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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.

Network148.78.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
148.78.0.0
Broadcast address
148.78.255.255
First usable
148.78.0.1
Last usable
148.78.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
B (default /16)
As numbers
Hex 944E0000 · Integer 2488139776 to 2488205311
Reverse DNS zone
78.148.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010100.01001110..00000000.00000000148.78.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network10010100.01001110..00000000.00000000148.78.0.0
Broadcast10010100.01001110..11111111.11111111148.78.255.255
Split into smaller subnets/25
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

148.78.0.0/16 makes 512 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1148.78.0.0/25148.78.0.1 to 148.78.0.126148.78.0.127126
2148.78.0.128/25148.78.0.129 to 148.78.0.254148.78.0.255126
3148.78.1.0/25148.78.1.1 to 148.78.1.126148.78.1.127126
4148.78.1.128/25148.78.1.129 to 148.78.1.254148.78.1.255126
5148.78.2.0/25148.78.2.1 to 148.78.2.126148.78.2.127126
6148.78.2.128/25148.78.2.129 to 148.78.2.254148.78.2.255126
7148.78.3.0/25148.78.3.1 to 148.78.3.126148.78.3.127126
8148.78.3.128/25148.78.3.129 to 148.78.3.254148.78.3.255126
9148.78.4.0/25148.78.4.1 to 148.78.4.126148.78.4.127126
10148.78.4.128/25148.78.4.129 to 148.78.4.254148.78.4.255126
11148.78.5.0/25148.78.5.1 to 148.78.5.126148.78.5.127126
12148.78.5.128/25148.78.5.129 to 148.78.5.254148.78.5.255126
13148.78.6.0/25148.78.6.1 to 148.78.6.126148.78.6.127126
14148.78.6.128/25148.78.6.129 to 148.78.6.254148.78.6.255126
15148.78.7.0/25148.78.7.1 to 148.78.7.126148.78.7.127126
16148.78.7.128/25148.78.7.129 to 148.78.7.254148.78.7.255126
17148.78.8.0/25148.78.8.1 to 148.78.8.126148.78.8.127126
18148.78.8.128/25148.78.8.129 to 148.78.8.254148.78.8.255126
19148.78.9.0/25148.78.9.1 to 148.78.9.126148.78.9.127126
20148.78.9.128/25148.78.9.129 to 148.78.9.254148.78.9.255126
21148.78.10.0/25148.78.10.1 to 148.78.10.126148.78.10.127126
22148.78.10.128/25148.78.10.129 to 148.78.10.254148.78.10.255126
23148.78.11.0/25148.78.11.1 to 148.78.11.126148.78.11.127126
24148.78.11.128/25148.78.11.129 to 148.78.11.254148.78.11.255126
25148.78.12.0/25148.78.12.1 to 148.78.12.126148.78.12.127126
26148.78.12.128/25148.78.12.129 to 148.78.12.254148.78.12.255126
27148.78.13.0/25148.78.13.1 to 148.78.13.126148.78.13.127126
28148.78.13.128/25148.78.13.129 to 148.78.13.254148.78.13.255126
29148.78.14.0/25148.78.14.1 to 148.78.14.126148.78.14.127126
30148.78.14.128/25148.78.14.129 to 148.78.14.254148.78.14.255126
31148.78.15.0/25148.78.15.1 to 148.78.15.126148.78.15.127126
32148.78.15.128/25148.78.15.129 to 148.78.15.254148.78.15.255126
33148.78.16.0/25148.78.16.1 to 148.78.16.126148.78.16.127126
34148.78.16.128/25148.78.16.129 to 148.78.16.254148.78.16.255126
