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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.

Network135.0.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
135.0.0.0
Broadcast address
135.7.255.255
First usable
135.0.0.1
Last usable
135.7.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
B (default /16)
As numbers
Hex 87000000 · Integer 2264924160 to 2265448447
Reverse DNS zones
0.135.in-addr.arpa
1.135.in-addr.arpa
2.135.in-addr.arpa
3.135.in-addr.arpa
4.135.in-addr.arpa
5.135.in-addr.arpa
6.135.in-addr.arpa
7.135.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10000111.00000000.00000000.00000000135.0.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network10000111.00000000.00000000.00000000135.0.0.0
Broadcast10000111.00000111.11111111.11111111135.7.255.255
Split into smaller subnets/21
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

135.0.0.0/13 makes 256 subnets of /21.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1135.0.0.0/21135.0.0.1 to 135.0.7.254135.0.7.2552,046
2135.0.8.0/21135.0.8.1 to 135.0.15.254135.0.15.2552,046
3135.0.16.0/21135.0.16.1 to 135.0.23.254135.0.23.2552,046
4135.0.24.0/21135.0.24.1 to 135.0.31.254135.0.31.2552,046
5135.0.32.0/21135.0.32.1 to 135.0.39.254135.0.39.2552,046
6135.0.40.0/21135.0.40.1 to 135.0.47.254135.0.47.2552,046
7135.0.48.0/21135.0.48.1 to 135.0.55.254135.0.55.2552,046
8135.0.56.0/21135.0.56.1 to 135.0.63.254135.0.63.2552,046
9135.0.64.0/21135.0.64.1 to 135.0.71.254135.0.71.2552,046
10135.0.72.0/21135.0.72.1 to 135.0.79.254135.0.79.2552,046
11135.0.80.0/21135.0.80.1 to 135.0.87.254135.0.87.2552,046
12135.0.88.0/21135.0.88.1 to 135.0.95.254135.0.95.2552,046
13135.0.96.0/21135.0.96.1 to 135.0.103.254135.0.103.2552,046
14135.0.104.0/21135.0.104.1 to 135.0.111.254135.0.111.2552,046
15135.0.112.0/21135.0.112.1 to 135.0.119.254135.0.119.2552,046
16135.0.120.0/21135.0.120.1 to 135.0.127.254135.0.127.2552,046
17135.0.128.0/21135.0.128.1 to 135.0.135.254135.0.135.2552,046
18135.0.136.0/21135.0.136.1 to 135.0.143.254135.0.143.2552,046
19135.0.144.0/21135.0.144.1 to 135.0.151.254135.0.151.2552,046
20135.0.152.0/21135.0.152.1 to 135.0.159.254135.0.159.2552,046
21135.0.160.0/21135.0.160.1 to 135.0.167.254135.0.167.2552,046
22135.0.168.0/21135.0.168.1 to 135.0.175.254135.0.175.2552,046
23135.0.176.0/21135.0.176.1 to 135.0.183.254135.0.183.2552,046
24135.0.184.0/21135.0.184.1 to 135.0.191.254135.0.191.2552,046
25135.0.192.0/21135.0.192.1 to 135.0.199.254135.0.199.2552,046
26135.0.200.0/21135.0.200.1 to 135.0.207.254135.0.207.2552,046
27135.0.208.0/21135.0.208.1 to 135.0.215.254135.0.215.2552,046
28135.0.216.0/21135.0.216.1 to 135.0.223.254135.0.223.2552,046
29135.0.224.0/21135.0.224.1 to 135.0.231.254135.0.231.2552,046
30135.0.232.0/21135.0.232.1 to 135.0.239.254135.0.239.2552,046
