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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.

Network152.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
152.0.0.0
Broadcast address
152.127.255.255
First usable
152.0.0.1
Last usable
152.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
B (default /16)
As numbers
Hex 98000000 · Integer 2550136832 to 2558525439
Reverse DNS zones
0.152.in-addr.arpa
1.152.in-addr.arpa
2.152.in-addr.arpa
3.152.in-addr.arpa
4.152.in-addr.arpa
5.152.in-addr.arpa
6.152.in-addr.arpa
7.152.in-addr.arpa
8.152.in-addr.arpa
9.152.in-addr.arpa
10.152.in-addr.arpa
11.152.in-addr.arpa
12.152.in-addr.arpa
13.152.in-addr.arpa
14.152.in-addr.arpa
15.152.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011000.00000000.00000000.00000000152.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network10011000.00000000.00000000.00000000152.0.0.0
Broadcast10011000.01111111.11111111.11111111152.127.255.255
Split into smaller subnets/21
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

152.0.0.0/9 makes 4,096 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1152.0.0.0/21152.0.0.1 to 152.0.7.254152.0.7.2552,046
2152.0.8.0/21152.0.8.1 to 152.0.15.254152.0.15.2552,046
3152.0.16.0/21152.0.16.1 to 152.0.23.254152.0.23.2552,046
4152.0.24.0/21152.0.24.1 to 152.0.31.254152.0.31.2552,046
5152.0.32.0/21152.0.32.1 to 152.0.39.254152.0.39.2552,046
6152.0.40.0/21152.0.40.1 to 152.0.47.254152.0.47.2552,046
7152.0.48.0/21152.0.48.1 to 152.0.55.254152.0.55.2552,046
8152.0.56.0/21152.0.56.1 to 152.0.63.254152.0.63.2552,046
9152.0.64.0/21152.0.64.1 to 152.0.71.254152.0.71.2552,046
10152.0.72.0/21152.0.72.1 to 152.0.79.254152.0.79.2552,046
11152.0.80.0/21152.0.80.1 to 152.0.87.254152.0.87.2552,046
12152.0.88.0/21152.0.88.1 to 152.0.95.254152.0.95.2552,046
13152.0.96.0/21152.0.96.1 to 152.0.103.254152.0.103.2552,046
14152.0.104.0/21152.0.104.1 to 152.0.111.254152.0.111.2552,046
15152.0.112.0/21152.0.112.1 to 152.0.119.254152.0.119.2552,046
16152.0.120.0/21152.0.120.1 to 152.0.127.254152.0.127.2552,046
17152.0.128.0/21152.0.128.1 to 152.0.135.254152.0.135.2552,046
18152.0.136.0/21152.0.136.1 to 152.0.143.254152.0.143.2552,046
19152.0.144.0/21152.0.144.1 to 152.0.151.254152.0.151.2552,046
20152.0.152.0/21152.0.152.1 to 152.0.159.254152.0.159.2552,046
21152.0.160.0/21152.0.160.1 to 152.0.167.254152.0.167.2552,046
22152.0.168.0/21152.0.168.1 to 152.0.175.254152.0.175.2552,046
23152.0.176.0/21152.0.176.1 to 152.0.183.254152.0.183.2552,046
24152.0.184.0/21152.0.184.1 to 152.0.191.254152.0.191.2552,046
25152.0.192.0/21152.0.192.1 to 152.0.199.254152.0.199.2552,046
26152.0.200.0/21152.0.200.1 to 152.0.207.254152.0.207.2552,046
27152.0.208.0/21152.0.208.1 to 152.0.215.254152.0.215.2552,046
28152.0.216.0/21152.0.216.1 to 152.0.223.254152.0.223.2552,046