35148.78.17.0/25148.78.17.1 to 148.78.17.126148.78.17.127126
36148.78.17.128/25148.78.17.129 to 148.78.17.254148.78.17.255126
37148.78.18.0/25148.78.18.1 to 148.78.18.126148.78.18.127126
38148.78.18.128/25148.78.18.129 to 148.78.18.254148.78.18.255126
39148.78.19.0/25148.78.19.1 to 148.78.19.126148.78.19.127126
40148.78.19.128/25148.78.19.129 to 148.78.19.254148.78.19.255126
41148.78.20.0/25148.78.20.1 to 148.78.20.126148.78.20.127126
42148.78.20.128/25148.78.20.129 to 148.78.20.254148.78.20.255126
43148.78.21.0/25148.78.21.1 to 148.78.21.126148.78.21.127126
44148.78.21.128/25148.78.21.129 to 148.78.21.254148.78.21.255126
45148.78.22.0/25148.78.22.1 to 148.78.22.126148.78.22.127126
46148.78.22.128/25148.78.22.129 to 148.78.22.254148.78.22.255126
47148.78.23.0/25148.78.23.1 to 148.78.23.126148.78.23.127126
48148.78.23.128/25148.78.23.129 to 148.78.23.254148.78.23.255126
49148.78.24.0/25148.78.24.1 to 148.78.24.126148.78.24.127126
50148.78.24.128/25148.78.24.129 to 148.78.24.254148.78.24.255126
51148.78.25.0/25148.78.25.1 to 148.78.25.126148.78.25.127126
52148.78.25.128/25148.78.25.129 to 148.78.25.254148.78.25.255126
53148.78.26.0/25148.78.26.1 to 148.78.26.126148.78.26.127126
54148.78.26.128/25148.78.26.129 to 148.78.26.254148.78.26.255126
55148.78.27.0/25148.78.27.1 to 148.78.27.126148.78.27.127126
56148.78.27.128/25148.78.27.129 to 148.78.27.254148.78.27.255126
57148.78.28.0/25148.78.28.1 to 148.78.28.126148.78.28.127126
58148.78.28.128/25148.78.28.129 to 148.78.28.254148.78.28.255126
59148.78.29.0/25148.78.29.1 to 148.78.29.126148.78.29.127126
60148.78.29.128/25148.78.29.129 to 148.78.29.254148.78.29.255126
61148.78.30.0/25148.78.30.1 to 148.78.30.126148.78.30.127126
62148.78.30.128/25148.78.30.129 to 148.78.30.254148.78.30.255126
63148.78.31.0/25148.78.31.1 to 148.78.31.126148.78.31.127126
64148.78.31.128/25148.78.31.129 to 148.78.31.254148.78.31.255126
65148.78.32.0/25148.78.32.1 to 148.78.32.126148.78.32.127126
66148.78.32.128/25148.78.32.129 to 148.78.32.254148.78.32.255126
67148.78.33.0/25148.78.33.1 to 148.78.33.126148.78.33.127126
68148.78.33.128/25148.78.33.129 to 148.78.33.254148.78.33.255126
69148.78.34.0/25148.78.34.1 to 148.78.34.126148.78.34.127126
70148.78.34.128/25148.78.34.129 to 148.78.34.254148.78.34.255126
71148.78.35.0/25148.78.35.1 to 148.78.35.126148.78.35.127126
72148.78.35.128/25148.78.35.129 to 148.78.35.254148.78.35.255126
73148.78.36.0/25148.78.36.1 to 148.78.36.126148.78.36.127126
74148.78.36.128/25148.78.36.129 to 148.78.36.254148.78.36.255126
75148.78.37.0/25148.78.37.1 to 148.78.37.126148.78.37.127126
76148.78.37.128/25148.78.37.129 to 148.78.37.254148.78.37.255126
77148.78.38.0/25148.78.38.1 to 148.78.38.126148.78.38.127126
78148.78.38.128/25148.78.38.129 to 148.78.38.254148.78.38.255126
79148.78.39.0/25148.78.39.1 to 148.78.39.126148.78.39.127126
80148.78.39.128/25148.78.39.129 to 148.78.39.254148.78.39.255126
