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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.

Network155.96.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
155.96.0.0
Broadcast address
155.127.255.255
First usable
155.96.0.1
Last usable
155.127.255.254
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
Public public
Old class
B (default /16)
As numbers
Hex 9B600000 · Integer 2606759936 to 2608857087
Reverse DNS zones
96.155.in-addr.arpa
97.155.in-addr.arpa
98.155.in-addr.arpa
99.155.in-addr.arpa
100.155.in-addr.arpa
101.155.in-addr.arpa
102.155.in-addr.arpa
103.155.in-addr.arpa
104.155.in-addr.arpa
105.155.in-addr.arpa
106.155.in-addr.arpa
107.155.in-addr.arpa
108.155.in-addr.arpa
109.155.in-addr.arpa
110.155.in-addr.arpa
111.155.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
Address10011011.01100000.00000000.00000000155.96.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network10011011.01100000.00000000.00000000155.96.0.0
Broadcast10011011.01111111.11111111.11111111155.127.255.255
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)

155.96.0.0/11 makes 256 subnets of /19.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1155.96.0.0/19155.96.0.1 to 155.96.31.254155.96.31.2558,190
2155.96.32.0/19155.96.32.1 to 155.96.63.254155.96.63.2558,190
3155.96.64.0/19155.96.64.1 to 155.96.95.254155.96.95.2558,190
4155.96.96.0/19155.96.96.1 to 155.96.127.254155.96.127.2558,190
5155.96.128.0/19155.96.128.1 to 155.96.159.254155.96.159.2558,190
6155.96.160.0/19155.96.160.1 to 155.96.191.254155.96.191.2558,190
7155.96.192.0/19155.96.192.1 to 155.96.223.254155.96.223.2558,190
8155.96.224.0/19155.96.224.1 to 155.96.255.254155.96.255.2558,190
9155.97.0.0/19155.97.0.1 to 155.97.31.254155.97.31.2558,190
10155.97.32.0/19155.97.32.1 to 155.97.63.254155.97.63.2558,190
11155.97.64.0/19155.97.64.1 to 155.97.95.254155.97.95.2558,190
12155.97.96.0/19155.97.96.1 to 155.97.127.254155.97.127.2558,190
13155.97.128.0/19155.97.128.1 to 155.97.159.254155.97.159.2558,190
14155.97.160.0/19155.97.160.1 to 155.97.191.254155.97.191.2558,190
15155.97.192.0/19155.97.192.1 to 155.97.223.254155.97.223.2558,190
16155.97.224.0/19155.97.224.1 to 155.97.255.254155.97.255.2558,190
17155.98.0.0/19155.98.0.1 to 155.98.31.254155.98.31.2558,190
18155.98.32.0/19155.98.32.1 to 155.98.63.254155.98.63.2558,190
19155.98.64.0/19155.98.64.1 to 155.98.95.254155.98.95.2558,190
20155.98.96.0/19155.98.96.1 to 155.98.127.254155.98.127.2558,190
21155.98.128.0/19155.98.128.1 to 155.98.159.254155.98.159.2558,190
22155.98.160.0/19155.98.160.1 to 155.98.191.254155.98.191.2558,190
23155.98.192.0/19155.98.192.1 to 155.98.223.254155.98.223.2558,190
24155.98.224.0/19155.98.224.1 to 155.98.255.254155.98.255.2558,190
25155.99.0.0/19155.99.0.1 to 155.99.31.254155.99.31.2558,190
26155.99.32.0/19155.99.32.1 to 155.99.63.254155.99.63.2558,190
27155.99.64.0/19155.99.64.1 to 155.99.95.254155.99.95.2558,190
28155.99.96.0/19155.99.96.1 to 155.99.127.254155.99.127.2558,190
29155.99.128.0/19155.99.128.1 to 155.99.159.254155.99.159.2558,190
30155.99.160.0/19155.99.160.1 to 155.99.191.254155.99.191.2558,190
31155.99.192.0/19155.99.192.1 to 155.99.223.254155.99.223.2558,190
