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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.

Network134.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
134.0.0.0
Broadcast address
134.127.255.255
First usable
134.0.0.1
Last usable
134.127.255.254
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 86000000 · Integer 2248146944 to 2256535551
Reverse DNS zones
0.134.in-addr.arpa
1.134.in-addr.arpa
2.134.in-addr.arpa
3.134.in-addr.arpa
4.134.in-addr.arpa
5.134.in-addr.arpa
6.134.in-addr.arpa
7.134.in-addr.arpa
8.134.in-addr.arpa
9.134.in-addr.arpa
10.134.in-addr.arpa
11.134.in-addr.arpa
12.134.in-addr.arpa
13.134.in-addr.arpa
14.134.in-addr.arpa
15.134.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
Address10000110.00000000.00000000.00000000134.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network10000110.00000000.00000000.00000000134.0.0.0
Broadcast10000110.01111111.11111111.11111111134.127.255.255
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)

134.0.0.0/9 makes 4,096 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1134.0.0.0/21134.0.0.1 to 134.0.7.254134.0.7.2552,046
2134.0.8.0/21134.0.8.1 to 134.0.15.254134.0.15.2552,046
3134.0.16.0/21134.0.16.1 to 134.0.23.254134.0.23.2552,046
4134.0.24.0/21134.0.24.1 to 134.0.31.254134.0.31.2552,046
5134.0.32.0/21134.0.32.1 to 134.0.39.254134.0.39.2552,046
6134.0.40.0/21134.0.40.1 to 134.0.47.254134.0.47.2552,046
7134.0.48.0/21134.0.48.1 to 134.0.55.254134.0.55.2552,046
8134.0.56.0/21134.0.56.1 to 134.0.63.254134.0.63.2552,046
9134.0.64.0/21134.0.64.1 to 134.0.71.254134.0.71.2552,046
10134.0.72.0/21134.0.72.1 to 134.0.79.254134.0.79.2552,046
11134.0.80.0/21134.0.80.1 to 134.0.87.254134.0.87.2552,046
12134.0.88.0/21134.0.88.1 to 134.0.95.254134.0.95.2552,046
13134.0.96.0/21134.0.96.1 to 134.0.103.254134.0.103.2552,046
14134.0.104.0/21134.0.104.1 to 134.0.111.254134.0.111.2552,046
15134.0.112.0/21134.0.112.1 to 134.0.119.254134.0.119.2552,046
16134.0.120.0/21134.0.120.1 to 134.0.127.254134.0.127.2552,046
17134.0.128.0/21134.0.128.1 to 134.0.135.254134.0.135.2552,046
18134.0.136.0/21134.0.136.1 to 134.0.143.254134.0.143.2552,046
19134.0.144.0/21134.0.144.1 to 134.0.151.254134.0.151.2552,046
20134.0.152.0/21134.0.152.1 to 134.0.159.254134.0.159.2552,046
21134.0.160.0/21134.0.160.1 to 134.0.167.254134.0.167.2552,046
22134.0.168.0/21134.0.168.1 to 134.0.175.254134.0.175.2552,046
23134.0.176.0/21134.0.176.1 to 134.0.183.254134.0.183.2552,046
24134.0.184.0/21134.0.184.1 to 134.0.191.254134.0.191.2552,046
25134.0.192.0/21134.0.192.1 to 134.0.199.254134.0.199.2552,046
26134.0.200.0/21134.0.200.1 to 134.0.207.254134.0.207.2552,046
27134.0.208.0/21134.0.208.1 to 134.0.215.254134.0.215.2552,046
28134.0.216.0/21134.0.216.1 to 134.0.223.254134.0.223.2552,046
29134.0.224.0/21134.0.224.1 to 134.0.231.254134.0.231.2552,046
