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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.

Network224.178.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
224.178.0.0
Broadcast address
224.179.255.255
First usable
224.178.0.1
Last usable
224.179.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E0B20000 · Integer 3769761792 to 3769892863
Reverse DNS zones
178.224.in-addr.arpa
179.224.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100000.10110010.00000000.00000000224.178.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network11100000.10110010.00000000.00000000224.178.0.0
Broadcast11100000.10110011.11111111.11111111224.179.255.255
Split into smaller subnets/27
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

224.178.0.0/15 makes 4,096 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1224.178.0.0/27224.178.0.1 to 224.178.0.30224.178.0.3130
2224.178.0.32/27224.178.0.33 to 224.178.0.62224.178.0.6330
3224.178.0.64/27224.178.0.65 to 224.178.0.94224.178.0.9530
4224.178.0.96/27224.178.0.97 to 224.178.0.126224.178.0.12730
5224.178.0.128/27224.178.0.129 to 224.178.0.158224.178.0.15930
6224.178.0.160/27224.178.0.161 to 224.178.0.190224.178.0.19130
7224.178.0.192/27224.178.0.193 to 224.178.0.222224.178.0.22330
8224.178.0.224/27224.178.0.225 to 224.178.0.254224.178.0.25530
9224.178.1.0/27224.178.1.1 to 224.178.1.30224.178.1.3130
10224.178.1.32/27224.178.1.33 to 224.178.1.62224.178.1.6330
11224.178.1.64/27224.178.1.65 to 224.178.1.94224.178.1.9530
12224.178.1.96/27224.178.1.97 to 224.178.1.126224.178.1.12730
13224.178.1.128/27224.178.1.129 to 224.178.1.158224.178.1.15930
14224.178.1.160/27224.178.1.161 to 224.178.1.190224.178.1.19130
15224.178.1.192/27224.178.1.193 to 224.178.1.222224.178.1.22330
16224.178.1.224/27224.178.1.225 to 224.178.1.254224.178.1.25530
17224.178.2.0/27224.178.2.1 to 224.178.2.30224.178.2.3130
18224.178.2.32/27224.178.2.33 to 224.178.2.62224.178.2.6330
19224.178.2.64/27224.178.2.65 to 224.178.2.94224.178.2.9530
20224.178.2.96/27224.178.2.97 to 224.178.2.126224.178.2.12730
21224.178.2.128/27224.178.2.129 to 224.178.2.158224.178.2.15930
22224.178.2.160/27224.178.2.161 to 224.178.2.190224.178.2.19130
23224.178.2.192/27224.178.2.193 to 224.178.2.222224.178.2.22330
24224.178.2.224/27224.178.2.225 to 224.178.2.254224.178.2.25530
25224.178.3.0/27224.178.3.1 to 224.178.3.30224.178.3.3130
26224.178.3.32/27224.178.3.33 to 224.178.3.62224.178.3.6330
27224.178.3.64/27224.178.3.65 to 224.178.3.94224.178.3.9530
28224.178.3.96/27224.178.3.97 to 224.178.3.126224.178.3.12730
29224.178.3.128/27224.178.3.129 to 224.178.3.158224.178.3.15930
30224.178.3.160/27224.178.3.161 to 224.178.3.190224.178.3.19130
31224.178.3.192/27224.178.3.193 to 224.178.3.222224.178.3.22330
32224.178.3.224/27224.178.3.225 to 224.178.3.254224.178.3.25530
33224.178.4.0/27224.178.4.1 to 224.178.4.30224.178.4.3130
34224.178.4.32/27224.178.4.33 to 224.178.4.62224.178.4.6330
