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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.

Network224.2.64.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
224.2.64.0
Broadcast address
224.2.127.255
First usable
224.2.64.1
Last usable
224.2.127.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E0024000 · Integer 3758243840 to 3758260223
Reverse DNS zones
64.2.224.in-addr.arpa
65.2.224.in-addr.arpa
66.2.224.in-addr.arpa
67.2.224.in-addr.arpa
68.2.224.in-addr.arpa
69.2.224.in-addr.arpa
70.2.224.in-addr.arpa
71.2.224.in-addr.arpa
72.2.224.in-addr.arpa
73.2.224.in-addr.arpa
74.2.224.in-addr.arpa
75.2.224.in-addr.arpa
76.2.224.in-addr.arpa
77.2.224.in-addr.arpa
78.2.224.in-addr.arpa
79.2.224.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100000.00000010.01000000.00000000224.2.64.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network11100000.00000010.01000000.00000000224.2.64.0
Broadcast11100000.00000010.01111111.11111111224.2.127.255
Split into smaller subnets/29
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

224.2.64.0/18 makes 2,048 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1224.2.64.0/29224.2.64.1 to 224.2.64.6224.2.64.76
2224.2.64.8/29224.2.64.9 to 224.2.64.14224.2.64.156
3224.2.64.16/29224.2.64.17 to 224.2.64.22224.2.64.236
4224.2.64.24/29224.2.64.25 to 224.2.64.30224.2.64.316
5224.2.64.32/29224.2.64.33 to 224.2.64.38224.2.64.396
6224.2.64.40/29224.2.64.41 to 224.2.64.46224.2.64.476
7224.2.64.48/29224.2.64.49 to 224.2.64.54224.2.64.556
8224.2.64.56/29224.2.64.57 to 224.2.64.62224.2.64.636
9224.2.64.64/29224.2.64.65 to 224.2.64.70224.2.64.716
10224.2.64.72/29224.2.64.73 to 224.2.64.78224.2.64.796
11224.2.64.80/29224.2.64.81 to 224.2.64.86224.2.64.876
12224.2.64.88/29224.2.64.89 to 224.2.64.94224.2.64.956
13224.2.64.96/29224.2.64.97 to 224.2.64.102224.2.64.1036
14224.2.64.104/29224.2.64.105 to 224.2.64.110224.2.64.1116
15224.2.64.112/29224.2.64.113 to 224.2.64.118224.2.64.1196
16224.2.64.120/29224.2.64.121 to 224.2.64.126224.2.64.1276
17224.2.64.128/29224.2.64.129 to 224.2.64.134224.2.64.1356
18224.2.64.136/29224.2.64.137 to 224.2.64.142224.2.64.1436
19224.2.64.144/29224.2.64.145 to 224.2.64.150224.2.64.1516
20224.2.64.152/29224.2.64.153 to 224.2.64.158224.2.64.1596
21224.2.64.160/29224.2.64.161 to 224.2.64.166224.2.64.1676
22224.2.64.168/29224.2.64.169 to 224.2.64.174224.2.64.1756
23224.2.64.176/29224.2.64.177 to 224.2.64.182224.2.64.1836
24224.2.64.184/29224.2.64.185 to 224.2.64.190224.2.64.1916
25224.2.64.192/29224.2.64.193 to 224.2.64.198224.2.64.1996
26224.2.64.200/29224.2.64.201 to 224.2.64.206224.2.64.2076
27224.2.64.208/29224.2.64.209 to 224.2.64.214224.2.64.2156
