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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.

Network248.64.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
248.64.0.0
Broadcast address
248.95.255.255
First usable
248.64.0.1
Last usable
248.95.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F8400000 · Integer 4164943872 to 4167041023
Reverse DNS zones
64.248.in-addr.arpa
65.248.in-addr.arpa
66.248.in-addr.arpa
67.248.in-addr.arpa
68.248.in-addr.arpa
69.248.in-addr.arpa
70.248.in-addr.arpa
71.248.in-addr.arpa
72.248.in-addr.arpa
73.248.in-addr.arpa
74.248.in-addr.arpa
75.248.in-addr.arpa
76.248.in-addr.arpa
77.248.in-addr.arpa
78.248.in-addr.arpa
79.248.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11111000.01000000.00000000.00000000248.64.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network11111000.01000000.00000000.00000000248.64.0.0
Broadcast11111000.01011111.11111111.11111111248.95.255.255
Split into smaller subnets/19
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

248.64.0.0/11 makes 256 subnets of /19.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1248.64.0.0/19248.64.0.1 to 248.64.31.254248.64.31.2558,190
2248.64.32.0/19248.64.32.1 to 248.64.63.254248.64.63.2558,190
3248.64.64.0/19248.64.64.1 to 248.64.95.254248.64.95.2558,190
4248.64.96.0/19248.64.96.1 to 248.64.127.254248.64.127.2558,190
5248.64.128.0/19248.64.128.1 to 248.64.159.254248.64.159.2558,190
6248.64.160.0/19248.64.160.1 to 248.64.191.254248.64.191.2558,190
7248.64.192.0/19248.64.192.1 to 248.64.223.254248.64.223.2558,190
8248.64.224.0/19248.64.224.1 to 248.64.255.254248.64.255.2558,190
9248.65.0.0/19248.65.0.1 to 248.65.31.254248.65.31.2558,190
10248.65.32.0/19248.65.32.1 to 248.65.63.254248.65.63.2558,190
11248.65.64.0/19248.65.64.1 to 248.65.95.254248.65.95.2558,190
12248.65.96.0/19248.65.96.1 to 248.65.127.254248.65.127.2558,190
13248.65.128.0/19248.65.128.1 to 248.65.159.254248.65.159.2558,190
14248.65.160.0/19248.65.160.1 to 248.65.191.254248.65.191.2558,190
15248.65.192.0/19248.65.192.1 to 248.65.223.254248.65.223.2558,190
16248.65.224.0/19248.65.224.1 to 248.65.255.254248.65.255.2558,190
17248.66.0.0/19248.66.0.1 to 248.66.31.254248.66.31.2558,190
18248.66.32.0/19248.66.32.1 to 248.66.63.254248.66.63.2558,190
19248.66.64.0/19248.66.64.1 to 248.66.95.254248.66.95.2558,190
20248.66.96.0/19248.66.96.1 to 248.66.127.254248.66.127.2558,190
21248.66.128.0/19248.66.128.1 to 248.66.159.254248.66.159.2558,190
22248.66.160.0/19248.66.160.1 to 248.66.191.254248.66.191.2558,190
23248.66.192.0/19248.66.192.1 to 248.66.223.254248.66.223.2558,190
24248.66.224.0/19248.66.224.1 to 248.66.255.254248.66.255.2558,190
25248.67.0.0/19248.67.0.1 to 248.67.31.254248.67.31.2558,190
26248.67.32.0/19248.67.32.1 to 248.67.63.254248.67.63.2558,190
27248.67.64.0/19248.67.64.1 to 248.67.95.254248.67.95.2558,190
28248.67.96.0/19248.67.96.1 to 248.67.127.254248.67.127.2558,190
29248.67.128.0/19248.67.128.1 to 248.67.159.254248.67.159.2558,190
