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

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1148.0.0.0/17148.0.0.1 to 148.0.127.254148.0.127.25532,766
2148.0.128.0/17148.0.128.1 to 148.0.255.254148.0.255.25532,766
3148.1.0.0/17148.1.0.1 to 148.1.127.254148.1.127.25532,766
4148.1.128.0/17148.1.128.1 to 148.1.255.254148.1.255.25532,766
5148.2.0.0/17148.2.0.1 to 148.2.127.254148.2.127.25532,766
6148.2.128.0/17148.2.128.1 to 148.2.255.254148.2.255.25532,766
7148.3.0.0/17148.3.0.1 to 148.3.127.254148.3.127.25532,766
8148.3.128.0/17148.3.128.1 to 148.3.255.254148.3.255.25532,766
9148.4.0.0/17148.4.0.1 to 148.4.127.254148.4.127.25532,766
10148.4.128.0/17148.4.128.1 to 148.4.255.254148.4.255.25532,766
11148.5.0.0/17148.5.0.1 to 148.5.127.254148.5.127.25532,766
12148.5.128.0/17148.5.128.1 to 148.5.255.254148.5.255.25532,766
13148.6.0.0/17148.6.0.1 to 148.6.127.254148.6.127.25532,766
14148.6.128.0/17148.6.128.1 to 148.6.255.254148.6.255.25532,766
15148.7.0.0/17148.7.0.1 to 148.7.127.254148.7.127.25532,766
16148.7.128.0/17148.7.128.1 to 148.7.255.254148.7.255.25532,766
17148.8.0.0/17148.8.0.1 to 148.8.127.254148.8.127.25532,766
18148.8.128.0/17148.8.128.1 to 148.8.255.254148.8.255.25532,766
19148.9.0.0/17148.9.0.1 to 148.9.127.254148.9.127.25532,766
20148.9.128.0/17148.9.128.1 to 148.9.255.254148.9.255.25532,766
21148.10.0.0/17148.10.0.1 to 148.10.127.254148.10.127.25532,766
22148.10.128.0/17148.10.128.1 to 148.10.255.254148.10.255.25532,766
23148.11.0.0/17148.11.0.1 to 148.11.127.254148.11.127.25532,766
24148.11.128.0/17148.11.128.1 to 148.11.255.254148.11.255.25532,766
25148.12.0.0/17148.12.0.1 to 148.12.127.254148.12.127.25532,766
26148.12.128.0/17148.12.128.1 to 148.12.255.254148.12.255.25532,766
27148.13.0.0/17148.13.0.1 to 148.13.127.254148.13.127.25532,766
28148.13.128.0/17148.13.128.1 to 148.13.255.254148.13.255.25532,766
29148.14.0.0/17148.14.0.1 to 148.14.127.254148.14.127.25532,766
30148.14.128.0/17148.14.128.1 to 148.14.255.254148.14.255.25532,766
31148.15.0.0/17148.15.0.1 to 148.15.127.254148.15.127.25532,766
32148.15.128.0/17148.15.128.1 to 148.15.255.254148.15.255.25532,766
33148.16.0.0/17148.16.0.1 to 148.16.127.254148.16.127.25532,766
34148.16.128.0/17148.16.128.1 to 148.16.255.254148.16.255.25532,766
35148.17.0.0/17148.17.0.1 to 148.17.127.254148.17.127.25532,766
36148.17.128.0/17148.17.128.1 to 148.17.255.254148.17.255.25532,766
37148.18.0.0/17148.18.0.1 to 148.18.127.254148.18.127.25532,766
38148.18.128.0/17148.18.128.1 to 148.18.255.254148.18.255.25532,766
39148.19.0.0/17148.19.0.1 to 148.19.127.254148.19.127.25532,766
40148.19.128.0/17148.19.128.1 to 148.19.255.254148.19.255.25532,766
41148.20.0.0/17148.20.0.1 to 148.20.127.254148.20.127.25532,766
42148.20.128.0/17148.20.128.1 to 148.20.255.254148.20.255.25532,766
43148.21.0.0/17148.21.0.1 to 148.21.127.254148.21.127.25532,766
44148.21.128.0/17148.21.128.1 to 148.21.255.254148.21.255.25532,766
