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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.

Network148.80.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
148.80.0.0
Broadcast address
148.80.127.255
First usable
148.80.0.1
Last usable
148.80.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
B (default /16)
As numbers
Hex 94500000 · Integer 2488270848 to 2488303615
Reverse DNS zones
0.80.148.in-addr.arpa
1.80.148.in-addr.arpa
2.80.148.in-addr.arpa
3.80.148.in-addr.arpa
4.80.148.in-addr.arpa
5.80.148.in-addr.arpa
6.80.148.in-addr.arpa
7.80.148.in-addr.arpa
8.80.148.in-addr.arpa
9.80.148.in-addr.arpa
10.80.148.in-addr.arpa
11.80.148.in-addr.arpa
12.80.148.in-addr.arpa
13.80.148.in-addr.arpa
14.80.148.in-addr.arpa
15.80.148.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010100.01010000.00000000.00000000148.80.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network10010100.01010000.00000000.00000000148.80.0.0
Broadcast10010100.01010000.01111111.11111111148.80.127.255
Split into smaller subnets/27
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

148.80.0.0/17 makes 1,024 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1148.80.0.0/27148.80.0.1 to 148.80.0.30148.80.0.3130
2148.80.0.32/27148.80.0.33 to 148.80.0.62148.80.0.6330
3148.80.0.64/27148.80.0.65 to 148.80.0.94148.80.0.9530
4148.80.0.96/27148.80.0.97 to 148.80.0.126148.80.0.12730
5148.80.0.128/27148.80.0.129 to 148.80.0.158148.80.0.15930
6148.80.0.160/27148.80.0.161 to 148.80.0.190148.80.0.19130
7148.80.0.192/27148.80.0.193 to 148.80.0.222148.80.0.22330
8148.80.0.224/27148.80.0.225 to 148.80.0.254148.80.0.25530
9148.80.1.0/27148.80.1.1 to 148.80.1.30148.80.1.3130
10148.80.1.32/27148.80.1.33 to 148.80.1.62148.80.1.6330
11148.80.1.64/27148.80.1.65 to 148.80.1.94148.80.1.9530
12148.80.1.96/27148.80.1.97 to 148.80.1.126148.80.1.12730
13148.80.1.128/27148.80.1.129 to 148.80.1.158148.80.1.15930
14148.80.1.160/27148.80.1.161 to 148.80.1.190148.80.1.19130
15148.80.1.192/27148.80.1.193 to 148.80.1.222148.80.1.22330
16148.80.1.224/27148.80.1.225 to 148.80.1.254148.80.1.25530
17148.80.2.0/27148.80.2.1 to 148.80.2.30148.80.2.3130
18148.80.2.32/27148.80.2.33 to 148.80.2.62148.80.2.6330
19148.80.2.64/27148.80.2.65 to 148.80.2.94148.80.2.9530
20148.80.2.96/27148.80.2.97 to 148.80.2.126148.80.2.12730
21148.80.2.128/27148.80.2.129 to 148.80.2.158148.80.2.15930
22148.80.2.160/27148.80.2.161 to 148.80.2.190148.80.2.19130
23148.80.2.192/27148.80.2.193 to 148.80.2.222148.80.2.22330
24148.80.2.224/27148.80.2.225 to 148.80.2.254148.80.2.25530
25148.80.3.0/27148.80.3.1 to 148.80.3.30148.80.3.3130
26148.80.3.32/27148.80.3.33 to 148.80.3.62148.80.3.6330
27148.80.3.64/27148.80.3.65 to 148.80.3.94148.80.3.9530
28148.80.3.96/27148.80.3.97 to 148.80.3.126148.80.3.12730
29148.80.3.128/27148.80.3.129 to 148.80.3.158148.80.3.15930