30248.67.160.0/19248.67.160.1 to 248.67.191.254248.67.191.2558,190
31248.67.192.0/19248.67.192.1 to 248.67.223.254248.67.223.2558,190
32248.67.224.0/19248.67.224.1 to 248.67.255.254248.67.255.2558,190
33248.68.0.0/19248.68.0.1 to 248.68.31.254248.68.31.2558,190
34248.68.32.0/19248.68.32.1 to 248.68.63.254248.68.63.2558,190
35248.68.64.0/19248.68.64.1 to 248.68.95.254248.68.95.2558,190
36248.68.96.0/19248.68.96.1 to 248.68.127.254248.68.127.2558,190
37248.68.128.0/19248.68.128.1 to 248.68.159.254248.68.159.2558,190
38248.68.160.0/19248.68.160.1 to 248.68.191.254248.68.191.2558,190
39248.68.192.0/19248.68.192.1 to 248.68.223.254248.68.223.2558,190
40248.68.224.0/19248.68.224.1 to 248.68.255.254248.68.255.2558,190
41248.69.0.0/19248.69.0.1 to 248.69.31.254248.69.31.2558,190
42248.69.32.0/19248.69.32.1 to 248.69.63.254248.69.63.2558,190
43248.69.64.0/19248.69.64.1 to 248.69.95.254248.69.95.2558,190
44248.69.96.0/19248.69.96.1 to 248.69.127.254248.69.127.2558,190
45248.69.128.0/19248.69.128.1 to 248.69.159.254248.69.159.2558,190
46248.69.160.0/19248.69.160.1 to 248.69.191.254248.69.191.2558,190
47248.69.192.0/19248.69.192.1 to 248.69.223.254248.69.223.2558,190
48248.69.224.0/19248.69.224.1 to 248.69.255.254248.69.255.2558,190
49248.70.0.0/19248.70.0.1 to 248.70.31.254248.70.31.2558,190
50248.70.32.0/19248.70.32.1 to 248.70.63.254248.70.63.2558,190
51248.70.64.0/19248.70.64.1 to 248.70.95.254248.70.95.2558,190
52248.70.96.0/19248.70.96.1 to 248.70.127.254248.70.127.2558,190
53248.70.128.0/19248.70.128.1 to 248.70.159.254248.70.159.2558,190
54248.70.160.0/19248.70.160.1 to 248.70.191.254248.70.191.2558,190
55248.70.192.0/19248.70.192.1 to 248.70.223.254248.70.223.2558,190
56248.70.224.0/19248.70.224.1 to 248.70.255.254248.70.255.2558,190
57248.71.0.0/19248.71.0.1 to 248.71.31.254248.71.31.2558,190
58248.71.32.0/19248.71.32.1 to 248.71.63.254248.71.63.2558,190
59248.71.64.0/19248.71.64.1 to 248.71.95.254248.71.95.2558,190
60248.71.96.0/19248.71.96.1 to 248.71.127.254248.71.127.2558,190
61248.71.128.0/19248.71.128.1 to 248.71.159.254248.71.159.2558,190
62248.71.160.0/19248.71.160.1 to 248.71.191.254248.71.191.2558,190
63248.71.192.0/19248.71.192.1 to 248.71.223.254248.71.223.2558,190
64248.71.224.0/19248.71.224.1 to 248.71.255.254248.71.255.2558,190
65248.72.0.0/19248.72.0.1 to 248.72.31.254248.72.31.2558,190
66248.72.32.0/19248.72.32.1 to 248.72.63.254248.72.63.2558,190
67248.72.64.0/19248.72.64.1 to 248.72.95.254248.72.95.2558,190
68248.72.96.0/19248.72.96.1 to 248.72.127.254248.72.127.2558,190
69248.72.128.0/19248.72.128.1 to 248.72.159.254248.72.159.2558,190
70248.72.160.0/19248.72.160.1 to 248.72.191.254248.72.191.2558,190
71248.72.192.0/19248.72.192.1 to 248.72.223.254248.72.223.2558,190
72248.72.224.0/19248.72.224.1 to 248.72.255.254248.72.255.2558,190
73248.73.0.0/19248.73.0.1 to 248.73.31.254248.73.31.2558,190
74248.73.32.0/19248.73.32.1 to 248.73.63.254248.73.63.2558,190
75248.73.64.0/19248.73.64.1 to 248.73.95.254248.73.95.2558,190