30134.0.232.0/21134.0.232.1 to 134.0.239.254134.0.239.2552,046
31134.0.240.0/21134.0.240.1 to 134.0.247.254134.0.247.2552,046
32134.0.248.0/21134.0.248.1 to 134.0.255.254134.0.255.2552,046
33134.1.0.0/21134.1.0.1 to 134.1.7.254134.1.7.2552,046
34134.1.8.0/21134.1.8.1 to 134.1.15.254134.1.15.2552,046
35134.1.16.0/21134.1.16.1 to 134.1.23.254134.1.23.2552,046
36134.1.24.0/21134.1.24.1 to 134.1.31.254134.1.31.2552,046
37134.1.32.0/21134.1.32.1 to 134.1.39.254134.1.39.2552,046
38134.1.40.0/21134.1.40.1 to 134.1.47.254134.1.47.2552,046
39134.1.48.0/21134.1.48.1 to 134.1.55.254134.1.55.2552,046
40134.1.56.0/21134.1.56.1 to 134.1.63.254134.1.63.2552,046
41134.1.64.0/21134.1.64.1 to 134.1.71.254134.1.71.2552,046
42134.1.72.0/21134.1.72.1 to 134.1.79.254134.1.79.2552,046
43134.1.80.0/21134.1.80.1 to 134.1.87.254134.1.87.2552,046
44134.1.88.0/21134.1.88.1 to 134.1.95.254134.1.95.2552,046
45134.1.96.0/21134.1.96.1 to 134.1.103.254134.1.103.2552,046
46134.1.104.0/21134.1.104.1 to 134.1.111.254134.1.111.2552,046
47134.1.112.0/21134.1.112.1 to 134.1.119.254134.1.119.2552,046
48134.1.120.0/21134.1.120.1 to 134.1.127.254134.1.127.2552,046
49134.1.128.0/21134.1.128.1 to 134.1.135.254134.1.135.2552,046
50134.1.136.0/21134.1.136.1 to 134.1.143.254134.1.143.2552,046
51134.1.144.0/21134.1.144.1 to 134.1.151.254134.1.151.2552,046
52134.1.152.0/21134.1.152.1 to 134.1.159.254134.1.159.2552,046
53134.1.160.0/21134.1.160.1 to 134.1.167.254134.1.167.2552,046
54134.1.168.0/21134.1.168.1 to 134.1.175.254134.1.175.2552,046
55134.1.176.0/21134.1.176.1 to 134.1.183.254134.1.183.2552,046
56134.1.184.0/21134.1.184.1 to 134.1.191.254134.1.191.2552,046
57134.1.192.0/21134.1.192.1 to 134.1.199.254134.1.199.2552,046
58134.1.200.0/21134.1.200.1 to 134.1.207.254134.1.207.2552,046
59134.1.208.0/21134.1.208.1 to 134.1.215.254134.1.215.2552,046
60134.1.216.0/21134.1.216.1 to 134.1.223.254134.1.223.2552,046
61134.1.224.0/21134.1.224.1 to 134.1.231.254134.1.231.2552,046
62134.1.232.0/21134.1.232.1 to 134.1.239.254134.1.239.2552,046
63134.1.240.0/21134.1.240.1 to 134.1.247.254134.1.247.2552,046
64134.1.248.0/21134.1.248.1 to 134.1.255.254134.1.255.2552,046
65134.2.0.0/21134.2.0.1 to 134.2.7.254134.2.7.2552,046
66134.2.8.0/21134.2.8.1 to 134.2.15.254134.2.15.2552,046
67134.2.16.0/21134.2.16.1 to 134.2.23.254134.2.23.2552,046
68134.2.24.0/21134.2.24.1 to 134.2.31.254134.2.31.2552,046
69134.2.32.0/21134.2.32.1 to 134.2.39.254134.2.39.2552,046
70134.2.40.0/21134.2.40.1 to 134.2.47.254134.2.47.2552,046
71134.2.48.0/21134.2.48.1 to 134.2.55.254134.2.55.2552,046
72134.2.56.0/21134.2.56.1 to 134.2.63.254134.2.63.2552,046
73134.2.64.0/21134.2.64.1 to 134.2.71.254134.2.71.2552,046
74134.2.72.0/21134.2.72.1 to 134.2.79.254134.2.79.2552,046
75134.2.80.0/21134.2.80.1 to 134.2.87.254134.2.87.2552,046
