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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.

Network210.167.2.0/24
Usable hosts254
Subnet mask255.255.255.0
Addresses256
Network address
210.167.2.0
Broadcast address
210.167.2.255
First usable
210.167.2.1
Last usable
210.167.2.254
Usable hosts
254 (256 less the network and broadcast addresses)
Subnet mask
255.255.255.0
Wildcard mask
0.0.0.255 (Cisco ACLs, OSPF)
Prefix length
/24
Type
Public public
Old class
C (default /24)
As numbers
Hex D2A70200 · Integer 3534160384 to 3534160639
Reverse DNS zone
2.167.210.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11010010.10100111.00000010..00000000210.167.2.0
Subnet mask11111111.11111111.11111111..00000000255.255.255.0
Network11010010.10100111.00000010..00000000210.167.2.0
Broadcast11010010.10100111.00000010..11111111210.167.2.255
Split into smaller subnets/32
/25 (2)/26 (4)/27 (8)/28 (16)/29 (32)/30 (64)/31 (128)/32 (256)

210.167.2.0/24 makes 256 subnets of /32.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1210.167.2.0/32210.167.2.0 to 210.167.2.0—1
2210.167.2.1/32210.167.2.1 to 210.167.2.1—1
3210.167.2.2/32210.167.2.2 to 210.167.2.2—1
4210.167.2.3/32210.167.2.3 to 210.167.2.3—1
5210.167.2.4/32210.167.2.4 to 210.167.2.4—1
6210.167.2.5/32210.167.2.5 to 210.167.2.5—1
7210.167.2.6/32210.167.2.6 to 210.167.2.6—1
8210.167.2.7/32210.167.2.7 to 210.167.2.7—1
9210.167.2.8/32210.167.2.8 to 210.167.2.8—1
10210.167.2.9/32210.167.2.9 to 210.167.2.9—1
11210.167.2.10/32210.167.2.10 to 210.167.2.10—1
12210.167.2.11/32210.167.2.11 to 210.167.2.11—1
13210.167.2.12/32210.167.2.12 to 210.167.2.12—1
14210.167.2.13/32210.167.2.13 to 210.167.2.13—1
15210.167.2.14/32210.167.2.14 to 210.167.2.14—1
16210.167.2.15/32210.167.2.15 to 210.167.2.15—1
17210.167.2.16/32210.167.2.16 to 210.167.2.16—1
18210.167.2.17/32210.167.2.17 to 210.167.2.17—1
19210.167.2.18/32210.167.2.18 to 210.167.2.18—1
20210.167.2.19/32210.167.2.19 to 210.167.2.19—1
21210.167.2.20/32210.167.2.20 to 210.167.2.20—1
22210.167.2.21/32210.167.2.21 to 210.167.2.21—1
23210.167.2.22/32210.167.2.22 to 210.167.2.22—1
24210.167.2.23/32210.167.2.23 to 210.167.2.23—1
25210.167.2.24/32210.167.2.24 to 210.167.2.24—1
26210.167.2.25/32210.167.2.25 to 210.167.2.25—1
27210.167.2.26/32210.167.2.26 to 210.167.2.26—1
28210.167.2.27/32210.167.2.27 to 210.167.2.27—1
29210.167.2.28/32210.167.2.28 to 210.167.2.28—1
30210.167.2.29/32210.167.2.29 to 210.167.2.29—1
31210.167.2.30/32210.167.2.30 to 210.167.2.30—1
32210.167.2.31/32210.167.2.31 to 210.167.2.31—1
33210.167.2.32/32210.167.2.32 to 210.167.2.32—1
34210.167.2.33/32210.167.2.33 to 210.167.2.33—1
35210.167.2.34/32210.167.2.34 to 210.167.2.34—1
36210.167.2.35/32210.167.2.35 to 210.167.2.35—1
37210.167.2.36/32210.167.2.36 to 210.167.2.36—1