76248.73.96.0/19248.73.96.1 to 248.73.127.254248.73.127.2558,190
77248.73.128.0/19248.73.128.1 to 248.73.159.254248.73.159.2558,190
78248.73.160.0/19248.73.160.1 to 248.73.191.254248.73.191.2558,190
79248.73.192.0/19248.73.192.1 to 248.73.223.254248.73.223.2558,190
80248.73.224.0/19248.73.224.1 to 248.73.255.254248.73.255.2558,190
81248.74.0.0/19248.74.0.1 to 248.74.31.254248.74.31.2558,190
82248.74.32.0/19248.74.32.1 to 248.74.63.254248.74.63.2558,190
83248.74.64.0/19248.74.64.1 to 248.74.95.254248.74.95.2558,190
84248.74.96.0/19248.74.96.1 to 248.74.127.254248.74.127.2558,190
85248.74.128.0/19248.74.128.1 to 248.74.159.254248.74.159.2558,190
86248.74.160.0/19248.74.160.1 to 248.74.191.254248.74.191.2558,190
87248.74.192.0/19248.74.192.1 to 248.74.223.254248.74.223.2558,190
88248.74.224.0/19248.74.224.1 to 248.74.255.254248.74.255.2558,190
89248.75.0.0/19248.75.0.1 to 248.75.31.254248.75.31.2558,190
90248.75.32.0/19248.75.32.1 to 248.75.63.254248.75.63.2558,190
91248.75.64.0/19248.75.64.1 to 248.75.95.254248.75.95.2558,190
92248.75.96.0/19248.75.96.1 to 248.75.127.254248.75.127.2558,190
93248.75.128.0/19248.75.128.1 to 248.75.159.254248.75.159.2558,190
94248.75.160.0/19248.75.160.1 to 248.75.191.254248.75.191.2558,190
95248.75.192.0/19248.75.192.1 to 248.75.223.254248.75.223.2558,190
96248.75.224.0/19248.75.224.1 to 248.75.255.254248.75.255.2558,190
97248.76.0.0/19248.76.0.1 to 248.76.31.254248.76.31.2558,190
98248.76.32.0/19248.76.32.1 to 248.76.63.254248.76.63.2558,190
99248.76.64.0/19248.76.64.1 to 248.76.95.254248.76.95.2558,190
100248.76.96.0/19248.76.96.1 to 248.76.127.254248.76.127.2558,190
101248.76.128.0/19248.76.128.1 to 248.76.159.254248.76.159.2558,190
102248.76.160.0/19248.76.160.1 to 248.76.191.254248.76.191.2558,190
103248.76.192.0/19248.76.192.1 to 248.76.223.254248.76.223.2558,190
104248.76.224.0/19248.76.224.1 to 248.76.255.254248.76.255.2558,190
105248.77.0.0/19248.77.0.1 to 248.77.31.254248.77.31.2558,190
106248.77.32.0/19248.77.32.1 to 248.77.63.254248.77.63.2558,190
107248.77.64.0/19248.77.64.1 to 248.77.95.254248.77.95.2558,190
108248.77.96.0/19248.77.96.1 to 248.77.127.254248.77.127.2558,190
109248.77.128.0/19248.77.128.1 to 248.77.159.254248.77.159.2558,190
110248.77.160.0/19248.77.160.1 to 248.77.191.254248.77.191.2558,190
111248.77.192.0/19248.77.192.1 to 248.77.223.254248.77.223.2558,190
112248.77.224.0/19248.77.224.1 to 248.77.255.254248.77.255.2558,190
113248.78.0.0/19248.78.0.1 to 248.78.31.254248.78.31.2558,190
114248.78.32.0/19248.78.32.1 to 248.78.63.254248.78.63.2558,190
115248.78.64.0/19248.78.64.1 to 248.78.95.254248.78.95.2558,190
116248.78.96.0/19248.78.96.1 to 248.78.127.254248.78.127.2558,190
117248.78.128.0/19248.78.128.1 to 248.78.159.254248.78.159.2558,190
118248.78.160.0/19248.78.160.1 to 248.78.191.254248.78.191.2558,190
119248.78.192.0/19248.78.192.1 to 248.78.223.254248.78.223.2558,190
120248.78.224.0/19248.78.224.1 to 248.78.255.254248.78.255.2558,190
121248.79.0.0/19248.79.0.1 to 248.79.31.254248.79.31.2558,190
