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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.

Network135.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
135.0.0.0
Broadcast address
135.255.255.255
First usable
135.0.0.1
Last usable
135.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
B (default /16)
As numbers
Hex 87000000 · Integer 2264924160 to 2281701375
Reverse DNS zone
135.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10000111..00000000.00000000.00000000135.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10000111..00000000.00000000.00000000135.0.0.0
Broadcast10000111..11111111.11111111.11111111135.255.255.255
Split into smaller subnets/19
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

135.0.0.0/8 makes 2,048 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1135.0.0.0/19135.0.0.1 to 135.0.31.254135.0.31.2558,190
2135.0.32.0/19135.0.32.1 to 135.0.63.254135.0.63.2558,190
3135.0.64.0/19135.0.64.1 to 135.0.95.254135.0.95.2558,190
4135.0.96.0/19135.0.96.1 to 135.0.127.254135.0.127.2558,190
5135.0.128.0/19135.0.128.1 to 135.0.159.254135.0.159.2558,190
6135.0.160.0/19135.0.160.1 to 135.0.191.254135.0.191.2558,190
7135.0.192.0/19135.0.192.1 to 135.0.223.254135.0.223.2558,190
8135.0.224.0/19135.0.224.1 to 135.0.255.254135.0.255.2558,190
9135.1.0.0/19135.1.0.1 to 135.1.31.254135.1.31.2558,190
10135.1.32.0/19135.1.32.1 to 135.1.63.254135.1.63.2558,190
11135.1.64.0/19135.1.64.1 to 135.1.95.254135.1.95.2558,190
12135.1.96.0/19135.1.96.1 to 135.1.127.254135.1.127.2558,190
13135.1.128.0/19135.1.128.1 to 135.1.159.254135.1.159.2558,190
14135.1.160.0/19135.1.160.1 to 135.1.191.254135.1.191.2558,190
15135.1.192.0/19135.1.192.1 to 135.1.223.254135.1.223.2558,190
16135.1.224.0/19135.1.224.1 to 135.1.255.254135.1.255.2558,190
17135.2.0.0/19135.2.0.1 to 135.2.31.254135.2.31.2558,190
18135.2.32.0/19135.2.32.1 to 135.2.63.254135.2.63.2558,190
19135.2.64.0/19135.2.64.1 to 135.2.95.254135.2.95.2558,190
20135.2.96.0/19135.2.96.1 to 135.2.127.254135.2.127.2558,190
21135.2.128.0/19135.2.128.1 to 135.2.159.254135.2.159.2558,190
22135.2.160.0/19135.2.160.1 to 135.2.191.254135.2.191.2558,190
23135.2.192.0/19135.2.192.1 to 135.2.223.254135.2.223.2558,190
24135.2.224.0/19135.2.224.1 to 135.2.255.254135.2.255.2558,190
25135.3.0.0/19135.3.0.1 to 135.3.31.254135.3.31.2558,190
26135.3.32.0/19135.3.32.1 to 135.3.63.254135.3.63.2558,190
27135.3.64.0/19135.3.64.1 to 135.3.95.254135.3.95.2558,190
28135.3.96.0/19135.3.96.1 to 135.3.127.254135.3.127.2558,190
29135.3.128.0/19135.3.128.1 to 135.3.159.254135.3.159.2558,190
30135.3.160.0/19135.3.160.1 to 135.3.191.254135.3.191.2558,190
31135.3.192.0/19135.3.192.1 to 135.3.223.254135.3.223.2558,190
32135.3.224.0/19135.3.224.1 to 135.3.255.254135.3.255.2558,190
33135.4.0.0/19135.4.0.1 to 135.4.31.254135.4.31.2558,190