76134.2.88.0/21134.2.88.1 to 134.2.95.254134.2.95.2552,046
77134.2.96.0/21134.2.96.1 to 134.2.103.254134.2.103.2552,046
78134.2.104.0/21134.2.104.1 to 134.2.111.254134.2.111.2552,046
79134.2.112.0/21134.2.112.1 to 134.2.119.254134.2.119.2552,046
80134.2.120.0/21134.2.120.1 to 134.2.127.254134.2.127.2552,046
81134.2.128.0/21134.2.128.1 to 134.2.135.254134.2.135.2552,046
82134.2.136.0/21134.2.136.1 to 134.2.143.254134.2.143.2552,046
83134.2.144.0/21134.2.144.1 to 134.2.151.254134.2.151.2552,046
84134.2.152.0/21134.2.152.1 to 134.2.159.254134.2.159.2552,046
85134.2.160.0/21134.2.160.1 to 134.2.167.254134.2.167.2552,046
86134.2.168.0/21134.2.168.1 to 134.2.175.254134.2.175.2552,046
87134.2.176.0/21134.2.176.1 to 134.2.183.254134.2.183.2552,046
88134.2.184.0/21134.2.184.1 to 134.2.191.254134.2.191.2552,046
89134.2.192.0/21134.2.192.1 to 134.2.199.254134.2.199.2552,046
90134.2.200.0/21134.2.200.1 to 134.2.207.254134.2.207.2552,046
91134.2.208.0/21134.2.208.1 to 134.2.215.254134.2.215.2552,046
92134.2.216.0/21134.2.216.1 to 134.2.223.254134.2.223.2552,046
93134.2.224.0/21134.2.224.1 to 134.2.231.254134.2.231.2552,046
94134.2.232.0/21134.2.232.1 to 134.2.239.254134.2.239.2552,046
95134.2.240.0/21134.2.240.1 to 134.2.247.254134.2.247.2552,046
96134.2.248.0/21134.2.248.1 to 134.2.255.254134.2.255.2552,046
97134.3.0.0/21134.3.0.1 to 134.3.7.254134.3.7.2552,046
98134.3.8.0/21134.3.8.1 to 134.3.15.254134.3.15.2552,046
99134.3.16.0/21134.3.16.1 to 134.3.23.254134.3.23.2552,046
100134.3.24.0/21134.3.24.1 to 134.3.31.254134.3.31.2552,046
101134.3.32.0/21134.3.32.1 to 134.3.39.254134.3.39.2552,046
102134.3.40.0/21134.3.40.1 to 134.3.47.254134.3.47.2552,046
103134.3.48.0/21134.3.48.1 to 134.3.55.254134.3.55.2552,046
104134.3.56.0/21134.3.56.1 to 134.3.63.254134.3.63.2552,046
105134.3.64.0/21134.3.64.1 to 134.3.71.254134.3.71.2552,046
106134.3.72.0/21134.3.72.1 to 134.3.79.254134.3.79.2552,046
107134.3.80.0/21134.3.80.1 to 134.3.87.254134.3.87.2552,046
108134.3.88.0/21134.3.88.1 to 134.3.95.254134.3.95.2552,046
109134.3.96.0/21134.3.96.1 to 134.3.103.254134.3.103.2552,046
110134.3.104.0/21134.3.104.1 to 134.3.111.254134.3.111.2552,046
111134.3.112.0/21134.3.112.1 to 134.3.119.254134.3.119.2552,046
112134.3.120.0/21134.3.120.1 to 134.3.127.254134.3.127.2552,046
113134.3.128.0/21134.3.128.1 to 134.3.135.254134.3.135.2552,046
114134.3.136.0/21134.3.136.1 to 134.3.143.254134.3.143.2552,046
115134.3.144.0/21134.3.144.1 to 134.3.151.254134.3.151.2552,046
116134.3.152.0/21134.3.152.1 to 134.3.159.254134.3.159.2552,046
117134.3.160.0/21134.3.160.1 to 134.3.167.254134.3.167.2552,046
118134.3.168.0/21134.3.168.1 to 134.3.175.254134.3.175.2552,046
119134.3.176.0/21134.3.176.1 to 134.3.183.254134.3.183.2552,046
120134.3.184.0/21134.3.184.1 to 134.3.191.254134.3.191.2552,046
121134.3.192.0/21134.3.192.1 to 134.3.199.254134.3.199.2552,046
