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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.

Network148.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
148.0.0.0
Broadcast address
149.255.255.255
First usable
148.0.0.1
Last usable
149.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
B (default /16)
As numbers
Hex 94000000 · Integer 2483027968 to 2516582399
Reverse DNS zones
148.in-addr.arpa
149.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010100.00000000.00000000.00000000148.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network10010100.00000000.00000000.00000000148.0.0.0
Broadcast10010101.11111111.11111111.11111111149.255.255.255
Split into smaller subnets/19
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

148.0.0.0/7 makes 4,096 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1148.0.0.0/19148.0.0.1 to 148.0.31.254148.0.31.2558,190
2148.0.32.0/19148.0.32.1 to 148.0.63.254148.0.63.2558,190
3148.0.64.0/19148.0.64.1 to 148.0.95.254148.0.95.2558,190
4148.0.96.0/19148.0.96.1 to 148.0.127.254148.0.127.2558,190
5148.0.128.0/19148.0.128.1 to 148.0.159.254148.0.159.2558,190
6148.0.160.0/19148.0.160.1 to 148.0.191.254148.0.191.2558,190
7148.0.192.0/19148.0.192.1 to 148.0.223.254148.0.223.2558,190
8148.0.224.0/19148.0.224.1 to 148.0.255.254148.0.255.2558,190
9148.1.0.0/19148.1.0.1 to 148.1.31.254148.1.31.2558,190
10148.1.32.0/19148.1.32.1 to 148.1.63.254148.1.63.2558,190
11148.1.64.0/19148.1.64.1 to 148.1.95.254148.1.95.2558,190
12148.1.96.0/19148.1.96.1 to 148.1.127.254148.1.127.2558,190
13148.1.128.0/19148.1.128.1 to 148.1.159.254148.1.159.2558,190
14148.1.160.0/19148.1.160.1 to 148.1.191.254148.1.191.2558,190
15148.1.192.0/19148.1.192.1 to 148.1.223.254148.1.223.2558,190
16148.1.224.0/19148.1.224.1 to 148.1.255.254148.1.255.2558,190
17148.2.0.0/19148.2.0.1 to 148.2.31.254148.2.31.2558,190
18148.2.32.0/19148.2.32.1 to 148.2.63.254148.2.63.2558,190
19148.2.64.0/19148.2.64.1 to 148.2.95.254148.2.95.2558,190
20148.2.96.0/19148.2.96.1 to 148.2.127.254148.2.127.2558,190
21148.2.128.0/19148.2.128.1 to 148.2.159.254148.2.159.2558,190
22148.2.160.0/19148.2.160.1 to 148.2.191.254148.2.191.2558,190
23148.2.192.0/19148.2.192.1 to 148.2.223.254148.2.223.2558,190
24148.2.224.0/19148.2.224.1 to 148.2.255.254148.2.255.2558,190
25148.3.0.0/19148.3.0.1 to 148.3.31.254148.3.31.2558,190
26148.3.32.0/19148.3.32.1 to 148.3.63.254148.3.63.2558,190
27148.3.64.0/19148.3.64.1 to 148.3.95.254148.3.95.2558,190
28148.3.96.0/19148.3.96.1 to 148.3.127.254148.3.127.2558,190
29148.3.128.0/19148.3.128.1 to 148.3.159.254148.3.159.2558,190
30148.3.160.0/19148.3.160.1 to 148.3.191.254148.3.191.2558,190
31148.3.192.0/19148.3.192.1 to 148.3.223.254148.3.223.2558,190
32148.3.224.0/19148.3.224.1 to 148.3.255.254148.3.255.2558,190
33148.4.0.0/19148.4.0.1 to 148.4.31.254148.4.31.2558,190
34148.4.32.0/19148.4.32.1 to 148.4.63.254148.4.63.2558,190