34135.4.32.0/19135.4.32.1 to 135.4.63.254135.4.63.2558,190
35135.4.64.0/19135.4.64.1 to 135.4.95.254135.4.95.2558,190
36135.4.96.0/19135.4.96.1 to 135.4.127.254135.4.127.2558,190
37135.4.128.0/19135.4.128.1 to 135.4.159.254135.4.159.2558,190
38135.4.160.0/19135.4.160.1 to 135.4.191.254135.4.191.2558,190
39135.4.192.0/19135.4.192.1 to 135.4.223.254135.4.223.2558,190
40135.4.224.0/19135.4.224.1 to 135.4.255.254135.4.255.2558,190
41135.5.0.0/19135.5.0.1 to 135.5.31.254135.5.31.2558,190
42135.5.32.0/19135.5.32.1 to 135.5.63.254135.5.63.2558,190
43135.5.64.0/19135.5.64.1 to 135.5.95.254135.5.95.2558,190
44135.5.96.0/19135.5.96.1 to 135.5.127.254135.5.127.2558,190
45135.5.128.0/19135.5.128.1 to 135.5.159.254135.5.159.2558,190
46135.5.160.0/19135.5.160.1 to 135.5.191.254135.5.191.2558,190
47135.5.192.0/19135.5.192.1 to 135.5.223.254135.5.223.2558,190
48135.5.224.0/19135.5.224.1 to 135.5.255.254135.5.255.2558,190
49135.6.0.0/19135.6.0.1 to 135.6.31.254135.6.31.2558,190
50135.6.32.0/19135.6.32.1 to 135.6.63.254135.6.63.2558,190
51135.6.64.0/19135.6.64.1 to 135.6.95.254135.6.95.2558,190
52135.6.96.0/19135.6.96.1 to 135.6.127.254135.6.127.2558,190
53135.6.128.0/19135.6.128.1 to 135.6.159.254135.6.159.2558,190
54135.6.160.0/19135.6.160.1 to 135.6.191.254135.6.191.2558,190
55135.6.192.0/19135.6.192.1 to 135.6.223.254135.6.223.2558,190
56135.6.224.0/19135.6.224.1 to 135.6.255.254135.6.255.2558,190
57135.7.0.0/19135.7.0.1 to 135.7.31.254135.7.31.2558,190
58135.7.32.0/19135.7.32.1 to 135.7.63.254135.7.63.2558,190
59135.7.64.0/19135.7.64.1 to 135.7.95.254135.7.95.2558,190
60135.7.96.0/19135.7.96.1 to 135.7.127.254135.7.127.2558,190
61135.7.128.0/19135.7.128.1 to 135.7.159.254135.7.159.2558,190
62135.7.160.0/19135.7.160.1 to 135.7.191.254135.7.191.2558,190
63135.7.192.0/19135.7.192.1 to 135.7.223.254135.7.223.2558,190
64135.7.224.0/19135.7.224.1 to 135.7.255.254135.7.255.2558,190
65135.8.0.0/19135.8.0.1 to 135.8.31.254135.8.31.2558,190
66135.8.32.0/19135.8.32.1 to 135.8.63.254135.8.63.2558,190
67135.8.64.0/19135.8.64.1 to 135.8.95.254135.8.95.2558,190
68135.8.96.0/19135.8.96.1 to 135.8.127.254135.8.127.2558,190
69135.8.128.0/19135.8.128.1 to 135.8.159.254135.8.159.2558,190
70135.8.160.0/19135.8.160.1 to 135.8.191.254135.8.191.2558,190
71135.8.192.0/19135.8.192.1 to 135.8.223.254135.8.223.2558,190
72135.8.224.0/19135.8.224.1 to 135.8.255.254135.8.255.2558,190
73135.9.0.0/19135.9.0.1 to 135.9.31.254135.9.31.2558,190
74135.9.32.0/19135.9.32.1 to 135.9.63.254135.9.63.2558,190
75135.9.64.0/19135.9.64.1 to 135.9.95.254135.9.95.2558,190
76135.9.96.0/19135.9.96.1 to 135.9.127.254135.9.127.2558,190
77135.9.128.0/19135.9.128.1 to 135.9.159.254135.9.159.2558,190
78135.9.160.0/19135.9.160.1 to 135.9.191.254135.9.191.2558,190
