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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.

Network162.64.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
162.64.0.0
Broadcast address
162.127.255.255
First usable
162.64.0.1
Last usable
162.127.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
B (default /16)
As numbers
Hex A2400000 · Integer 2722103296 to 2726297599
Reverse DNS zones
64.162.in-addr.arpa
65.162.in-addr.arpa
66.162.in-addr.arpa
67.162.in-addr.arpa
68.162.in-addr.arpa
69.162.in-addr.arpa
70.162.in-addr.arpa
71.162.in-addr.arpa
72.162.in-addr.arpa
73.162.in-addr.arpa
74.162.in-addr.arpa
75.162.in-addr.arpa
76.162.in-addr.arpa
77.162.in-addr.arpa
78.162.in-addr.arpa
79.162.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10100010.01000000.00000000.00000000162.64.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network10100010.01000000.00000000.00000000162.64.0.0
Broadcast10100010.01111111.11111111.11111111162.127.255.255
Split into smaller subnets/18
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

162.64.0.0/10 makes 256 subnets of /18.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1162.64.0.0/18162.64.0.1 to 162.64.63.254162.64.63.25516,382
2162.64.64.0/18162.64.64.1 to 162.64.127.254162.64.127.25516,382
3162.64.128.0/18162.64.128.1 to 162.64.191.254162.64.191.25516,382
4162.64.192.0/18162.64.192.1 to 162.64.255.254162.64.255.25516,382
5162.65.0.0/18162.65.0.1 to 162.65.63.254162.65.63.25516,382
6162.65.64.0/18162.65.64.1 to 162.65.127.254162.65.127.25516,382
7162.65.128.0/18162.65.128.1 to 162.65.191.254162.65.191.25516,382
8162.65.192.0/18162.65.192.1 to 162.65.255.254162.65.255.25516,382
9162.66.0.0/18162.66.0.1 to 162.66.63.254162.66.63.25516,382
10162.66.64.0/18162.66.64.1 to 162.66.127.254162.66.127.25516,382
11162.66.128.0/18162.66.128.1 to 162.66.191.254162.66.191.25516,382
12162.66.192.0/18162.66.192.1 to 162.66.255.254162.66.255.25516,382
13162.67.0.0/18162.67.0.1 to 162.67.63.254162.67.63.25516,382
14162.67.64.0/18162.67.64.1 to 162.67.127.254162.67.127.25516,382
15162.67.128.0/18162.67.128.1 to 162.67.191.254162.67.191.25516,382
16162.67.192.0/18162.67.192.1 to 162.67.255.254162.67.255.25516,382
17162.68.0.0/18162.68.0.1 to 162.68.63.254162.68.63.25516,382
18162.68.64.0/18162.68.64.1 to 162.68.127.254162.68.127.25516,382
19162.68.128.0/18162.68.128.1 to 162.68.191.254162.68.191.25516,382
20162.68.192.0/18162.68.192.1 to 162.68.255.254162.68.255.25516,382
21162.69.0.0/18162.69.0.1 to 162.69.63.254162.69.63.25516,382
22162.69.64.0/18162.69.64.1 to 162.69.127.254162.69.127.25516,382
23162.69.128.0/18162.69.128.1 to 162.69.191.254162.69.191.25516,382
24162.69.192.0/18162.69.192.1 to 162.69.255.254162.69.255.25516,382
25162.70.0.0/18162.70.0.1 to 162.70.63.254162.70.63.25516,382
26162.70.64.0/18162.70.64.1 to 162.70.127.254162.70.127.25516,382
27162.70.128.0/18162.70.128.1 to 162.70.191.254162.70.191.25516,382
28162.70.192.0/18162.70.192.1 to 162.70.255.254162.70.255.25516,382
29162.71.0.0/18162.71.0.1 to 162.71.63.254162.71.63.25516,382
30162.71.64.0/18162.71.64.1 to 162.71.127.254162.71.127.25516,382