32155.99.224.0/19155.99.224.1 to 155.99.255.254155.99.255.2558,190
33155.100.0.0/19155.100.0.1 to 155.100.31.254155.100.31.2558,190
34155.100.32.0/19155.100.32.1 to 155.100.63.254155.100.63.2558,190
35155.100.64.0/19155.100.64.1 to 155.100.95.254155.100.95.2558,190
36155.100.96.0/19155.100.96.1 to 155.100.127.254155.100.127.2558,190
37155.100.128.0/19155.100.128.1 to 155.100.159.254155.100.159.2558,190
38155.100.160.0/19155.100.160.1 to 155.100.191.254155.100.191.2558,190
39155.100.192.0/19155.100.192.1 to 155.100.223.254155.100.223.2558,190
40155.100.224.0/19155.100.224.1 to 155.100.255.254155.100.255.2558,190
41155.101.0.0/19155.101.0.1 to 155.101.31.254155.101.31.2558,190
42155.101.32.0/19155.101.32.1 to 155.101.63.254155.101.63.2558,190
43155.101.64.0/19155.101.64.1 to 155.101.95.254155.101.95.2558,190
44155.101.96.0/19155.101.96.1 to 155.101.127.254155.101.127.2558,190
45155.101.128.0/19155.101.128.1 to 155.101.159.254155.101.159.2558,190
46155.101.160.0/19155.101.160.1 to 155.101.191.254155.101.191.2558,190
47155.101.192.0/19155.101.192.1 to 155.101.223.254155.101.223.2558,190
48155.101.224.0/19155.101.224.1 to 155.101.255.254155.101.255.2558,190
49155.102.0.0/19155.102.0.1 to 155.102.31.254155.102.31.2558,190
50155.102.32.0/19155.102.32.1 to 155.102.63.254155.102.63.2558,190
51155.102.64.0/19155.102.64.1 to 155.102.95.254155.102.95.2558,190
52155.102.96.0/19155.102.96.1 to 155.102.127.254155.102.127.2558,190
53155.102.128.0/19155.102.128.1 to 155.102.159.254155.102.159.2558,190
54155.102.160.0/19155.102.160.1 to 155.102.191.254155.102.191.2558,190
55155.102.192.0/19155.102.192.1 to 155.102.223.254155.102.223.2558,190
56155.102.224.0/19155.102.224.1 to 155.102.255.254155.102.255.2558,190
57155.103.0.0/19155.103.0.1 to 155.103.31.254155.103.31.2558,190
58155.103.32.0/19155.103.32.1 to 155.103.63.254155.103.63.2558,190
59155.103.64.0/19155.103.64.1 to 155.103.95.254155.103.95.2558,190
60155.103.96.0/19155.103.96.1 to 155.103.127.254155.103.127.2558,190
61155.103.128.0/19155.103.128.1 to 155.103.159.254155.103.159.2558,190
62155.103.160.0/19155.103.160.1 to 155.103.191.254155.103.191.2558,190
63155.103.192.0/19155.103.192.1 to 155.103.223.254155.103.223.2558,190
64155.103.224.0/19155.103.224.1 to 155.103.255.254155.103.255.2558,190
65155.104.0.0/19155.104.0.1 to 155.104.31.254155.104.31.2558,190
66155.104.32.0/19155.104.32.1 to 155.104.63.254155.104.63.2558,190
67155.104.64.0/19155.104.64.1 to 155.104.95.254155.104.95.2558,190
68155.104.96.0/19155.104.96.1 to 155.104.127.254155.104.127.2558,190
69155.104.128.0/19155.104.128.1 to 155.104.159.254155.104.159.2558,190
70155.104.160.0/19155.104.160.1 to 155.104.191.254155.104.191.2558,190
71155.104.192.0/19155.104.192.1 to 155.104.223.254155.104.223.2558,190
72155.104.224.0/19155.104.224.1 to 155.104.255.254155.104.255.2558,190
73155.105.0.0/19155.105.0.1 to 155.105.31.254155.105.31.2558,190
74155.105.32.0/19155.105.32.1 to 155.105.63.254155.105.63.2558,190
75155.105.64.0/19155.105.64.1 to 155.105.95.254155.105.95.2558,190
76155.105.96.0/19155.105.96.1 to 155.105.127.254155.105.127.2558,190