35224.178.4.64/27224.178.4.65 to 224.178.4.94224.178.4.9530
36224.178.4.96/27224.178.4.97 to 224.178.4.126224.178.4.12730
37224.178.4.128/27224.178.4.129 to 224.178.4.158224.178.4.15930
38224.178.4.160/27224.178.4.161 to 224.178.4.190224.178.4.19130
39224.178.4.192/27224.178.4.193 to 224.178.4.222224.178.4.22330
40224.178.4.224/27224.178.4.225 to 224.178.4.254224.178.4.25530
41224.178.5.0/27224.178.5.1 to 224.178.5.30224.178.5.3130
42224.178.5.32/27224.178.5.33 to 224.178.5.62224.178.5.6330
43224.178.5.64/27224.178.5.65 to 224.178.5.94224.178.5.9530
44224.178.5.96/27224.178.5.97 to 224.178.5.126224.178.5.12730
45224.178.5.128/27224.178.5.129 to 224.178.5.158224.178.5.15930
46224.178.5.160/27224.178.5.161 to 224.178.5.190224.178.5.19130
47224.178.5.192/27224.178.5.193 to 224.178.5.222224.178.5.22330
48224.178.5.224/27224.178.5.225 to 224.178.5.254224.178.5.25530
49224.178.6.0/27224.178.6.1 to 224.178.6.30224.178.6.3130
50224.178.6.32/27224.178.6.33 to 224.178.6.62224.178.6.6330
51224.178.6.64/27224.178.6.65 to 224.178.6.94224.178.6.9530
52224.178.6.96/27224.178.6.97 to 224.178.6.126224.178.6.12730
53224.178.6.128/27224.178.6.129 to 224.178.6.158224.178.6.15930
54224.178.6.160/27224.178.6.161 to 224.178.6.190224.178.6.19130
55224.178.6.192/27224.178.6.193 to 224.178.6.222224.178.6.22330
56224.178.6.224/27224.178.6.225 to 224.178.6.254224.178.6.25530
57224.178.7.0/27224.178.7.1 to 224.178.7.30224.178.7.3130
58224.178.7.32/27224.178.7.33 to 224.178.7.62224.178.7.6330
59224.178.7.64/27224.178.7.65 to 224.178.7.94224.178.7.9530
60224.178.7.96/27224.178.7.97 to 224.178.7.126224.178.7.12730
61224.178.7.128/27224.178.7.129 to 224.178.7.158224.178.7.15930
62224.178.7.160/27224.178.7.161 to 224.178.7.190224.178.7.19130
63224.178.7.192/27224.178.7.193 to 224.178.7.222224.178.7.22330
64224.178.7.224/27224.178.7.225 to 224.178.7.254224.178.7.25530
65224.178.8.0/27224.178.8.1 to 224.178.8.30224.178.8.3130
66224.178.8.32/27224.178.8.33 to 224.178.8.62224.178.8.6330
67224.178.8.64/27224.178.8.65 to 224.178.8.94224.178.8.9530
68224.178.8.96/27224.178.8.97 to 224.178.8.126224.178.8.12730
69224.178.8.128/27224.178.8.129 to 224.178.8.158224.178.8.15930
70224.178.8.160/27224.178.8.161 to 224.178.8.190224.178.8.19130
71224.178.8.192/27224.178.8.193 to 224.178.8.222224.178.8.22330
72224.178.8.224/27224.178.8.225 to 224.178.8.254224.178.8.25530
73224.178.9.0/27224.178.9.1 to 224.178.9.30224.178.9.3130
74224.178.9.32/27224.178.9.33 to 224.178.9.62224.178.9.6330
75224.178.9.64/27224.178.9.65 to 224.178.9.94224.178.9.9530
76224.178.9.96/27224.178.9.97 to 224.178.9.126224.178.9.12730
77224.178.9.128/27224.178.9.129 to 224.178.9.158224.178.9.15930
78224.178.9.160/27224.178.9.161 to 224.178.9.190224.178.9.19130
79224.178.9.192/27224.178.9.193 to 224.178.9.222224.178.9.22330
80224.178.9.224/27224.178.9.225 to 224.178.9.254224.178.9.25530
81224.178.10.0/27224.178.10.1 to 224.178.10.30224.178.10.3130