45148.22.0.0/17148.22.0.1 to 148.22.127.254148.22.127.25532,766
46148.22.128.0/17148.22.128.1 to 148.22.255.254148.22.255.25532,766
47148.23.0.0/17148.23.0.1 to 148.23.127.254148.23.127.25532,766
48148.23.128.0/17148.23.128.1 to 148.23.255.254148.23.255.25532,766
49148.24.0.0/17148.24.0.1 to 148.24.127.254148.24.127.25532,766
50148.24.128.0/17148.24.128.1 to 148.24.255.254148.24.255.25532,766
51148.25.0.0/17148.25.0.1 to 148.25.127.254148.25.127.25532,766
52148.25.128.0/17148.25.128.1 to 148.25.255.254148.25.255.25532,766
53148.26.0.0/17148.26.0.1 to 148.26.127.254148.26.127.25532,766
54148.26.128.0/17148.26.128.1 to 148.26.255.254148.26.255.25532,766
55148.27.0.0/17148.27.0.1 to 148.27.127.254148.27.127.25532,766
56148.27.128.0/17148.27.128.1 to 148.27.255.254148.27.255.25532,766
57148.28.0.0/17148.28.0.1 to 148.28.127.254148.28.127.25532,766
58148.28.128.0/17148.28.128.1 to 148.28.255.254148.28.255.25532,766
59148.29.0.0/17148.29.0.1 to 148.29.127.254148.29.127.25532,766
60148.29.128.0/17148.29.128.1 to 148.29.255.254148.29.255.25532,766
61148.30.0.0/17148.30.0.1 to 148.30.127.254148.30.127.25532,766
62148.30.128.0/17148.30.128.1 to 148.30.255.254148.30.255.25532,766
63148.31.0.0/17148.31.0.1 to 148.31.127.254148.31.127.25532,766
64148.31.128.0/17148.31.128.1 to 148.31.255.254148.31.255.25532,766
65148.32.0.0/17148.32.0.1 to 148.32.127.254148.32.127.25532,766
66148.32.128.0/17148.32.128.1 to 148.32.255.254148.32.255.25532,766
67148.33.0.0/17148.33.0.1 to 148.33.127.254148.33.127.25532,766
68148.33.128.0/17148.33.128.1 to 148.33.255.254148.33.255.25532,766
69148.34.0.0/17148.34.0.1 to 148.34.127.254148.34.127.25532,766
70148.34.128.0/17148.34.128.1 to 148.34.255.254148.34.255.25532,766
71148.35.0.0/17148.35.0.1 to 148.35.127.254148.35.127.25532,766
72148.35.128.0/17148.35.128.1 to 148.35.255.254148.35.255.25532,766
73148.36.0.0/17148.36.0.1 to 148.36.127.254148.36.127.25532,766
74148.36.128.0/17148.36.128.1 to 148.36.255.254148.36.255.25532,766
75148.37.0.0/17148.37.0.1 to 148.37.127.254148.37.127.25532,766
76148.37.128.0/17148.37.128.1 to 148.37.255.254148.37.255.25532,766
77148.38.0.0/17148.38.0.1 to 148.38.127.254148.38.127.25532,766
78148.38.128.0/17148.38.128.1 to 148.38.255.254148.38.255.25532,766
79148.39.0.0/17148.39.0.1 to 148.39.127.254148.39.127.25532,766
80148.39.128.0/17148.39.128.1 to 148.39.255.254148.39.255.25532,766
81148.40.0.0/17148.40.0.1 to 148.40.127.254148.40.127.25532,766
82148.40.128.0/17148.40.128.1 to 148.40.255.254148.40.255.25532,766
83148.41.0.0/17148.41.0.1 to 148.41.127.254148.41.127.25532,766
84148.41.128.0/17148.41.128.1 to 148.41.255.254148.41.255.25532,766
85148.42.0.0/17148.42.0.1 to 148.42.127.254148.42.127.25532,766
86148.42.128.0/17148.42.128.1 to 148.42.255.254148.42.255.25532,766
87148.43.0.0/17148.43.0.1 to 148.43.127.254148.43.127.25532,766