81148.78.40.0/25148.78.40.1 to 148.78.40.126148.78.40.127126
82148.78.40.128/25148.78.40.129 to 148.78.40.254148.78.40.255126
83148.78.41.0/25148.78.41.1 to 148.78.41.126148.78.41.127126
84148.78.41.128/25148.78.41.129 to 148.78.41.254148.78.41.255126
85148.78.42.0/25148.78.42.1 to 148.78.42.126148.78.42.127126
86148.78.42.128/25148.78.42.129 to 148.78.42.254148.78.42.255126
87148.78.43.0/25148.78.43.1 to 148.78.43.126148.78.43.127126
88148.78.43.128/25148.78.43.129 to 148.78.43.254148.78.43.255126
89148.78.44.0/25148.78.44.1 to 148.78.44.126148.78.44.127126
90148.78.44.128/25148.78.44.129 to 148.78.44.254148.78.44.255126
91148.78.45.0/25148.78.45.1 to 148.78.45.126148.78.45.127126
92148.78.45.128/25148.78.45.129 to 148.78.45.254148.78.45.255126
93148.78.46.0/25148.78.46.1 to 148.78.46.126148.78.46.127126
94148.78.46.128/25148.78.46.129 to 148.78.46.254148.78.46.255126
95148.78.47.0/25148.78.47.1 to 148.78.47.126148.78.47.127126
96148.78.47.128/25148.78.47.129 to 148.78.47.254148.78.47.255126
97148.78.48.0/25148.78.48.1 to 148.78.48.126148.78.48.127126
98148.78.48.128/25148.78.48.129 to 148.78.48.254148.78.48.255126
99148.78.49.0/25148.78.49.1 to 148.78.49.126148.78.49.127126
100148.78.49.128/25148.78.49.129 to 148.78.49.254148.78.49.255126
101148.78.50.0/25148.78.50.1 to 148.78.50.126148.78.50.127126
102148.78.50.128/25148.78.50.129 to 148.78.50.254148.78.50.255126
103148.78.51.0/25148.78.51.1 to 148.78.51.126148.78.51.127126
104148.78.51.128/25148.78.51.129 to 148.78.51.254148.78.51.255126
105148.78.52.0/25148.78.52.1 to 148.78.52.126148.78.52.127126
106148.78.52.128/25148.78.52.129 to 148.78.52.254148.78.52.255126
107148.78.53.0/25148.78.53.1 to 148.78.53.126148.78.53.127126
108148.78.53.128/25148.78.53.129 to 148.78.53.254148.78.53.255126
109148.78.54.0/25148.78.54.1 to 148.78.54.126148.78.54.127126
110148.78.54.128/25148.78.54.129 to 148.78.54.254148.78.54.255126
111148.78.55.0/25148.78.55.1 to 148.78.55.126148.78.55.127126
112148.78.55.128/25148.78.55.129 to 148.78.55.254148.78.55.255126
113148.78.56.0/25148.78.56.1 to 148.78.56.126148.78.56.127126
114148.78.56.128/25148.78.56.129 to 148.78.56.254148.78.56.255126
115148.78.57.0/25148.78.57.1 to 148.78.57.126148.78.57.127126
116148.78.57.128/25148.78.57.129 to 148.78.57.254148.78.57.255126
117148.78.58.0/25148.78.58.1 to 148.78.58.126148.78.58.127126
118148.78.58.128/25148.78.58.129 to 148.78.58.254148.78.58.255126
119148.78.59.0/25148.78.59.1 to 148.78.59.126148.78.59.127126
120148.78.59.128/25148.78.59.129 to 148.78.59.254148.78.59.255126
121148.78.60.0/25148.78.60.1 to 148.78.60.126148.78.60.127126
122148.78.60.128/25148.78.60.129 to 148.78.60.254148.78.60.255126
123148.78.61.0/25148.78.61.1 to 148.78.61.126148.78.61.127126
124148.78.61.128/25148.78.61.129 to 148.78.61.254148.78.61.255126
125148.78.62.0/25148.78.62.1 to 148.78.62.126148.78.62.127126