82224.178.10.32/27224.178.10.33 to 224.178.10.62224.178.10.6330
83224.178.10.64/27224.178.10.65 to 224.178.10.94224.178.10.9530
84224.178.10.96/27224.178.10.97 to 224.178.10.126224.178.10.12730
85224.178.10.128/27224.178.10.129 to 224.178.10.158224.178.10.15930
86224.178.10.160/27224.178.10.161 to 224.178.10.190224.178.10.19130
87224.178.10.192/27224.178.10.193 to 224.178.10.222224.178.10.22330
88224.178.10.224/27224.178.10.225 to 224.178.10.254224.178.10.25530
89224.178.11.0/27224.178.11.1 to 224.178.11.30224.178.11.3130
90224.178.11.32/27224.178.11.33 to 224.178.11.62224.178.11.6330
91224.178.11.64/27224.178.11.65 to 224.178.11.94224.178.11.9530
92224.178.11.96/27224.178.11.97 to 224.178.11.126224.178.11.12730
93224.178.11.128/27224.178.11.129 to 224.178.11.158224.178.11.15930
94224.178.11.160/27224.178.11.161 to 224.178.11.190224.178.11.19130
95224.178.11.192/27224.178.11.193 to 224.178.11.222224.178.11.22330
96224.178.11.224/27224.178.11.225 to 224.178.11.254224.178.11.25530
97224.178.12.0/27224.178.12.1 to 224.178.12.30224.178.12.3130
98224.178.12.32/27224.178.12.33 to 224.178.12.62224.178.12.6330
99224.178.12.64/27224.178.12.65 to 224.178.12.94224.178.12.9530
100224.178.12.96/27224.178.12.97 to 224.178.12.126224.178.12.12730
101224.178.12.128/27224.178.12.129 to 224.178.12.158224.178.12.15930
102224.178.12.160/27224.178.12.161 to 224.178.12.190224.178.12.19130
103224.178.12.192/27224.178.12.193 to 224.178.12.222224.178.12.22330
104224.178.12.224/27224.178.12.225 to 224.178.12.254224.178.12.25530
105224.178.13.0/27224.178.13.1 to 224.178.13.30224.178.13.3130
106224.178.13.32/27224.178.13.33 to 224.178.13.62224.178.13.6330
107224.178.13.64/27224.178.13.65 to 224.178.13.94224.178.13.9530
108224.178.13.96/27224.178.13.97 to 224.178.13.126224.178.13.12730
109224.178.13.128/27224.178.13.129 to 224.178.13.158224.178.13.15930
110224.178.13.160/27224.178.13.161 to 224.178.13.190224.178.13.19130
111224.178.13.192/27224.178.13.193 to 224.178.13.222224.178.13.22330
112224.178.13.224/27224.178.13.225 to 224.178.13.254224.178.13.25530
113224.178.14.0/27224.178.14.1 to 224.178.14.30224.178.14.3130
114224.178.14.32/27224.178.14.33 to 224.178.14.62224.178.14.6330
115224.178.14.64/27224.178.14.65 to 224.178.14.94224.178.14.9530
116224.178.14.96/27224.178.14.97 to 224.178.14.126224.178.14.12730
117224.178.14.128/27224.178.14.129 to 224.178.14.158224.178.14.15930
118224.178.14.160/27224.178.14.161 to 224.178.14.190224.178.14.19130
119224.178.14.192/27224.178.14.193 to 224.178.14.222224.178.14.22330
120224.178.14.224/27224.178.14.225 to 224.178.14.254224.178.14.25530
121224.178.15.0/27224.178.15.1 to 224.178.15.30224.178.15.3130
122224.178.15.32/27224.178.15.33 to 224.178.15.62224.178.15.6330
123224.178.15.64/27224.178.15.65 to 224.178.15.94224.178.15.9530
124224.178.15.96/27224.178.15.97 to 224.178.15.126224.178.15.12730
125224.178.15.128/27224.178.15.129 to 224.178.15.158224.178.15.15930