88148.43.128.0/17148.43.128.1 to 148.43.255.254148.43.255.25532,766
89148.44.0.0/17148.44.0.1 to 148.44.127.254148.44.127.25532,766
90148.44.128.0/17148.44.128.1 to 148.44.255.254148.44.255.25532,766
91148.45.0.0/17148.45.0.1 to 148.45.127.254148.45.127.25532,766
92148.45.128.0/17148.45.128.1 to 148.45.255.254148.45.255.25532,766
93148.46.0.0/17148.46.0.1 to 148.46.127.254148.46.127.25532,766
94148.46.128.0/17148.46.128.1 to 148.46.255.254148.46.255.25532,766
95148.47.0.0/17148.47.0.1 to 148.47.127.254148.47.127.25532,766
96148.47.128.0/17148.47.128.1 to 148.47.255.254148.47.255.25532,766
97148.48.0.0/17148.48.0.1 to 148.48.127.254148.48.127.25532,766
98148.48.128.0/17148.48.128.1 to 148.48.255.254148.48.255.25532,766
99148.49.0.0/17148.49.0.1 to 148.49.127.254148.49.127.25532,766
100148.49.128.0/17148.49.128.1 to 148.49.255.254148.49.255.25532,766
101148.50.0.0/17148.50.0.1 to 148.50.127.254148.50.127.25532,766
102148.50.128.0/17148.50.128.1 to 148.50.255.254148.50.255.25532,766
103148.51.0.0/17148.51.0.1 to 148.51.127.254148.51.127.25532,766
104148.51.128.0/17148.51.128.1 to 148.51.255.254148.51.255.25532,766
105148.52.0.0/17148.52.0.1 to 148.52.127.254148.52.127.25532,766
106148.52.128.0/17148.52.128.1 to 148.52.255.254148.52.255.25532,766
107148.53.0.0/17148.53.0.1 to 148.53.127.254148.53.127.25532,766
108148.53.128.0/17148.53.128.1 to 148.53.255.254148.53.255.25532,766
109148.54.0.0/17148.54.0.1 to 148.54.127.254148.54.127.25532,766
110148.54.128.0/17148.54.128.1 to 148.54.255.254148.54.255.25532,766
111148.55.0.0/17148.55.0.1 to 148.55.127.254148.55.127.25532,766
112148.55.128.0/17148.55.128.1 to 148.55.255.254148.55.255.25532,766
113148.56.0.0/17148.56.0.1 to 148.56.127.254148.56.127.25532,766
114148.56.128.0/17148.56.128.1 to 148.56.255.254148.56.255.25532,766
115148.57.0.0/17148.57.0.1 to 148.57.127.254148.57.127.25532,766
116148.57.128.0/17148.57.128.1 to 148.57.255.254148.57.255.25532,766
117148.58.0.0/17148.58.0.1 to 148.58.127.254148.58.127.25532,766
118148.58.128.0/17148.58.128.1 to 148.58.255.254148.58.255.25532,766
119148.59.0.0/17148.59.0.1 to 148.59.127.254148.59.127.25532,766
120148.59.128.0/17148.59.128.1 to 148.59.255.254148.59.255.25532,766
121148.60.0.0/17148.60.0.1 to 148.60.127.254148.60.127.25532,766
122148.60.128.0/17148.60.128.1 to 148.60.255.254148.60.255.25532,766
123148.61.0.0/17148.61.0.1 to 148.61.127.254148.61.127.25532,766
124148.61.128.0/17148.61.128.1 to 148.61.255.254148.61.255.25532,766
125148.62.0.0/17148.62.0.1 to 148.62.127.254148.62.127.25532,766
126148.62.128.0/17148.62.128.1 to 148.62.255.254148.62.255.25532,766
127148.63.0.0/17148.63.0.1 to 148.63.127.254148.63.127.25532,766
128148.63.128.0/17148.63.128.1 to 148.63.255.254148.63.255.25532,766
129148.64.0.0/17148.64.0.1 to 148.64.127.254148.64.127.25532,766
130148.64.128.0/17148.64.128.1 to 148.64.255.254148.64.255.25532,766
131148.65.0.0/17148.65.0.1 to 148.65.127.254148.65.127.25532,766