126148.78.62.128/25148.78.62.129 to 148.78.62.254148.78.62.255126
127148.78.63.0/25148.78.63.1 to 148.78.63.126148.78.63.127126
128148.78.63.128/25148.78.63.129 to 148.78.63.254148.78.63.255126
129148.78.64.0/25148.78.64.1 to 148.78.64.126148.78.64.127126
130148.78.64.128/25148.78.64.129 to 148.78.64.254148.78.64.255126
131148.78.65.0/25148.78.65.1 to 148.78.65.126148.78.65.127126
132148.78.65.128/25148.78.65.129 to 148.78.65.254148.78.65.255126
133148.78.66.0/25148.78.66.1 to 148.78.66.126148.78.66.127126
134148.78.66.128/25148.78.66.129 to 148.78.66.254148.78.66.255126
135148.78.67.0/25148.78.67.1 to 148.78.67.126148.78.67.127126
136148.78.67.128/25148.78.67.129 to 148.78.67.254148.78.67.255126
137148.78.68.0/25148.78.68.1 to 148.78.68.126148.78.68.127126
138148.78.68.128/25148.78.68.129 to 148.78.68.254148.78.68.255126
139148.78.69.0/25148.78.69.1 to 148.78.69.126148.78.69.127126
140148.78.69.128/25148.78.69.129 to 148.78.69.254148.78.69.255126
141148.78.70.0/25148.78.70.1 to 148.78.70.126148.78.70.127126
142148.78.70.128/25148.78.70.129 to 148.78.70.254148.78.70.255126
143148.78.71.0/25148.78.71.1 to 148.78.71.126148.78.71.127126
144148.78.71.128/25148.78.71.129 to 148.78.71.254148.78.71.255126
145148.78.72.0/25148.78.72.1 to 148.78.72.126148.78.72.127126
146148.78.72.128/25148.78.72.129 to 148.78.72.254148.78.72.255126
147148.78.73.0/25148.78.73.1 to 148.78.73.126148.78.73.127126
148148.78.73.128/25148.78.73.129 to 148.78.73.254148.78.73.255126
149148.78.74.0/25148.78.74.1 to 148.78.74.126148.78.74.127126
150148.78.74.128/25148.78.74.129 to 148.78.74.254148.78.74.255126
151148.78.75.0/25148.78.75.1 to 148.78.75.126148.78.75.127126
152148.78.75.128/25148.78.75.129 to 148.78.75.254148.78.75.255126
153148.78.76.0/25148.78.76.1 to 148.78.76.126148.78.76.127126
154148.78.76.128/25148.78.76.129 to 148.78.76.254148.78.76.255126
155148.78.77.0/25148.78.77.1 to 148.78.77.126148.78.77.127126
156148.78.77.128/25148.78.77.129 to 148.78.77.254148.78.77.255126
157148.78.78.0/25148.78.78.1 to 148.78.78.126148.78.78.127126
158148.78.78.128/25148.78.78.129 to 148.78.78.254148.78.78.255126
159148.78.79.0/25148.78.79.1 to 148.78.79.126148.78.79.127126
160148.78.79.128/25148.78.79.129 to 148.78.79.254148.78.79.255126
161148.78.80.0/25148.78.80.1 to 148.78.80.126148.78.80.127126
162148.78.80.128/25148.78.80.129 to 148.78.80.254148.78.80.255126
163148.78.81.0/25148.78.81.1 to 148.78.81.126148.78.81.127126
164148.78.81.128/25148.78.81.129 to 148.78.81.254148.78.81.255126
165148.78.82.0/25148.78.82.1 to 148.78.82.126148.78.82.127126
166148.78.82.128/25148.78.82.129 to 148.78.82.254148.78.82.255126
167148.78.83.0/25148.78.83.1 to 148.78.83.126148.78.83.127126
168148.78.83.128/25148.78.83.129 to 148.78.83.254148.78.83.255126
169148.78.84.0/25148.78.84.1 to 148.78.84.126148.78.84.127126
170148.78.84.128/25148.78.84.129 to 148.78.84.254148.78.84.255126