35148.4.64.0/19148.4.64.1 to 148.4.95.254148.4.95.2558,190
36148.4.96.0/19148.4.96.1 to 148.4.127.254148.4.127.2558,190
37148.4.128.0/19148.4.128.1 to 148.4.159.254148.4.159.2558,190
38148.4.160.0/19148.4.160.1 to 148.4.191.254148.4.191.2558,190
39148.4.192.0/19148.4.192.1 to 148.4.223.254148.4.223.2558,190
40148.4.224.0/19148.4.224.1 to 148.4.255.254148.4.255.2558,190
41148.5.0.0/19148.5.0.1 to 148.5.31.254148.5.31.2558,190
42148.5.32.0/19148.5.32.1 to 148.5.63.254148.5.63.2558,190
43148.5.64.0/19148.5.64.1 to 148.5.95.254148.5.95.2558,190
44148.5.96.0/19148.5.96.1 to 148.5.127.254148.5.127.2558,190
45148.5.128.0/19148.5.128.1 to 148.5.159.254148.5.159.2558,190
46148.5.160.0/19148.5.160.1 to 148.5.191.254148.5.191.2558,190
47148.5.192.0/19148.5.192.1 to 148.5.223.254148.5.223.2558,190
48148.5.224.0/19148.5.224.1 to 148.5.255.254148.5.255.2558,190
49148.6.0.0/19148.6.0.1 to 148.6.31.254148.6.31.2558,190
50148.6.32.0/19148.6.32.1 to 148.6.63.254148.6.63.2558,190
51148.6.64.0/19148.6.64.1 to 148.6.95.254148.6.95.2558,190
52148.6.96.0/19148.6.96.1 to 148.6.127.254148.6.127.2558,190
53148.6.128.0/19148.6.128.1 to 148.6.159.254148.6.159.2558,190
54148.6.160.0/19148.6.160.1 to 148.6.191.254148.6.191.2558,190
55148.6.192.0/19148.6.192.1 to 148.6.223.254148.6.223.2558,190
56148.6.224.0/19148.6.224.1 to 148.6.255.254148.6.255.2558,190
57148.7.0.0/19148.7.0.1 to 148.7.31.254148.7.31.2558,190
58148.7.32.0/19148.7.32.1 to 148.7.63.254148.7.63.2558,190
59148.7.64.0/19148.7.64.1 to 148.7.95.254148.7.95.2558,190
60148.7.96.0/19148.7.96.1 to 148.7.127.254148.7.127.2558,190
61148.7.128.0/19148.7.128.1 to 148.7.159.254148.7.159.2558,190
62148.7.160.0/19148.7.160.1 to 148.7.191.254148.7.191.2558,190
63148.7.192.0/19148.7.192.1 to 148.7.223.254148.7.223.2558,190
64148.7.224.0/19148.7.224.1 to 148.7.255.254148.7.255.2558,190
65148.8.0.0/19148.8.0.1 to 148.8.31.254148.8.31.2558,190
66148.8.32.0/19148.8.32.1 to 148.8.63.254148.8.63.2558,190
67148.8.64.0/19148.8.64.1 to 148.8.95.254148.8.95.2558,190
68148.8.96.0/19148.8.96.1 to 148.8.127.254148.8.127.2558,190
69148.8.128.0/19148.8.128.1 to 148.8.159.254148.8.159.2558,190
70148.8.160.0/19148.8.160.1 to 148.8.191.254148.8.191.2558,190
71148.8.192.0/19148.8.192.1 to 148.8.223.254148.8.223.2558,190
72148.8.224.0/19148.8.224.1 to 148.8.255.254148.8.255.2558,190
73148.9.0.0/19148.9.0.1 to 148.9.31.254148.9.31.2558,190
74148.9.32.0/19148.9.32.1 to 148.9.63.254148.9.63.2558,190
75148.9.64.0/19148.9.64.1 to 148.9.95.254148.9.95.2558,190
76148.9.96.0/19148.9.96.1 to 148.9.127.254148.9.127.2558,190
77148.9.128.0/19148.9.128.1 to 148.9.159.254148.9.159.2558,190
78148.9.160.0/19148.9.160.1 to 148.9.191.254148.9.191.2558,190
79148.9.192.0/19148.9.192.1 to 148.9.223.254148.9.223.2558,190
80148.9.224.0/19148.9.224.1 to 148.9.255.254148.9.255.2558,190
81148.10.0.0/19148.10.0.1 to 148.10.31.254148.10.31.2558,190