29152.0.224.0/21152.0.224.1 to 152.0.231.254152.0.231.2552,046
30152.0.232.0/21152.0.232.1 to 152.0.239.254152.0.239.2552,046
31152.0.240.0/21152.0.240.1 to 152.0.247.254152.0.247.2552,046
32152.0.248.0/21152.0.248.1 to 152.0.255.254152.0.255.2552,046
33152.1.0.0/21152.1.0.1 to 152.1.7.254152.1.7.2552,046
34152.1.8.0/21152.1.8.1 to 152.1.15.254152.1.15.2552,046
35152.1.16.0/21152.1.16.1 to 152.1.23.254152.1.23.2552,046
36152.1.24.0/21152.1.24.1 to 152.1.31.254152.1.31.2552,046
37152.1.32.0/21152.1.32.1 to 152.1.39.254152.1.39.2552,046
38152.1.40.0/21152.1.40.1 to 152.1.47.254152.1.47.2552,046
39152.1.48.0/21152.1.48.1 to 152.1.55.254152.1.55.2552,046
40152.1.56.0/21152.1.56.1 to 152.1.63.254152.1.63.2552,046
41152.1.64.0/21152.1.64.1 to 152.1.71.254152.1.71.2552,046
42152.1.72.0/21152.1.72.1 to 152.1.79.254152.1.79.2552,046
43152.1.80.0/21152.1.80.1 to 152.1.87.254152.1.87.2552,046
44152.1.88.0/21152.1.88.1 to 152.1.95.254152.1.95.2552,046
45152.1.96.0/21152.1.96.1 to 152.1.103.254152.1.103.2552,046
46152.1.104.0/21152.1.104.1 to 152.1.111.254152.1.111.2552,046
47152.1.112.0/21152.1.112.1 to 152.1.119.254152.1.119.2552,046
48152.1.120.0/21152.1.120.1 to 152.1.127.254152.1.127.2552,046
49152.1.128.0/21152.1.128.1 to 152.1.135.254152.1.135.2552,046
50152.1.136.0/21152.1.136.1 to 152.1.143.254152.1.143.2552,046
51152.1.144.0/21152.1.144.1 to 152.1.151.254152.1.151.2552,046
52152.1.152.0/21152.1.152.1 to 152.1.159.254152.1.159.2552,046
53152.1.160.0/21152.1.160.1 to 152.1.167.254152.1.167.2552,046
54152.1.168.0/21152.1.168.1 to 152.1.175.254152.1.175.2552,046
55152.1.176.0/21152.1.176.1 to 152.1.183.254152.1.183.2552,046
56152.1.184.0/21152.1.184.1 to 152.1.191.254152.1.191.2552,046
57152.1.192.0/21152.1.192.1 to 152.1.199.254152.1.199.2552,046
58152.1.200.0/21152.1.200.1 to 152.1.207.254152.1.207.2552,046
59152.1.208.0/21152.1.208.1 to 152.1.215.254152.1.215.2552,046
60152.1.216.0/21152.1.216.1 to 152.1.223.254152.1.223.2552,046
61152.1.224.0/21152.1.224.1 to 152.1.231.254152.1.231.2552,046
62152.1.232.0/21152.1.232.1 to 152.1.239.254152.1.239.2552,046
63152.1.240.0/21152.1.240.1 to 152.1.247.254152.1.247.2552,046
64152.1.248.0/21152.1.248.1 to 152.1.255.254152.1.255.2552,046
65152.2.0.0/21152.2.0.1 to 152.2.7.254152.2.7.2552,046
66152.2.8.0/21152.2.8.1 to 152.2.15.254152.2.15.2552,046
67152.2.16.0/21152.2.16.1 to 152.2.23.254152.2.23.2552,046
68152.2.24.0/21152.2.24.1 to 152.2.31.254152.2.31.2552,046
69152.2.32.0/21152.2.32.1 to 152.2.39.254152.2.39.2552,046
70152.2.40.0/21152.2.40.1 to 152.2.47.254152.2.47.2552,046
71152.2.48.0/21152.2.48.1 to 152.2.55.254152.2.55.2552,046
72152.2.56.0/21152.2.56.1 to 152.2.63.254152.2.63.2552,046
73152.2.64.0/21152.2.64.1 to 152.2.71.254152.2.71.2552,046
74152.2.72.0/21152.2.72.1 to 152.2.79.254152.2.79.2552,046
75152.2.80.0/21152.2.80.1 to 152.2.87.254152.2.87.2552,046