30148.80.3.160/27148.80.3.161 to 148.80.3.190148.80.3.19130
31148.80.3.192/27148.80.3.193 to 148.80.3.222148.80.3.22330
32148.80.3.224/27148.80.3.225 to 148.80.3.254148.80.3.25530
33148.80.4.0/27148.80.4.1 to 148.80.4.30148.80.4.3130
34148.80.4.32/27148.80.4.33 to 148.80.4.62148.80.4.6330
35148.80.4.64/27148.80.4.65 to 148.80.4.94148.80.4.9530
36148.80.4.96/27148.80.4.97 to 148.80.4.126148.80.4.12730
37148.80.4.128/27148.80.4.129 to 148.80.4.158148.80.4.15930
38148.80.4.160/27148.80.4.161 to 148.80.4.190148.80.4.19130
39148.80.4.192/27148.80.4.193 to 148.80.4.222148.80.4.22330
40148.80.4.224/27148.80.4.225 to 148.80.4.254148.80.4.25530
41148.80.5.0/27148.80.5.1 to 148.80.5.30148.80.5.3130
42148.80.5.32/27148.80.5.33 to 148.80.5.62148.80.5.6330
43148.80.5.64/27148.80.5.65 to 148.80.5.94148.80.5.9530
44148.80.5.96/27148.80.5.97 to 148.80.5.126148.80.5.12730
45148.80.5.128/27148.80.5.129 to 148.80.5.158148.80.5.15930
46148.80.5.160/27148.80.5.161 to 148.80.5.190148.80.5.19130
47148.80.5.192/27148.80.5.193 to 148.80.5.222148.80.5.22330
48148.80.5.224/27148.80.5.225 to 148.80.5.254148.80.5.25530
49148.80.6.0/27148.80.6.1 to 148.80.6.30148.80.6.3130
50148.80.6.32/27148.80.6.33 to 148.80.6.62148.80.6.6330
51148.80.6.64/27148.80.6.65 to 148.80.6.94148.80.6.9530
52148.80.6.96/27148.80.6.97 to 148.80.6.126148.80.6.12730
53148.80.6.128/27148.80.6.129 to 148.80.6.158148.80.6.15930
54148.80.6.160/27148.80.6.161 to 148.80.6.190148.80.6.19130
55148.80.6.192/27148.80.6.193 to 148.80.6.222148.80.6.22330
56148.80.6.224/27148.80.6.225 to 148.80.6.254148.80.6.25530
57148.80.7.0/27148.80.7.1 to 148.80.7.30148.80.7.3130
58148.80.7.32/27148.80.7.33 to 148.80.7.62148.80.7.6330
59148.80.7.64/27148.80.7.65 to 148.80.7.94148.80.7.9530
60148.80.7.96/27148.80.7.97 to 148.80.7.126148.80.7.12730
61148.80.7.128/27148.80.7.129 to 148.80.7.158148.80.7.15930
62148.80.7.160/27148.80.7.161 to 148.80.7.190148.80.7.19130
63148.80.7.192/27148.80.7.193 to 148.80.7.222148.80.7.22330
64148.80.7.224/27148.80.7.225 to 148.80.7.254148.80.7.25530
65148.80.8.0/27148.80.8.1 to 148.80.8.30148.80.8.3130
66148.80.8.32/27148.80.8.33 to 148.80.8.62148.80.8.6330
67148.80.8.64/27148.80.8.65 to 148.80.8.94148.80.8.9530
68148.80.8.96/27148.80.8.97 to 148.80.8.126148.80.8.12730
69148.80.8.128/27148.80.8.129 to 148.80.8.158148.80.8.15930
70148.80.8.160/27148.80.8.161 to 148.80.8.190148.80.8.19130
71148.80.8.192/27148.80.8.193 to 148.80.8.222148.80.8.22330
72148.80.8.224/27148.80.8.225 to 148.80.8.254148.80.8.25530
73148.80.9.0/27148.80.9.1 to 148.80.9.30148.80.9.3130
74148.80.9.32/27148.80.9.33 to 148.80.9.62148.80.9.6330
75148.80.9.64/27148.80.9.65 to 148.80.9.94148.80.9.9530
76148.80.9.96/27148.80.9.97 to 148.80.9.126148.80.9.12730
77148.80.9.128/27148.80.9.129 to 148.80.9.158148.80.9.15930