82148.10.32.0/19148.10.32.1 to 148.10.63.254148.10.63.2558,190
83148.10.64.0/19148.10.64.1 to 148.10.95.254148.10.95.2558,190
84148.10.96.0/19148.10.96.1 to 148.10.127.254148.10.127.2558,190
85148.10.128.0/19148.10.128.1 to 148.10.159.254148.10.159.2558,190
86148.10.160.0/19148.10.160.1 to 148.10.191.254148.10.191.2558,190
87148.10.192.0/19148.10.192.1 to 148.10.223.254148.10.223.2558,190
88148.10.224.0/19148.10.224.1 to 148.10.255.254148.10.255.2558,190
89148.11.0.0/19148.11.0.1 to 148.11.31.254148.11.31.2558,190
90148.11.32.0/19148.11.32.1 to 148.11.63.254148.11.63.2558,190
91148.11.64.0/19148.11.64.1 to 148.11.95.254148.11.95.2558,190
92148.11.96.0/19148.11.96.1 to 148.11.127.254148.11.127.2558,190
93148.11.128.0/19148.11.128.1 to 148.11.159.254148.11.159.2558,190
94148.11.160.0/19148.11.160.1 to 148.11.191.254148.11.191.2558,190
95148.11.192.0/19148.11.192.1 to 148.11.223.254148.11.223.2558,190
96148.11.224.0/19148.11.224.1 to 148.11.255.254148.11.255.2558,190
97148.12.0.0/19148.12.0.1 to 148.12.31.254148.12.31.2558,190
98148.12.32.0/19148.12.32.1 to 148.12.63.254148.12.63.2558,190
99148.12.64.0/19148.12.64.1 to 148.12.95.254148.12.95.2558,190
100148.12.96.0/19148.12.96.1 to 148.12.127.254148.12.127.2558,190
101148.12.128.0/19148.12.128.1 to 148.12.159.254148.12.159.2558,190
102148.12.160.0/19148.12.160.1 to 148.12.191.254148.12.191.2558,190
103148.12.192.0/19148.12.192.1 to 148.12.223.254148.12.223.2558,190
104148.12.224.0/19148.12.224.1 to 148.12.255.254148.12.255.2558,190
105148.13.0.0/19148.13.0.1 to 148.13.31.254148.13.31.2558,190
106148.13.32.0/19148.13.32.1 to 148.13.63.254148.13.63.2558,190
107148.13.64.0/19148.13.64.1 to 148.13.95.254148.13.95.2558,190
108148.13.96.0/19148.13.96.1 to 148.13.127.254148.13.127.2558,190
109148.13.128.0/19148.13.128.1 to 148.13.159.254148.13.159.2558,190
110148.13.160.0/19148.13.160.1 to 148.13.191.254148.13.191.2558,190
111148.13.192.0/19148.13.192.1 to 148.13.223.254148.13.223.2558,190
112148.13.224.0/19148.13.224.1 to 148.13.255.254148.13.255.2558,190
113148.14.0.0/19148.14.0.1 to 148.14.31.254148.14.31.2558,190
114148.14.32.0/19148.14.32.1 to 148.14.63.254148.14.63.2558,190
115148.14.64.0/19148.14.64.1 to 148.14.95.254148.14.95.2558,190
116148.14.96.0/19148.14.96.1 to 148.14.127.254148.14.127.2558,190
117148.14.128.0/19148.14.128.1 to 148.14.159.254148.14.159.2558,190
118148.14.160.0/19148.14.160.1 to 148.14.191.254148.14.191.2558,190
119148.14.192.0/19148.14.192.1 to 148.14.223.254148.14.223.2558,190
120148.14.224.0/19148.14.224.1 to 148.14.255.254148.14.255.2558,190
121148.15.0.0/19148.15.0.1 to 148.15.31.254148.15.31.2558,190
122148.15.32.0/19148.15.32.1 to 148.15.63.254148.15.63.2558,190
123148.15.64.0/19148.15.64.1 to 148.15.95.254148.15.95.2558,190
124148.15.96.0/19148.15.96.1 to 148.15.127.254148.15.127.2558,190
125148.15.128.0/19148.15.128.1 to 148.15.159.254148.15.159.2558,190
