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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.

Network214.2.32.0/20
Usable hosts4,094
Subnet mask255.255.240.0
Addresses4,096
Network address
214.2.32.0
Broadcast address
214.2.47.255
First usable
214.2.32.1
Last usable
214.2.47.254
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
C (default /24)
As numbers
Hex D6022000 · Integer 3590463488 to 3590467583
Reverse DNS zones
32.2.214.in-addr.arpa
33.2.214.in-addr.arpa
34.2.214.in-addr.arpa
35.2.214.in-addr.arpa
36.2.214.in-addr.arpa
37.2.214.in-addr.arpa
38.2.214.in-addr.arpa
39.2.214.in-addr.arpa
40.2.214.in-addr.arpa
41.2.214.in-addr.arpa
42.2.214.in-addr.arpa
43.2.214.in-addr.arpa
44.2.214.in-addr.arpa
45.2.214.in-addr.arpa
46.2.214.in-addr.arpa
47.2.214.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
Address11010110.00000010.00100000.00000000214.2.32.0
Subnet mask11111111.11111111.11110000.00000000255.255.240.0
Network11010110.00000010.00100000.00000000214.2.32.0
Broadcast11010110.00000010.00101111.11111111214.2.47.255
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)

214.2.32.0/20 makes 4,096 subnets of /32; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1214.2.32.0/32214.2.32.0 to 214.2.32.0—1
2214.2.32.1/32214.2.32.1 to 214.2.32.1—1
3214.2.32.2/32214.2.32.2 to 214.2.32.2—1
4214.2.32.3/32214.2.32.3 to 214.2.32.3—1
5214.2.32.4/32214.2.32.4 to 214.2.32.4—1
6214.2.32.5/32214.2.32.5 to 214.2.32.5—1
7214.2.32.6/32214.2.32.6 to 214.2.32.6—1
8214.2.32.7/32214.2.32.7 to 214.2.32.7—1
9214.2.32.8/32214.2.32.8 to 214.2.32.8—1
10214.2.32.9/32214.2.32.9 to 214.2.32.9—1
11214.2.32.10/32214.2.32.10 to 214.2.32.10—1
12214.2.32.11/32214.2.32.11 to 214.2.32.11—1
13214.2.32.12/32214.2.32.12 to 214.2.32.12—1
14214.2.32.13/32214.2.32.13 to 214.2.32.13—1
15214.2.32.14/32214.2.32.14 to 214.2.32.14—1
16214.2.32.15/32214.2.32.15 to 214.2.32.15—1
17214.2.32.16/32214.2.32.16 to 214.2.32.16—1
18214.2.32.17/32214.2.32.17 to 214.2.32.17—1
19214.2.32.18/32214.2.32.18 to 214.2.32.18—1
20214.2.32.19/32214.2.32.19 to 214.2.32.19—1
21214.2.32.20/32214.2.32.20 to 214.2.32.20—1
22214.2.32.21/32214.2.32.21 to 214.2.32.21—1
23214.2.32.22/32214.2.32.22 to 214.2.32.22—1
24214.2.32.23/32214.2.32.23 to 214.2.32.23—1
25214.2.32.24/32214.2.32.24 to 214.2.32.24—1
26214.2.32.25/32214.2.32.25 to 214.2.32.25—1
27214.2.32.26/32214.2.32.26 to 214.2.32.26—1
28214.2.32.27/32214.2.32.27 to 214.2.32.27—1
29214.2.32.28/32214.2.32.28 to 214.2.32.28—1
30214.2.32.29/32214.2.32.29 to 214.2.32.29—1
31214.2.32.30/32214.2.32.30 to 214.2.32.30—1
32214.2.32.31/32214.2.32.31 to 214.2.32.31—1
33214.2.32.32/32214.2.32.32 to 214.2.32.32—1