171148.78.85.0/25148.78.85.1 to 148.78.85.126148.78.85.127126
172148.78.85.128/25148.78.85.129 to 148.78.85.254148.78.85.255126
173148.78.86.0/25148.78.86.1 to 148.78.86.126148.78.86.127126
174148.78.86.128/25148.78.86.129 to 148.78.86.254148.78.86.255126
175148.78.87.0/25148.78.87.1 to 148.78.87.126148.78.87.127126
176148.78.87.128/25148.78.87.129 to 148.78.87.254148.78.87.255126
177148.78.88.0/25148.78.88.1 to 148.78.88.126148.78.88.127126
178148.78.88.128/25148.78.88.129 to 148.78.88.254148.78.88.255126
179148.78.89.0/25148.78.89.1 to 148.78.89.126148.78.89.127126
180148.78.89.128/25148.78.89.129 to 148.78.89.254148.78.89.255126
181148.78.90.0/25148.78.90.1 to 148.78.90.126148.78.90.127126
182148.78.90.128/25148.78.90.129 to 148.78.90.254148.78.90.255126
183148.78.91.0/25148.78.91.1 to 148.78.91.126148.78.91.127126
184148.78.91.128/25148.78.91.129 to 148.78.91.254148.78.91.255126
185148.78.92.0/25148.78.92.1 to 148.78.92.126148.78.92.127126
186148.78.92.128/25148.78.92.129 to 148.78.92.254148.78.92.255126
187148.78.93.0/25148.78.93.1 to 148.78.93.126148.78.93.127126
188148.78.93.128/25148.78.93.129 to 148.78.93.254148.78.93.255126
189148.78.94.0/25148.78.94.1 to 148.78.94.126148.78.94.127126
190148.78.94.128/25148.78.94.129 to 148.78.94.254148.78.94.255126
191148.78.95.0/25148.78.95.1 to 148.78.95.126148.78.95.127126
192148.78.95.128/25148.78.95.129 to 148.78.95.254148.78.95.255126
193148.78.96.0/25148.78.96.1 to 148.78.96.126148.78.96.127126
194148.78.96.128/25148.78.96.129 to 148.78.96.254148.78.96.255126
195148.78.97.0/25148.78.97.1 to 148.78.97.126148.78.97.127126
196148.78.97.128/25148.78.97.129 to 148.78.97.254148.78.97.255126
197148.78.98.0/25148.78.98.1 to 148.78.98.126148.78.98.127126
198148.78.98.128/25148.78.98.129 to 148.78.98.254148.78.98.255126
199148.78.99.0/25148.78.99.1 to 148.78.99.126148.78.99.127126
200148.78.99.128/25148.78.99.129 to 148.78.99.254148.78.99.255126
201148.78.100.0/25148.78.100.1 to 148.78.100.126148.78.100.127126
202148.78.100.128/25148.78.100.129 to 148.78.100.254148.78.100.255126
203148.78.101.0/25148.78.101.1 to 148.78.101.126148.78.101.127126
204148.78.101.128/25148.78.101.129 to 148.78.101.254148.78.101.255126
205148.78.102.0/25148.78.102.1 to 148.78.102.126148.78.102.127126
206148.78.102.128/25148.78.102.129 to 148.78.102.254148.78.102.255126
207148.78.103.0/25148.78.103.1 to 148.78.103.126148.78.103.127126
208148.78.103.128/25148.78.103.129 to 148.78.103.254148.78.103.255126
209148.78.104.0/25148.78.104.1 to 148.78.104.126148.78.104.127126
210148.78.104.128/25148.78.104.129 to 148.78.104.254148.78.104.255126
211148.78.105.0/25148.78.105.1 to 148.78.105.126148.78.105.127126
212148.78.105.128/25148.78.105.129 to 148.78.105.254148.78.105.255126
213148.78.106.0/25148.78.106.1 to 148.78.106.126148.78.106.127126
214148.78.106.128/25148.78.106.129 to 148.78.106.254148.78.106.255126