28224.2.64.216/29224.2.64.217 to 224.2.64.222224.2.64.2236
29224.2.64.224/29224.2.64.225 to 224.2.64.230224.2.64.2316
30224.2.64.232/29224.2.64.233 to 224.2.64.238224.2.64.2396
31224.2.64.240/29224.2.64.241 to 224.2.64.246224.2.64.2476
32224.2.64.248/29224.2.64.249 to 224.2.64.254224.2.64.2556
33224.2.65.0/29224.2.65.1 to 224.2.65.6224.2.65.76
34224.2.65.8/29224.2.65.9 to 224.2.65.14224.2.65.156
35224.2.65.16/29224.2.65.17 to 224.2.65.22224.2.65.236
36224.2.65.24/29224.2.65.25 to 224.2.65.30224.2.65.316
37224.2.65.32/29224.2.65.33 to 224.2.65.38224.2.65.396
38224.2.65.40/29224.2.65.41 to 224.2.65.46224.2.65.476
39224.2.65.48/29224.2.65.49 to 224.2.65.54224.2.65.556
40224.2.65.56/29224.2.65.57 to 224.2.65.62224.2.65.636
41224.2.65.64/29224.2.65.65 to 224.2.65.70224.2.65.716
42224.2.65.72/29224.2.65.73 to 224.2.65.78224.2.65.796
43224.2.65.80/29224.2.65.81 to 224.2.65.86224.2.65.876
44224.2.65.88/29224.2.65.89 to 224.2.65.94224.2.65.956
45224.2.65.96/29224.2.65.97 to 224.2.65.102224.2.65.1036
46224.2.65.104/29224.2.65.105 to 224.2.65.110224.2.65.1116
47224.2.65.112/29224.2.65.113 to 224.2.65.118224.2.65.1196
48224.2.65.120/29224.2.65.121 to 224.2.65.126224.2.65.1276
49224.2.65.128/29224.2.65.129 to 224.2.65.134224.2.65.1356
50224.2.65.136/29224.2.65.137 to 224.2.65.142224.2.65.1436
51224.2.65.144/29224.2.65.145 to 224.2.65.150224.2.65.1516
52224.2.65.152/29224.2.65.153 to 224.2.65.158224.2.65.1596
53224.2.65.160/29224.2.65.161 to 224.2.65.166224.2.65.1676
54224.2.65.168/29224.2.65.169 to 224.2.65.174224.2.65.1756
55224.2.65.176/29224.2.65.177 to 224.2.65.182224.2.65.1836
56224.2.65.184/29224.2.65.185 to 224.2.65.190224.2.65.1916
57224.2.65.192/29224.2.65.193 to 224.2.65.198224.2.65.1996
58224.2.65.200/29224.2.65.201 to 224.2.65.206224.2.65.2076
59224.2.65.208/29224.2.65.209 to 224.2.65.214224.2.65.2156
60224.2.65.216/29224.2.65.217 to 224.2.65.222224.2.65.2236
61224.2.65.224/29224.2.65.225 to 224.2.65.230224.2.65.2316
62224.2.65.232/29224.2.65.233 to 224.2.65.238224.2.65.2396
63224.2.65.240/29224.2.65.241 to 224.2.65.246224.2.65.2476
64224.2.65.248/29224.2.65.249 to 224.2.65.254224.2.65.2556
65224.2.66.0/29224.2.66.1 to 224.2.66.6224.2.66.76
66224.2.66.8/29224.2.66.9 to 224.2.66.14224.2.66.156
67224.2.66.16/29224.2.66.17 to 224.2.66.22224.2.66.236
68224.2.66.24/29224.2.66.25 to 224.2.66.30224.2.66.316
69224.2.66.32/29224.2.66.33 to 224.2.66.38224.2.66.396
70224.2.66.40/29224.2.66.41 to 224.2.66.46224.2.66.476
71224.2.66.48/29224.2.66.49 to 224.2.66.54224.2.66.556
72224.2.66.56/29224.2.66.57 to 224.2.66.62224.2.66.636
73224.2.66.64/29224.2.66.65 to 224.2.66.70224.2.66.716
74224.2.66.72/29224.2.66.73 to 224.2.66.78224.2.66.796