34214.2.32.33/32214.2.32.33 to 214.2.32.33—1
35214.2.32.34/32214.2.32.34 to 214.2.32.34—1
36214.2.32.35/32214.2.32.35 to 214.2.32.35—1
37214.2.32.36/32214.2.32.36 to 214.2.32.36—1
38214.2.32.37/32214.2.32.37 to 214.2.32.37—1
39214.2.32.38/32214.2.32.38 to 214.2.32.38—1
40214.2.32.39/32214.2.32.39 to 214.2.32.39—1
41214.2.32.40/32214.2.32.40 to 214.2.32.40—1
42214.2.32.41/32214.2.32.41 to 214.2.32.41—1
43214.2.32.42/32214.2.32.42 to 214.2.32.42—1
44214.2.32.43/32214.2.32.43 to 214.2.32.43—1
45214.2.32.44/32214.2.32.44 to 214.2.32.44—1
46214.2.32.45/32214.2.32.45 to 214.2.32.45—1
47214.2.32.46/32214.2.32.46 to 214.2.32.46—1
48214.2.32.47/32214.2.32.47 to 214.2.32.47—1
49214.2.32.48/32214.2.32.48 to 214.2.32.48—1
50214.2.32.49/32214.2.32.49 to 214.2.32.49—1
51214.2.32.50/32214.2.32.50 to 214.2.32.50—1
52214.2.32.51/32214.2.32.51 to 214.2.32.51—1
53214.2.32.52/32214.2.32.52 to 214.2.32.52—1
54214.2.32.53/32214.2.32.53 to 214.2.32.53—1
55214.2.32.54/32214.2.32.54 to 214.2.32.54—1
56214.2.32.55/32214.2.32.55 to 214.2.32.55—1
57214.2.32.56/32214.2.32.56 to 214.2.32.56—1
58214.2.32.57/32214.2.32.57 to 214.2.32.57—1
59214.2.32.58/32214.2.32.58 to 214.2.32.58—1
60214.2.32.59/32214.2.32.59 to 214.2.32.59—1
61214.2.32.60/32214.2.32.60 to 214.2.32.60—1
62214.2.32.61/32214.2.32.61 to 214.2.32.61—1
63214.2.32.62/32214.2.32.62 to 214.2.32.62—1
64214.2.32.63/32214.2.32.63 to 214.2.32.63—1
65214.2.32.64/32214.2.32.64 to 214.2.32.64—1
66214.2.32.65/32214.2.32.65 to 214.2.32.65—1
67214.2.32.66/32214.2.32.66 to 214.2.32.66—1
68214.2.32.67/32214.2.32.67 to 214.2.32.67—1
69214.2.32.68/32214.2.32.68 to 214.2.32.68—1
70214.2.32.69/32214.2.32.69 to 214.2.32.69—1
71214.2.32.70/32214.2.32.70 to 214.2.32.70—1
72214.2.32.71/32214.2.32.71 to 214.2.32.71—1
73214.2.32.72/32214.2.32.72 to 214.2.32.72—1
74214.2.32.73/32214.2.32.73 to 214.2.32.73—1
75214.2.32.74/32214.2.32.74 to 214.2.32.74—1
76214.2.32.75/32214.2.32.75 to 214.2.32.75—1
77214.2.32.76/32214.2.32.76 to 214.2.32.76—1
78214.2.32.77/32214.2.32.77 to 214.2.32.77—1
79214.2.32.78/32214.2.32.78 to 214.2.32.78—1
80214.2.32.79/32214.2.32.79 to 214.2.32.79—1
81214.2.32.80/32214.2.32.80 to 214.2.32.80—1
82214.2.32.81/32214.2.32.81 to 214.2.32.81—1
83214.2.32.82/32214.2.32.82 to 214.2.32.82—1
84214.2.32.83/32214.2.32.83 to 214.2.32.83—1
85214.2.32.84/32214.2.32.84 to 214.2.32.84—1
86214.2.32.85/32214.2.32.85 to 214.2.32.85—1
87214.2.32.86/32214.2.32.86 to 214.2.32.86—1
88214.2.32.87/32214.2.32.87 to 214.2.32.87—1
89214.2.32.88/32214.2.32.88 to 214.2.32.88—1
90214.2.32.89/32214.2.32.89 to 214.2.32.89—1
91214.2.32.90/32214.2.32.90 to 214.2.32.90—1
92214.2.32.91/32214.2.32.91 to 214.2.32.91—1
93214.2.32.92/32214.2.32.92 to 214.2.32.92—1