122248.79.32.0/19248.79.32.1 to 248.79.63.254248.79.63.2558,190
123248.79.64.0/19248.79.64.1 to 248.79.95.254248.79.95.2558,190
124248.79.96.0/19248.79.96.1 to 248.79.127.254248.79.127.2558,190
125248.79.128.0/19248.79.128.1 to 248.79.159.254248.79.159.2558,190
126248.79.160.0/19248.79.160.1 to 248.79.191.254248.79.191.2558,190
127248.79.192.0/19248.79.192.1 to 248.79.223.254248.79.223.2558,190
128248.79.224.0/19248.79.224.1 to 248.79.255.254248.79.255.2558,190
129248.80.0.0/19248.80.0.1 to 248.80.31.254248.80.31.2558,190
130248.80.32.0/19248.80.32.1 to 248.80.63.254248.80.63.2558,190
131248.80.64.0/19248.80.64.1 to 248.80.95.254248.80.95.2558,190
132248.80.96.0/19248.80.96.1 to 248.80.127.254248.80.127.2558,190
133248.80.128.0/19248.80.128.1 to 248.80.159.254248.80.159.2558,190
134248.80.160.0/19248.80.160.1 to 248.80.191.254248.80.191.2558,190
135248.80.192.0/19248.80.192.1 to 248.80.223.254248.80.223.2558,190
136248.80.224.0/19248.80.224.1 to 248.80.255.254248.80.255.2558,190
137248.81.0.0/19248.81.0.1 to 248.81.31.254248.81.31.2558,190
138248.81.32.0/19248.81.32.1 to 248.81.63.254248.81.63.2558,190
139248.81.64.0/19248.81.64.1 to 248.81.95.254248.81.95.2558,190
140248.81.96.0/19248.81.96.1 to 248.81.127.254248.81.127.2558,190
141248.81.128.0/19248.81.128.1 to 248.81.159.254248.81.159.2558,190
142248.81.160.0/19248.81.160.1 to 248.81.191.254248.81.191.2558,190
143248.81.192.0/19248.81.192.1 to 248.81.223.254248.81.223.2558,190
144248.81.224.0/19248.81.224.1 to 248.81.255.254248.81.255.2558,190
145248.82.0.0/19248.82.0.1 to 248.82.31.254248.82.31.2558,190
146248.82.32.0/19248.82.32.1 to 248.82.63.254248.82.63.2558,190
147248.82.64.0/19248.82.64.1 to 248.82.95.254248.82.95.2558,190
148248.82.96.0/19248.82.96.1 to 248.82.127.254248.82.127.2558,190
149248.82.128.0/19248.82.128.1 to 248.82.159.254248.82.159.2558,190
150248.82.160.0/19248.82.160.1 to 248.82.191.254248.82.191.2558,190
151248.82.192.0/19248.82.192.1 to 248.82.223.254248.82.223.2558,190
152248.82.224.0/19248.82.224.1 to 248.82.255.254248.82.255.2558,190
153248.83.0.0/19248.83.0.1 to 248.83.31.254248.83.31.2558,190
154248.83.32.0/19248.83.32.1 to 248.83.63.254248.83.63.2558,190
155248.83.64.0/19248.83.64.1 to 248.83.95.254248.83.95.2558,190
156248.83.96.0/19248.83.96.1 to 248.83.127.254248.83.127.2558,190
157248.83.128.0/19248.83.128.1 to 248.83.159.254248.83.159.2558,190
158248.83.160.0/19248.83.160.1 to 248.83.191.254248.83.191.2558,190
159248.83.192.0/19248.83.192.1 to 248.83.223.254248.83.223.2558,190
160248.83.224.0/19248.83.224.1 to 248.83.255.254248.83.255.2558,190
161248.84.0.0/19248.84.0.1 to 248.84.31.254248.84.31.2558,190
162248.84.32.0/19248.84.32.1 to 248.84.63.254248.84.63.2558,190
163248.84.64.0/19248.84.64.1 to 248.84.95.254248.84.95.2558,190
164248.84.96.0/19248.84.96.1 to 248.84.127.254248.84.127.2558,190
165248.84.128.0/19248.84.128.1 to 248.84.159.254248.84.159.2558,190
166248.84.160.0/19248.84.160.1 to 248.84.191.254248.84.191.2558,190