77155.105.128.0/19155.105.128.1 to 155.105.159.254155.105.159.2558,190
78155.105.160.0/19155.105.160.1 to 155.105.191.254155.105.191.2558,190
79155.105.192.0/19155.105.192.1 to 155.105.223.254155.105.223.2558,190
80155.105.224.0/19155.105.224.1 to 155.105.255.254155.105.255.2558,190
81155.106.0.0/19155.106.0.1 to 155.106.31.254155.106.31.2558,190
82155.106.32.0/19155.106.32.1 to 155.106.63.254155.106.63.2558,190
83155.106.64.0/19155.106.64.1 to 155.106.95.254155.106.95.2558,190
84155.106.96.0/19155.106.96.1 to 155.106.127.254155.106.127.2558,190
85155.106.128.0/19155.106.128.1 to 155.106.159.254155.106.159.2558,190
86155.106.160.0/19155.106.160.1 to 155.106.191.254155.106.191.2558,190
87155.106.192.0/19155.106.192.1 to 155.106.223.254155.106.223.2558,190
88155.106.224.0/19155.106.224.1 to 155.106.255.254155.106.255.2558,190
89155.107.0.0/19155.107.0.1 to 155.107.31.254155.107.31.2558,190
90155.107.32.0/19155.107.32.1 to 155.107.63.254155.107.63.2558,190
91155.107.64.0/19155.107.64.1 to 155.107.95.254155.107.95.2558,190
92155.107.96.0/19155.107.96.1 to 155.107.127.254155.107.127.2558,190
93155.107.128.0/19155.107.128.1 to 155.107.159.254155.107.159.2558,190
94155.107.160.0/19155.107.160.1 to 155.107.191.254155.107.191.2558,190
95155.107.192.0/19155.107.192.1 to 155.107.223.254155.107.223.2558,190
96155.107.224.0/19155.107.224.1 to 155.107.255.254155.107.255.2558,190
97155.108.0.0/19155.108.0.1 to 155.108.31.254155.108.31.2558,190
98155.108.32.0/19155.108.32.1 to 155.108.63.254155.108.63.2558,190
99155.108.64.0/19155.108.64.1 to 155.108.95.254155.108.95.2558,190
100155.108.96.0/19155.108.96.1 to 155.108.127.254155.108.127.2558,190
101155.108.128.0/19155.108.128.1 to 155.108.159.254155.108.159.2558,190
102155.108.160.0/19155.108.160.1 to 155.108.191.254155.108.191.2558,190
103155.108.192.0/19155.108.192.1 to 155.108.223.254155.108.223.2558,190
104155.108.224.0/19155.108.224.1 to 155.108.255.254155.108.255.2558,190
105155.109.0.0/19155.109.0.1 to 155.109.31.254155.109.31.2558,190
106155.109.32.0/19155.109.32.1 to 155.109.63.254155.109.63.2558,190
107155.109.64.0/19155.109.64.1 to 155.109.95.254155.109.95.2558,190
108155.109.96.0/19155.109.96.1 to 155.109.127.254155.109.127.2558,190
109155.109.128.0/19155.109.128.1 to 155.109.159.254155.109.159.2558,190
110155.109.160.0/19155.109.160.1 to 155.109.191.254155.109.191.2558,190
111155.109.192.0/19155.109.192.1 to 155.109.223.254155.109.223.2558,190
112155.109.224.0/19155.109.224.1 to 155.109.255.254155.109.255.2558,190
113155.110.0.0/19155.110.0.1 to 155.110.31.254155.110.31.2558,190
114155.110.32.0/19155.110.32.1 to 155.110.63.254155.110.63.2558,190
115155.110.64.0/19155.110.64.1 to 155.110.95.254155.110.95.2558,190
116155.110.96.0/19155.110.96.1 to 155.110.127.254155.110.127.2558,190
117155.110.128.0/19155.110.128.1 to 155.110.159.254155.110.159.2558,190
118155.110.160.0/19155.110.160.1 to 155.110.191.254155.110.191.2558,190
119155.110.192.0/19155.110.192.1 to 155.110.223.254155.110.223.2558,190
120155.110.224.0/19155.110.224.1 to 155.110.255.254155.110.255.2558,190
121155.111.0.0/19155.111.0.1 to 155.111.31.254155.111.31.2558,190
122155.111.32.0/19155.111.32.1 to 155.111.63.254155.111.63.2558,190