94214.2.32.93/32214.2.32.93 to 214.2.32.93—1
95214.2.32.94/32214.2.32.94 to 214.2.32.94—1
96214.2.32.95/32214.2.32.95 to 214.2.32.95—1
97214.2.32.96/32214.2.32.96 to 214.2.32.96—1
98214.2.32.97/32214.2.32.97 to 214.2.32.97—1
99214.2.32.98/32214.2.32.98 to 214.2.32.98—1
100214.2.32.99/32214.2.32.99 to 214.2.32.99—1
101214.2.32.100/32214.2.32.100 to 214.2.32.100—1
102214.2.32.101/32214.2.32.101 to 214.2.32.101—1
103214.2.32.102/32214.2.32.102 to 214.2.32.102—1
104214.2.32.103/32214.2.32.103 to 214.2.32.103—1
105214.2.32.104/32214.2.32.104 to 214.2.32.104—1
106214.2.32.105/32214.2.32.105 to 214.2.32.105—1
107214.2.32.106/32214.2.32.106 to 214.2.32.106—1
108214.2.32.107/32214.2.32.107 to 214.2.32.107—1
109214.2.32.108/32214.2.32.108 to 214.2.32.108—1
110214.2.32.109/32214.2.32.109 to 214.2.32.109—1
111214.2.32.110/32214.2.32.110 to 214.2.32.110—1
112214.2.32.111/32214.2.32.111 to 214.2.32.111—1
113214.2.32.112/32214.2.32.112 to 214.2.32.112—1
114214.2.32.113/32214.2.32.113 to 214.2.32.113—1
115214.2.32.114/32214.2.32.114 to 214.2.32.114—1
116214.2.32.115/32214.2.32.115 to 214.2.32.115—1
117214.2.32.116/32214.2.32.116 to 214.2.32.116—1
118214.2.32.117/32214.2.32.117 to 214.2.32.117—1
119214.2.32.118/32214.2.32.118 to 214.2.32.118—1
120214.2.32.119/32214.2.32.119 to 214.2.32.119—1
121214.2.32.120/32214.2.32.120 to 214.2.32.120—1
122214.2.32.121/32214.2.32.121 to 214.2.32.121—1
123214.2.32.122/32214.2.32.122 to 214.2.32.122—1
124214.2.32.123/32214.2.32.123 to 214.2.32.123—1
125214.2.32.124/32214.2.32.124 to 214.2.32.124—1
126214.2.32.125/32214.2.32.125 to 214.2.32.125—1
127214.2.32.126/32214.2.32.126 to 214.2.32.126—1
128214.2.32.127/32214.2.32.127 to 214.2.32.127—1
129214.2.32.128/32214.2.32.128 to 214.2.32.128—1
130214.2.32.129/32214.2.32.129 to 214.2.32.129—1
131214.2.32.130/32214.2.32.130 to 214.2.32.130—1
132214.2.32.131/32214.2.32.131 to 214.2.32.131—1
133214.2.32.132/32214.2.32.132 to 214.2.32.132—1
134214.2.32.133/32214.2.32.133 to 214.2.32.133—1
135214.2.32.134/32214.2.32.134 to 214.2.32.134—1
136214.2.32.135/32214.2.32.135 to 214.2.32.135—1
137214.2.32.136/32214.2.32.136 to 214.2.32.136—1
138214.2.32.137/32214.2.32.137 to 214.2.32.137—1
139214.2.32.138/32214.2.32.138 to 214.2.32.138—1
140214.2.32.139/32214.2.32.139 to 214.2.32.139—1
141214.2.32.140/32214.2.32.140 to 214.2.32.140—1
142214.2.32.141/32214.2.32.141 to 214.2.32.141—1
143214.2.32.142/32214.2.32.142 to 214.2.32.142—1
144214.2.32.143/32214.2.32.143 to 214.2.32.143—1
145214.2.32.144/32214.2.32.144 to 214.2.32.144—1
146214.2.32.145/32214.2.32.145 to 214.2.32.145—1
147214.2.32.146/32214.2.32.146 to 214.2.32.146—1
148214.2.32.147/32214.2.32.147 to 214.2.32.147—1