76152.2.88.0/21152.2.88.1 to 152.2.95.254152.2.95.2552,046
77152.2.96.0/21152.2.96.1 to 152.2.103.254152.2.103.2552,046
78152.2.104.0/21152.2.104.1 to 152.2.111.254152.2.111.2552,046
79152.2.112.0/21152.2.112.1 to 152.2.119.254152.2.119.2552,046
80152.2.120.0/21152.2.120.1 to 152.2.127.254152.2.127.2552,046
81152.2.128.0/21152.2.128.1 to 152.2.135.254152.2.135.2552,046
82152.2.136.0/21152.2.136.1 to 152.2.143.254152.2.143.2552,046
83152.2.144.0/21152.2.144.1 to 152.2.151.254152.2.151.2552,046
84152.2.152.0/21152.2.152.1 to 152.2.159.254152.2.159.2552,046
85152.2.160.0/21152.2.160.1 to 152.2.167.254152.2.167.2552,046
86152.2.168.0/21152.2.168.1 to 152.2.175.254152.2.175.2552,046
87152.2.176.0/21152.2.176.1 to 152.2.183.254152.2.183.2552,046
88152.2.184.0/21152.2.184.1 to 152.2.191.254152.2.191.2552,046
89152.2.192.0/21152.2.192.1 to 152.2.199.254152.2.199.2552,046
90152.2.200.0/21152.2.200.1 to 152.2.207.254152.2.207.2552,046
91152.2.208.0/21152.2.208.1 to 152.2.215.254152.2.215.2552,046
92152.2.216.0/21152.2.216.1 to 152.2.223.254152.2.223.2552,046
93152.2.224.0/21152.2.224.1 to 152.2.231.254152.2.231.2552,046
94152.2.232.0/21152.2.232.1 to 152.2.239.254152.2.239.2552,046
95152.2.240.0/21152.2.240.1 to 152.2.247.254152.2.247.2552,046
96152.2.248.0/21152.2.248.1 to 152.2.255.254152.2.255.2552,046
97152.3.0.0/21152.3.0.1 to 152.3.7.254152.3.7.2552,046
98152.3.8.0/21152.3.8.1 to 152.3.15.254152.3.15.2552,046
99152.3.16.0/21152.3.16.1 to 152.3.23.254152.3.23.2552,046
100152.3.24.0/21152.3.24.1 to 152.3.31.254152.3.31.2552,046
101152.3.32.0/21152.3.32.1 to 152.3.39.254152.3.39.2552,046
102152.3.40.0/21152.3.40.1 to 152.3.47.254152.3.47.2552,046
103152.3.48.0/21152.3.48.1 to 152.3.55.254152.3.55.2552,046
104152.3.56.0/21152.3.56.1 to 152.3.63.254152.3.63.2552,046
105152.3.64.0/21152.3.64.1 to 152.3.71.254152.3.71.2552,046
106152.3.72.0/21152.3.72.1 to 152.3.79.254152.3.79.2552,046
107152.3.80.0/21152.3.80.1 to 152.3.87.254152.3.87.2552,046
108152.3.88.0/21152.3.88.1 to 152.3.95.254152.3.95.2552,046
109152.3.96.0/21152.3.96.1 to 152.3.103.254152.3.103.2552,046
110152.3.104.0/21152.3.104.1 to 152.3.111.254152.3.111.2552,046
111152.3.112.0/21152.3.112.1 to 152.3.119.254152.3.119.2552,046
112152.3.120.0/21152.3.120.1 to 152.3.127.254152.3.127.2552,046
113152.3.128.0/21152.3.128.1 to 152.3.135.254152.3.135.2552,046
114152.3.136.0/21152.3.136.1 to 152.3.143.254152.3.143.2552,046
115152.3.144.0/21152.3.144.1 to 152.3.151.254152.3.151.2552,046
116152.3.152.0/21152.3.152.1 to 152.3.159.254152.3.159.2552,046
117152.3.160.0/21152.3.160.1 to 152.3.167.254152.3.167.2552,046
118152.3.168.0/21152.3.168.1 to 152.3.175.254152.3.175.2552,046
119152.3.176.0/21152.3.176.1 to 152.3.183.254152.3.183.2552,046
120152.3.184.0/21152.3.184.1 to 152.3.191.254152.3.191.2552,046
121152.3.192.0/21152.3.192.1 to 152.3.199.254152.3.199.2552,046