79135.9.192.0/19135.9.192.1 to 135.9.223.254135.9.223.2558,190
80135.9.224.0/19135.9.224.1 to 135.9.255.254135.9.255.2558,190
81135.10.0.0/19135.10.0.1 to 135.10.31.254135.10.31.2558,190
82135.10.32.0/19135.10.32.1 to 135.10.63.254135.10.63.2558,190
83135.10.64.0/19135.10.64.1 to 135.10.95.254135.10.95.2558,190
84135.10.96.0/19135.10.96.1 to 135.10.127.254135.10.127.2558,190
85135.10.128.0/19135.10.128.1 to 135.10.159.254135.10.159.2558,190
86135.10.160.0/19135.10.160.1 to 135.10.191.254135.10.191.2558,190
87135.10.192.0/19135.10.192.1 to 135.10.223.254135.10.223.2558,190
88135.10.224.0/19135.10.224.1 to 135.10.255.254135.10.255.2558,190
89135.11.0.0/19135.11.0.1 to 135.11.31.254135.11.31.2558,190
90135.11.32.0/19135.11.32.1 to 135.11.63.254135.11.63.2558,190
91135.11.64.0/19135.11.64.1 to 135.11.95.254135.11.95.2558,190
92135.11.96.0/19135.11.96.1 to 135.11.127.254135.11.127.2558,190
93135.11.128.0/19135.11.128.1 to 135.11.159.254135.11.159.2558,190
94135.11.160.0/19135.11.160.1 to 135.11.191.254135.11.191.2558,190
95135.11.192.0/19135.11.192.1 to 135.11.223.254135.11.223.2558,190
96135.11.224.0/19135.11.224.1 to 135.11.255.254135.11.255.2558,190
97135.12.0.0/19135.12.0.1 to 135.12.31.254135.12.31.2558,190
98135.12.32.0/19135.12.32.1 to 135.12.63.254135.12.63.2558,190
99135.12.64.0/19135.12.64.1 to 135.12.95.254135.12.95.2558,190
100135.12.96.0/19135.12.96.1 to 135.12.127.254135.12.127.2558,190
101135.12.128.0/19135.12.128.1 to 135.12.159.254135.12.159.2558,190
102135.12.160.0/19135.12.160.1 to 135.12.191.254135.12.191.2558,190
103135.12.192.0/19135.12.192.1 to 135.12.223.254135.12.223.2558,190
104135.12.224.0/19135.12.224.1 to 135.12.255.254135.12.255.2558,190
105135.13.0.0/19135.13.0.1 to 135.13.31.254135.13.31.2558,190
106135.13.32.0/19135.13.32.1 to 135.13.63.254135.13.63.2558,190
107135.13.64.0/19135.13.64.1 to 135.13.95.254135.13.95.2558,190
108135.13.96.0/19135.13.96.1 to 135.13.127.254135.13.127.2558,190
109135.13.128.0/19135.13.128.1 to 135.13.159.254135.13.159.2558,190
110135.13.160.0/19135.13.160.1 to 135.13.191.254135.13.191.2558,190
111135.13.192.0/19135.13.192.1 to 135.13.223.254135.13.223.2558,190
112135.13.224.0/19135.13.224.1 to 135.13.255.254135.13.255.2558,190
113135.14.0.0/19135.14.0.1 to 135.14.31.254135.14.31.2558,190
114135.14.32.0/19135.14.32.1 to 135.14.63.254135.14.63.2558,190
115135.14.64.0/19135.14.64.1 to 135.14.95.254135.14.95.2558,190
116135.14.96.0/19135.14.96.1 to 135.14.127.254135.14.127.2558,190
117135.14.128.0/19135.14.128.1 to 135.14.159.254135.14.159.2558,190
118135.14.160.0/19135.14.160.1 to 135.14.191.254135.14.191.2558,190
119135.14.192.0/19135.14.192.1 to 135.14.223.254135.14.223.2558,190
120135.14.224.0/19135.14.224.1 to 135.14.255.254135.14.255.2558,190
121135.15.0.0/19135.15.0.1 to 135.15.31.254135.15.31.2558,190