75224.2.66.80/29224.2.66.81 to 224.2.66.86224.2.66.876
76224.2.66.88/29224.2.66.89 to 224.2.66.94224.2.66.956
77224.2.66.96/29224.2.66.97 to 224.2.66.102224.2.66.1036
78224.2.66.104/29224.2.66.105 to 224.2.66.110224.2.66.1116
79224.2.66.112/29224.2.66.113 to 224.2.66.118224.2.66.1196
80224.2.66.120/29224.2.66.121 to 224.2.66.126224.2.66.1276
81224.2.66.128/29224.2.66.129 to 224.2.66.134224.2.66.1356
82224.2.66.136/29224.2.66.137 to 224.2.66.142224.2.66.1436
83224.2.66.144/29224.2.66.145 to 224.2.66.150224.2.66.1516
84224.2.66.152/29224.2.66.153 to 224.2.66.158224.2.66.1596
85224.2.66.160/29224.2.66.161 to 224.2.66.166224.2.66.1676
86224.2.66.168/29224.2.66.169 to 224.2.66.174224.2.66.1756
87224.2.66.176/29224.2.66.177 to 224.2.66.182224.2.66.1836
88224.2.66.184/29224.2.66.185 to 224.2.66.190224.2.66.1916
89224.2.66.192/29224.2.66.193 to 224.2.66.198224.2.66.1996
90224.2.66.200/29224.2.66.201 to 224.2.66.206224.2.66.2076
91224.2.66.208/29224.2.66.209 to 224.2.66.214224.2.66.2156
92224.2.66.216/29224.2.66.217 to 224.2.66.222224.2.66.2236
93224.2.66.224/29224.2.66.225 to 224.2.66.230224.2.66.2316
94224.2.66.232/29224.2.66.233 to 224.2.66.238224.2.66.2396
95224.2.66.240/29224.2.66.241 to 224.2.66.246224.2.66.2476
96224.2.66.248/29224.2.66.249 to 224.2.66.254224.2.66.2556
97224.2.67.0/29224.2.67.1 to 224.2.67.6224.2.67.76
98224.2.67.8/29224.2.67.9 to 224.2.67.14224.2.67.156
99224.2.67.16/29224.2.67.17 to 224.2.67.22224.2.67.236
100224.2.67.24/29224.2.67.25 to 224.2.67.30224.2.67.316
101224.2.67.32/29224.2.67.33 to 224.2.67.38224.2.67.396
102224.2.67.40/29224.2.67.41 to 224.2.67.46224.2.67.476
103224.2.67.48/29224.2.67.49 to 224.2.67.54224.2.67.556
104224.2.67.56/29224.2.67.57 to 224.2.67.62224.2.67.636
105224.2.67.64/29224.2.67.65 to 224.2.67.70224.2.67.716
106224.2.67.72/29224.2.67.73 to 224.2.67.78224.2.67.796
107224.2.67.80/29224.2.67.81 to 224.2.67.86224.2.67.876
108224.2.67.88/29224.2.67.89 to 224.2.67.94224.2.67.956
109224.2.67.96/29224.2.67.97 to 224.2.67.102224.2.67.1036
110224.2.67.104/29224.2.67.105 to 224.2.67.110224.2.67.1116
111224.2.67.112/29224.2.67.113 to 224.2.67.118224.2.67.1196
112224.2.67.120/29224.2.67.121 to 224.2.67.126224.2.67.1276
113224.2.67.128/29224.2.67.129 to 224.2.67.134224.2.67.1356
114224.2.67.136/29224.2.67.137 to 224.2.67.142224.2.67.1436
115224.2.67.144/29224.2.67.145 to 224.2.67.150224.2.67.1516
116224.2.67.152/29224.2.67.153 to 224.2.67.158224.2.67.1596
117224.2.67.160/29224.2.67.161 to 224.2.67.166224.2.67.1676
118224.2.67.168/29224.2.67.169 to 224.2.67.174224.2.67.1756
119224.2.67.176/29224.2.67.177 to 224.2.67.182224.2.67.1836
120224.2.67.184/29224.2.67.185 to 224.2.67.190224.2.67.1916