31162.71.128.0/18162.71.128.1 to 162.71.191.254162.71.191.25516,382
32162.71.192.0/18162.71.192.1 to 162.71.255.254162.71.255.25516,382
33162.72.0.0/18162.72.0.1 to 162.72.63.254162.72.63.25516,382
34162.72.64.0/18162.72.64.1 to 162.72.127.254162.72.127.25516,382
35162.72.128.0/18162.72.128.1 to 162.72.191.254162.72.191.25516,382
36162.72.192.0/18162.72.192.1 to 162.72.255.254162.72.255.25516,382
37162.73.0.0/18162.73.0.1 to 162.73.63.254162.73.63.25516,382
38162.73.64.0/18162.73.64.1 to 162.73.127.254162.73.127.25516,382
39162.73.128.0/18162.73.128.1 to 162.73.191.254162.73.191.25516,382
40162.73.192.0/18162.73.192.1 to 162.73.255.254162.73.255.25516,382
41162.74.0.0/18162.74.0.1 to 162.74.63.254162.74.63.25516,382
42162.74.64.0/18162.74.64.1 to 162.74.127.254162.74.127.25516,382
43162.74.128.0/18162.74.128.1 to 162.74.191.254162.74.191.25516,382
44162.74.192.0/18162.74.192.1 to 162.74.255.254162.74.255.25516,382
45162.75.0.0/18162.75.0.1 to 162.75.63.254162.75.63.25516,382
46162.75.64.0/18162.75.64.1 to 162.75.127.254162.75.127.25516,382
47162.75.128.0/18162.75.128.1 to 162.75.191.254162.75.191.25516,382
48162.75.192.0/18162.75.192.1 to 162.75.255.254162.75.255.25516,382
49162.76.0.0/18162.76.0.1 to 162.76.63.254162.76.63.25516,382
50162.76.64.0/18162.76.64.1 to 162.76.127.254162.76.127.25516,382
51162.76.128.0/18162.76.128.1 to 162.76.191.254162.76.191.25516,382
52162.76.192.0/18162.76.192.1 to 162.76.255.254162.76.255.25516,382
53162.77.0.0/18162.77.0.1 to 162.77.63.254162.77.63.25516,382
54162.77.64.0/18162.77.64.1 to 162.77.127.254162.77.127.25516,382
55162.77.128.0/18162.77.128.1 to 162.77.191.254162.77.191.25516,382
56162.77.192.0/18162.77.192.1 to 162.77.255.254162.77.255.25516,382
57162.78.0.0/18162.78.0.1 to 162.78.63.254162.78.63.25516,382
58162.78.64.0/18162.78.64.1 to 162.78.127.254162.78.127.25516,382
59162.78.128.0/18162.78.128.1 to 162.78.191.254162.78.191.25516,382
60162.78.192.0/18162.78.192.1 to 162.78.255.254162.78.255.25516,382
61162.79.0.0/18162.79.0.1 to 162.79.63.254162.79.63.25516,382
62162.79.64.0/18162.79.64.1 to 162.79.127.254162.79.127.25516,382
63162.79.128.0/18162.79.128.1 to 162.79.191.254162.79.191.25516,382
64162.79.192.0/18162.79.192.1 to 162.79.255.254162.79.255.25516,382
65162.80.0.0/18162.80.0.1 to 162.80.63.254162.80.63.25516,382
66162.80.64.0/18162.80.64.1 to 162.80.127.254162.80.127.25516,382
67162.80.128.0/18162.80.128.1 to 162.80.191.254162.80.191.25516,382
68162.80.192.0/18162.80.192.1 to 162.80.255.254162.80.255.25516,382
69162.81.0.0/18162.81.0.1 to 162.81.63.254162.81.63.25516,382
70162.81.64.0/18162.81.64.1 to 162.81.127.254162.81.127.25516,382
71162.81.128.0/18162.81.128.1 to 162.81.191.254162.81.191.25516,382
72162.81.192.0/18162.81.192.1 to 162.81.255.254162.81.255.25516,382
73162.82.0.0/18162.82.0.1 to 162.82.63.254162.82.63.25516,382
74162.82.64.0/18162.82.64.1 to 162.82.127.254162.82.127.25516,382
75162.82.128.0/18162.82.128.1 to 162.82.191.254162.82.191.25516,382
76162.82.192.0/18162.82.192.1 to 162.82.255.254162.82.255.25516,382
77162.83.0.0/18162.83.0.1 to 162.83.63.254162.83.63.25516,382