122134.3.200.0/21134.3.200.1 to 134.3.207.254134.3.207.2552,046
123134.3.208.0/21134.3.208.1 to 134.3.215.254134.3.215.2552,046
124134.3.216.0/21134.3.216.1 to 134.3.223.254134.3.223.2552,046
125134.3.224.0/21134.3.224.1 to 134.3.231.254134.3.231.2552,046
126134.3.232.0/21134.3.232.1 to 134.3.239.254134.3.239.2552,046
127134.3.240.0/21134.3.240.1 to 134.3.247.254134.3.247.2552,046
128134.3.248.0/21134.3.248.1 to 134.3.255.254134.3.255.2552,046
129134.4.0.0/21134.4.0.1 to 134.4.7.254134.4.7.2552,046
130134.4.8.0/21134.4.8.1 to 134.4.15.254134.4.15.2552,046
131134.4.16.0/21134.4.16.1 to 134.4.23.254134.4.23.2552,046
132134.4.24.0/21134.4.24.1 to 134.4.31.254134.4.31.2552,046
133134.4.32.0/21134.4.32.1 to 134.4.39.254134.4.39.2552,046
134134.4.40.0/21134.4.40.1 to 134.4.47.254134.4.47.2552,046
135134.4.48.0/21134.4.48.1 to 134.4.55.254134.4.55.2552,046
136134.4.56.0/21134.4.56.1 to 134.4.63.254134.4.63.2552,046
137134.4.64.0/21134.4.64.1 to 134.4.71.254134.4.71.2552,046
138134.4.72.0/21134.4.72.1 to 134.4.79.254134.4.79.2552,046
139134.4.80.0/21134.4.80.1 to 134.4.87.254134.4.87.2552,046
140134.4.88.0/21134.4.88.1 to 134.4.95.254134.4.95.2552,046
141134.4.96.0/21134.4.96.1 to 134.4.103.254134.4.103.2552,046
142134.4.104.0/21134.4.104.1 to 134.4.111.254134.4.111.2552,046
143134.4.112.0/21134.4.112.1 to 134.4.119.254134.4.119.2552,046
144134.4.120.0/21134.4.120.1 to 134.4.127.254134.4.127.2552,046
145134.4.128.0/21134.4.128.1 to 134.4.135.254134.4.135.2552,046
146134.4.136.0/21134.4.136.1 to 134.4.143.254134.4.143.2552,046
147134.4.144.0/21134.4.144.1 to 134.4.151.254134.4.151.2552,046
148134.4.152.0/21134.4.152.1 to 134.4.159.254134.4.159.2552,046
149134.4.160.0/21134.4.160.1 to 134.4.167.254134.4.167.2552,046
150134.4.168.0/21134.4.168.1 to 134.4.175.254134.4.175.2552,046
151134.4.176.0/21134.4.176.1 to 134.4.183.254134.4.183.2552,046
152134.4.184.0/21134.4.184.1 to 134.4.191.254134.4.191.2552,046
153134.4.192.0/21134.4.192.1 to 134.4.199.254134.4.199.2552,046
154134.4.200.0/21134.4.200.1 to 134.4.207.254134.4.207.2552,046
155134.4.208.0/21134.4.208.1 to 134.4.215.254134.4.215.2552,046
156134.4.216.0/21134.4.216.1 to 134.4.223.254134.4.223.2552,046
157134.4.224.0/21134.4.224.1 to 134.4.231.254134.4.231.2552,046
158134.4.232.0/21134.4.232.1 to 134.4.239.254134.4.239.2552,046
159134.4.240.0/21134.4.240.1 to 134.4.247.254134.4.247.2552,046
160134.4.248.0/21134.4.248.1 to 134.4.255.254134.4.255.2552,046
161134.5.0.0/21134.5.0.1 to 134.5.7.254134.5.7.2552,046
162134.5.8.0/21134.5.8.1 to 134.5.15.254134.5.15.2552,046
163134.5.16.0/21134.5.16.1 to 134.5.23.254134.5.23.2552,046
164134.5.24.0/21134.5.24.1 to 134.5.31.254134.5.31.2552,046
165134.5.32.0/21134.5.32.1 to 134.5.39.254134.5.39.2552,046
166134.5.40.0/21134.5.40.1 to 134.5.47.254134.5.47.2552,046