121224.2.67.192/29224.2.67.193 to 224.2.67.198224.2.67.1996
122224.2.67.200/29224.2.67.201 to 224.2.67.206224.2.67.2076
123224.2.67.208/29224.2.67.209 to 224.2.67.214224.2.67.2156
124224.2.67.216/29224.2.67.217 to 224.2.67.222224.2.67.2236
125224.2.67.224/29224.2.67.225 to 224.2.67.230224.2.67.2316
126224.2.67.232/29224.2.67.233 to 224.2.67.238224.2.67.2396
127224.2.67.240/29224.2.67.241 to 224.2.67.246224.2.67.2476
128224.2.67.248/29224.2.67.249 to 224.2.67.254224.2.67.2556
129224.2.68.0/29224.2.68.1 to 224.2.68.6224.2.68.76
130224.2.68.8/29224.2.68.9 to 224.2.68.14224.2.68.156
131224.2.68.16/29224.2.68.17 to 224.2.68.22224.2.68.236
132224.2.68.24/29224.2.68.25 to 224.2.68.30224.2.68.316
133224.2.68.32/29224.2.68.33 to 224.2.68.38224.2.68.396
134224.2.68.40/29224.2.68.41 to 224.2.68.46224.2.68.476
135224.2.68.48/29224.2.68.49 to 224.2.68.54224.2.68.556
136224.2.68.56/29224.2.68.57 to 224.2.68.62224.2.68.636
137224.2.68.64/29224.2.68.65 to 224.2.68.70224.2.68.716
138224.2.68.72/29224.2.68.73 to 224.2.68.78224.2.68.796
139224.2.68.80/29224.2.68.81 to 224.2.68.86224.2.68.876
140224.2.68.88/29224.2.68.89 to 224.2.68.94224.2.68.956
141224.2.68.96/29224.2.68.97 to 224.2.68.102224.2.68.1036
142224.2.68.104/29224.2.68.105 to 224.2.68.110224.2.68.1116
143224.2.68.112/29224.2.68.113 to 224.2.68.118224.2.68.1196
144224.2.68.120/29224.2.68.121 to 224.2.68.126224.2.68.1276
145224.2.68.128/29224.2.68.129 to 224.2.68.134224.2.68.1356
146224.2.68.136/29224.2.68.137 to 224.2.68.142224.2.68.1436
147224.2.68.144/29224.2.68.145 to 224.2.68.150224.2.68.1516
148224.2.68.152/29224.2.68.153 to 224.2.68.158224.2.68.1596
149224.2.68.160/29224.2.68.161 to 224.2.68.166224.2.68.1676
150224.2.68.168/29224.2.68.169 to 224.2.68.174224.2.68.1756
151224.2.68.176/29224.2.68.177 to 224.2.68.182224.2.68.1836
152224.2.68.184/29224.2.68.185 to 224.2.68.190224.2.68.1916
153224.2.68.192/29224.2.68.193 to 224.2.68.198224.2.68.1996
154224.2.68.200/29224.2.68.201 to 224.2.68.206224.2.68.2076
155224.2.68.208/29224.2.68.209 to 224.2.68.214224.2.68.2156
156224.2.68.216/29224.2.68.217 to 224.2.68.222224.2.68.2236
157224.2.68.224/29224.2.68.225 to 224.2.68.230224.2.68.2316
158224.2.68.232/29224.2.68.233 to 224.2.68.238224.2.68.2396
159224.2.68.240/29224.2.68.241 to 224.2.68.246224.2.68.2476
160224.2.68.248/29224.2.68.249 to 224.2.68.254224.2.68.2556
161224.2.69.0/29224.2.69.1 to 224.2.69.6224.2.69.76
162224.2.69.8/29224.2.69.9 to 224.2.69.14224.2.69.156
163224.2.69.16/29224.2.69.17 to 224.2.69.22224.2.69.236
164224.2.69.24/29224.2.69.25 to 224.2.69.30224.2.69.316
165224.2.69.32/29224.2.69.33 to 224.2.69.38224.2.69.396
166224.2.69.40/29224.2.69.41 to 224.2.69.46224.2.69.476