122152.3.200.0/21152.3.200.1 to 152.3.207.254152.3.207.2552,046
123152.3.208.0/21152.3.208.1 to 152.3.215.254152.3.215.2552,046
124152.3.216.0/21152.3.216.1 to 152.3.223.254152.3.223.2552,046
125152.3.224.0/21152.3.224.1 to 152.3.231.254152.3.231.2552,046
126152.3.232.0/21152.3.232.1 to 152.3.239.254152.3.239.2552,046
127152.3.240.0/21152.3.240.1 to 152.3.247.254152.3.247.2552,046
128152.3.248.0/21152.3.248.1 to 152.3.255.254152.3.255.2552,046
129152.4.0.0/21152.4.0.1 to 152.4.7.254152.4.7.2552,046
130152.4.8.0/21152.4.8.1 to 152.4.15.254152.4.15.2552,046
131152.4.16.0/21152.4.16.1 to 152.4.23.254152.4.23.2552,046
132152.4.24.0/21152.4.24.1 to 152.4.31.254152.4.31.2552,046
133152.4.32.0/21152.4.32.1 to 152.4.39.254152.4.39.2552,046
134152.4.40.0/21152.4.40.1 to 152.4.47.254152.4.47.2552,046
135152.4.48.0/21152.4.48.1 to 152.4.55.254152.4.55.2552,046
136152.4.56.0/21152.4.56.1 to 152.4.63.254152.4.63.2552,046
137152.4.64.0/21152.4.64.1 to 152.4.71.254152.4.71.2552,046
138152.4.72.0/21152.4.72.1 to 152.4.79.254152.4.79.2552,046
139152.4.80.0/21152.4.80.1 to 152.4.87.254152.4.87.2552,046
140152.4.88.0/21152.4.88.1 to 152.4.95.254152.4.95.2552,046
141152.4.96.0/21152.4.96.1 to 152.4.103.254152.4.103.2552,046
142152.4.104.0/21152.4.104.1 to 152.4.111.254152.4.111.2552,046
143152.4.112.0/21152.4.112.1 to 152.4.119.254152.4.119.2552,046
144152.4.120.0/21152.4.120.1 to 152.4.127.254152.4.127.2552,046
145152.4.128.0/21152.4.128.1 to 152.4.135.254152.4.135.2552,046
146152.4.136.0/21152.4.136.1 to 152.4.143.254152.4.143.2552,046
147152.4.144.0/21152.4.144.1 to 152.4.151.254152.4.151.2552,046
148152.4.152.0/21152.4.152.1 to 152.4.159.254152.4.159.2552,046
149152.4.160.0/21152.4.160.1 to 152.4.167.254152.4.167.2552,046
150152.4.168.0/21152.4.168.1 to 152.4.175.254152.4.175.2552,046
151152.4.176.0/21152.4.176.1 to 152.4.183.254152.4.183.2552,046
152152.4.184.0/21152.4.184.1 to 152.4.191.254152.4.191.2552,046
153152.4.192.0/21152.4.192.1 to 152.4.199.254152.4.199.2552,046
154152.4.200.0/21152.4.200.1 to 152.4.207.254152.4.207.2552,046
155152.4.208.0/21152.4.208.1 to 152.4.215.254152.4.215.2552,046
156152.4.216.0/21152.4.216.1 to 152.4.223.254152.4.223.2552,046
157152.4.224.0/21152.4.224.1 to 152.4.231.254152.4.231.2552,046
158152.4.232.0/21152.4.232.1 to 152.4.239.254152.4.239.2552,046
159152.4.240.0/21152.4.240.1 to 152.4.247.254152.4.247.2552,046
160152.4.248.0/21152.4.248.1 to 152.4.255.254152.4.255.2552,046
161152.5.0.0/21152.5.0.1 to 152.5.7.254152.5.7.2552,046
162152.5.8.0/21152.5.8.1 to 152.5.15.254152.5.15.2552,046
163152.5.16.0/21152.5.16.1 to 152.5.23.254152.5.23.2552,046
164152.5.24.0/21152.5.24.1 to 152.5.31.254152.5.31.2552,046
165152.5.32.0/21152.5.32.1 to 152.5.39.254152.5.39.2552,046
166152.5.40.0/21152.5.40.1 to 152.5.47.254152.5.47.2552,046