132148.65.128.0/17148.65.128.1 to 148.65.255.254148.65.255.25532,766
133148.66.0.0/17148.66.0.1 to 148.66.127.254148.66.127.25532,766
134148.66.128.0/17148.66.128.1 to 148.66.255.254148.66.255.25532,766
135148.67.0.0/17148.67.0.1 to 148.67.127.254148.67.127.25532,766
136148.67.128.0/17148.67.128.1 to 148.67.255.254148.67.255.25532,766
137148.68.0.0/17148.68.0.1 to 148.68.127.254148.68.127.25532,766
138148.68.128.0/17148.68.128.1 to 148.68.255.254148.68.255.25532,766
139148.69.0.0/17148.69.0.1 to 148.69.127.254148.69.127.25532,766
140148.69.128.0/17148.69.128.1 to 148.69.255.254148.69.255.25532,766
141148.70.0.0/17148.70.0.1 to 148.70.127.254148.70.127.25532,766
142148.70.128.0/17148.70.128.1 to 148.70.255.254148.70.255.25532,766
143148.71.0.0/17148.71.0.1 to 148.71.127.254148.71.127.25532,766
144148.71.128.0/17148.71.128.1 to 148.71.255.254148.71.255.25532,766
145148.72.0.0/17148.72.0.1 to 148.72.127.254148.72.127.25532,766
146148.72.128.0/17148.72.128.1 to 148.72.255.254148.72.255.25532,766
147148.73.0.0/17148.73.0.1 to 148.73.127.254148.73.127.25532,766
148148.73.128.0/17148.73.128.1 to 148.73.255.254148.73.255.25532,766
149148.74.0.0/17148.74.0.1 to 148.74.127.254148.74.127.25532,766
150148.74.128.0/17148.74.128.1 to 148.74.255.254148.74.255.25532,766
151148.75.0.0/17148.75.0.1 to 148.75.127.254148.75.127.25532,766
152148.75.128.0/17148.75.128.1 to 148.75.255.254148.75.255.25532,766
153148.76.0.0/17148.76.0.1 to 148.76.127.254148.76.127.25532,766
154148.76.128.0/17148.76.128.1 to 148.76.255.254148.76.255.25532,766
155148.77.0.0/17148.77.0.1 to 148.77.127.254148.77.127.25532,766
156148.77.128.0/17148.77.128.1 to 148.77.255.254148.77.255.25532,766
157148.78.0.0/17148.78.0.1 to 148.78.127.254148.78.127.25532,766
158148.78.128.0/17148.78.128.1 to 148.78.255.254148.78.255.25532,766
159148.79.0.0/17148.79.0.1 to 148.79.127.254148.79.127.25532,766
160148.79.128.0/17148.79.128.1 to 148.79.255.254148.79.255.25532,766
161148.80.0.0/17148.80.0.1 to 148.80.127.254148.80.127.25532,766
162148.80.128.0/17148.80.128.1 to 148.80.255.254148.80.255.25532,766
163148.81.0.0/17148.81.0.1 to 148.81.127.254148.81.127.25532,766
164148.81.128.0/17148.81.128.1 to 148.81.255.254148.81.255.25532,766
165148.82.0.0/17148.82.0.1 to 148.82.127.254148.82.127.25532,766
166148.82.128.0/17148.82.128.1 to 148.82.255.254148.82.255.25532,766
167148.83.0.0/17148.83.0.1 to 148.83.127.254148.83.127.25532,766
168148.83.128.0/17148.83.128.1 to 148.83.255.254148.83.255.25532,766
169148.84.0.0/17148.84.0.1 to 148.84.127.254148.84.127.25532,766
170148.84.128.0/17148.84.128.1 to 148.84.255.254148.84.255.25532,766
171148.85.0.0/17148.85.0.1 to 148.85.127.254148.85.127.25532,766
172148.85.128.0/17148.85.128.1 to 148.85.255.254148.85.255.25532,766
173148.86.0.0/17148.86.0.1 to 148.86.127.254148.86.127.25532,766
174148.86.128.0/17148.86.128.1 to 148.86.255.254148.86.255.25532,766