126224.178.15.160/27224.178.15.161 to 224.178.15.190224.178.15.19130
127224.178.15.192/27224.178.15.193 to 224.178.15.222224.178.15.22330
128224.178.15.224/27224.178.15.225 to 224.178.15.254224.178.15.25530
129224.178.16.0/27224.178.16.1 to 224.178.16.30224.178.16.3130
130224.178.16.32/27224.178.16.33 to 224.178.16.62224.178.16.6330
131224.178.16.64/27224.178.16.65 to 224.178.16.94224.178.16.9530
132224.178.16.96/27224.178.16.97 to 224.178.16.126224.178.16.12730
133224.178.16.128/27224.178.16.129 to 224.178.16.158224.178.16.15930
134224.178.16.160/27224.178.16.161 to 224.178.16.190224.178.16.19130
135224.178.16.192/27224.178.16.193 to 224.178.16.222224.178.16.22330
136224.178.16.224/27224.178.16.225 to 224.178.16.254224.178.16.25530
137224.178.17.0/27224.178.17.1 to 224.178.17.30224.178.17.3130
138224.178.17.32/27224.178.17.33 to 224.178.17.62224.178.17.6330
139224.178.17.64/27224.178.17.65 to 224.178.17.94224.178.17.9530
140224.178.17.96/27224.178.17.97 to 224.178.17.126224.178.17.12730
141224.178.17.128/27224.178.17.129 to 224.178.17.158224.178.17.15930
142224.178.17.160/27224.178.17.161 to 224.178.17.190224.178.17.19130
143224.178.17.192/27224.178.17.193 to 224.178.17.222224.178.17.22330
144224.178.17.224/27224.178.17.225 to 224.178.17.254224.178.17.25530
145224.178.18.0/27224.178.18.1 to 224.178.18.30224.178.18.3130
146224.178.18.32/27224.178.18.33 to 224.178.18.62224.178.18.6330
147224.178.18.64/27224.178.18.65 to 224.178.18.94224.178.18.9530
148224.178.18.96/27224.178.18.97 to 224.178.18.126224.178.18.12730
149224.178.18.128/27224.178.18.129 to 224.178.18.158224.178.18.15930
150224.178.18.160/27224.178.18.161 to 224.178.18.190224.178.18.19130
151224.178.18.192/27224.178.18.193 to 224.178.18.222224.178.18.22330
152224.178.18.224/27224.178.18.225 to 224.178.18.254224.178.18.25530
153224.178.19.0/27224.178.19.1 to 224.178.19.30224.178.19.3130
154224.178.19.32/27224.178.19.33 to 224.178.19.62224.178.19.6330
155224.178.19.64/27224.178.19.65 to 224.178.19.94224.178.19.9530
156224.178.19.96/27224.178.19.97 to 224.178.19.126224.178.19.12730
157224.178.19.128/27224.178.19.129 to 224.178.19.158224.178.19.15930
158224.178.19.160/27224.178.19.161 to 224.178.19.190224.178.19.19130
159224.178.19.192/27224.178.19.193 to 224.178.19.222224.178.19.22330
160224.178.19.224/27224.178.19.225 to 224.178.19.254224.178.19.25530
161224.178.20.0/27224.178.20.1 to 224.178.20.30224.178.20.3130
162224.178.20.32/27224.178.20.33 to 224.178.20.62224.178.20.6330
163224.178.20.64/27224.178.20.65 to 224.178.20.94224.178.20.9530
164224.178.20.96/27224.178.20.97 to 224.178.20.126224.178.20.12730
165224.178.20.128/27224.178.20.129 to 224.178.20.158224.178.20.15930
166224.178.20.160/27224.178.20.161 to 224.178.20.190224.178.20.19130
167224.178.20.192/27224.178.20.193 to 224.178.20.222224.178.20.22330
168224.178.20.224/27224.178.20.225 to 224.178.20.254224.178.20.25530
169224.178.21.0/27224.178.21.1 to 224.178.21.30224.178.21.3130