126148.15.160.0/19148.15.160.1 to 148.15.191.254148.15.191.2558,190
127148.15.192.0/19148.15.192.1 to 148.15.223.254148.15.223.2558,190
128148.15.224.0/19148.15.224.1 to 148.15.255.254148.15.255.2558,190
129148.16.0.0/19148.16.0.1 to 148.16.31.254148.16.31.2558,190
130148.16.32.0/19148.16.32.1 to 148.16.63.254148.16.63.2558,190
131148.16.64.0/19148.16.64.1 to 148.16.95.254148.16.95.2558,190
132148.16.96.0/19148.16.96.1 to 148.16.127.254148.16.127.2558,190
133148.16.128.0/19148.16.128.1 to 148.16.159.254148.16.159.2558,190
134148.16.160.0/19148.16.160.1 to 148.16.191.254148.16.191.2558,190
135148.16.192.0/19148.16.192.1 to 148.16.223.254148.16.223.2558,190
136148.16.224.0/19148.16.224.1 to 148.16.255.254148.16.255.2558,190
137148.17.0.0/19148.17.0.1 to 148.17.31.254148.17.31.2558,190
138148.17.32.0/19148.17.32.1 to 148.17.63.254148.17.63.2558,190
139148.17.64.0/19148.17.64.1 to 148.17.95.254148.17.95.2558,190
140148.17.96.0/19148.17.96.1 to 148.17.127.254148.17.127.2558,190
141148.17.128.0/19148.17.128.1 to 148.17.159.254148.17.159.2558,190
142148.17.160.0/19148.17.160.1 to 148.17.191.254148.17.191.2558,190
143148.17.192.0/19148.17.192.1 to 148.17.223.254148.17.223.2558,190
144148.17.224.0/19148.17.224.1 to 148.17.255.254148.17.255.2558,190
145148.18.0.0/19148.18.0.1 to 148.18.31.254148.18.31.2558,190
146148.18.32.0/19148.18.32.1 to 148.18.63.254148.18.63.2558,190
147148.18.64.0/19148.18.64.1 to 148.18.95.254148.18.95.2558,190
148148.18.96.0/19148.18.96.1 to 148.18.127.254148.18.127.2558,190
149148.18.128.0/19148.18.128.1 to 148.18.159.254148.18.159.2558,190
150148.18.160.0/19148.18.160.1 to 148.18.191.254148.18.191.2558,190
151148.18.192.0/19148.18.192.1 to 148.18.223.254148.18.223.2558,190
152148.18.224.0/19148.18.224.1 to 148.18.255.254148.18.255.2558,190
153148.19.0.0/19148.19.0.1 to 148.19.31.254148.19.31.2558,190
154148.19.32.0/19148.19.32.1 to 148.19.63.254148.19.63.2558,190
155148.19.64.0/19148.19.64.1 to 148.19.95.254148.19.95.2558,190
156148.19.96.0/19148.19.96.1 to 148.19.127.254148.19.127.2558,190
157148.19.128.0/19148.19.128.1 to 148.19.159.254148.19.159.2558,190
158148.19.160.0/19148.19.160.1 to 148.19.191.254148.19.191.2558,190
159148.19.192.0/19148.19.192.1 to 148.19.223.254148.19.223.2558,190
160148.19.224.0/19148.19.224.1 to 148.19.255.254148.19.255.2558,190
161148.20.0.0/19148.20.0.1 to 148.20.31.254148.20.31.2558,190
162148.20.32.0/19148.20.32.1 to 148.20.63.254148.20.63.2558,190
163148.20.64.0/19148.20.64.1 to 148.20.95.254148.20.95.2558,190
164148.20.96.0/19148.20.96.1 to 148.20.127.254148.20.127.2558,190
165148.20.128.0/19148.20.128.1 to 148.20.159.254148.20.159.2558,190
166148.20.160.0/19148.20.160.1 to 148.20.191.254148.20.191.2558,190
167148.20.192.0/19148.20.192.1 to 148.20.223.254148.20.223.2558,190
168148.20.224.0/19148.20.224.1 to 148.20.255.254148.20.255.2558,190
169148.21.0.0/19148.21.0.1 to 148.21.31.254148.21.31.2558,190