167248.84.192.0/19248.84.192.1 to 248.84.223.254248.84.223.2558,190
168248.84.224.0/19248.84.224.1 to 248.84.255.254248.84.255.2558,190
169248.85.0.0/19248.85.0.1 to 248.85.31.254248.85.31.2558,190
170248.85.32.0/19248.85.32.1 to 248.85.63.254248.85.63.2558,190
171248.85.64.0/19248.85.64.1 to 248.85.95.254248.85.95.2558,190
172248.85.96.0/19248.85.96.1 to 248.85.127.254248.85.127.2558,190
173248.85.128.0/19248.85.128.1 to 248.85.159.254248.85.159.2558,190
174248.85.160.0/19248.85.160.1 to 248.85.191.254248.85.191.2558,190
175248.85.192.0/19248.85.192.1 to 248.85.223.254248.85.223.2558,190
176248.85.224.0/19248.85.224.1 to 248.85.255.254248.85.255.2558,190
177248.86.0.0/19248.86.0.1 to 248.86.31.254248.86.31.2558,190
178248.86.32.0/19248.86.32.1 to 248.86.63.254248.86.63.2558,190
179248.86.64.0/19248.86.64.1 to 248.86.95.254248.86.95.2558,190
180248.86.96.0/19248.86.96.1 to 248.86.127.254248.86.127.2558,190
181248.86.128.0/19248.86.128.1 to 248.86.159.254248.86.159.2558,190
182248.86.160.0/19248.86.160.1 to 248.86.191.254248.86.191.2558,190
183248.86.192.0/19248.86.192.1 to 248.86.223.254248.86.223.2558,190
184248.86.224.0/19248.86.224.1 to 248.86.255.254248.86.255.2558,190
185248.87.0.0/19248.87.0.1 to 248.87.31.254248.87.31.2558,190
186248.87.32.0/19248.87.32.1 to 248.87.63.254248.87.63.2558,190
187248.87.64.0/19248.87.64.1 to 248.87.95.254248.87.95.2558,190
188248.87.96.0/19248.87.96.1 to 248.87.127.254248.87.127.2558,190
189248.87.128.0/19248.87.128.1 to 248.87.159.254248.87.159.2558,190
190248.87.160.0/19248.87.160.1 to 248.87.191.254248.87.191.2558,190
191248.87.192.0/19248.87.192.1 to 248.87.223.254248.87.223.2558,190
192248.87.224.0/19248.87.224.1 to 248.87.255.254248.87.255.2558,190
193248.88.0.0/19248.88.0.1 to 248.88.31.254248.88.31.2558,190
194248.88.32.0/19248.88.32.1 to 248.88.63.254248.88.63.2558,190
195248.88.64.0/19248.88.64.1 to 248.88.95.254248.88.95.2558,190
196248.88.96.0/19248.88.96.1 to 248.88.127.254248.88.127.2558,190
197248.88.128.0/19248.88.128.1 to 248.88.159.254248.88.159.2558,190
198248.88.160.0/19248.88.160.1 to 248.88.191.254248.88.191.2558,190
199248.88.192.0/19248.88.192.1 to 248.88.223.254248.88.223.2558,190
200248.88.224.0/19248.88.224.1 to 248.88.255.254248.88.255.2558,190
201248.89.0.0/19248.89.0.1 to 248.89.31.254248.89.31.2558,190
202248.89.32.0/19248.89.32.1 to 248.89.63.254248.89.63.2558,190
203248.89.64.0/19248.89.64.1 to 248.89.95.254248.89.95.2558,190
204248.89.96.0/19248.89.96.1 to 248.89.127.254248.89.127.2558,190
205248.89.128.0/19248.89.128.1 to 248.89.159.254248.89.159.2558,190
206248.89.160.0/19248.89.160.1 to 248.89.191.254248.89.191.2558,190
207248.89.192.0/19248.89.192.1 to 248.89.223.254248.89.223.2558,190
208248.89.224.0/19248.89.224.1 to 248.89.255.254248.89.255.2558,190
209248.90.0.0/19248.90.0.1 to 248.90.31.254248.90.31.2558,190
210248.90.32.0/19248.90.32.1 to 248.90.63.254248.90.63.2558,190
211248.90.64.0/19248.90.64.1 to 248.90.95.254248.90.95.2558,190
212248.90.96.0/19248.90.96.1 to 248.90.127.254248.90.127.2558,190