78162.83.64.0/18162.83.64.1 to 162.83.127.254162.83.127.25516,382
79162.83.128.0/18162.83.128.1 to 162.83.191.254162.83.191.25516,382
80162.83.192.0/18162.83.192.1 to 162.83.255.254162.83.255.25516,382
81162.84.0.0/18162.84.0.1 to 162.84.63.254162.84.63.25516,382
82162.84.64.0/18162.84.64.1 to 162.84.127.254162.84.127.25516,382
83162.84.128.0/18162.84.128.1 to 162.84.191.254162.84.191.25516,382
84162.84.192.0/18162.84.192.1 to 162.84.255.254162.84.255.25516,382
85162.85.0.0/18162.85.0.1 to 162.85.63.254162.85.63.25516,382
86162.85.64.0/18162.85.64.1 to 162.85.127.254162.85.127.25516,382
87162.85.128.0/18162.85.128.1 to 162.85.191.254162.85.191.25516,382
88162.85.192.0/18162.85.192.1 to 162.85.255.254162.85.255.25516,382
89162.86.0.0/18162.86.0.1 to 162.86.63.254162.86.63.25516,382
90162.86.64.0/18162.86.64.1 to 162.86.127.254162.86.127.25516,382
91162.86.128.0/18162.86.128.1 to 162.86.191.254162.86.191.25516,382
92162.86.192.0/18162.86.192.1 to 162.86.255.254162.86.255.25516,382
93162.87.0.0/18162.87.0.1 to 162.87.63.254162.87.63.25516,382
94162.87.64.0/18162.87.64.1 to 162.87.127.254162.87.127.25516,382
95162.87.128.0/18162.87.128.1 to 162.87.191.254162.87.191.25516,382
96162.87.192.0/18162.87.192.1 to 162.87.255.254162.87.255.25516,382
97162.88.0.0/18162.88.0.1 to 162.88.63.254162.88.63.25516,382
98162.88.64.0/18162.88.64.1 to 162.88.127.254162.88.127.25516,382
99162.88.128.0/18162.88.128.1 to 162.88.191.254162.88.191.25516,382
100162.88.192.0/18162.88.192.1 to 162.88.255.254162.88.255.25516,382
101162.89.0.0/18162.89.0.1 to 162.89.63.254162.89.63.25516,382
102162.89.64.0/18162.89.64.1 to 162.89.127.254162.89.127.25516,382
103162.89.128.0/18162.89.128.1 to 162.89.191.254162.89.191.25516,382
104162.89.192.0/18162.89.192.1 to 162.89.255.254162.89.255.25516,382
105162.90.0.0/18162.90.0.1 to 162.90.63.254162.90.63.25516,382
106162.90.64.0/18162.90.64.1 to 162.90.127.254162.90.127.25516,382
107162.90.128.0/18162.90.128.1 to 162.90.191.254162.90.191.25516,382
108162.90.192.0/18162.90.192.1 to 162.90.255.254162.90.255.25516,382
109162.91.0.0/18162.91.0.1 to 162.91.63.254162.91.63.25516,382
110162.91.64.0/18162.91.64.1 to 162.91.127.254162.91.127.25516,382
111162.91.128.0/18162.91.128.1 to 162.91.191.254162.91.191.25516,382
112162.91.192.0/18162.91.192.1 to 162.91.255.254162.91.255.25516,382
113162.92.0.0/18162.92.0.1 to 162.92.63.254162.92.63.25516,382
114162.92.64.0/18162.92.64.1 to 162.92.127.254162.92.127.25516,382
115162.92.128.0/18162.92.128.1 to 162.92.191.254162.92.191.25516,382
116162.92.192.0/18162.92.192.1 to 162.92.255.254162.92.255.25516,382
117162.93.0.0/18162.93.0.1 to 162.93.63.254162.93.63.25516,382
118162.93.64.0/18162.93.64.1 to 162.93.127.254162.93.127.25516,382
119162.93.128.0/18162.93.128.1 to 162.93.191.254162.93.191.25516,382
120162.93.192.0/18162.93.192.1 to 162.93.255.254162.93.255.25516,382
121162.94.0.0/18162.94.0.1 to 162.94.63.254162.94.63.25516,382
122162.94.64.0/18162.94.64.1 to 162.94.127.254162.94.127.25516,382
123162.94.128.0/18162.94.128.1 to 162.94.191.254162.94.191.25516,382
124162.94.192.0/18162.94.192.1 to 162.94.255.254162.94.255.25516,382