167134.5.48.0/21134.5.48.1 to 134.5.55.254134.5.55.2552,046
168134.5.56.0/21134.5.56.1 to 134.5.63.254134.5.63.2552,046
169134.5.64.0/21134.5.64.1 to 134.5.71.254134.5.71.2552,046
170134.5.72.0/21134.5.72.1 to 134.5.79.254134.5.79.2552,046
171134.5.80.0/21134.5.80.1 to 134.5.87.254134.5.87.2552,046
172134.5.88.0/21134.5.88.1 to 134.5.95.254134.5.95.2552,046
173134.5.96.0/21134.5.96.1 to 134.5.103.254134.5.103.2552,046
174134.5.104.0/21134.5.104.1 to 134.5.111.254134.5.111.2552,046
175134.5.112.0/21134.5.112.1 to 134.5.119.254134.5.119.2552,046
176134.5.120.0/21134.5.120.1 to 134.5.127.254134.5.127.2552,046
177134.5.128.0/21134.5.128.1 to 134.5.135.254134.5.135.2552,046
178134.5.136.0/21134.5.136.1 to 134.5.143.254134.5.143.2552,046
179134.5.144.0/21134.5.144.1 to 134.5.151.254134.5.151.2552,046
180134.5.152.0/21134.5.152.1 to 134.5.159.254134.5.159.2552,046
181134.5.160.0/21134.5.160.1 to 134.5.167.254134.5.167.2552,046
182134.5.168.0/21134.5.168.1 to 134.5.175.254134.5.175.2552,046
183134.5.176.0/21134.5.176.1 to 134.5.183.254134.5.183.2552,046
184134.5.184.0/21134.5.184.1 to 134.5.191.254134.5.191.2552,046
185134.5.192.0/21134.5.192.1 to 134.5.199.254134.5.199.2552,046
186134.5.200.0/21134.5.200.1 to 134.5.207.254134.5.207.2552,046
187134.5.208.0/21134.5.208.1 to 134.5.215.254134.5.215.2552,046
188134.5.216.0/21134.5.216.1 to 134.5.223.254134.5.223.2552,046
189134.5.224.0/21134.5.224.1 to 134.5.231.254134.5.231.2552,046
190134.5.232.0/21134.5.232.1 to 134.5.239.254134.5.239.2552,046
191134.5.240.0/21134.5.240.1 to 134.5.247.254134.5.247.2552,046
192134.5.248.0/21134.5.248.1 to 134.5.255.254134.5.255.2552,046
193134.6.0.0/21134.6.0.1 to 134.6.7.254134.6.7.2552,046
194134.6.8.0/21134.6.8.1 to 134.6.15.254134.6.15.2552,046
195134.6.16.0/21134.6.16.1 to 134.6.23.254134.6.23.2552,046
196134.6.24.0/21134.6.24.1 to 134.6.31.254134.6.31.2552,046
197134.6.32.0/21134.6.32.1 to 134.6.39.254134.6.39.2552,046
198134.6.40.0/21134.6.40.1 to 134.6.47.254134.6.47.2552,046
199134.6.48.0/21134.6.48.1 to 134.6.55.254134.6.55.2552,046
200134.6.56.0/21134.6.56.1 to 134.6.63.254134.6.63.2552,046
201134.6.64.0/21134.6.64.1 to 134.6.71.254134.6.71.2552,046
202134.6.72.0/21134.6.72.1 to 134.6.79.254134.6.79.2552,046
203134.6.80.0/21134.6.80.1 to 134.6.87.254134.6.87.2552,046
204134.6.88.0/21134.6.88.1 to 134.6.95.254134.6.95.2552,046
205134.6.96.0/21134.6.96.1 to 134.6.103.254134.6.103.2552,046
206134.6.104.0/21134.6.104.1 to 134.6.111.254134.6.111.2552,046
207134.6.112.0/21134.6.112.1 to 134.6.119.254134.6.119.2552,046
208134.6.120.0/21134.6.120.1 to 134.6.127.254134.6.127.2552,046
209134.6.128.0/21134.6.128.1 to 134.6.135.254134.6.135.2552,046
210134.6.136.0/21134.6.136.1 to 134.6.143.254134.6.143.2552,046
211134.6.144.0/21134.6.144.1 to 134.6.151.254134.6.151.2552,046
212134.6.152.0/21134.6.152.1 to 134.6.159.254134.6.159.2552,046