78148.80.9.160/27148.80.9.161 to 148.80.9.190148.80.9.19130
79148.80.9.192/27148.80.9.193 to 148.80.9.222148.80.9.22330
80148.80.9.224/27148.80.9.225 to 148.80.9.254148.80.9.25530
81148.80.10.0/27148.80.10.1 to 148.80.10.30148.80.10.3130
82148.80.10.32/27148.80.10.33 to 148.80.10.62148.80.10.6330
83148.80.10.64/27148.80.10.65 to 148.80.10.94148.80.10.9530
84148.80.10.96/27148.80.10.97 to 148.80.10.126148.80.10.12730
85148.80.10.128/27148.80.10.129 to 148.80.10.158148.80.10.15930
86148.80.10.160/27148.80.10.161 to 148.80.10.190148.80.10.19130
87148.80.10.192/27148.80.10.193 to 148.80.10.222148.80.10.22330
88148.80.10.224/27148.80.10.225 to 148.80.10.254148.80.10.25530
89148.80.11.0/27148.80.11.1 to 148.80.11.30148.80.11.3130
90148.80.11.32/27148.80.11.33 to 148.80.11.62148.80.11.6330
91148.80.11.64/27148.80.11.65 to 148.80.11.94148.80.11.9530
92148.80.11.96/27148.80.11.97 to 148.80.11.126148.80.11.12730
93148.80.11.128/27148.80.11.129 to 148.80.11.158148.80.11.15930
94148.80.11.160/27148.80.11.161 to 148.80.11.190148.80.11.19130
95148.80.11.192/27148.80.11.193 to 148.80.11.222148.80.11.22330
96148.80.11.224/27148.80.11.225 to 148.80.11.254148.80.11.25530
97148.80.12.0/27148.80.12.1 to 148.80.12.30148.80.12.3130
98148.80.12.32/27148.80.12.33 to 148.80.12.62148.80.12.6330
99148.80.12.64/27148.80.12.65 to 148.80.12.94148.80.12.9530
100148.80.12.96/27148.80.12.97 to 148.80.12.126148.80.12.12730
101148.80.12.128/27148.80.12.129 to 148.80.12.158148.80.12.15930
102148.80.12.160/27148.80.12.161 to 148.80.12.190148.80.12.19130
103148.80.12.192/27148.80.12.193 to 148.80.12.222148.80.12.22330
104148.80.12.224/27148.80.12.225 to 148.80.12.254148.80.12.25530
105148.80.13.0/27148.80.13.1 to 148.80.13.30148.80.13.3130
106148.80.13.32/27148.80.13.33 to 148.80.13.62148.80.13.6330
107148.80.13.64/27148.80.13.65 to 148.80.13.94148.80.13.9530
108148.80.13.96/27148.80.13.97 to 148.80.13.126148.80.13.12730
109148.80.13.128/27148.80.13.129 to 148.80.13.158148.80.13.15930
110148.80.13.160/27148.80.13.161 to 148.80.13.190148.80.13.19130
111148.80.13.192/27148.80.13.193 to 148.80.13.222148.80.13.22330
112148.80.13.224/27148.80.13.225 to 148.80.13.254148.80.13.25530
113148.80.14.0/27148.80.14.1 to 148.80.14.30148.80.14.3130
114148.80.14.32/27148.80.14.33 to 148.80.14.62148.80.14.6330
115148.80.14.64/27148.80.14.65 to 148.80.14.94148.80.14.9530
116148.80.14.96/27148.80.14.97 to 148.80.14.126148.80.14.12730
117148.80.14.128/27148.80.14.129 to 148.80.14.158148.80.14.15930
118148.80.14.160/27148.80.14.161 to 148.80.14.190148.80.14.19130
119148.80.14.192/27148.80.14.193 to 148.80.14.222148.80.14.22330
120148.80.14.224/27148.80.14.225 to 148.80.14.254148.80.14.25530
121148.80.15.0/27148.80.15.1 to 148.80.15.30148.80.15.3130
122148.80.15.32/27148.80.15.33 to 148.80.15.62148.80.15.6330
123148.80.15.64/27148.80.15.65 to 148.80.15.94148.80.15.9530