167224.2.69.48/29224.2.69.49 to 224.2.69.54224.2.69.556
168224.2.69.56/29224.2.69.57 to 224.2.69.62224.2.69.636
169224.2.69.64/29224.2.69.65 to 224.2.69.70224.2.69.716
170224.2.69.72/29224.2.69.73 to 224.2.69.78224.2.69.796
171224.2.69.80/29224.2.69.81 to 224.2.69.86224.2.69.876
172224.2.69.88/29224.2.69.89 to 224.2.69.94224.2.69.956
173224.2.69.96/29224.2.69.97 to 224.2.69.102224.2.69.1036
174224.2.69.104/29224.2.69.105 to 224.2.69.110224.2.69.1116
175224.2.69.112/29224.2.69.113 to 224.2.69.118224.2.69.1196
176224.2.69.120/29224.2.69.121 to 224.2.69.126224.2.69.1276
177224.2.69.128/29224.2.69.129 to 224.2.69.134224.2.69.1356
178224.2.69.136/29224.2.69.137 to 224.2.69.142224.2.69.1436
179224.2.69.144/29224.2.69.145 to 224.2.69.150224.2.69.1516
180224.2.69.152/29224.2.69.153 to 224.2.69.158224.2.69.1596
181224.2.69.160/29224.2.69.161 to 224.2.69.166224.2.69.1676
182224.2.69.168/29224.2.69.169 to 224.2.69.174224.2.69.1756
183224.2.69.176/29224.2.69.177 to 224.2.69.182224.2.69.1836
184224.2.69.184/29224.2.69.185 to 224.2.69.190224.2.69.1916
185224.2.69.192/29224.2.69.193 to 224.2.69.198224.2.69.1996
186224.2.69.200/29224.2.69.201 to 224.2.69.206224.2.69.2076
187224.2.69.208/29224.2.69.209 to 224.2.69.214224.2.69.2156
188224.2.69.216/29224.2.69.217 to 224.2.69.222224.2.69.2236
189224.2.69.224/29224.2.69.225 to 224.2.69.230224.2.69.2316
190224.2.69.232/29224.2.69.233 to 224.2.69.238224.2.69.2396
191224.2.69.240/29224.2.69.241 to 224.2.69.246224.2.69.2476
192224.2.69.248/29224.2.69.249 to 224.2.69.254224.2.69.2556
193224.2.70.0/29224.2.70.1 to 224.2.70.6224.2.70.76
194224.2.70.8/29224.2.70.9 to 224.2.70.14224.2.70.156
195224.2.70.16/29224.2.70.17 to 224.2.70.22224.2.70.236
196224.2.70.24/29224.2.70.25 to 224.2.70.30224.2.70.316
197224.2.70.32/29224.2.70.33 to 224.2.70.38224.2.70.396
198224.2.70.40/29224.2.70.41 to 224.2.70.46224.2.70.476
199224.2.70.48/29224.2.70.49 to 224.2.70.54224.2.70.556
200224.2.70.56/29224.2.70.57 to 224.2.70.62224.2.70.636
201224.2.70.64/29224.2.70.65 to 224.2.70.70224.2.70.716
202224.2.70.72/29224.2.70.73 to 224.2.70.78224.2.70.796
203224.2.70.80/29224.2.70.81 to 224.2.70.86224.2.70.876
204224.2.70.88/29224.2.70.89 to 224.2.70.94224.2.70.956
205224.2.70.96/29224.2.70.97 to 224.2.70.102224.2.70.1036
206224.2.70.104/29224.2.70.105 to 224.2.70.110224.2.70.1116
207224.2.70.112/29224.2.70.113 to 224.2.70.118224.2.70.1196
208224.2.70.120/29224.2.70.121 to 224.2.70.126224.2.70.1276
209224.2.70.128/29224.2.70.129 to 224.2.70.134224.2.70.1356
210224.2.70.136/29224.2.70.137 to 224.2.70.142224.2.70.1436
211224.2.70.144/29224.2.70.145 to 224.2.70.150224.2.70.1516
212224.2.70.152/29224.2.70.153 to 224.2.70.158224.2.70.1596
