to 246.3.136.203—1
205246.3.136.204/32246.3.136.204 to 246.3.136.204—1
206246.3.136.205/32246.3.136.205 to 246.3.136.205—1
207246.3.136.206/32246.3.136.206 to 246.3.136.206—1
208246.3.136.207/32246.3.136.207 to 246.3.136.207—1
209246.3.136.208/32246.3.136.208 to 246.3.136.208—1
210246.3.136.209/32246.3.136.209 to 246.3.136.209—1
211246.3.136.210/32246.3.136.210 to 246.3.136.210—1
212246.3.136.211/32246.3.136.211 to 246.3.136.211—1
213246.3.136.212/32246.3.136.212 to 246.3.136.212—1
214246.3.136.213/32246.3.136.213 to 246.3.136.213—1
215246.3.136.214/32246.3.136.214 to 246.3.136.214—1
216246.3.136.215/32246.3.136.215 to 246.3.136.215—1
217246.3.136.216/32246.3.136.216 to 246.3.136.216—1
218246.3.136.217/32246.3.136.217 to 246.3.136.217—1
219246.3.136.218/32246.3.136.218 to 246.3.136.218—1
220246.3.136.219/32246.3.136.219 to 246.3.136.219—1
221246.3.136.220/32246.3.136.220 to 246.3.136.220—1
222246.3.136.221/32246.3.136.221 to 246.3.136.221—1
223246.3.136.222/32246.3.136.222 to 246.3.136.222—1
224246.3.136.223/32246.3.136.223 to 246.3.136.223—1
225246.3.136.224/32246.3.136.224 to 246.3.136.224—1
226246.3.136.225/32246.3.136.225 to 246.3.136.225—1
227246.3.136.226/32246.3.136.226 to 246.3.136.226—1
228246.3.136.227/32246.3.136.227 to 246.3.136.227—1
229246.3.136.228/32246.3.136.228 to 246.3.136.228—1
230246.3.136.229/32246.3.136.229 to 246.3.136.229—1
231246.3.136.230/32246.3.136.230 to 246.3.136.230—1
232246.3.136.231/32246.3.136.231 to 246.3.136.231—1
233246.3.136.232/32246.3.136.232 to 246.3.136.232—1
234246.3.136.233/32246.3.136.233 to 246.3.136.233—1
235246.3.136.234/32246.3.136.234 to 246.3.136.234—1
236246.3.136.235/32246.3.136.235 to 246.3.136.235—1
237246.3.136.236/32246.3.136.236 to 246.3.136.236—1
238246.3.136.237/32246.3.136.237 to 246.3.136.237—1
239246.3.136.238/32246.3.136.238 to 246.3.136.238—1
240246.3.136.239/32246.3.136.239 to 246.3.136.239—1
241246.3.136.240/32246.3.136.240 to 246.3.136.240—1
242246.3.136.241/32246.3.136.241 to 246.3.136.241—1
243246.3.136.242/32246.3.136.242 to 246.3.136.242—1
244246.3.136.243/32246.3.136.243 to 246.3.136.243—1
245246.3.136.244/32246.3.136.244 to 246.3.136.244—1
246246.3.136.245/32246.3.136.245 to 246.3.136.245—1
247246.3.136.246/32246.3.136.246 to 246.3.136.246—1
248246.3.136.247/32246.3.136.247 to 246.3.136.247—1
249246.3.136.248/32246.3.136.248 to 246.3.136.248—1
250246.3.136.249/32246.3.136.249 to 246.3.136.249—1
251246.3.136.250/32246.3.136.250 to 246.3.136.250—1
252246.3.136.251/32246.3.136.251 to 246.3.136.251—1
253246.3.136.252/32246.3.136.252 to 246.3.136.252—1
254246.3.136.253/32246.3.136.253 to 246.3.136.253—1
255246.3.136.254/32246.3.136.254 to 246.3.136.254—1
256246.3.136.255/32246.3.136.255 to 246.3.136.255—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.