123155.111.64.0/19155.111.64.1 to 155.111.95.254155.111.95.2558,190
124155.111.96.0/19155.111.96.1 to 155.111.127.254155.111.127.2558,190
125155.111.128.0/19155.111.128.1 to 155.111.159.254155.111.159.2558,190
126155.111.160.0/19155.111.160.1 to 155.111.191.254155.111.191.2558,190
127155.111.192.0/19155.111.192.1 to 155.111.223.254155.111.223.2558,190
128155.111.224.0/19155.111.224.1 to 155.111.255.254155.111.255.2558,190
129155.112.0.0/19155.112.0.1 to 155.112.31.254155.112.31.2558,190
130155.112.32.0/19155.112.32.1 to 155.112.63.254155.112.63.2558,190
131155.112.64.0/19155.112.64.1 to 155.112.95.254155.112.95.2558,190
132155.112.96.0/19155.112.96.1 to 155.112.127.254155.112.127.2558,190
133155.112.128.0/19155.112.128.1 to 155.112.159.254155.112.159.2558,190
134155.112.160.0/19155.112.160.1 to 155.112.191.254155.112.191.2558,190
135155.112.192.0/19155.112.192.1 to 155.112.223.254155.112.223.2558,190
136155.112.224.0/19155.112.224.1 to 155.112.255.254155.112.255.2558,190
137155.113.0.0/19155.113.0.1 to 155.113.31.254155.113.31.2558,190
138155.113.32.0/19155.113.32.1 to 155.113.63.254155.113.63.2558,190
139155.113.64.0/19155.113.64.1 to 155.113.95.254155.113.95.2558,190
140155.113.96.0/19155.113.96.1 to 155.113.127.254155.113.127.2558,190
141155.113.128.0/19155.113.128.1 to 155.113.159.254155.113.159.2558,190
142155.113.160.0/19155.113.160.1 to 155.113.191.254155.113.191.2558,190
143155.113.192.0/19155.113.192.1 to 155.113.223.254155.113.223.2558,190
144155.113.224.0/19155.113.224.1 to 155.113.255.254155.113.255.2558,190
145155.114.0.0/19155.114.0.1 to 155.114.31.254155.114.31.2558,190
146155.114.32.0/19155.114.32.1 to 155.114.63.254155.114.63.2558,190
147155.114.64.0/19155.114.64.1 to 155.114.95.254155.114.95.2558,190
148155.114.96.0/19155.114.96.1 to 155.114.127.254155.114.127.2558,190
149155.114.128.0/19155.114.128.1 to 155.114.159.254155.114.159.2558,190
150155.114.160.0/19155.114.160.1 to 155.114.191.254155.114.191.2558,190
151155.114.192.0/19155.114.192.1 to 155.114.223.254155.114.223.2558,190
152155.114.224.0/19155.114.224.1 to 155.114.255.254155.114.255.2558,190
153155.115.0.0/19155.115.0.1 to 155.115.31.254155.115.31.2558,190
154155.115.32.0/19155.115.32.1 to 155.115.63.254155.115.63.2558,190
155155.115.64.0/19155.115.64.1 to 155.115.95.254155.115.95.2558,190
156155.115.96.0/19155.115.96.1 to 155.115.127.254155.115.127.2558,190
157155.115.128.0/19155.115.128.1 to 155.115.159.254155.115.159.2558,190
158155.115.160.0/19155.115.160.1 to 155.115.191.254155.115.191.2558,190
159155.115.192.0/19155.115.192.1 to 155.115.223.254155.115.223.2558,190
160155.115.224.0/19155.115.224.1 to 155.115.255.254155.115.255.2558,190
161155.116.0.0/19155.116.0.1 to 155.116.31.254155.116.31.2558,190
162155.116.32.0/19155.116.32.1 to 155.116.63.254155.116.63.2558,190
163155.116.64.0/19155.116.64.1 to 155.116.95.254155.116.95.2558,190
164155.116.96.0/19155.116.96.1 to 155.116.127.254155.116.127.2558,190
165155.116.128.0/19155.116.128.1 to 155.116.159.254155.116.159.2558,190
166155.116.160.0/19155.116.160.1 to 155.116.191.254155.116.191.2558,190
167155.116.192.0/19155.116.192.1 to 155.116.223.254155.116.223.2558,190