149214.2.32.148/32214.2.32.148 to 214.2.32.148—1
150214.2.32.149/32214.2.32.149 to 214.2.32.149—1
151214.2.32.150/32214.2.32.150 to 214.2.32.150—1
152214.2.32.151/32214.2.32.151 to 214.2.32.151—1
153214.2.32.152/32214.2.32.152 to 214.2.32.152—1
154214.2.32.153/32214.2.32.153 to 214.2.32.153—1
155214.2.32.154/32214.2.32.154 to 214.2.32.154—1
156214.2.32.155/32214.2.32.155 to 214.2.32.155—1
157214.2.32.156/32214.2.32.156 to 214.2.32.156—1
158214.2.32.157/32214.2.32.157 to 214.2.32.157—1
159214.2.32.158/32214.2.32.158 to 214.2.32.158—1
160214.2.32.159/32214.2.32.159 to 214.2.32.159—1
161214.2.32.160/32214.2.32.160 to 214.2.32.160—1
162214.2.32.161/32214.2.32.161 to 214.2.32.161—1
163214.2.32.162/32214.2.32.162 to 214.2.32.162—1
164214.2.32.163/32214.2.32.163 to 214.2.32.163—1
165214.2.32.164/32214.2.32.164 to 214.2.32.164—1
166214.2.32.165/32214.2.32.165 to 214.2.32.165—1
167214.2.32.166/32214.2.32.166 to 214.2.32.166—1
168214.2.32.167/32214.2.32.167 to 214.2.32.167—1
169214.2.32.168/32214.2.32.168 to 214.2.32.168—1
170214.2.32.169/32214.2.32.169 to 214.2.32.169—1
171214.2.32.170/32214.2.32.170 to 214.2.32.170—1
172214.2.32.171/32214.2.32.171 to 214.2.32.171—1
173214.2.32.172/32214.2.32.172 to 214.2.32.172—1
174214.2.32.173/32214.2.32.173 to 214.2.32.173—1
175214.2.32.174/32214.2.32.174 to 214.2.32.174—1
176214.2.32.175/32214.2.32.175 to 214.2.32.175—1
177214.2.32.176/32214.2.32.176 to 214.2.32.176—1
178214.2.32.177/32214.2.32.177 to 214.2.32.177—1
179214.2.32.178/32214.2.32.178 to 214.2.32.178—1
180214.2.32.179/32214.2.32.179 to 214.2.32.179—1
181214.2.32.180/32214.2.32.180 to 214.2.32.180—1
182214.2.32.181/32214.2.32.181 to 214.2.32.181—1
183214.2.32.182/32214.2.32.182 to 214.2.32.182—1
184214.2.32.183/32214.2.32.183 to 214.2.32.183—1
185214.2.32.184/32214.2.32.184 to 214.2.32.184—1
186214.2.32.185/32214.2.32.185 to 214.2.32.185—1
187214.2.32.186/32214.2.32.186 to 214.2.32.186—1
188214.2.32.187/32214.2.32.187 to 214.2.32.187—1
189214.2.32.188/32214.2.32.188 to 214.2.32.188—1
190214.2.32.189/32214.2.32.189 to 214.2.32.189—1
191214.2.32.190/32214.2.32.190 to 214.2.32.190—1
192214.2.32.191/32214.2.32.191 to 214.2.32.191—1
193214.2.32.192/32214.2.32.192 to 214.2.32.192—1
194214.2.32.193/32214.2.32.193 to 214.2.32.193—1
195214.2.32.194/32214.2.32.194 to 214.2.32.194—1
196214.2.32.195/32214.2.32.195 to 214.2.32.195—1
197214.2.32.196/32214.2.32.196 to 214.2.32.196—1
198214.2.32.197/32214.2.32.197 to 214.2.32.197—1
199214.2.32.198/32214.2.32.198 to 214.2.32.198—1
200214.2.32.199/32214.2.32.199 to 214.2.32.199—1
201214.2.32.200/32214.2.32.200 to 214.2.32.200—1
202214.2.32.201/32214.2.32.201 to 214.2.32.201—1
203214.2.32.202/32214.2.32.202 to 214.2.32.202—1