167152.5.48.0/21152.5.48.1 to 152.5.55.254152.5.55.2552,046
168152.5.56.0/21152.5.56.1 to 152.5.63.254152.5.63.2552,046
169152.5.64.0/21152.5.64.1 to 152.5.71.254152.5.71.2552,046
170152.5.72.0/21152.5.72.1 to 152.5.79.254152.5.79.2552,046
171152.5.80.0/21152.5.80.1 to 152.5.87.254152.5.87.2552,046
172152.5.88.0/21152.5.88.1 to 152.5.95.254152.5.95.2552,046
173152.5.96.0/21152.5.96.1 to 152.5.103.254152.5.103.2552,046
174152.5.104.0/21152.5.104.1 to 152.5.111.254152.5.111.2552,046
175152.5.112.0/21152.5.112.1 to 152.5.119.254152.5.119.2552,046
176152.5.120.0/21152.5.120.1 to 152.5.127.254152.5.127.2552,046
177152.5.128.0/21152.5.128.1 to 152.5.135.254152.5.135.2552,046
178152.5.136.0/21152.5.136.1 to 152.5.143.254152.5.143.2552,046
179152.5.144.0/21152.5.144.1 to 152.5.151.254152.5.151.2552,046
180152.5.152.0/21152.5.152.1 to 152.5.159.254152.5.159.2552,046
181152.5.160.0/21152.5.160.1 to 152.5.167.254152.5.167.2552,046
182152.5.168.0/21152.5.168.1 to 152.5.175.254152.5.175.2552,046
183152.5.176.0/21152.5.176.1 to 152.5.183.254152.5.183.2552,046
184152.5.184.0/21152.5.184.1 to 152.5.191.254152.5.191.2552,046
185152.5.192.0/21152.5.192.1 to 152.5.199.254152.5.199.2552,046
186152.5.200.0/21152.5.200.1 to 152.5.207.254152.5.207.2552,046
187152.5.208.0/21152.5.208.1 to 152.5.215.254152.5.215.2552,046
188152.5.216.0/21152.5.216.1 to 152.5.223.254152.5.223.2552,046
189152.5.224.0/21152.5.224.1 to 152.5.231.254152.5.231.2552,046
190152.5.232.0/21152.5.232.1 to 152.5.239.254152.5.239.2552,046
191152.5.240.0/21152.5.240.1 to 152.5.247.254152.5.247.2552,046
192152.5.248.0/21152.5.248.1 to 152.5.255.254152.5.255.2552,046
193152.6.0.0/21152.6.0.1 to 152.6.7.254152.6.7.2552,046
194152.6.8.0/21152.6.8.1 to 152.6.15.254152.6.15.2552,046
195152.6.16.0/21152.6.16.1 to 152.6.23.254152.6.23.2552,046
196152.6.24.0/21152.6.24.1 to 152.6.31.254152.6.31.2552,046
197152.6.32.0/21152.6.32.1 to 152.6.39.254152.6.39.2552,046
198152.6.40.0/21152.6.40.1 to 152.6.47.254152.6.47.2552,046
199152.6.48.0/21152.6.48.1 to 152.6.55.254152.6.55.2552,046
200152.6.56.0/21152.6.56.1 to 152.6.63.254152.6.63.2552,046
201152.6.64.0/21152.6.64.1 to 152.6.71.254152.6.71.2552,046
202152.6.72.0/21152.6.72.1 to 152.6.79.254152.6.79.2552,046
203152.6.80.0/21152.6.80.1 to 152.6.87.254152.6.87.2552,046
204152.6.88.0/21152.6.88.1 to 152.6.95.254152.6.95.2552,046
205152.6.96.0/21152.6.96.1 to 152.6.103.254152.6.103.2552,046
206152.6.104.0/21152.6.104.1 to 152.6.111.254152.6.111.2552,046
207152.6.112.0/21152.6.112.1 to 152.6.119.254152.6.119.2552,046
208152.6.120.0/21152.6.120.1 to 152.6.127.254152.6.127.2552,046
209152.6.128.0/21152.6.128.1 to 152.6.135.254152.6.135.2552,046
210152.6.136.0/21152.6.136.1 to 152.6.143.254152.6.143.2552,046
211152.6.144.0/21152.6.144.1 to 152.6.151.254152.6.151.2552,046
212152.6.152.0/21152.6.152.1 to 152.6.159.254152.6.159.2552,046