175148.87.0.0/17148.87.0.1 to 148.87.127.254148.87.127.25532,766
176148.87.128.0/17148.87.128.1 to 148.87.255.254148.87.255.25532,766
177148.88.0.0/17148.88.0.1 to 148.88.127.254148.88.127.25532,766
178148.88.128.0/17148.88.128.1 to 148.88.255.254148.88.255.25532,766
179148.89.0.0/17148.89.0.1 to 148.89.127.254148.89.127.25532,766
180148.89.128.0/17148.89.128.1 to 148.89.255.254148.89.255.25532,766
181148.90.0.0/17148.90.0.1 to 148.90.127.254148.90.127.25532,766
182148.90.128.0/17148.90.128.1 to 148.90.255.254148.90.255.25532,766
183148.91.0.0/17148.91.0.1 to 148.91.127.254148.91.127.25532,766
184148.91.128.0/17148.91.128.1 to 148.91.255.254148.91.255.25532,766
185148.92.0.0/17148.92.0.1 to 148.92.127.254148.92.127.25532,766
186148.92.128.0/17148.92.128.1 to 148.92.255.254148.92.255.25532,766
187148.93.0.0/17148.93.0.1 to 148.93.127.254148.93.127.25532,766
188148.93.128.0/17148.93.128.1 to 148.93.255.254148.93.255.25532,766
189148.94.0.0/17148.94.0.1 to 148.94.127.254148.94.127.25532,766
190148.94.128.0/17148.94.128.1 to 148.94.255.254148.94.255.25532,766
191148.95.0.0/17148.95.0.1 to 148.95.127.254148.95.127.25532,766
192148.95.128.0/17148.95.128.1 to 148.95.255.254148.95.255.25532,766
193148.96.0.0/17148.96.0.1 to 148.96.127.254148.96.127.25532,766
194148.96.128.0/17148.96.128.1 to 148.96.255.254148.96.255.25532,766
195148.97.0.0/17148.97.0.1 to 148.97.127.254148.97.127.25532,766
196148.97.128.0/17148.97.128.1 to 148.97.255.254148.97.255.25532,766
197148.98.0.0/17148.98.0.1 to 148.98.127.254148.98.127.25532,766
198148.98.128.0/17148.98.128.1 to 148.98.255.254148.98.255.25532,766
199148.99.0.0/17148.99.0.1 to 148.99.127.254148.99.127.25532,766
200148.99.128.0/17148.99.128.1 to 148.99.255.254148.99.255.25532,766
201148.100.0.0/17148.100.0.1 to 148.100.127.254148.100.127.25532,766
202148.100.128.0/17148.100.128.1 to 148.100.255.254148.100.255.25532,766
203148.101.0.0/17148.101.0.1 to 148.101.127.254148.101.127.25532,766
204148.101.128.0/17148.101.128.1 to 148.101.255.254148.101.255.25532,766
205148.102.0.0/17148.102.0.1 to 148.102.127.254148.102.127.25532,766
206148.102.128.0/17148.102.128.1 to 148.102.255.254148.102.255.25532,766
207148.103.0.0/17148.103.0.1 to 148.103.127.254148.103.127.25532,766
208148.103.128.0/17148.103.128.1 to 148.103.255.254148.103.255.25532,766
209148.104.0.0/17148.104.0.1 to 148.104.127.254148.104.127.25532,766
210148.104.128.0/17148.104.128.1 to 148.104.255.254148.104.255.25532,766
211148.105.0.0/17148.105.0.1 to 148.105.127.254148.105.127.25532,766
212148.105.128.0/17148.105.128.1 to 148.105.255.254148.105.255.25532,766
213148.106.0.0/17148.106.0.1 to 148.106.127.254148.106.127.25532,766
214148.106.128.0/17148.106.128.1 to 148.106.255.254148.106.255.25532,766
215148.107.0.0/17148.107.0.1 to 148.107.127.254148.107.127.25532,766
216148.107.128.0/17148.107.128.1 to 148.107.255.254148.107.255.25532,766