31135.0.240.0/21135.0.240.1 to 135.0.247.254135.0.247.2552,046
32135.0.248.0/21135.0.248.1 to 135.0.255.254135.0.255.2552,046
33135.1.0.0/21135.1.0.1 to 135.1.7.254135.1.7.2552,046
34135.1.8.0/21135.1.8.1 to 135.1.15.254135.1.15.2552,046
35135.1.16.0/21135.1.16.1 to 135.1.23.254135.1.23.2552,046
36135.1.24.0/21135.1.24.1 to 135.1.31.254135.1.31.2552,046
37135.1.32.0/21135.1.32.1 to 135.1.39.254135.1.39.2552,046
38135.1.40.0/21135.1.40.1 to 135.1.47.254135.1.47.2552,046
39135.1.48.0/21135.1.48.1 to 135.1.55.254135.1.55.2552,046
40135.1.56.0/21135.1.56.1 to 135.1.63.254135.1.63.2552,046
41135.1.64.0/21135.1.64.1 to 135.1.71.254135.1.71.2552,046
42135.1.72.0/21135.1.72.1 to 135.1.79.254135.1.79.2552,046
43135.1.80.0/21135.1.80.1 to 135.1.87.254135.1.87.2552,046
44135.1.88.0/21135.1.88.1 to 135.1.95.254135.1.95.2552,046
45135.1.96.0/21135.1.96.1 to 135.1.103.254135.1.103.2552,046
46135.1.104.0/21135.1.104.1 to 135.1.111.254135.1.111.2552,046
47135.1.112.0/21135.1.112.1 to 135.1.119.254135.1.119.2552,046
48135.1.120.0/21135.1.120.1 to 135.1.127.254135.1.127.2552,046
49135.1.128.0/21135.1.128.1 to 135.1.135.254135.1.135.2552,046
50135.1.136.0/21135.1.136.1 to 135.1.143.254135.1.143.2552,046
51135.1.144.0/21135.1.144.1 to 135.1.151.254135.1.151.2552,046
52135.1.152.0/21135.1.152.1 to 135.1.159.254135.1.159.2552,046
53135.1.160.0/21135.1.160.1 to 135.1.167.254135.1.167.2552,046
54135.1.168.0/21135.1.168.1 to 135.1.175.254135.1.175.2552,046
55135.1.176.0/21135.1.176.1 to 135.1.183.254135.1.183.2552,046
56135.1.184.0/21135.1.184.1 to 135.1.191.254135.1.191.2552,046
57135.1.192.0/21135.1.192.1 to 135.1.199.254135.1.199.2552,046
58135.1.200.0/21135.1.200.1 to 135.1.207.254135.1.207.2552,046
59135.1.208.0/21135.1.208.1 to 135.1.215.254135.1.215.2552,046
60135.1.216.0/21135.1.216.1 to 135.1.223.254135.1.223.2552,046
61135.1.224.0/21135.1.224.1 to 135.1.231.254135.1.231.2552,046
62135.1.232.0/21135.1.232.1 to 135.1.239.254135.1.239.2552,046
63135.1.240.0/21135.1.240.1 to 135.1.247.254135.1.247.2552,046
64135.1.248.0/21135.1.248.1 to 135.1.255.254135.1.255.2552,046
65135.2.0.0/21135.2.0.1 to 135.2.7.254135.2.7.2552,046
66135.2.8.0/21135.2.8.1 to 135.2.15.254135.2.15.2552,046
67135.2.16.0/21135.2.16.1 to 135.2.23.254135.2.23.2552,046
68135.2.24.0/21135.2.24.1 to 135.2.31.254135.2.31.2552,046
69135.2.32.0/21135.2.32.1 to 135.2.39.254135.2.39.2552,046
70135.2.40.0/21135.2.40.1 to 135.2.47.254135.2.47.2552,046
71135.2.48.0/21135.2.48.1 to 135.2.55.254135.2.55.2552,046
72135.2.56.0/21135.2.56.1 to 135.2.63.254135.2.63.2552,046
73135.2.64.0/21135.2.64.1 to 135.2.71.254135.2.71.2552,046
74135.2.72.0/21135.2.72.1 to 135.2.79.254135.2.79.2552,046
75135.2.80.0/21135.2.80.1 to 135.2.87.254135.2.87.2552,046
76135.2.88.0/21135.2.88.1 to 135.2.95.254135.2.95.2552,046