168155.116.224.0/19155.116.224.1 to 155.116.255.254155.116.255.2558,190
169155.117.0.0/19155.117.0.1 to 155.117.31.254155.117.31.2558,190
170155.117.32.0/19155.117.32.1 to 155.117.63.254155.117.63.2558,190
171155.117.64.0/19155.117.64.1 to 155.117.95.254155.117.95.2558,190
172155.117.96.0/19155.117.96.1 to 155.117.127.254155.117.127.2558,190
173155.117.128.0/19155.117.128.1 to 155.117.159.254155.117.159.2558,190
174155.117.160.0/19155.117.160.1 to 155.117.191.254155.117.191.2558,190
175155.117.192.0/19155.117.192.1 to 155.117.223.254155.117.223.2558,190
176155.117.224.0/19155.117.224.1 to 155.117.255.254155.117.255.2558,190
177155.118.0.0/19155.118.0.1 to 155.118.31.254155.118.31.2558,190
178155.118.32.0/19155.118.32.1 to 155.118.63.254155.118.63.2558,190
179155.118.64.0/19155.118.64.1 to 155.118.95.254155.118.95.2558,190
180155.118.96.0/19155.118.96.1 to 155.118.127.254155.118.127.2558,190
181155.118.128.0/19155.118.128.1 to 155.118.159.254155.118.159.2558,190
182155.118.160.0/19155.118.160.1 to 155.118.191.254155.118.191.2558,190
183155.118.192.0/19155.118.192.1 to 155.118.223.254155.118.223.2558,190
184155.118.224.0/19155.118.224.1 to 155.118.255.254155.118.255.2558,190
185155.119.0.0/19155.119.0.1 to 155.119.31.254155.119.31.2558,190
186155.119.32.0/19155.119.32.1 to 155.119.63.254155.119.63.2558,190
187155.119.64.0/19155.119.64.1 to 155.119.95.254155.119.95.2558,190
188155.119.96.0/19155.119.96.1 to 155.119.127.254155.119.127.2558,190
189155.119.128.0/19155.119.128.1 to 155.119.159.254155.119.159.2558,190
190155.119.160.0/19155.119.160.1 to 155.119.191.254155.119.191.2558,190
191155.119.192.0/19155.119.192.1 to 155.119.223.254155.119.223.2558,190
192155.119.224.0/19155.119.224.1 to 155.119.255.254155.119.255.2558,190
193155.120.0.0/19155.120.0.1 to 155.120.31.254155.120.31.2558,190
194155.120.32.0/19155.120.32.1 to 155.120.63.254155.120.63.2558,190
195155.120.64.0/19155.120.64.1 to 155.120.95.254155.120.95.2558,190
196155.120.96.0/19155.120.96.1 to 155.120.127.254155.120.127.2558,190
197155.120.128.0/19155.120.128.1 to 155.120.159.254155.120.159.2558,190
198155.120.160.0/19155.120.160.1 to 155.120.191.254155.120.191.2558,190
199155.120.192.0/19155.120.192.1 to 155.120.223.254155.120.223.2558,190
200155.120.224.0/19155.120.224.1 to 155.120.255.254155.120.255.2558,190
201155.121.0.0/19155.121.0.1 to 155.121.31.254155.121.31.2558,190
202155.121.32.0/19155.121.32.1 to 155.121.63.254155.121.63.2558,190
203155.121.64.0/19155.121.64.1 to 155.121.95.254155.121.95.2558,190
204155.121.96.0/19155.121.96.1 to 155.121.127.254155.121.127.2558,190
205155.121.128.0/19155.121.128.1 to 155.121.159.254155.121.159.2558,190
206155.121.160.0/19155.121.160.1 to 155.121.191.254155.121.191.2558,190
207155.121.192.0/19155.121.192.1 to 155.121.223.254155.121.223.2558,190
208155.121.224.0/19155.121.224.1 to 155.121.255.254155.121.255.2558,190
209155.122.0.0/19155.122.0.1 to 155.122.31.254155.122.31.2558,190
210155.122.32.0/19155.122.32.1 to 155.122.63.254155.122.63.2558,190
211155.122.64.0/19155.122.64.1 to 155.122.95.254155.122.95.2558,190
212155.122.96.0/19155.122.96.1 to 155.122.127.254155.122.127.2558,190