38210.167.2.37/32210.167.2.37 to 210.167.2.37—1
39210.167.2.38/32210.167.2.38 to 210.167.2.38—1
40210.167.2.39/32210.167.2.39 to 210.167.2.39—1
41210.167.2.40/32210.167.2.40 to 210.167.2.40—1
42210.167.2.41/32210.167.2.41 to 210.167.2.41—1
43210.167.2.42/32210.167.2.42 to 210.167.2.42—1
44210.167.2.43/32210.167.2.43 to 210.167.2.43—1
45210.167.2.44/32210.167.2.44 to 210.167.2.44—1
46210.167.2.45/32210.167.2.45 to 210.167.2.45—1
47210.167.2.46/32210.167.2.46 to 210.167.2.46—1
48210.167.2.47/32210.167.2.47 to 210.167.2.47—1
49210.167.2.48/32210.167.2.48 to 210.167.2.48—1
50210.167.2.49/32210.167.2.49 to 210.167.2.49—1
51210.167.2.50/32210.167.2.50 to 210.167.2.50—1
52210.167.2.51/32210.167.2.51 to 210.167.2.51—1
53210.167.2.52/32210.167.2.52 to 210.167.2.52—1
54210.167.2.53/32210.167.2.53 to 210.167.2.53—1
55210.167.2.54/32210.167.2.54 to 210.167.2.54—1
56210.167.2.55/32210.167.2.55 to 210.167.2.55—1
57210.167.2.56/32210.167.2.56 to 210.167.2.56—1
58210.167.2.57/32210.167.2.57 to 210.167.2.57—1
59210.167.2.58/32210.167.2.58 to 210.167.2.58—1
60210.167.2.59/32210.167.2.59 to 210.167.2.59—1
61210.167.2.60/32210.167.2.60 to 210.167.2.60—1
62210.167.2.61/32210.167.2.61 to 210.167.2.61—1
63210.167.2.62/32210.167.2.62 to 210.167.2.62—1
64210.167.2.63/32210.167.2.63 to 210.167.2.63—1
65210.167.2.64/32210.167.2.64 to 210.167.2.64—1
66210.167.2.65/32210.167.2.65 to 210.167.2.65—1
67210.167.2.66/32210.167.2.66 to 210.167.2.66—1
68210.167.2.67/32210.167.2.67 to 210.167.2.67—1
69210.167.2.68/32210.167.2.68 to 210.167.2.68—1
70210.167.2.69/32210.167.2.69 to 210.167.2.69—1
71210.167.2.70/32210.167.2.70 to 210.167.2.70—1
72210.167.2.71/32210.167.2.71 to 210.167.2.71—1
73210.167.2.72/32210.167.2.72 to 210.167.2.72—1
74210.167.2.73/32210.167.2.73 to 210.167.2.73—1
75210.167.2.74/32210.167.2.74 to 210.167.2.74—1
76210.167.2.75/32210.167.2.75 to 210.167.2.75—1
77210.167.2.76/32210.167.2.76 to 210.167.2.76—1
78210.167.2.77/32210.167.2.77 to 210.167.2.77—1
79210.167.2.78/32210.167.2.78 to 210.167.2.78—1
80210.167.2.79/32210.167.2.79 to 210.167.2.79—1
81210.167.2.80/32210.167.2.80 to 210.167.2.80—1
82210.167.2.81/32210.167.2.81 to 210.167.2.81—1
83210.167.2.82/32210.167.2.82 to 210.167.2.82—1
84210.167.2.83/32210.167.2.83 to 210.167.2.83—1
85210.167.2.84/32210.167.2.84 to 210.167.2.84—1
86210.167.2.85/32210.167.2.85 to 210.167.2.85—1
87210.167.2.86/32210.167.2.86 to 210.167.2.86—1
88210.167.2.87/32210.167.2.87 to 210.167.2.87—1
89210.167.2.88/32210.167.2.88 to 210.167.2.88—1
90210.167.2.89/32210.167.2.89 to 210.167.2.89—1
91210.167.2.90/32210.167.2.90 to 210.167.2.90—1
92210.167.2.91/32210.167.2.91 to 210.167.2.91—1
93210.167.2.92/32210.167.2.92 to 210.167.2.92—1
94210.167.2.93/32210.167.2.93 to 210.167.2.93—1
95210.167.2.94/32210.167.2.94 to 210.167.2.94—1
96210.167.2.95/32210.167.2.95 to 210.167.2.95—1