125162.95.0.0/18162.95.0.1 to 162.95.63.254162.95.63.25516,382
126162.95.64.0/18162.95.64.1 to 162.95.127.254162.95.127.25516,382
127162.95.128.0/18162.95.128.1 to 162.95.191.254162.95.191.25516,382
128162.95.192.0/18162.95.192.1 to 162.95.255.254162.95.255.25516,382
129162.96.0.0/18162.96.0.1 to 162.96.63.254162.96.63.25516,382
130162.96.64.0/18162.96.64.1 to 162.96.127.254162.96.127.25516,382
131162.96.128.0/18162.96.128.1 to 162.96.191.254162.96.191.25516,382
132162.96.192.0/18162.96.192.1 to 162.96.255.254162.96.255.25516,382
133162.97.0.0/18162.97.0.1 to 162.97.63.254162.97.63.25516,382
134162.97.64.0/18162.97.64.1 to 162.97.127.254162.97.127.25516,382
135162.97.128.0/18162.97.128.1 to 162.97.191.254162.97.191.25516,382
136162.97.192.0/18162.97.192.1 to 162.97.255.254162.97.255.25516,382
137162.98.0.0/18162.98.0.1 to 162.98.63.254162.98.63.25516,382
138162.98.64.0/18162.98.64.1 to 162.98.127.254162.98.127.25516,382
139162.98.128.0/18162.98.128.1 to 162.98.191.254162.98.191.25516,382
140162.98.192.0/18162.98.192.1 to 162.98.255.254162.98.255.25516,382
141162.99.0.0/18162.99.0.1 to 162.99.63.254162.99.63.25516,382
142162.99.64.0/18162.99.64.1 to 162.99.127.254162.99.127.25516,382
143162.99.128.0/18162.99.128.1 to 162.99.191.254162.99.191.25516,382
144162.99.192.0/18162.99.192.1 to 162.99.255.254162.99.255.25516,382
145162.100.0.0/18162.100.0.1 to 162.100.63.254162.100.63.25516,382
146162.100.64.0/18162.100.64.1 to 162.100.127.254162.100.127.25516,382
147162.100.128.0/18162.100.128.1 to 162.100.191.254162.100.191.25516,382
148162.100.192.0/18162.100.192.1 to 162.100.255.254162.100.255.25516,382
149162.101.0.0/18162.101.0.1 to 162.101.63.254162.101.63.25516,382
150162.101.64.0/18162.101.64.1 to 162.101.127.254162.101.127.25516,382
151162.101.128.0/18162.101.128.1 to 162.101.191.254162.101.191.25516,382
152162.101.192.0/18162.101.192.1 to 162.101.255.254162.101.255.25516,382
153162.102.0.0/18162.102.0.1 to 162.102.63.254162.102.63.25516,382
154162.102.64.0/18162.102.64.1 to 162.102.127.254162.102.127.25516,382
155162.102.128.0/18162.102.128.1 to 162.102.191.254162.102.191.25516,382
156162.102.192.0/18162.102.192.1 to 162.102.255.254162.102.255.25516,382
157162.103.0.0/18162.103.0.1 to 162.103.63.254162.103.63.25516,382
158162.103.64.0/18162.103.64.1 to 162.103.127.254162.103.127.25516,382
159162.103.128.0/18162.103.128.1 to 162.103.191.254162.103.191.25516,382
160162.103.192.0/18162.103.192.1 to 162.103.255.254162.103.255.25516,382
161162.104.0.0/18162.104.0.1 to 162.104.63.254162.104.63.25516,382
162162.104.64.0/18162.104.64.1 to 162.104.127.254162.104.127.25516,382
163162.104.128.0/18162.104.128.1 to 162.104.191.254162.104.191.25516,382
164162.104.192.0/18162.104.192.1 to 162.104.255.254162.104.255.25516,382
165162.105.0.0/18162.105.0.1 to 162.105.63.254162.105.63.25516,382
166162.105.64.0/18162.105.64.1 to 162.105.127.254162.105.127.25516,382
167162.105.128.0/18162.105.128.1 to 162.105.191.254162.105.191.25516,382
168162.105.192.0/18162.105.192.1 to 162.105.255.254162.105.255.25516,382
169162.106.0.0/18162.106.0.1 to 162.106.63.254162.106.63.25516,382