213224.2.70.160/29224.2.70.161 to 224.2.70.166224.2.70.1676
214224.2.70.168/29224.2.70.169 to 224.2.70.174224.2.70.1756
215224.2.70.176/29224.2.70.177 to 224.2.70.182224.2.70.1836
216224.2.70.184/29224.2.70.185 to 224.2.70.190224.2.70.1916
217224.2.70.192/29224.2.70.193 to 224.2.70.198224.2.70.1996
218224.2.70.200/29224.2.70.201 to 224.2.70.206224.2.70.2076
219224.2.70.208/29224.2.70.209 to 224.2.70.214224.2.70.2156
220224.2.70.216/29224.2.70.217 to 224.2.70.222224.2.70.2236
221224.2.70.224/29224.2.70.225 to 224.2.70.230224.2.70.2316
222224.2.70.232/29224.2.70.233 to 224.2.70.238224.2.70.2396
223224.2.70.240/29224.2.70.241 to 224.2.70.246224.2.70.2476
224224.2.70.248/29224.2.70.249 to 224.2.70.254224.2.70.2556
225224.2.71.0/29224.2.71.1 to 224.2.71.6224.2.71.76
226224.2.71.8/29224.2.71.9 to 224.2.71.14224.2.71.156
227224.2.71.16/29224.2.71.17 to 224.2.71.22224.2.71.236
228224.2.71.24/29224.2.71.25 to 224.2.71.30224.2.71.316
229224.2.71.32/29224.2.71.33 to 224.2.71.38224.2.71.396
230224.2.71.40/29224.2.71.41 to 224.2.71.46224.2.71.476
231224.2.71.48/29224.2.71.49 to 224.2.71.54224.2.71.556
232224.2.71.56/29224.2.71.57 to 224.2.71.62224.2.71.636
233224.2.71.64/29224.2.71.65 to 224.2.71.70224.2.71.716
234224.2.71.72/29224.2.71.73 to 224.2.71.78224.2.71.796
235224.2.71.80/29224.2.71.81 to 224.2.71.86224.2.71.876
236224.2.71.88/29224.2.71.89 to 224.2.71.94224.2.71.956
237224.2.71.96/29224.2.71.97 to 224.2.71.102224.2.71.1036
238224.2.71.104/29224.2.71.105 to 224.2.71.110224.2.71.1116
239224.2.71.112/29224.2.71.113 to 224.2.71.118224.2.71.1196
240224.2.71.120/29224.2.71.121 to 224.2.71.126224.2.71.1276
241224.2.71.128/29224.2.71.129 to 224.2.71.134224.2.71.1356
242224.2.71.136/29224.2.71.137 to 224.2.71.142224.2.71.1436
243224.2.71.144/29224.2.71.145 to 224.2.71.150224.2.71.1516
244224.2.71.152/29224.2.71.153 to 224.2.71.158224.2.71.1596
245224.2.71.160/29224.2.71.161 to 224.2.71.166224.2.71.1676
246224.2.71.168/29224.2.71.169 to 224.2.71.174224.2.71.1756
247224.2.71.176/29224.2.71.177 to 224.2.71.182224.2.71.1836
248224.2.71.184/29224.2.71.185 to 224.2.71.190224.2.71.1916
249224.2.71.192/29224.2.71.193 to 224.2.71.198224.2.71.1996
250224.2.71.200/29224.2.71.201 to 224.2.71.206224.2.71.2076
251224.2.71.208/29224.2.71.209 to 224.2.71.214224.2.71.2156
252224.2.71.216/29224.2.71.217 to 224.2.71.222224.2.71.2236
253224.2.71.224/29224.2.71.225 to 224.2.71.230224.2.71.2316
254224.2.71.232/29224.2.71.233 to 224.2.71.238224.2.71.2396
255224.2.71.240/29224.2.71.241 to 224.2.71.246224.2.71.2476
256224.2.71.248/29224.2.71.249 to 224.2.71.254224.2.71.2556

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.