217148.108.0.0/17148.108.0.1 to 148.108.127.254148.108.127.25532,766
218148.108.128.0/17148.108.128.1 to 148.108.255.254148.108.255.25532,766
219148.109.0.0/17148.109.0.1 to 148.109.127.254148.109.127.25532,766
220148.109.128.0/17148.109.128.1 to 148.109.255.254148.109.255.25532,766
221148.110.0.0/17148.110.0.1 to 148.110.127.254148.110.127.25532,766
222148.110.128.0/17148.110.128.1 to 148.110.255.254148.110.255.25532,766
223148.111.0.0/17148.111.0.1 to 148.111.127.254148.111.127.25532,766
224148.111.128.0/17148.111.128.1 to 148.111.255.254148.111.255.25532,766
225148.112.0.0/17148.112.0.1 to 148.112.127.254148.112.127.25532,766
226148.112.128.0/17148.112.128.1 to 148.112.255.254148.112.255.25532,766
227148.113.0.0/17148.113.0.1 to 148.113.127.254148.113.127.25532,766
228148.113.128.0/17148.113.128.1 to 148.113.255.254148.113.255.25532,766
229148.114.0.0/17148.114.0.1 to 148.114.127.254148.114.127.25532,766
230148.114.128.0/17148.114.128.1 to 148.114.255.254148.114.255.25532,766
231148.115.0.0/17148.115.0.1 to 148.115.127.254148.115.127.25532,766
232148.115.128.0/17148.115.128.1 to 148.115.255.254148.115.255.25532,766
233148.116.0.0/17148.116.0.1 to 148.116.127.254148.116.127.25532,766
234148.116.128.0/17148.116.128.1 to 148.116.255.254148.116.255.25532,766
235148.117.0.0/17148.117.0.1 to 148.117.127.254148.117.127.25532,766
236148.117.128.0/17148.117.128.1 to 148.117.255.254148.117.255.25532,766
237148.118.0.0/17148.118.0.1 to 148.118.127.254148.118.127.25532,766
238148.118.128.0/17148.118.128.1 to 148.118.255.254148.118.255.25532,766
239148.119.0.0/17148.119.0.1 to 148.119.127.254148.119.127.25532,766
240148.119.128.0/17148.119.128.1 to 148.119.255.254148.119.255.25532,766
241148.120.0.0/17148.120.0.1 to 148.120.127.254148.120.127.25532,766
242148.120.128.0/17148.120.128.1 to 148.120.255.254148.120.255.25532,766
243148.121.0.0/17148.121.0.1 to 148.121.127.254148.121.127.25532,766
244148.121.128.0/17148.121.128.1 to 148.121.255.254148.121.255.25532,766
245148.122.0.0/17148.122.0.1 to 148.122.127.254148.122.127.25532,766
246148.122.128.0/17148.122.128.1 to 148.122.255.254148.122.255.25532,766
247148.123.0.0/17148.123.0.1 to 148.123.127.254148.123.127.25532,766
248148.123.128.0/17148.123.128.1 to 148.123.255.254148.123.255.25532,766
249148.124.0.0/17148.124.0.1 to 148.124.127.254148.124.127.25532,766
250148.124.128.0/17148.124.128.1 to 148.124.255.254148.124.255.25532,766
251148.125.0.0/17148.125.0.1 to 148.125.127.254148.125.127.25532,766
252148.125.128.0/17148.125.128.1 to 148.125.255.254148.125.255.25532,766
253148.126.0.0/17148.126.0.1 to 148.126.127.254148.126.127.25532,766
254148.126.128.0/17148.126.128.1 to 148.126.255.254148.126.255.25532,766
255148.127.0.0/17148.127.0.1 to 148.127.127.254148.127.127.25532,766
256148.127.128.0/17148.127.128.1 to 148.127.255.254148.127.255.25532,766

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.