213152.6.160.0/21152.6.160.1 to 152.6.167.254152.6.167.2552,046
214152.6.168.0/21152.6.168.1 to 152.6.175.254152.6.175.2552,046
215152.6.176.0/21152.6.176.1 to 152.6.183.254152.6.183.2552,046
216152.6.184.0/21152.6.184.1 to 152.6.191.254152.6.191.2552,046
217152.6.192.0/21152.6.192.1 to 152.6.199.254152.6.199.2552,046
218152.6.200.0/21152.6.200.1 to 152.6.207.254152.6.207.2552,046
219152.6.208.0/21152.6.208.1 to 152.6.215.254152.6.215.2552,046
220152.6.216.0/21152.6.216.1 to 152.6.223.254152.6.223.2552,046
221152.6.224.0/21152.6.224.1 to 152.6.231.254152.6.231.2552,046
222152.6.232.0/21152.6.232.1 to 152.6.239.254152.6.239.2552,046
223152.6.240.0/21152.6.240.1 to 152.6.247.254152.6.247.2552,046
224152.6.248.0/21152.6.248.1 to 152.6.255.254152.6.255.2552,046
225152.7.0.0/21152.7.0.1 to 152.7.7.254152.7.7.2552,046
226152.7.8.0/21152.7.8.1 to 152.7.15.254152.7.15.2552,046
227152.7.16.0/21152.7.16.1 to 152.7.23.254152.7.23.2552,046
228152.7.24.0/21152.7.24.1 to 152.7.31.254152.7.31.2552,046
229152.7.32.0/21152.7.32.1 to 152.7.39.254152.7.39.2552,046
230152.7.40.0/21152.7.40.1 to 152.7.47.254152.7.47.2552,046
231152.7.48.0/21152.7.48.1 to 152.7.55.254152.7.55.2552,046
232152.7.56.0/21152.7.56.1 to 152.7.63.254152.7.63.2552,046
233152.7.64.0/21152.7.64.1 to 152.7.71.254152.7.71.2552,046
234152.7.72.0/21152.7.72.1 to 152.7.79.254152.7.79.2552,046
235152.7.80.0/21152.7.80.1 to 152.7.87.254152.7.87.2552,046
236152.7.88.0/21152.7.88.1 to 152.7.95.254152.7.95.2552,046
237152.7.96.0/21152.7.96.1 to 152.7.103.254152.7.103.2552,046
238152.7.104.0/21152.7.104.1 to 152.7.111.254152.7.111.2552,046
239152.7.112.0/21152.7.112.1 to 152.7.119.254152.7.119.2552,046
240152.7.120.0/21152.7.120.1 to 152.7.127.254152.7.127.2552,046
241152.7.128.0/21152.7.128.1 to 152.7.135.254152.7.135.2552,046
242152.7.136.0/21152.7.136.1 to 152.7.143.254152.7.143.2552,046
243152.7.144.0/21152.7.144.1 to 152.7.151.254152.7.151.2552,046
244152.7.152.0/21152.7.152.1 to 152.7.159.254152.7.159.2552,046
245152.7.160.0/21152.7.160.1 to 152.7.167.254152.7.167.2552,046
246152.7.168.0/21152.7.168.1 to 152.7.175.254152.7.175.2552,046
247152.7.176.0/21152.7.176.1 to 152.7.183.254152.7.183.2552,046
248152.7.184.0/21152.7.184.1 to 152.7.191.254152.7.191.2552,046
249152.7.192.0/21152.7.192.1 to 152.7.199.254152.7.199.2552,046
250152.7.200.0/21152.7.200.1 to 152.7.207.254152.7.207.2552,046
251152.7.208.0/21152.7.208.1 to 152.7.215.254152.7.215.2552,046
252152.7.216.0/21152.7.216.1 to 152.7.223.254152.7.223.2552,046
253152.7.224.0/21152.7.224.1 to 152.7.231.254152.7.231.2552,046
254152.7.232.0/21152.7.232.1 to 152.7.239.254152.7.239.2552,046
255152.7.240.0/21152.7.240.1 to 152.7.247.254152.7.247.2552,046
256152.7.248.0/21152.7.248.1 to 152.7.255.254152.7.255.2552,046

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.