170224.178.21.32/27224.178.21.33 to 224.178.21.62224.178.21.6330
171224.178.21.64/27224.178.21.65 to 224.178.21.94224.178.21.9530
172224.178.21.96/27224.178.21.97 to 224.178.21.126224.178.21.12730
173224.178.21.128/27224.178.21.129 to 224.178.21.158224.178.21.15930
174224.178.21.160/27224.178.21.161 to 224.178.21.190224.178.21.19130
175224.178.21.192/27224.178.21.193 to 224.178.21.222224.178.21.22330
176224.178.21.224/27224.178.21.225 to 224.178.21.254224.178.21.25530
177224.178.22.0/27224.178.22.1 to 224.178.22.30224.178.22.3130
178224.178.22.32/27224.178.22.33 to 224.178.22.62224.178.22.6330
179224.178.22.64/27224.178.22.65 to 224.178.22.94224.178.22.9530
180224.178.22.96/27224.178.22.97 to 224.178.22.126224.178.22.12730
181224.178.22.128/27224.178.22.129 to 224.178.22.158224.178.22.15930
182224.178.22.160/27224.178.22.161 to 224.178.22.190224.178.22.19130
183224.178.22.192/27224.178.22.193 to 224.178.22.222224.178.22.22330
184224.178.22.224/27224.178.22.225 to 224.178.22.254224.178.22.25530
185224.178.23.0/27224.178.23.1 to 224.178.23.30224.178.23.3130
186224.178.23.32/27224.178.23.33 to 224.178.23.62224.178.23.6330
187224.178.23.64/27224.178.23.65 to 224.178.23.94224.178.23.9530
188224.178.23.96/27224.178.23.97 to 224.178.23.126224.178.23.12730
189224.178.23.128/27224.178.23.129 to 224.178.23.158224.178.23.15930
190224.178.23.160/27224.178.23.161 to 224.178.23.190224.178.23.19130
191224.178.23.192/27224.178.23.193 to 224.178.23.222224.178.23.22330
192224.178.23.224/27224.178.23.225 to 224.178.23.254224.178.23.25530
193224.178.24.0/27224.178.24.1 to 224.178.24.30224.178.24.3130
194224.178.24.32/27224.178.24.33 to 224.178.24.62224.178.24.6330
195224.178.24.64/27224.178.24.65 to 224.178.24.94224.178.24.9530
196224.178.24.96/27224.178.24.97 to 224.178.24.126224.178.24.12730
197224.178.24.128/27224.178.24.129 to 224.178.24.158224.178.24.15930
198224.178.24.160/27224.178.24.161 to 224.178.24.190224.178.24.19130
199224.178.24.192/27224.178.24.193 to 224.178.24.222224.178.24.22330
200224.178.24.224/27224.178.24.225 to 224.178.24.254224.178.24.25530
201224.178.25.0/27224.178.25.1 to 224.178.25.30224.178.25.3130
202224.178.25.32/27224.178.25.33 to 224.178.25.62224.178.25.6330
203224.178.25.64/27224.178.25.65 to 224.178.25.94224.178.25.9530
204224.178.25.96/27224.178.25.97 to 224.178.25.126224.178.25.12730
205224.178.25.128/27224.178.25.129 to 224.178.25.158224.178.25.15930
206224.178.25.160/27224.178.25.161 to 224.178.25.190224.178.25.19130
207224.178.25.192/27224.178.25.193 to 224.178.25.222224.178.25.22330
208224.178.25.224/27224.178.25.225 to 224.178.25.254224.178.25.25530
209224.178.26.0/27224.178.26.1 to 224.178.26.30224.178.26.3130
210224.178.26.32/27224.178.26.33 to 224.178.26.62224.178.26.6330
211224.178.26.64/27224.178.26.65 to 224.178.26.94224.178.26.9530
212224.178.26.96/27224.178.26.97 to 224.178.26.126224.178.26.12730
213224.178.26.128/27224.178.26.129 to 224.178.26.158224.178.26.15930