170148.21.32.0/19148.21.32.1 to 148.21.63.254148.21.63.2558,190
171148.21.64.0/19148.21.64.1 to 148.21.95.254148.21.95.2558,190
172148.21.96.0/19148.21.96.1 to 148.21.127.254148.21.127.2558,190
173148.21.128.0/19148.21.128.1 to 148.21.159.254148.21.159.2558,190
174148.21.160.0/19148.21.160.1 to 148.21.191.254148.21.191.2558,190
175148.21.192.0/19148.21.192.1 to 148.21.223.254148.21.223.2558,190
176148.21.224.0/19148.21.224.1 to 148.21.255.254148.21.255.2558,190
177148.22.0.0/19148.22.0.1 to 148.22.31.254148.22.31.2558,190
178148.22.32.0/19148.22.32.1 to 148.22.63.254148.22.63.2558,190
179148.22.64.0/19148.22.64.1 to 148.22.95.254148.22.95.2558,190
180148.22.96.0/19148.22.96.1 to 148.22.127.254148.22.127.2558,190
181148.22.128.0/19148.22.128.1 to 148.22.159.254148.22.159.2558,190
182148.22.160.0/19148.22.160.1 to 148.22.191.254148.22.191.2558,190
183148.22.192.0/19148.22.192.1 to 148.22.223.254148.22.223.2558,190
184148.22.224.0/19148.22.224.1 to 148.22.255.254148.22.255.2558,190
185148.23.0.0/19148.23.0.1 to 148.23.31.254148.23.31.2558,190
186148.23.32.0/19148.23.32.1 to 148.23.63.254148.23.63.2558,190
187148.23.64.0/19148.23.64.1 to 148.23.95.254148.23.95.2558,190
188148.23.96.0/19148.23.96.1 to 148.23.127.254148.23.127.2558,190
189148.23.128.0/19148.23.128.1 to 148.23.159.254148.23.159.2558,190
190148.23.160.0/19148.23.160.1 to 148.23.191.254148.23.191.2558,190
191148.23.192.0/19148.23.192.1 to 148.23.223.254148.23.223.2558,190
192148.23.224.0/19148.23.224.1 to 148.23.255.254148.23.255.2558,190
193148.24.0.0/19148.24.0.1 to 148.24.31.254148.24.31.2558,190
194148.24.32.0/19148.24.32.1 to 148.24.63.254148.24.63.2558,190
195148.24.64.0/19148.24.64.1 to 148.24.95.254148.24.95.2558,190
196148.24.96.0/19148.24.96.1 to 148.24.127.254148.24.127.2558,190
197148.24.128.0/19148.24.128.1 to 148.24.159.254148.24.159.2558,190
198148.24.160.0/19148.24.160.1 to 148.24.191.254148.24.191.2558,190
199148.24.192.0/19148.24.192.1 to 148.24.223.254148.24.223.2558,190
200148.24.224.0/19148.24.224.1 to 148.24.255.254148.24.255.2558,190
201148.25.0.0/19148.25.0.1 to 148.25.31.254148.25.31.2558,190
202148.25.32.0/19148.25.32.1 to 148.25.63.254148.25.63.2558,190
203148.25.64.0/19148.25.64.1 to 148.25.95.254148.25.95.2558,190
204148.25.96.0/19148.25.96.1 to 148.25.127.254148.25.127.2558,190
205148.25.128.0/19148.25.128.1 to 148.25.159.254148.25.159.2558,190
206148.25.160.0/19148.25.160.1 to 148.25.191.254148.25.191.2558,190
207148.25.192.0/19148.25.192.1 to 148.25.223.254148.25.223.2558,190
208148.25.224.0/19148.25.224.1 to 148.25.255.254148.25.255.2558,190
209148.26.0.0/19148.26.0.1 to 148.26.31.254148.26.31.2558,190
210148.26.32.0/19148.26.32.1 to 148.26.63.254148.26.63.2558,190
211148.26.64.0/19148.26.64.1 to 148.26.95.254148.26.95.2558,190
212148.26.96.0/19148.26.96.1 to 148.26.127.254148.26.127.2558,190
213148.26.128.0/19148.26.128.1 to 148.26.159.254148.26.159.2558,190