124148.80.15.96/27148.80.15.97 to 148.80.15.126148.80.15.12730
125148.80.15.128/27148.80.15.129 to 148.80.15.158148.80.15.15930
126148.80.15.160/27148.80.15.161 to 148.80.15.190148.80.15.19130
127148.80.15.192/27148.80.15.193 to 148.80.15.222148.80.15.22330
128148.80.15.224/27148.80.15.225 to 148.80.15.254148.80.15.25530
129148.80.16.0/27148.80.16.1 to 148.80.16.30148.80.16.3130
130148.80.16.32/27148.80.16.33 to 148.80.16.62148.80.16.6330
131148.80.16.64/27148.80.16.65 to 148.80.16.94148.80.16.9530
132148.80.16.96/27148.80.16.97 to 148.80.16.126148.80.16.12730
133148.80.16.128/27148.80.16.129 to 148.80.16.158148.80.16.15930
134148.80.16.160/27148.80.16.161 to 148.80.16.190148.80.16.19130
135148.80.16.192/27148.80.16.193 to 148.80.16.222148.80.16.22330
136148.80.16.224/27148.80.16.225 to 148.80.16.254148.80.16.25530
137148.80.17.0/27148.80.17.1 to 148.80.17.30148.80.17.3130
138148.80.17.32/27148.80.17.33 to 148.80.17.62148.80.17.6330
139148.80.17.64/27148.80.17.65 to 148.80.17.94148.80.17.9530
140148.80.17.96/27148.80.17.97 to 148.80.17.126148.80.17.12730
141148.80.17.128/27148.80.17.129 to 148.80.17.158148.80.17.15930
142148.80.17.160/27148.80.17.161 to 148.80.17.190148.80.17.19130
143148.80.17.192/27148.80.17.193 to 148.80.17.222148.80.17.22330
144148.80.17.224/27148.80.17.225 to 148.80.17.254148.80.17.25530
145148.80.18.0/27148.80.18.1 to 148.80.18.30148.80.18.3130
146148.80.18.32/27148.80.18.33 to 148.80.18.62148.80.18.6330
147148.80.18.64/27148.80.18.65 to 148.80.18.94148.80.18.9530
148148.80.18.96/27148.80.18.97 to 148.80.18.126148.80.18.12730
149148.80.18.128/27148.80.18.129 to 148.80.18.158148.80.18.15930
150148.80.18.160/27148.80.18.161 to 148.80.18.190148.80.18.19130
151148.80.18.192/27148.80.18.193 to 148.80.18.222148.80.18.22330
152148.80.18.224/27148.80.18.225 to 148.80.18.254148.80.18.25530
153148.80.19.0/27148.80.19.1 to 148.80.19.30148.80.19.3130
154148.80.19.32/27148.80.19.33 to 148.80.19.62148.80.19.6330
155148.80.19.64/27148.80.19.65 to 148.80.19.94148.80.19.9530
156148.80.19.96/27148.80.19.97 to 148.80.19.126148.80.19.12730
157148.80.19.128/27148.80.19.129 to 148.80.19.158148.80.19.15930
158148.80.19.160/27148.80.19.161 to 148.80.19.190148.80.19.19130
159148.80.19.192/27148.80.19.193 to 148.80.19.222148.80.19.22330
160148.80.19.224/27148.80.19.225 to 148.80.19.254148.80.19.25530
161148.80.20.0/27148.80.20.1 to 148.80.20.30148.80.20.3130
162148.80.20.32/27148.80.20.33 to 148.80.20.62148.80.20.6330
163148.80.20.64/27148.80.20.65 to 148.80.20.94148.80.20.9530
164148.80.20.96/27148.80.20.97 to 148.80.20.126148.80.20.12730
165148.80.20.128/27148.80.20.129 to 148.80.20.158148.80.20.15930
166148.80.20.160/27148.80.20.161 to 148.80.20.190148.80.20.19130
167148.80.20.192/27148.80.20.193 to 148.80.20.222148.80.20.22330