77135.2.96.0/21135.2.96.1 to 135.2.103.254135.2.103.2552,046
78135.2.104.0/21135.2.104.1 to 135.2.111.254135.2.111.2552,046
79135.2.112.0/21135.2.112.1 to 135.2.119.254135.2.119.2552,046
80135.2.120.0/21135.2.120.1 to 135.2.127.254135.2.127.2552,046
81135.2.128.0/21135.2.128.1 to 135.2.135.254135.2.135.2552,046
82135.2.136.0/21135.2.136.1 to 135.2.143.254135.2.143.2552,046
83135.2.144.0/21135.2.144.1 to 135.2.151.254135.2.151.2552,046
84135.2.152.0/21135.2.152.1 to 135.2.159.254135.2.159.2552,046
85135.2.160.0/21135.2.160.1 to 135.2.167.254135.2.167.2552,046
86135.2.168.0/21135.2.168.1 to 135.2.175.254135.2.175.2552,046
87135.2.176.0/21135.2.176.1 to 135.2.183.254135.2.183.2552,046
88135.2.184.0/21135.2.184.1 to 135.2.191.254135.2.191.2552,046
89135.2.192.0/21135.2.192.1 to 135.2.199.254135.2.199.2552,046
90135.2.200.0/21135.2.200.1 to 135.2.207.254135.2.207.2552,046
91135.2.208.0/21135.2.208.1 to 135.2.215.254135.2.215.2552,046
92135.2.216.0/21135.2.216.1 to 135.2.223.254135.2.223.2552,046
93135.2.224.0/21135.2.224.1 to 135.2.231.254135.2.231.2552,046
94135.2.232.0/21135.2.232.1 to 135.2.239.254135.2.239.2552,046
95135.2.240.0/21135.2.240.1 to 135.2.247.254135.2.247.2552,046
96135.2.248.0/21135.2.248.1 to 135.2.255.254135.2.255.2552,046
97135.3.0.0/21135.3.0.1 to 135.3.7.254135.3.7.2552,046
98135.3.8.0/21135.3.8.1 to 135.3.15.254135.3.15.2552,046
99135.3.16.0/21135.3.16.1 to 135.3.23.254135.3.23.2552,046
100135.3.24.0/21135.3.24.1 to 135.3.31.254135.3.31.2552,046
101135.3.32.0/21135.3.32.1 to 135.3.39.254135.3.39.2552,046
102135.3.40.0/21135.3.40.1 to 135.3.47.254135.3.47.2552,046
103135.3.48.0/21135.3.48.1 to 135.3.55.254135.3.55.2552,046
104135.3.56.0/21135.3.56.1 to 135.3.63.254135.3.63.2552,046
105135.3.64.0/21135.3.64.1 to 135.3.71.254135.3.71.2552,046
106135.3.72.0/21135.3.72.1 to 135.3.79.254135.3.79.2552,046
107135.3.80.0/21135.3.80.1 to 135.3.87.254135.3.87.2552,046
108135.3.88.0/21135.3.88.1 to 135.3.95.254135.3.95.2552,046
109135.3.96.0/21135.3.96.1 to 135.3.103.254135.3.103.2552,046
110135.3.104.0/21135.3.104.1 to 135.3.111.254135.3.111.2552,046
111135.3.112.0/21135.3.112.1 to 135.3.119.254135.3.119.2552,046
112135.3.120.0/21135.3.120.1 to 135.3.127.254135.3.127.2552,046
113135.3.128.0/21135.3.128.1 to 135.3.135.254135.3.135.2552,046
114135.3.136.0/21135.3.136.1 to 135.3.143.254135.3.143.2552,046
115135.3.144.0/21135.3.144.1 to 135.3.151.254135.3.151.2552,046
116135.3.152.0/21135.3.152.1 to 135.3.159.254135.3.159.2552,046
117135.3.160.0/21135.3.160.1 to 135.3.167.254135.3.167.2552,046
118135.3.168.0/21135.3.168.1 to 135.3.175.254135.3.175.2552,046
119135.3.176.0/21135.3.176.1 to 135.3.183.254135.3.183.2552,046
120135.3.184.0/21135.3.184.1 to 135.3.191.254135.3.191.2552,046
121135.3.192.0/21135.3.192.1 to 135.3.199.254135.3.199.2552,046
122135.3.200.0/21135.3.200.1 to 135.3.207.254135.3.207.2552,046