170162.106.64.0/18162.106.64.1 to 162.106.127.254162.106.127.25516,382
171162.106.128.0/18162.106.128.1 to 162.106.191.254162.106.191.25516,382
172162.106.192.0/18162.106.192.1 to 162.106.255.254162.106.255.25516,382
173162.107.0.0/18162.107.0.1 to 162.107.63.254162.107.63.25516,382
174162.107.64.0/18162.107.64.1 to 162.107.127.254162.107.127.25516,382
175162.107.128.0/18162.107.128.1 to 162.107.191.254162.107.191.25516,382
176162.107.192.0/18162.107.192.1 to 162.107.255.254162.107.255.25516,382
177162.108.0.0/18162.108.0.1 to 162.108.63.254162.108.63.25516,382
178162.108.64.0/18162.108.64.1 to 162.108.127.254162.108.127.25516,382
179162.108.128.0/18162.108.128.1 to 162.108.191.254162.108.191.25516,382
180162.108.192.0/18162.108.192.1 to 162.108.255.254162.108.255.25516,382
181162.109.0.0/18162.109.0.1 to 162.109.63.254162.109.63.25516,382
182162.109.64.0/18162.109.64.1 to 162.109.127.254162.109.127.25516,382
183162.109.128.0/18162.109.128.1 to 162.109.191.254162.109.191.25516,382
184162.109.192.0/18162.109.192.1 to 162.109.255.254162.109.255.25516,382
185162.110.0.0/18162.110.0.1 to 162.110.63.254162.110.63.25516,382
186162.110.64.0/18162.110.64.1 to 162.110.127.254162.110.127.25516,382
187162.110.128.0/18162.110.128.1 to 162.110.191.254162.110.191.25516,382
188162.110.192.0/18162.110.192.1 to 162.110.255.254162.110.255.25516,382
189162.111.0.0/18162.111.0.1 to 162.111.63.254162.111.63.25516,382
190162.111.64.0/18162.111.64.1 to 162.111.127.254162.111.127.25516,382
191162.111.128.0/18162.111.128.1 to 162.111.191.254162.111.191.25516,382
192162.111.192.0/18162.111.192.1 to 162.111.255.254162.111.255.25516,382
193162.112.0.0/18162.112.0.1 to 162.112.63.254162.112.63.25516,382
194162.112.64.0/18162.112.64.1 to 162.112.127.254162.112.127.25516,382
195162.112.128.0/18162.112.128.1 to 162.112.191.254162.112.191.25516,382
196162.112.192.0/18162.112.192.1 to 162.112.255.254162.112.255.25516,382
197162.113.0.0/18162.113.0.1 to 162.113.63.254162.113.63.25516,382
198162.113.64.0/18162.113.64.1 to 162.113.127.254162.113.127.25516,382
199162.113.128.0/18162.113.128.1 to 162.113.191.254162.113.191.25516,382
200162.113.192.0/18162.113.192.1 to 162.113.255.254162.113.255.25516,382
201162.114.0.0/18162.114.0.1 to 162.114.63.254162.114.63.25516,382
202162.114.64.0/18162.114.64.1 to 162.114.127.254162.114.127.25516,382
203162.114.128.0/18162.114.128.1 to 162.114.191.254162.114.191.25516,382
204162.114.192.0/18162.114.192.1 to 162.114.255.254162.114.255.25516,382
205162.115.0.0/18162.115.0.1 to 162.115.63.254162.115.63.25516,382
206162.115.64.0/18162.115.64.1 to 162.115.127.254162.115.127.25516,382
207162.115.128.0/18162.115.128.1 to 162.115.191.254162.115.191.25516,382
208162.115.192.0/18162.115.192.1 to 162.115.255.254162.115.255.25516,382
209162.116.0.0/18162.116.0.1 to 162.116.63.254162.116.63.25516,382
210162.116.64.0/18162.116.64.1 to 162.116.127.254162.116.127.25516,382
211162.116.128.0/18162.116.128.1 to 162.116.191.254162.116.191.25516,382
212162.116.192.0/18162.116.192.1 to 162.116.255.254162.116.255.25516,382
213162.117.0.0/18162.117.0.1 to 162.117.63.254162.117.63.25516,382