213248.90.128.0/19248.90.128.1 to 248.90.159.254248.90.159.2558,190
214248.90.160.0/19248.90.160.1 to 248.90.191.254248.90.191.2558,190
215248.90.192.0/19248.90.192.1 to 248.90.223.254248.90.223.2558,190
216248.90.224.0/19248.90.224.1 to 248.90.255.254248.90.255.2558,190
217248.91.0.0/19248.91.0.1 to 248.91.31.254248.91.31.2558,190
218248.91.32.0/19248.91.32.1 to 248.91.63.254248.91.63.2558,190
219248.91.64.0/19248.91.64.1 to 248.91.95.254248.91.95.2558,190
220248.91.96.0/19248.91.96.1 to 248.91.127.254248.91.127.2558,190
221248.91.128.0/19248.91.128.1 to 248.91.159.254248.91.159.2558,190
222248.91.160.0/19248.91.160.1 to 248.91.191.254248.91.191.2558,190
223248.91.192.0/19248.91.192.1 to 248.91.223.254248.91.223.2558,190
224248.91.224.0/19248.91.224.1 to 248.91.255.254248.91.255.2558,190
225248.92.0.0/19248.92.0.1 to 248.92.31.254248.92.31.2558,190
226248.92.32.0/19248.92.32.1 to 248.92.63.254248.92.63.2558,190
227248.92.64.0/19248.92.64.1 to 248.92.95.254248.92.95.2558,190
228248.92.96.0/19248.92.96.1 to 248.92.127.254248.92.127.2558,190
229248.92.128.0/19248.92.128.1 to 248.92.159.254248.92.159.2558,190
230248.92.160.0/19248.92.160.1 to 248.92.191.254248.92.191.2558,190
231248.92.192.0/19248.92.192.1 to 248.92.223.254248.92.223.2558,190
232248.92.224.0/19248.92.224.1 to 248.92.255.254248.92.255.2558,190
233248.93.0.0/19248.93.0.1 to 248.93.31.254248.93.31.2558,190
234248.93.32.0/19248.93.32.1 to 248.93.63.254248.93.63.2558,190
235248.93.64.0/19248.93.64.1 to 248.93.95.254248.93.95.2558,190
236248.93.96.0/19248.93.96.1 to 248.93.127.254248.93.127.2558,190
237248.93.128.0/19248.93.128.1 to 248.93.159.254248.93.159.2558,190
238248.93.160.0/19248.93.160.1 to 248.93.191.254248.93.191.2558,190
239248.93.192.0/19248.93.192.1 to 248.93.223.254248.93.223.2558,190
240248.93.224.0/19248.93.224.1 to 248.93.255.254248.93.255.2558,190
241248.94.0.0/19248.94.0.1 to 248.94.31.254248.94.31.2558,190
242248.94.32.0/19248.94.32.1 to 248.94.63.254248.94.63.2558,190
243248.94.64.0/19248.94.64.1 to 248.94.95.254248.94.95.2558,190
244248.94.96.0/19248.94.96.1 to 248.94.127.254248.94.127.2558,190
245248.94.128.0/19248.94.128.1 to 248.94.159.254248.94.159.2558,190
246248.94.160.0/19248.94.160.1 to 248.94.191.254248.94.191.2558,190
247248.94.192.0/19248.94.192.1 to 248.94.223.254248.94.223.2558,190
248248.94.224.0/19248.94.224.1 to 248.94.255.254248.94.255.2558,190
249248.95.0.0/19248.95.0.1 to 248.95.31.254248.95.31.2558,190
250248.95.32.0/19248.95.32.1 to 248.95.63.254248.95.63.2558,190
251248.95.64.0/19248.95.64.1 to 248.95.95.254248.95.95.2558,190
252248.95.96.0/19248.95.96.1 to 248.95.127.254248.95.127.2558,190
253248.95.128.0/19248.95.128.1 to 248.95.159.254248.95.159.2558,190
254248.95.160.0/19248.95.160.1 to 248.95.191.254248.95.191.2558,190
255248.95.192.0/19248.95.192.1 to 248.95.223.254248.95.223.2558,190
256248.95.224.0/19248.95.224.1 to 248.95.255.254248.95.255.2558,190

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.