97210.167.2.96/32210.167.2.96 to 210.167.2.96—1
98210.167.2.97/32210.167.2.97 to 210.167.2.97—1
99210.167.2.98/32210.167.2.98 to 210.167.2.98—1
100210.167.2.99/32210.167.2.99 to 210.167.2.99—1
101210.167.2.100/32210.167.2.100 to 210.167.2.100—1
102210.167.2.101/32210.167.2.101 to 210.167.2.101—1
103210.167.2.102/32210.167.2.102 to 210.167.2.102—1
104210.167.2.103/32210.167.2.103 to 210.167.2.103—1
105210.167.2.104/32210.167.2.104 to 210.167.2.104—1
106210.167.2.105/32210.167.2.105 to 210.167.2.105—1
107210.167.2.106/32210.167.2.106 to 210.167.2.106—1
108210.167.2.107/32210.167.2.107 to 210.167.2.107—1
109210.167.2.108/32210.167.2.108 to 210.167.2.108—1
110210.167.2.109/32210.167.2.109 to 210.167.2.109—1
111210.167.2.110/32210.167.2.110 to 210.167.2.110—1
112210.167.2.111/32210.167.2.111 to 210.167.2.111—1
113210.167.2.112/32210.167.2.112 to 210.167.2.112—1
114210.167.2.113/32210.167.2.113 to 210.167.2.113—1
115210.167.2.114/32210.167.2.114 to 210.167.2.114—1
116210.167.2.115/32210.167.2.115 to 210.167.2.115—1
117210.167.2.116/32210.167.2.116 to 210.167.2.116—1
118210.167.2.117/32210.167.2.117 to 210.167.2.117—1
119210.167.2.118/32210.167.2.118 to 210.167.2.118—1
120210.167.2.119/32210.167.2.119 to 210.167.2.119—1
121210.167.2.120/32210.167.2.120 to 210.167.2.120—1
122210.167.2.121/32210.167.2.121 to 210.167.2.121—1
123210.167.2.122/32210.167.2.122 to 210.167.2.122—1
124210.167.2.123/32210.167.2.123 to 210.167.2.123—1
125210.167.2.124/32210.167.2.124 to 210.167.2.124—1
126210.167.2.125/32210.167.2.125 to 210.167.2.125—1
127210.167.2.126/32210.167.2.126 to 210.167.2.126—1
128210.167.2.127/32210.167.2.127 to 210.167.2.127—1
129210.167.2.128/32210.167.2.128 to 210.167.2.128—1
130210.167.2.129/32210.167.2.129 to 210.167.2.129—1
131210.167.2.130/32210.167.2.130 to 210.167.2.130—1
132210.167.2.131/32210.167.2.131 to 210.167.2.131—1
133210.167.2.132/32210.167.2.132 to 210.167.2.132—1
134210.167.2.133/32210.167.2.133 to 210.167.2.133—1
135210.167.2.134/32210.167.2.134 to 210.167.2.134—1
136210.167.2.135/32210.167.2.135 to 210.167.2.135—1
137210.167.2.136/32210.167.2.136 to 210.167.2.136—1
138210.167.2.137/32210.167.2.137 to 210.167.2.137—1
139210.167.2.138/32210.167.2.138 to 210.167.2.138—1
140210.167.2.139/32210.167.2.139 to 210.167.2.139—1
141210.167.2.140/32210.167.2.140 to 210.167.2.140—1
142210.167.2.141/32210.167.2.141 to 210.167.2.141—1
143210.167.2.142/32210.167.2.142 to 210.167.2.142—1
144210.167.2.143/32210.167.2.143 to 210.167.2.143—1
145210.167.2.144/32210.167.2.144 to 210.167.2.144—1
146210.167.2.145/32210.167.2.145 to 210.167.2.145—1
147210.167.2.146/32210.167.2.146 to 210.167.2.146—1
148210.167.2.147/32210.167.2.147 to 210.167.2.147—1
149210.167.2.148/32210.167.2.148 to 210.167.2.148—1
150210.167.2.149/32210.167.2.149 to 210.167.2.149—1