168148.80.20.224/27148.80.20.225 to 148.80.20.254148.80.20.25530
169148.80.21.0/27148.80.21.1 to 148.80.21.30148.80.21.3130
170148.80.21.32/27148.80.21.33 to 148.80.21.62148.80.21.6330
171148.80.21.64/27148.80.21.65 to 148.80.21.94148.80.21.9530
172148.80.21.96/27148.80.21.97 to 148.80.21.126148.80.21.12730
173148.80.21.128/27148.80.21.129 to 148.80.21.158148.80.21.15930
174148.80.21.160/27148.80.21.161 to 148.80.21.190148.80.21.19130
175148.80.21.192/27148.80.21.193 to 148.80.21.222148.80.21.22330
176148.80.21.224/27148.80.21.225 to 148.80.21.254148.80.21.25530
177148.80.22.0/27148.80.22.1 to 148.80.22.30148.80.22.3130
178148.80.22.32/27148.80.22.33 to 148.80.22.62148.80.22.6330
179148.80.22.64/27148.80.22.65 to 148.80.22.94148.80.22.9530
180148.80.22.96/27148.80.22.97 to 148.80.22.126148.80.22.12730
181148.80.22.128/27148.80.22.129 to 148.80.22.158148.80.22.15930
182148.80.22.160/27148.80.22.161 to 148.80.22.190148.80.22.19130
183148.80.22.192/27148.80.22.193 to 148.80.22.222148.80.22.22330
184148.80.22.224/27148.80.22.225 to 148.80.22.254148.80.22.25530
185148.80.23.0/27148.80.23.1 to 148.80.23.30148.80.23.3130
186148.80.23.32/27148.80.23.33 to 148.80.23.62148.80.23.6330
187148.80.23.64/27148.80.23.65 to 148.80.23.94148.80.23.9530
188148.80.23.96/27148.80.23.97 to 148.80.23.126148.80.23.12730
189148.80.23.128/27148.80.23.129 to 148.80.23.158148.80.23.15930
190148.80.23.160/27148.80.23.161 to 148.80.23.190148.80.23.19130
191148.80.23.192/27148.80.23.193 to 148.80.23.222148.80.23.22330
192148.80.23.224/27148.80.23.225 to 148.80.23.254148.80.23.25530
193148.80.24.0/27148.80.24.1 to 148.80.24.30148.80.24.3130
194148.80.24.32/27148.80.24.33 to 148.80.24.62148.80.24.6330
195148.80.24.64/27148.80.24.65 to 148.80.24.94148.80.24.9530
196148.80.24.96/27148.80.24.97 to 148.80.24.126148.80.24.12730
197148.80.24.128/27148.80.24.129 to 148.80.24.158148.80.24.15930
198148.80.24.160/27148.80.24.161 to 148.80.24.190148.80.24.19130
199148.80.24.192/27148.80.24.193 to 148.80.24.222148.80.24.22330
200148.80.24.224/27148.80.24.225 to 148.80.24.254148.80.24.25530
201148.80.25.0/27148.80.25.1 to 148.80.25.30148.80.25.3130
202148.80.25.32/27148.80.25.33 to 148.80.25.62148.80.25.6330
203148.80.25.64/27148.80.25.65 to 148.80.25.94148.80.25.9530
204148.80.25.96/27148.80.25.97 to 148.80.25.126148.80.25.12730
205148.80.25.128/27148.80.25.129 to 148.80.25.158148.80.25.15930
206148.80.25.160/27148.80.25.161 to 148.80.25.190148.80.25.19130
207148.80.25.192/27148.80.25.193 to 148.80.25.222148.80.25.22330
208148.80.25.224/27148.80.25.225 to 148.80.25.254148.80.25.25530
209148.80.26.0/27148.80.26.1 to 148.80.26.30148.80.26.3130
210148.80.26.32/27148.80.26.33 to 148.80.26.62148.80.26.6330
211148.80.26.64/27148.80.26.65 to 148.80.26.94148.80.26.9530
212148.80.26.96/27148.80.26.97 to 148.80.26.126148.80.26.12730