213134.6.160.0/21134.6.160.1 to 134.6.167.254134.6.167.2552,046
214134.6.168.0/21134.6.168.1 to 134.6.175.254134.6.175.2552,046
215134.6.176.0/21134.6.176.1 to 134.6.183.254134.6.183.2552,046
216134.6.184.0/21134.6.184.1 to 134.6.191.254134.6.191.2552,046
217134.6.192.0/21134.6.192.1 to 134.6.199.254134.6.199.2552,046
218134.6.200.0/21134.6.200.1 to 134.6.207.254134.6.207.2552,046
219134.6.208.0/21134.6.208.1 to 134.6.215.254134.6.215.2552,046
220134.6.216.0/21134.6.216.1 to 134.6.223.254134.6.223.2552,046
221134.6.224.0/21134.6.224.1 to 134.6.231.254134.6.231.2552,046
222134.6.232.0/21134.6.232.1 to 134.6.239.254134.6.239.2552,046
223134.6.240.0/21134.6.240.1 to 134.6.247.254134.6.247.2552,046
224134.6.248.0/21134.6.248.1 to 134.6.255.254134.6.255.2552,046
225134.7.0.0/21134.7.0.1 to 134.7.7.254134.7.7.2552,046
226134.7.8.0/21134.7.8.1 to 134.7.15.254134.7.15.2552,046
227134.7.16.0/21134.7.16.1 to 134.7.23.254134.7.23.2552,046
228134.7.24.0/21134.7.24.1 to 134.7.31.254134.7.31.2552,046
229134.7.32.0/21134.7.32.1 to 134.7.39.254134.7.39.2552,046
230134.7.40.0/21134.7.40.1 to 134.7.47.254134.7.47.2552,046
231134.7.48.0/21134.7.48.1 to 134.7.55.254134.7.55.2552,046
232134.7.56.0/21134.7.56.1 to 134.7.63.254134.7.63.2552,046
233134.7.64.0/21134.7.64.1 to 134.7.71.254134.7.71.2552,046
234134.7.72.0/21134.7.72.1 to 134.7.79.254134.7.79.2552,046
235134.7.80.0/21134.7.80.1 to 134.7.87.254134.7.87.2552,046
236134.7.88.0/21134.7.88.1 to 134.7.95.254134.7.95.2552,046
237134.7.96.0/21134.7.96.1 to 134.7.103.254134.7.103.2552,046
238134.7.104.0/21134.7.104.1 to 134.7.111.254134.7.111.2552,046
239134.7.112.0/21134.7.112.1 to 134.7.119.254134.7.119.2552,046
240134.7.120.0/21134.7.120.1 to 134.7.127.254134.7.127.2552,046
241134.7.128.0/21134.7.128.1 to 134.7.135.254134.7.135.2552,046
242134.7.136.0/21134.7.136.1 to 134.7.143.254134.7.143.2552,046
243134.7.144.0/21134.7.144.1 to 134.7.151.254134.7.151.2552,046
244134.7.152.0/21134.7.152.1 to 134.7.159.254134.7.159.2552,046
245134.7.160.0/21134.7.160.1 to 134.7.167.254134.7.167.2552,046
246134.7.168.0/21134.7.168.1 to 134.7.175.254134.7.175.2552,046
247134.7.176.0/21134.7.176.1 to 134.7.183.254134.7.183.2552,046
248134.7.184.0/21134.7.184.1 to 134.7.191.254134.7.191.2552,046
249134.7.192.0/21134.7.192.1 to 134.7.199.254134.7.199.2552,046
250134.7.200.0/21134.7.200.1 to 134.7.207.254134.7.207.2552,046
251134.7.208.0/21134.7.208.1 to 134.7.215.254134.7.215.2552,046
252134.7.216.0/21134.7.216.1 to 134.7.223.254134.7.223.2552,046
253134.7.224.0/21134.7.224.1 to 134.7.231.254134.7.231.2552,046
254134.7.232.0/21134.7.232.1 to 134.7.239.254134.7.239.2552,046
255134.7.240.0/21134.7.240.1 to 134.7.247.254134.7.247.2552,046
256134.7.248.0/21134.7.248.1 to 134.7.255.254134.7.255.2552,046

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.