151210.167.2.150/32210.167.2.150 to 210.167.2.150—1
152210.167.2.151/32210.167.2.151 to 210.167.2.151—1
153210.167.2.152/32210.167.2.152 to 210.167.2.152—1
154210.167.2.153/32210.167.2.153 to 210.167.2.153—1
155210.167.2.154/32210.167.2.154 to 210.167.2.154—1
156210.167.2.155/32210.167.2.155 to 210.167.2.155—1
157210.167.2.156/32210.167.2.156 to 210.167.2.156—1
158210.167.2.157/32210.167.2.157 to 210.167.2.157—1
159210.167.2.158/32210.167.2.158 to 210.167.2.158—1
160210.167.2.159/32210.167.2.159 to 210.167.2.159—1
161210.167.2.160/32210.167.2.160 to 210.167.2.160—1
162210.167.2.161/32210.167.2.161 to 210.167.2.161—1
163210.167.2.162/32210.167.2.162 to 210.167.2.162—1
164210.167.2.163/32210.167.2.163 to 210.167.2.163—1
165210.167.2.164/32210.167.2.164 to 210.167.2.164—1
166210.167.2.165/32210.167.2.165 to 210.167.2.165—1
167210.167.2.166/32210.167.2.166 to 210.167.2.166—1
168210.167.2.167/32210.167.2.167 to 210.167.2.167—1
169210.167.2.168/32210.167.2.168 to 210.167.2.168—1
170210.167.2.169/32210.167.2.169 to 210.167.2.169—1
171210.167.2.170/32210.167.2.170 to 210.167.2.170—1
172210.167.2.171/32210.167.2.171 to 210.167.2.171—1
173210.167.2.172/32210.167.2.172 to 210.167.2.172—1
174210.167.2.173/32210.167.2.173 to 210.167.2.173—1
175210.167.2.174/32210.167.2.174 to 210.167.2.174—1
176210.167.2.175/32210.167.2.175 to 210.167.2.175—1
177210.167.2.176/32210.167.2.176 to 210.167.2.176—1
178210.167.2.177/32210.167.2.177 to 210.167.2.177—1
179210.167.2.178/32210.167.2.178 to 210.167.2.178—1
180210.167.2.179/32210.167.2.179 to 210.167.2.179—1
181210.167.2.180/32210.167.2.180 to 210.167.2.180—1
182210.167.2.181/32210.167.2.181 to 210.167.2.181—1
183210.167.2.182/32210.167.2.182 to 210.167.2.182—1
184210.167.2.183/32210.167.2.183 to 210.167.2.183—1
185210.167.2.184/32210.167.2.184 to 210.167.2.184—1
186210.167.2.185/32210.167.2.185 to 210.167.2.185—1
187210.167.2.186/32210.167.2.186 to 210.167.2.186—1
188210.167.2.187/32210.167.2.187 to 210.167.2.187—1
189210.167.2.188/32210.167.2.188 to 210.167.2.188—1
190210.167.2.189/32210.167.2.189 to 210.167.2.189—1
191210.167.2.190/32210.167.2.190 to 210.167.2.190—1
192210.167.2.191/32210.167.2.191 to 210.167.2.191—1
193210.167.2.192/32210.167.2.192 to 210.167.2.192—1
194210.167.2.193/32210.167.2.193 to 210.167.2.193—1
195210.167.2.194/32210.167.2.194 to 210.167.2.194—1
196210.167.2.195/32210.167.2.195 to 210.167.2.195—1
197210.167.2.196/32210.167.2.196 to 210.167.2.196—1
198210.167.2.197/32210.167.2.197 to 210.167.2.197—1
199210.167.2.198/32210.167.2.198 to 210.167.2.198—1
200210.167.2.199/32210.167.2.199 to 210.167.2.199—1
201210.167.2.200/32210.167.2.200 to 210.167.2.200—1
202210.167.2.201/32210.167.2.201 to 210.167.2.201—1
203210.167.2.202/32210.167.2.202 to 210.167.2.202—1