123135.3.208.0/21135.3.208.1 to 135.3.215.254135.3.215.2552,046
124135.3.216.0/21135.3.216.1 to 135.3.223.254135.3.223.2552,046
125135.3.224.0/21135.3.224.1 to 135.3.231.254135.3.231.2552,046
126135.3.232.0/21135.3.232.1 to 135.3.239.254135.3.239.2552,046
127135.3.240.0/21135.3.240.1 to 135.3.247.254135.3.247.2552,046
128135.3.248.0/21135.3.248.1 to 135.3.255.254135.3.255.2552,046
129135.4.0.0/21135.4.0.1 to 135.4.7.254135.4.7.2552,046
130135.4.8.0/21135.4.8.1 to 135.4.15.254135.4.15.2552,046
131135.4.16.0/21135.4.16.1 to 135.4.23.254135.4.23.2552,046
132135.4.24.0/21135.4.24.1 to 135.4.31.254135.4.31.2552,046
133135.4.32.0/21135.4.32.1 to 135.4.39.254135.4.39.2552,046
134135.4.40.0/21135.4.40.1 to 135.4.47.254135.4.47.2552,046
135135.4.48.0/21135.4.48.1 to 135.4.55.254135.4.55.2552,046
136135.4.56.0/21135.4.56.1 to 135.4.63.254135.4.63.2552,046
137135.4.64.0/21135.4.64.1 to 135.4.71.254135.4.71.2552,046
138135.4.72.0/21135.4.72.1 to 135.4.79.254135.4.79.2552,046
139135.4.80.0/21135.4.80.1 to 135.4.87.254135.4.87.2552,046
140135.4.88.0/21135.4.88.1 to 135.4.95.254135.4.95.2552,046
141135.4.96.0/21135.4.96.1 to 135.4.103.254135.4.103.2552,046
142135.4.104.0/21135.4.104.1 to 135.4.111.254135.4.111.2552,046
143135.4.112.0/21135.4.112.1 to 135.4.119.254135.4.119.2552,046
144135.4.120.0/21135.4.120.1 to 135.4.127.254135.4.127.2552,046
145135.4.128.0/21135.4.128.1 to 135.4.135.254135.4.135.2552,046
146135.4.136.0/21135.4.136.1 to 135.4.143.254135.4.143.2552,046
147135.4.144.0/21135.4.144.1 to 135.4.151.254135.4.151.2552,046
148135.4.152.0/21135.4.152.1 to 135.4.159.254135.4.159.2552,046
149135.4.160.0/21135.4.160.1 to 135.4.167.254135.4.167.2552,046
150135.4.168.0/21135.4.168.1 to 135.4.175.254135.4.175.2552,046
151135.4.176.0/21135.4.176.1 to 135.4.183.254135.4.183.2552,046
152135.4.184.0/21135.4.184.1 to 135.4.191.254135.4.191.2552,046
153135.4.192.0/21135.4.192.1 to 135.4.199.254135.4.199.2552,046
154135.4.200.0/21135.4.200.1 to 135.4.207.254135.4.207.2552,046
155135.4.208.0/21135.4.208.1 to 135.4.215.254135.4.215.2552,046
156135.4.216.0/21135.4.216.1 to 135.4.223.254135.4.223.2552,046
157135.4.224.0/21135.4.224.1 to 135.4.231.254135.4.231.2552,046
158135.4.232.0/21135.4.232.1 to 135.4.239.254135.4.239.2552,046
159135.4.240.0/21135.4.240.1 to 135.4.247.254135.4.247.2552,046
160135.4.248.0/21135.4.248.1 to 135.4.255.254135.4.255.2552,046
161135.5.0.0/21135.5.0.1 to 135.5.7.254135.5.7.2552,046
162135.5.8.0/21135.5.8.1 to 135.5.15.254135.5.15.2552,046
163135.5.16.0/21135.5.16.1 to 135.5.23.254135.5.23.2552,046
164135.5.24.0/21135.5.24.1 to 135.5.31.254135.5.31.2552,046
165135.5.32.0/21135.5.32.1 to 135.5.39.254135.5.39.2552,046
166135.5.40.0/21135.5.40.1 to 135.5.47.254135.5.47.2552,046
167135.5.48.0/21135.5.48.1 to 135.5.55.254135.5.55.2552,046