215148.78.107.0/25148.78.107.1 to 148.78.107.126148.78.107.127126
216148.78.107.128/25148.78.107.129 to 148.78.107.254148.78.107.255126
217148.78.108.0/25148.78.108.1 to 148.78.108.126148.78.108.127126
218148.78.108.128/25148.78.108.129 to 148.78.108.254148.78.108.255126
219148.78.109.0/25148.78.109.1 to 148.78.109.126148.78.109.127126
220148.78.109.128/25148.78.109.129 to 148.78.109.254148.78.109.255126
221148.78.110.0/25148.78.110.1 to 148.78.110.126148.78.110.127126
222148.78.110.128/25148.78.110.129 to 148.78.110.254148.78.110.255126
223148.78.111.0/25148.78.111.1 to 148.78.111.126148.78.111.127126
224148.78.111.128/25148.78.111.129 to 148.78.111.254148.78.111.255126
225148.78.112.0/25148.78.112.1 to 148.78.112.126148.78.112.127126
226148.78.112.128/25148.78.112.129 to 148.78.112.254148.78.112.255126
227148.78.113.0/25148.78.113.1 to 148.78.113.126148.78.113.127126
228148.78.113.128/25148.78.113.129 to 148.78.113.254148.78.113.255126
229148.78.114.0/25148.78.114.1 to 148.78.114.126148.78.114.127126
230148.78.114.128/25148.78.114.129 to 148.78.114.254148.78.114.255126
231148.78.115.0/25148.78.115.1 to 148.78.115.126148.78.115.127126
232148.78.115.128/25148.78.115.129 to 148.78.115.254148.78.115.255126
233148.78.116.0/25148.78.116.1 to 148.78.116.126148.78.116.127126
234148.78.116.128/25148.78.116.129 to 148.78.116.254148.78.116.255126
235148.78.117.0/25148.78.117.1 to 148.78.117.126148.78.117.127126
236148.78.117.128/25148.78.117.129 to 148.78.117.254148.78.117.255126
237148.78.118.0/25148.78.118.1 to 148.78.118.126148.78.118.127126
238148.78.118.128/25148.78.118.129 to 148.78.118.254148.78.118.255126
239148.78.119.0/25148.78.119.1 to 148.78.119.126148.78.119.127126
240148.78.119.128/25148.78.119.129 to 148.78.119.254148.78.119.255126
241148.78.120.0/25148.78.120.1 to 148.78.120.126148.78.120.127126
242148.78.120.128/25148.78.120.129 to 148.78.120.254148.78.120.255126
243148.78.121.0/25148.78.121.1 to 148.78.121.126148.78.121.127126
244148.78.121.128/25148.78.121.129 to 148.78.121.254148.78.121.255126
245148.78.122.0/25148.78.122.1 to 148.78.122.126148.78.122.127126
246148.78.122.128/25148.78.122.129 to 148.78.122.254148.78.122.255126
247148.78.123.0/25148.78.123.1 to 148.78.123.126148.78.123.127126
248148.78.123.128/25148.78.123.129 to 148.78.123.254148.78.123.255126
249148.78.124.0/25148.78.124.1 to 148.78.124.126148.78.124.127126
250148.78.124.128/25148.78.124.129 to 148.78.124.254148.78.124.255126
251148.78.125.0/25148.78.125.1 to 148.78.125.126148.78.125.127126
252148.78.125.128/25148.78.125.129 to 148.78.125.254148.78.125.255126
253148.78.126.0/25148.78.126.1 to 148.78.126.126148.78.126.127126
254148.78.126.128/25148.78.126.129 to 148.78.126.254148.78.126.255126
255148.78.127.0/25148.78.127.1 to 148.78.127.126148.78.127.127126
256148.78.127.128/25148.78.127.129 to 148.78.127.254148.78.127.255126

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.