122135.15.32.0/19135.15.32.1 to 135.15.63.254135.15.63.2558,190
123135.15.64.0/19135.15.64.1 to 135.15.95.254135.15.95.2558,190
124135.15.96.0/19135.15.96.1 to 135.15.127.254135.15.127.2558,190
125135.15.128.0/19135.15.128.1 to 135.15.159.254135.15.159.2558,190
126135.15.160.0/19135.15.160.1 to 135.15.191.254135.15.191.2558,190
127135.15.192.0/19135.15.192.1 to 135.15.223.254135.15.223.2558,190
128135.15.224.0/19135.15.224.1 to 135.15.255.254135.15.255.2558,190
129135.16.0.0/19135.16.0.1 to 135.16.31.254135.16.31.2558,190
130135.16.32.0/19135.16.32.1 to 135.16.63.254135.16.63.2558,190
131135.16.64.0/19135.16.64.1 to 135.16.95.254135.16.95.2558,190
132135.16.96.0/19135.16.96.1 to 135.16.127.254135.16.127.2558,190
133135.16.128.0/19135.16.128.1 to 135.16.159.254135.16.159.2558,190
134135.16.160.0/19135.16.160.1 to 135.16.191.254135.16.191.2558,190
135135.16.192.0/19135.16.192.1 to 135.16.223.254135.16.223.2558,190
136135.16.224.0/19135.16.224.1 to 135.16.255.254135.16.255.2558,190
137135.17.0.0/19135.17.0.1 to 135.17.31.254135.17.31.2558,190
138135.17.32.0/19135.17.32.1 to 135.17.63.254135.17.63.2558,190
139135.17.64.0/19135.17.64.1 to 135.17.95.254135.17.95.2558,190
140135.17.96.0/19135.17.96.1 to 135.17.127.254135.17.127.2558,190
141135.17.128.0/19135.17.128.1 to 135.17.159.254135.17.159.2558,190
142135.17.160.0/19135.17.160.1 to 135.17.191.254135.17.191.2558,190
143135.17.192.0/19135.17.192.1 to 135.17.223.254135.17.223.2558,190
144135.17.224.0/19135.17.224.1 to 135.17.255.254135.17.255.2558,190
145135.18.0.0/19135.18.0.1 to 135.18.31.254135.18.31.2558,190
146135.18.32.0/19135.18.32.1 to 135.18.63.254135.18.63.2558,190
147135.18.64.0/19135.18.64.1 to 135.18.95.254135.18.95.2558,190
148135.18.96.0/19135.18.96.1 to 135.18.127.254135.18.127.2558,190
149135.18.128.0/19135.18.128.1 to 135.18.159.254135.18.159.2558,190
150135.18.160.0/19135.18.160.1 to 135.18.191.254135.18.191.2558,190
151135.18.192.0/19135.18.192.1 to 135.18.223.254135.18.223.2558,190
152135.18.224.0/19135.18.224.1 to 135.18.255.254135.18.255.2558,190
153135.19.0.0/19135.19.0.1 to 135.19.31.254135.19.31.2558,190
154135.19.32.0/19135.19.32.1 to 135.19.63.254135.19.63.2558,190
155135.19.64.0/19135.19.64.1 to 135.19.95.254135.19.95.2558,190
156135.19.96.0/19135.19.96.1 to 135.19.127.254135.19.127.2558,190
157135.19.128.0/19135.19.128.1 to 135.19.159.254135.19.159.2558,190
158135.19.160.0/19135.19.160.1 to 135.19.191.254135.19.191.2558,190
159135.19.192.0/19135.19.192.1 to 135.19.223.254135.19.223.2558,190
160135.19.224.0/19135.19.224.1 to 135.19.255.254135.19.255.2558,190
161135.20.0.0/19135.20.0.1 to 135.20.31.254135.20.31.2558,190
162135.20.32.0/19135.20.32.1 to 135.20.63.254135.20.63.2558,190
163135.20.64.0/19135.20.64.1 to 135.20.95.254135.20.95.2558,190
164135.20.96.0/19135.20.96.1 to 135.20.127.254135.20.127.2558,190