214162.117.64.0/18162.117.64.1 to 162.117.127.254162.117.127.25516,382
215162.117.128.0/18162.117.128.1 to 162.117.191.254162.117.191.25516,382
216162.117.192.0/18162.117.192.1 to 162.117.255.254162.117.255.25516,382
217162.118.0.0/18162.118.0.1 to 162.118.63.254162.118.63.25516,382
218162.118.64.0/18162.118.64.1 to 162.118.127.254162.118.127.25516,382
219162.118.128.0/18162.118.128.1 to 162.118.191.254162.118.191.25516,382
220162.118.192.0/18162.118.192.1 to 162.118.255.254162.118.255.25516,382
221162.119.0.0/18162.119.0.1 to 162.119.63.254162.119.63.25516,382
222162.119.64.0/18162.119.64.1 to 162.119.127.254162.119.127.25516,382
223162.119.128.0/18162.119.128.1 to 162.119.191.254162.119.191.25516,382
224162.119.192.0/18162.119.192.1 to 162.119.255.254162.119.255.25516,382
225162.120.0.0/18162.120.0.1 to 162.120.63.254162.120.63.25516,382
226162.120.64.0/18162.120.64.1 to 162.120.127.254162.120.127.25516,382
227162.120.128.0/18162.120.128.1 to 162.120.191.254162.120.191.25516,382
228162.120.192.0/18162.120.192.1 to 162.120.255.254162.120.255.25516,382
229162.121.0.0/18162.121.0.1 to 162.121.63.254162.121.63.25516,382
230162.121.64.0/18162.121.64.1 to 162.121.127.254162.121.127.25516,382
231162.121.128.0/18162.121.128.1 to 162.121.191.254162.121.191.25516,382
232162.121.192.0/18162.121.192.1 to 162.121.255.254162.121.255.25516,382
233162.122.0.0/18162.122.0.1 to 162.122.63.254162.122.63.25516,382
234162.122.64.0/18162.122.64.1 to 162.122.127.254162.122.127.25516,382
235162.122.128.0/18162.122.128.1 to 162.122.191.254162.122.191.25516,382
236162.122.192.0/18162.122.192.1 to 162.122.255.254162.122.255.25516,382
237162.123.0.0/18162.123.0.1 to 162.123.63.254162.123.63.25516,382
238162.123.64.0/18162.123.64.1 to 162.123.127.254162.123.127.25516,382
239162.123.128.0/18162.123.128.1 to 162.123.191.254162.123.191.25516,382
240162.123.192.0/18162.123.192.1 to 162.123.255.254162.123.255.25516,382
241162.124.0.0/18162.124.0.1 to 162.124.63.254162.124.63.25516,382
242162.124.64.0/18162.124.64.1 to 162.124.127.254162.124.127.25516,382
243162.124.128.0/18162.124.128.1 to 162.124.191.254162.124.191.25516,382
244162.124.192.0/18162.124.192.1 to 162.124.255.254162.124.255.25516,382
245162.125.0.0/18162.125.0.1 to 162.125.63.254162.125.63.25516,382
246162.125.64.0/18162.125.64.1 to 162.125.127.254162.125.127.25516,382
247162.125.128.0/18162.125.128.1 to 162.125.191.254162.125.191.25516,382
248162.125.192.0/18162.125.192.1 to 162.125.255.254162.125.255.25516,382
249162.126.0.0/18162.126.0.1 to 162.126.63.254162.126.63.25516,382
250162.126.64.0/18162.126.64.1 to 162.126.127.254162.126.127.25516,382
251162.126.128.0/18162.126.128.1 to 162.126.191.254162.126.191.25516,382
252162.126.192.0/18162.126.192.1 to 162.126.255.254162.126.255.25516,382
253162.127.0.0/18162.127.0.1 to 162.127.63.254162.127.63.25516,382
254162.127.64.0/18162.127.64.1 to 162.127.127.254162.127.127.25516,382
255162.127.128.0/18162.127.128.1 to 162.127.191.254162.127.191.25516,382
256162.127.192.0/18162.127.192.1 to 162.127.255.254162.127.255.25516,382

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.