214148.26.160.0/19148.26.160.1 to 148.26.191.254148.26.191.2558,190
215148.26.192.0/19148.26.192.1 to 148.26.223.254148.26.223.2558,190
216148.26.224.0/19148.26.224.1 to 148.26.255.254148.26.255.2558,190
217148.27.0.0/19148.27.0.1 to 148.27.31.254148.27.31.2558,190
218148.27.32.0/19148.27.32.1 to 148.27.63.254148.27.63.2558,190
219148.27.64.0/19148.27.64.1 to 148.27.95.254148.27.95.2558,190
220148.27.96.0/19148.27.96.1 to 148.27.127.254148.27.127.2558,190
221148.27.128.0/19148.27.128.1 to 148.27.159.254148.27.159.2558,190
222148.27.160.0/19148.27.160.1 to 148.27.191.254148.27.191.2558,190
223148.27.192.0/19148.27.192.1 to 148.27.223.254148.27.223.2558,190
224148.27.224.0/19148.27.224.1 to 148.27.255.254148.27.255.2558,190
225148.28.0.0/19148.28.0.1 to 148.28.31.254148.28.31.2558,190
226148.28.32.0/19148.28.32.1 to 148.28.63.254148.28.63.2558,190
227148.28.64.0/19148.28.64.1 to 148.28.95.254148.28.95.2558,190
228148.28.96.0/19148.28.96.1 to 148.28.127.254148.28.127.2558,190
229148.28.128.0/19148.28.128.1 to 148.28.159.254148.28.159.2558,190
230148.28.160.0/19148.28.160.1 to 148.28.191.254148.28.191.2558,190
231148.28.192.0/19148.28.192.1 to 148.28.223.254148.28.223.2558,190
232148.28.224.0/19148.28.224.1 to 148.28.255.254148.28.255.2558,190
233148.29.0.0/19148.29.0.1 to 148.29.31.254148.29.31.2558,190
234148.29.32.0/19148.29.32.1 to 148.29.63.254148.29.63.2558,190
235148.29.64.0/19148.29.64.1 to 148.29.95.254148.29.95.2558,190
236148.29.96.0/19148.29.96.1 to 148.29.127.254148.29.127.2558,190
237148.29.128.0/19148.29.128.1 to 148.29.159.254148.29.159.2558,190
238148.29.160.0/19148.29.160.1 to 148.29.191.254148.29.191.2558,190
239148.29.192.0/19148.29.192.1 to 148.29.223.254148.29.223.2558,190
240148.29.224.0/19148.29.224.1 to 148.29.255.254148.29.255.2558,190
241148.30.0.0/19148.30.0.1 to 148.30.31.254148.30.31.2558,190
242148.30.32.0/19148.30.32.1 to 148.30.63.254148.30.63.2558,190
243148.30.64.0/19148.30.64.1 to 148.30.95.254148.30.95.2558,190
244148.30.96.0/19148.30.96.1 to 148.30.127.254148.30.127.2558,190
245148.30.128.0/19148.30.128.1 to 148.30.159.254148.30.159.2558,190
246148.30.160.0/19148.30.160.1 to 148.30.191.254148.30.191.2558,190
247148.30.192.0/19148.30.192.1 to 148.30.223.254148.30.223.2558,190
248148.30.224.0/19148.30.224.1 to 148.30.255.254148.30.255.2558,190
249148.31.0.0/19148.31.0.1 to 148.31.31.254148.31.31.2558,190
250148.31.32.0/19148.31.32.1 to 148.31.63.254148.31.63.2558,190
251148.31.64.0/19148.31.64.1 to 148.31.95.254148.31.95.2558,190
252148.31.96.0/19148.31.96.1 to 148.31.127.254148.31.127.2558,190
253148.31.128.0/19148.31.128.1 to 148.31.159.254148.31.159.2558,190
254148.31.160.0/19148.31.160.1 to 148.31.191.254148.31.191.2558,190
255148.31.192.0/19148.31.192.1 to 148.31.223.254148.31.223.2558,190
256148.31.224.0/19148.31.224.1 to 148.31.255.254148.31.255.2558,190

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.