165135.20.128.0/19135.20.128.1 to 135.20.159.254135.20.159.2558,190
166135.20.160.0/19135.20.160.1 to 135.20.191.254135.20.191.2558,190
167135.20.192.0/19135.20.192.1 to 135.20.223.254135.20.223.2558,190
168135.20.224.0/19135.20.224.1 to 135.20.255.254135.20.255.2558,190
169135.21.0.0/19135.21.0.1 to 135.21.31.254135.21.31.2558,190
170135.21.32.0/19135.21.32.1 to 135.21.63.254135.21.63.2558,190
171135.21.64.0/19135.21.64.1 to 135.21.95.254135.21.95.2558,190
172135.21.96.0/19135.21.96.1 to 135.21.127.254135.21.127.2558,190
173135.21.128.0/19135.21.128.1 to 135.21.159.254135.21.159.2558,190
174135.21.160.0/19135.21.160.1 to 135.21.191.254135.21.191.2558,190
175135.21.192.0/19135.21.192.1 to 135.21.223.254135.21.223.2558,190
176135.21.224.0/19135.21.224.1 to 135.21.255.254135.21.255.2558,190
177135.22.0.0/19135.22.0.1 to 135.22.31.254135.22.31.2558,190
178135.22.32.0/19135.22.32.1 to 135.22.63.254135.22.63.2558,190
179135.22.64.0/19135.22.64.1 to 135.22.95.254135.22.95.2558,190
180135.22.96.0/19135.22.96.1 to 135.22.127.254135.22.127.2558,190
181135.22.128.0/19135.22.128.1 to 135.22.159.254135.22.159.2558,190
182135.22.160.0/19135.22.160.1 to 135.22.191.254135.22.191.2558,190
183135.22.192.0/19135.22.192.1 to 135.22.223.254135.22.223.2558,190
184135.22.224.0/19135.22.224.1 to 135.22.255.254135.22.255.2558,190
185135.23.0.0/19135.23.0.1 to 135.23.31.254135.23.31.2558,190
186135.23.32.0/19135.23.32.1 to 135.23.63.254135.23.63.2558,190
187135.23.64.0/19135.23.64.1 to 135.23.95.254135.23.95.2558,190
188135.23.96.0/19135.23.96.1 to 135.23.127.254135.23.127.2558,190
189135.23.128.0/19135.23.128.1 to 135.23.159.254135.23.159.2558,190
190135.23.160.0/19135.23.160.1 to 135.23.191.254135.23.191.2558,190
191135.23.192.0/19135.23.192.1 to 135.23.223.254135.23.223.2558,190
192135.23.224.0/19135.23.224.1 to 135.23.255.254135.23.255.2558,190
193135.24.0.0/19135.24.0.1 to 135.24.31.254135.24.31.2558,190
194135.24.32.0/19135.24.32.1 to 135.24.63.254135.24.63.2558,190
195135.24.64.0/19135.24.64.1 to 135.24.95.254135.24.95.2558,190
196135.24.96.0/19135.24.96.1 to 135.24.127.254135.24.127.2558,190
197135.24.128.0/19135.24.128.1 to 135.24.159.254135.24.159.2558,190
198135.24.160.0/19135.24.160.1 to 135.24.191.254135.24.191.2558,190
199135.24.192.0/19135.24.192.1 to 135.24.223.254135.24.223.2558,190
200135.24.224.0/19135.24.224.1 to 135.24.255.254135.24.255.2558,190
201135.25.0.0/19135.25.0.1 to 135.25.31.254135.25.31.2558,190
202135.25.32.0/19135.25.32.1 to 135.25.63.254135.25.63.2558,190
203135.25.64.0/19135.25.64.1 to 135.25.95.254135.25.95.2558,190
204135.25.96.0/19135.25.96.1 to 135.25.127.254135.25.127.2558,190
205135.25.128.0/19135.25.128.1 to 135.25.159.254135.25.159.2558,190
206135.25.160.0/19135.25.160.1 to 135.25.191.254135.25.191.2558,190