204214.2.32.203/32214.2.32.203 to 214.2.32.203—1
205214.2.32.204/32214.2.32.204 to 214.2.32.204—1
206214.2.32.205/32214.2.32.205 to 214.2.32.205—1
207214.2.32.206/32214.2.32.206 to 214.2.32.206—1
208214.2.32.207/32214.2.32.207 to 214.2.32.207—1
209214.2.32.208/32214.2.32.208 to 214.2.32.208—1
210214.2.32.209/32214.2.32.209 to 214.2.32.209—1
211214.2.32.210/32214.2.32.210 to 214.2.32.210—1
212214.2.32.211/32214.2.32.211 to 214.2.32.211—1
213214.2.32.212/32214.2.32.212 to 214.2.32.212—1
214214.2.32.213/32214.2.32.213 to 214.2.32.213—1
215214.2.32.214/32214.2.32.214 to 214.2.32.214—1
216214.2.32.215/32214.2.32.215 to 214.2.32.215—1
217214.2.32.216/32214.2.32.216 to 214.2.32.216—1
218214.2.32.217/32214.2.32.217 to 214.2.32.217—1
219214.2.32.218/32214.2.32.218 to 214.2.32.218—1
220214.2.32.219/32214.2.32.219 to 214.2.32.219—1
221214.2.32.220/32214.2.32.220 to 214.2.32.220—1
222214.2.32.221/32214.2.32.221 to 214.2.32.221—1
223214.2.32.222/32214.2.32.222 to 214.2.32.222—1
224214.2.32.223/32214.2.32.223 to 214.2.32.223—1
225214.2.32.224/32214.2.32.224 to 214.2.32.224—1
226214.2.32.225/32214.2.32.225 to 214.2.32.225—1
227214.2.32.226/32214.2.32.226 to 214.2.32.226—1
228214.2.32.227/32214.2.32.227 to 214.2.32.227—1
229214.2.32.228/32214.2.32.228 to 214.2.32.228—1
230214.2.32.229/32214.2.32.229 to 214.2.32.229—1
231214.2.32.230/32214.2.32.230 to 214.2.32.230—1
232214.2.32.231/32214.2.32.231 to 214.2.32.231—1
233214.2.32.232/32214.2.32.232 to 214.2.32.232—1
234214.2.32.233/32214.2.32.233 to 214.2.32.233—1
235214.2.32.234/32214.2.32.234 to 214.2.32.234—1
236214.2.32.235/32214.2.32.235 to 214.2.32.235—1
237214.2.32.236/32214.2.32.236 to 214.2.32.236—1
238214.2.32.237/32214.2.32.237 to 214.2.32.237—1
239214.2.32.238/32214.2.32.238 to 214.2.32.238—1
240214.2.32.239/32214.2.32.239 to 214.2.32.239—1
241214.2.32.240/32214.2.32.240 to 214.2.32.240—1
242214.2.32.241/32214.2.32.241 to 214.2.32.241—1
243214.2.32.242/32214.2.32.242 to 214.2.32.242—1
244214.2.32.243/32214.2.32.243 to 214.2.32.243—1
245214.2.32.244/32214.2.32.244 to 214.2.32.244—1
246214.2.32.245/32214.2.32.245 to 214.2.32.245—1
247214.2.32.246/32214.2.32.246 to 214.2.32.246—1
248214.2.32.247/32214.2.32.247 to 214.2.32.247—1
249214.2.32.248/32214.2.32.248 to 214.2.32.248—1
250214.2.32.249/32214.2.32.249 to 214.2.32.249—1
251214.2.32.250/32214.2.32.250 to 214.2.32.250—1
252214.2.32.251/32214.2.32.251 to 214.2.32.251—1
253214.2.32.252/32214.2.32.252 to 214.2.32.252—1
254214.2.32.253/32214.2.32.253 to 214.2.32.253—1
255214.2.32.254/32214.2.32.254 to 214.2.32.254—1
256214.2.32.255/32214.2.32.255 to 214.2.32.255—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.