213148.80.26.128/27148.80.26.129 to 148.80.26.158148.80.26.15930
214148.80.26.160/27148.80.26.161 to 148.80.26.190148.80.26.19130
215148.80.26.192/27148.80.26.193 to 148.80.26.222148.80.26.22330
216148.80.26.224/27148.80.26.225 to 148.80.26.254148.80.26.25530
217148.80.27.0/27148.80.27.1 to 148.80.27.30148.80.27.3130
218148.80.27.32/27148.80.27.33 to 148.80.27.62148.80.27.6330
219148.80.27.64/27148.80.27.65 to 148.80.27.94148.80.27.9530
220148.80.27.96/27148.80.27.97 to 148.80.27.126148.80.27.12730
221148.80.27.128/27148.80.27.129 to 148.80.27.158148.80.27.15930
222148.80.27.160/27148.80.27.161 to 148.80.27.190148.80.27.19130
223148.80.27.192/27148.80.27.193 to 148.80.27.222148.80.27.22330
224148.80.27.224/27148.80.27.225 to 148.80.27.254148.80.27.25530
225148.80.28.0/27148.80.28.1 to 148.80.28.30148.80.28.3130
226148.80.28.32/27148.80.28.33 to 148.80.28.62148.80.28.6330
227148.80.28.64/27148.80.28.65 to 148.80.28.94148.80.28.9530
228148.80.28.96/27148.80.28.97 to 148.80.28.126148.80.28.12730
229148.80.28.128/27148.80.28.129 to 148.80.28.158148.80.28.15930
230148.80.28.160/27148.80.28.161 to 148.80.28.190148.80.28.19130
231148.80.28.192/27148.80.28.193 to 148.80.28.222148.80.28.22330
232148.80.28.224/27148.80.28.225 to 148.80.28.254148.80.28.25530
233148.80.29.0/27148.80.29.1 to 148.80.29.30148.80.29.3130
234148.80.29.32/27148.80.29.33 to 148.80.29.62148.80.29.6330
235148.80.29.64/27148.80.29.65 to 148.80.29.94148.80.29.9530
236148.80.29.96/27148.80.29.97 to 148.80.29.126148.80.29.12730
237148.80.29.128/27148.80.29.129 to 148.80.29.158148.80.29.15930
238148.80.29.160/27148.80.29.161 to 148.80.29.190148.80.29.19130
239148.80.29.192/27148.80.29.193 to 148.80.29.222148.80.29.22330
240148.80.29.224/27148.80.29.225 to 148.80.29.254148.80.29.25530
241148.80.30.0/27148.80.30.1 to 148.80.30.30148.80.30.3130
242148.80.30.32/27148.80.30.33 to 148.80.30.62148.80.30.6330
243148.80.30.64/27148.80.30.65 to 148.80.30.94148.80.30.9530
244148.80.30.96/27148.80.30.97 to 148.80.30.126148.80.30.12730
245148.80.30.128/27148.80.30.129 to 148.80.30.158148.80.30.15930
246148.80.30.160/27148.80.30.161 to 148.80.30.190148.80.30.19130
247148.80.30.192/27148.80.30.193 to 148.80.30.222148.80.30.22330
248148.80.30.224/27148.80.30.225 to 148.80.30.254148.80.30.25530
249148.80.31.0/27148.80.31.1 to 148.80.31.30148.80.31.3130
250148.80.31.32/27148.80.31.33 to 148.80.31.62148.80.31.6330
251148.80.31.64/27148.80.31.65 to 148.80.31.94148.80.31.9530
252148.80.31.96/27148.80.31.97 to 148.80.31.126148.80.31.12730
253148.80.31.128/27148.80.31.129 to 148.80.31.158148.80.31.15930
254148.80.31.160/27148.80.31.161 to 148.80.31.190148.80.31.19130
255148.80.31.192/27148.80.31.193 to 148.80.31.222148.80.31.22330
256148.80.31.224/27148.80.31.225 to 148.80.31.254148.80.31.25530

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.