168135.5.56.0/21135.5.56.1 to 135.5.63.254135.5.63.2552,046
169135.5.64.0/21135.5.64.1 to 135.5.71.254135.5.71.2552,046
170135.5.72.0/21135.5.72.1 to 135.5.79.254135.5.79.2552,046
171135.5.80.0/21135.5.80.1 to 135.5.87.254135.5.87.2552,046
172135.5.88.0/21135.5.88.1 to 135.5.95.254135.5.95.2552,046
173135.5.96.0/21135.5.96.1 to 135.5.103.254135.5.103.2552,046
174135.5.104.0/21135.5.104.1 to 135.5.111.254135.5.111.2552,046
175135.5.112.0/21135.5.112.1 to 135.5.119.254135.5.119.2552,046
176135.5.120.0/21135.5.120.1 to 135.5.127.254135.5.127.2552,046
177135.5.128.0/21135.5.128.1 to 135.5.135.254135.5.135.2552,046
178135.5.136.0/21135.5.136.1 to 135.5.143.254135.5.143.2552,046
179135.5.144.0/21135.5.144.1 to 135.5.151.254135.5.151.2552,046
180135.5.152.0/21135.5.152.1 to 135.5.159.254135.5.159.2552,046
181135.5.160.0/21135.5.160.1 to 135.5.167.254135.5.167.2552,046
182135.5.168.0/21135.5.168.1 to 135.5.175.254135.5.175.2552,046
183135.5.176.0/21135.5.176.1 to 135.5.183.254135.5.183.2552,046
184135.5.184.0/21135.5.184.1 to 135.5.191.254135.5.191.2552,046
185135.5.192.0/21135.5.192.1 to 135.5.199.254135.5.199.2552,046
186135.5.200.0/21135.5.200.1 to 135.5.207.254135.5.207.2552,046
187135.5.208.0/21135.5.208.1 to 135.5.215.254135.5.215.2552,046
188135.5.216.0/21135.5.216.1 to 135.5.223.254135.5.223.2552,046
189135.5.224.0/21135.5.224.1 to 135.5.231.254135.5.231.2552,046
190135.5.232.0/21135.5.232.1 to 135.5.239.254135.5.239.2552,046
191135.5.240.0/21135.5.240.1 to 135.5.247.254135.5.247.2552,046
192135.5.248.0/21135.5.248.1 to 135.5.255.254135.5.255.2552,046
193135.6.0.0/21135.6.0.1 to 135.6.7.254135.6.7.2552,046
194135.6.8.0/21135.6.8.1 to 135.6.15.254135.6.15.2552,046
195135.6.16.0/21135.6.16.1 to 135.6.23.254135.6.23.2552,046
196135.6.24.0/21135.6.24.1 to 135.6.31.254135.6.31.2552,046
197135.6.32.0/21135.6.32.1 to 135.6.39.254135.6.39.2552,046
198135.6.40.0/21135.6.40.1 to 135.6.47.254135.6.47.2552,046
199135.6.48.0/21135.6.48.1 to 135.6.55.254135.6.55.2552,046
200135.6.56.0/21135.6.56.1 to 135.6.63.254135.6.63.2552,046
201135.6.64.0/21135.6.64.1 to 135.6.71.254135.6.71.2552,046
202135.6.72.0/21135.6.72.1 to 135.6.79.254135.6.79.2552,046
203135.6.80.0/21135.6.80.1 to 135.6.87.254135.6.87.2552,046
204135.6.88.0/21135.6.88.1 to 135.6.95.254135.6.95.2552,046
205135.6.96.0/21135.6.96.1 to 135.6.103.254135.6.103.2552,046
206135.6.104.0/21135.6.104.1 to 135.6.111.254135.6.111.2552,046
207135.6.112.0/21135.6.112.1 to 135.6.119.254135.6.119.2552,046
208135.6.120.0/21135.6.120.1 to 135.6.127.254135.6.127.2552,046
209135.6.128.0/21135.6.128.1 to 135.6.135.254135.6.135.2552,046
210135.6.136.0/21135.6.136.1 to 135.6.143.254135.6.143.2552,046
211135.6.144.0/21135.6.144.1 to 135.6.151.254135.6.151.2552,046
212135.6.152.0/21135.6.152.1 to 135.6.159.254135.6.159.2552,046