214224.178.26.160/27224.178.26.161 to 224.178.26.190224.178.26.19130
215224.178.26.192/27224.178.26.193 to 224.178.26.222224.178.26.22330
216224.178.26.224/27224.178.26.225 to 224.178.26.254224.178.26.25530
217224.178.27.0/27224.178.27.1 to 224.178.27.30224.178.27.3130
218224.178.27.32/27224.178.27.33 to 224.178.27.62224.178.27.6330
219224.178.27.64/27224.178.27.65 to 224.178.27.94224.178.27.9530
220224.178.27.96/27224.178.27.97 to 224.178.27.126224.178.27.12730
221224.178.27.128/27224.178.27.129 to 224.178.27.158224.178.27.15930
222224.178.27.160/27224.178.27.161 to 224.178.27.190224.178.27.19130
223224.178.27.192/27224.178.27.193 to 224.178.27.222224.178.27.22330
224224.178.27.224/27224.178.27.225 to 224.178.27.254224.178.27.25530
225224.178.28.0/27224.178.28.1 to 224.178.28.30224.178.28.3130
226224.178.28.32/27224.178.28.33 to 224.178.28.62224.178.28.6330
227224.178.28.64/27224.178.28.65 to 224.178.28.94224.178.28.9530
228224.178.28.96/27224.178.28.97 to 224.178.28.126224.178.28.12730
229224.178.28.128/27224.178.28.129 to 224.178.28.158224.178.28.15930
230224.178.28.160/27224.178.28.161 to 224.178.28.190224.178.28.19130
231224.178.28.192/27224.178.28.193 to 224.178.28.222224.178.28.22330
232224.178.28.224/27224.178.28.225 to 224.178.28.254224.178.28.25530
233224.178.29.0/27224.178.29.1 to 224.178.29.30224.178.29.3130
234224.178.29.32/27224.178.29.33 to 224.178.29.62224.178.29.6330
235224.178.29.64/27224.178.29.65 to 224.178.29.94224.178.29.9530
236224.178.29.96/27224.178.29.97 to 224.178.29.126224.178.29.12730
237224.178.29.128/27224.178.29.129 to 224.178.29.158224.178.29.15930
238224.178.29.160/27224.178.29.161 to 224.178.29.190224.178.29.19130
239224.178.29.192/27224.178.29.193 to 224.178.29.222224.178.29.22330
240224.178.29.224/27224.178.29.225 to 224.178.29.254224.178.29.25530
241224.178.30.0/27224.178.30.1 to 224.178.30.30224.178.30.3130
242224.178.30.32/27224.178.30.33 to 224.178.30.62224.178.30.6330
243224.178.30.64/27224.178.30.65 to 224.178.30.94224.178.30.9530
244224.178.30.96/27224.178.30.97 to 224.178.30.126224.178.30.12730
245224.178.30.128/27224.178.30.129 to 224.178.30.158224.178.30.15930
246224.178.30.160/27224.178.30.161 to 224.178.30.190224.178.30.19130
247224.178.30.192/27224.178.30.193 to 224.178.30.222224.178.30.22330
248224.178.30.224/27224.178.30.225 to 224.178.30.254224.178.30.25530
249224.178.31.0/27224.178.31.1 to 224.178.31.30224.178.31.3130
250224.178.31.32/27224.178.31.33 to 224.178.31.62224.178.31.6330
251224.178.31.64/27224.178.31.65 to 224.178.31.94224.178.31.9530
252224.178.31.96/27224.178.31.97 to 224.178.31.126224.178.31.12730
253224.178.31.128/27224.178.31.129 to 224.178.31.158224.178.31.15930
254224.178.31.160/27224.178.31.161 to 224.178.31.190224.178.31.19130
255224.178.31.192/27224.178.31.193 to 224.178.31.222224.178.31.22330
256224.178.31.224/27224.178.31.225 to 224.178.31.254224.178.31.25530

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.