213155.122.128.0/19155.122.128.1 to 155.122.159.254155.122.159.2558,190
214155.122.160.0/19155.122.160.1 to 155.122.191.254155.122.191.2558,190
215155.122.192.0/19155.122.192.1 to 155.122.223.254155.122.223.2558,190
216155.122.224.0/19155.122.224.1 to 155.122.255.254155.122.255.2558,190
217155.123.0.0/19155.123.0.1 to 155.123.31.254155.123.31.2558,190
218155.123.32.0/19155.123.32.1 to 155.123.63.254155.123.63.2558,190
219155.123.64.0/19155.123.64.1 to 155.123.95.254155.123.95.2558,190
220155.123.96.0/19155.123.96.1 to 155.123.127.254155.123.127.2558,190
221155.123.128.0/19155.123.128.1 to 155.123.159.254155.123.159.2558,190
222155.123.160.0/19155.123.160.1 to 155.123.191.254155.123.191.2558,190
223155.123.192.0/19155.123.192.1 to 155.123.223.254155.123.223.2558,190
224155.123.224.0/19155.123.224.1 to 155.123.255.254155.123.255.2558,190
225155.124.0.0/19155.124.0.1 to 155.124.31.254155.124.31.2558,190
226155.124.32.0/19155.124.32.1 to 155.124.63.254155.124.63.2558,190
227155.124.64.0/19155.124.64.1 to 155.124.95.254155.124.95.2558,190
228155.124.96.0/19155.124.96.1 to 155.124.127.254155.124.127.2558,190
229155.124.128.0/19155.124.128.1 to 155.124.159.254155.124.159.2558,190
230155.124.160.0/19155.124.160.1 to 155.124.191.254155.124.191.2558,190
231155.124.192.0/19155.124.192.1 to 155.124.223.254155.124.223.2558,190
232155.124.224.0/19155.124.224.1 to 155.124.255.254155.124.255.2558,190
233155.125.0.0/19155.125.0.1 to 155.125.31.254155.125.31.2558,190
234155.125.32.0/19155.125.32.1 to 155.125.63.254155.125.63.2558,190
235155.125.64.0/19155.125.64.1 to 155.125.95.254155.125.95.2558,190
236155.125.96.0/19155.125.96.1 to 155.125.127.254155.125.127.2558,190
237155.125.128.0/19155.125.128.1 to 155.125.159.254155.125.159.2558,190
238155.125.160.0/19155.125.160.1 to 155.125.191.254155.125.191.2558,190
239155.125.192.0/19155.125.192.1 to 155.125.223.254155.125.223.2558,190
240155.125.224.0/19155.125.224.1 to 155.125.255.254155.125.255.2558,190
241155.126.0.0/19155.126.0.1 to 155.126.31.254155.126.31.2558,190
242155.126.32.0/19155.126.32.1 to 155.126.63.254155.126.63.2558,190
243155.126.64.0/19155.126.64.1 to 155.126.95.254155.126.95.2558,190
244155.126.96.0/19155.126.96.1 to 155.126.127.254155.126.127.2558,190
245155.126.128.0/19155.126.128.1 to 155.126.159.254155.126.159.2558,190
246155.126.160.0/19155.126.160.1 to 155.126.191.254155.126.191.2558,190
247155.126.192.0/19155.126.192.1 to 155.126.223.254155.126.223.2558,190
248155.126.224.0/19155.126.224.1 to 155.126.255.254155.126.255.2558,190
249155.127.0.0/19155.127.0.1 to 155.127.31.254155.127.31.2558,190
250155.127.32.0/19155.127.32.1 to 155.127.63.254155.127.63.2558,190
251155.127.64.0/19155.127.64.1 to 155.127.95.254155.127.95.2558,190
252155.127.96.0/19155.127.96.1 to 155.127.127.254155.127.127.2558,190
253155.127.128.0/19155.127.128.1 to 155.127.159.254155.127.159.2558,190
254155.127.160.0/19155.127.160.1 to 155.127.191.254155.127.191.2558,190
255155.127.192.0/19155.127.192.1 to 155.127.223.254155.127.223.2558,190
256155.127.224.0/19155.127.224.1 to 155.127.255.254155.127.255.2558,190

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.