213135.6.160.0/21135.6.160.1 to 135.6.167.254135.6.167.2552,046
214135.6.168.0/21135.6.168.1 to 135.6.175.254135.6.175.2552,046
215135.6.176.0/21135.6.176.1 to 135.6.183.254135.6.183.2552,046
216135.6.184.0/21135.6.184.1 to 135.6.191.254135.6.191.2552,046
217135.6.192.0/21135.6.192.1 to 135.6.199.254135.6.199.2552,046
218135.6.200.0/21135.6.200.1 to 135.6.207.254135.6.207.2552,046
219135.6.208.0/21135.6.208.1 to 135.6.215.254135.6.215.2552,046
220135.6.216.0/21135.6.216.1 to 135.6.223.254135.6.223.2552,046
221135.6.224.0/21135.6.224.1 to 135.6.231.254135.6.231.2552,046
222135.6.232.0/21135.6.232.1 to 135.6.239.254135.6.239.2552,046
223135.6.240.0/21135.6.240.1 to 135.6.247.254135.6.247.2552,046
224135.6.248.0/21135.6.248.1 to 135.6.255.254135.6.255.2552,046
225135.7.0.0/21135.7.0.1 to 135.7.7.254135.7.7.2552,046
226135.7.8.0/21135.7.8.1 to 135.7.15.254135.7.15.2552,046
227135.7.16.0/21135.7.16.1 to 135.7.23.254135.7.23.2552,046
228135.7.24.0/21135.7.24.1 to 135.7.31.254135.7.31.2552,046
229135.7.32.0/21135.7.32.1 to 135.7.39.254135.7.39.2552,046
230135.7.40.0/21135.7.40.1 to 135.7.47.254135.7.47.2552,046
231135.7.48.0/21135.7.48.1 to 135.7.55.254135.7.55.2552,046
232135.7.56.0/21135.7.56.1 to 135.7.63.254135.7.63.2552,046
233135.7.64.0/21135.7.64.1 to 135.7.71.254135.7.71.2552,046
234135.7.72.0/21135.7.72.1 to 135.7.79.254135.7.79.2552,046
235135.7.80.0/21135.7.80.1 to 135.7.87.254135.7.87.2552,046
236135.7.88.0/21135.7.88.1 to 135.7.95.254135.7.95.2552,046
237135.7.96.0/21135.7.96.1 to 135.7.103.254135.7.103.2552,046
238135.7.104.0/21135.7.104.1 to 135.7.111.254135.7.111.2552,046
239135.7.112.0/21135.7.112.1 to 135.7.119.254135.7.119.2552,046
240135.7.120.0/21135.7.120.1 to 135.7.127.254135.7.127.2552,046
241135.7.128.0/21135.7.128.1 to 135.7.135.254135.7.135.2552,046
242135.7.136.0/21135.7.136.1 to 135.7.143.254135.7.143.2552,046
243135.7.144.0/21135.7.144.1 to 135.7.151.254135.7.151.2552,046
244135.7.152.0/21135.7.152.1 to 135.7.159.254135.7.159.2552,046
245135.7.160.0/21135.7.160.1 to 135.7.167.254135.7.167.2552,046
246135.7.168.0/21135.7.168.1 to 135.7.175.254135.7.175.2552,046
247135.7.176.0/21135.7.176.1 to 135.7.183.254135.7.183.2552,046
248135.7.184.0/21135.7.184.1 to 135.7.191.254135.7.191.2552,046
249135.7.192.0/21135.7.192.1 to 135.7.199.254135.7.199.2552,046
250135.7.200.0/21135.7.200.1 to 135.7.207.254135.7.207.2552,046
251135.7.208.0/21135.7.208.1 to 135.7.215.254135.7.215.2552,046
252135.7.216.0/21135.7.216.1 to 135.7.223.254135.7.223.2552,046
253135.7.224.0/21135.7.224.1 to 135.7.231.254135.7.231.2552,046
254135.7.232.0/21135.7.232.1 to 135.7.239.254135.7.239.2552,046
255135.7.240.0/21135.7.240.1 to 135.7.247.254135.7.247.2552,046
256135.7.248.0/21135.7.248.1 to 135.7.255.254135.7.255.2552,046

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.