204210.167.2.203/32210.167.2.203 to 210.167.2.203—1
205210.167.2.204/32210.167.2.204 to 210.167.2.204—1
206210.167.2.205/32210.167.2.205 to 210.167.2.205—1
207210.167.2.206/32210.167.2.206 to 210.167.2.206—1
208210.167.2.207/32210.167.2.207 to 210.167.2.207—1
209210.167.2.208/32210.167.2.208 to 210.167.2.208—1
210210.167.2.209/32210.167.2.209 to 210.167.2.209—1
211210.167.2.210/32210.167.2.210 to 210.167.2.210—1
212210.167.2.211/32210.167.2.211 to 210.167.2.211—1
213210.167.2.212/32210.167.2.212 to 210.167.2.212—1
214210.167.2.213/32210.167.2.213 to 210.167.2.213—1
215210.167.2.214/32210.167.2.214 to 210.167.2.214—1
216210.167.2.215/32210.167.2.215 to 210.167.2.215—1
217210.167.2.216/32210.167.2.216 to 210.167.2.216—1
218210.167.2.217/32210.167.2.217 to 210.167.2.217—1
219210.167.2.218/32210.167.2.218 to 210.167.2.218—1
220210.167.2.219/32210.167.2.219 to 210.167.2.219—1
221210.167.2.220/32210.167.2.220 to 210.167.2.220—1
222210.167.2.221/32210.167.2.221 to 210.167.2.221—1
223210.167.2.222/32210.167.2.222 to 210.167.2.222—1
224210.167.2.223/32210.167.2.223 to 210.167.2.223—1
225210.167.2.224/32210.167.2.224 to 210.167.2.224—1
226210.167.2.225/32210.167.2.225 to 210.167.2.225—1
227210.167.2.226/32210.167.2.226 to 210.167.2.226—1
228210.167.2.227/32210.167.2.227 to 210.167.2.227—1
229210.167.2.228/32210.167.2.228 to 210.167.2.228—1
230210.167.2.229/32210.167.2.229 to 210.167.2.229—1
231210.167.2.230/32210.167.2.230 to 210.167.2.230—1
232210.167.2.231/32210.167.2.231 to 210.167.2.231—1
233210.167.2.232/32210.167.2.232 to 210.167.2.232—1
234210.167.2.233/32210.167.2.233 to 210.167.2.233—1
235210.167.2.234/32210.167.2.234 to 210.167.2.234—1
236210.167.2.235/32210.167.2.235 to 210.167.2.235—1
237210.167.2.236/32210.167.2.236 to 210.167.2.236—1
238210.167.2.237/32210.167.2.237 to 210.167.2.237—1
239210.167.2.238/32210.167.2.238 to 210.167.2.238—1
240210.167.2.239/32210.167.2.239 to 210.167.2.239—1
241210.167.2.240/32210.167.2.240 to 210.167.2.240—1
242210.167.2.241/32210.167.2.241 to 210.167.2.241—1
243210.167.2.242/32210.167.2.242 to 210.167.2.242—1
244210.167.2.243/32210.167.2.243 to 210.167.2.243—1
245210.167.2.244/32210.167.2.244 to 210.167.2.244—1
246210.167.2.245/32210.167.2.245 to 210.167.2.245—1
247210.167.2.246/32210.167.2.246 to 210.167.2.246—1
248210.167.2.247/32210.167.2.247 to 210.167.2.247—1
249210.167.2.248/32210.167.2.248 to 210.167.2.248—1
250210.167.2.249/32210.167.2.249 to 210.167.2.249—1
251210.167.2.250/32210.167.2.250 to 210.167.2.250—1
252210.167.2.251/32210.167.2.251 to 210.167.2.251—1
253210.167.2.252/32210.167.2.252 to 210.167.2.252—1
254210.167.2.253/32210.167.2.253 to 210.167.2.253—1
255210.167.2.254/32210.167.2.254 to 210.167.2.254—1
256210.167.2.255/32210.167.2.255 to 210.167.2.255—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.