207135.25.192.0/19135.25.192.1 to 135.25.223.254135.25.223.2558,190
208135.25.224.0/19135.25.224.1 to 135.25.255.254135.25.255.2558,190
209135.26.0.0/19135.26.0.1 to 135.26.31.254135.26.31.2558,190
210135.26.32.0/19135.26.32.1 to 135.26.63.254135.26.63.2558,190
211135.26.64.0/19135.26.64.1 to 135.26.95.254135.26.95.2558,190
212135.26.96.0/19135.26.96.1 to 135.26.127.254135.26.127.2558,190
213135.26.128.0/19135.26.128.1 to 135.26.159.254135.26.159.2558,190
214135.26.160.0/19135.26.160.1 to 135.26.191.254135.26.191.2558,190
215135.26.192.0/19135.26.192.1 to 135.26.223.254135.26.223.2558,190
216135.26.224.0/19135.26.224.1 to 135.26.255.254135.26.255.2558,190
217135.27.0.0/19135.27.0.1 to 135.27.31.254135.27.31.2558,190
218135.27.32.0/19135.27.32.1 to 135.27.63.254135.27.63.2558,190
219135.27.64.0/19135.27.64.1 to 135.27.95.254135.27.95.2558,190
220135.27.96.0/19135.27.96.1 to 135.27.127.254135.27.127.2558,190
221135.27.128.0/19135.27.128.1 to 135.27.159.254135.27.159.2558,190
222135.27.160.0/19135.27.160.1 to 135.27.191.254135.27.191.2558,190
223135.27.192.0/19135.27.192.1 to 135.27.223.254135.27.223.2558,190
224135.27.224.0/19135.27.224.1 to 135.27.255.254135.27.255.2558,190
225135.28.0.0/19135.28.0.1 to 135.28.31.254135.28.31.2558,190
226135.28.32.0/19135.28.32.1 to 135.28.63.254135.28.63.2558,190
227135.28.64.0/19135.28.64.1 to 135.28.95.254135.28.95.2558,190
228135.28.96.0/19135.28.96.1 to 135.28.127.254135.28.127.2558,190
229135.28.128.0/19135.28.128.1 to 135.28.159.254135.28.159.2558,190
230135.28.160.0/19135.28.160.1 to 135.28.191.254135.28.191.2558,190
231135.28.192.0/19135.28.192.1 to 135.28.223.254135.28.223.2558,190
232135.28.224.0/19135.28.224.1 to 135.28.255.254135.28.255.2558,190
233135.29.0.0/19135.29.0.1 to 135.29.31.254135.29.31.2558,190
234135.29.32.0/19135.29.32.1 to 135.29.63.254135.29.63.2558,190
235135.29.64.0/19135.29.64.1 to 135.29.95.254135.29.95.2558,190
236135.29.96.0/19135.29.96.1 to 135.29.127.254135.29.127.2558,190
237135.29.128.0/19135.29.128.1 to 135.29.159.254135.29.159.2558,190
238135.29.160.0/19135.29.160.1 to 135.29.191.254135.29.191.2558,190
239135.29.192.0/19135.29.192.1 to 135.29.223.254135.29.223.2558,190
240135.29.224.0/19135.29.224.1 to 135.29.255.254135.29.255.2558,190
241135.30.0.0/19135.30.0.1 to 135.30.31.254135.30.31.2558,190
242135.30.32.0/19135.30.32.1 to 135.30.63.254135.30.63.2558,190
243135.30.64.0/19135.30.64.1 to 135.30.95.254135.30.95.2558,190
244135.30.96.0/19135.30.96.1 to 135.30.127.254135.30.127.2558,190
245135.30.128.0/19135.30.128.1 to 135.30.159.254135.30.159.2558,190
246135.30.160.0/19135.30.160.1 to 135.30.191.254135.30.191.2558,190
247135.30.192.0/19135.30.192.1 to 135.30.223.254135.30.223.2558,190
248135.30.224.0/19135.30.224.1 to 135.30.255.254135.30.255.2558,190
249135.31.0.0/19135.31.0.1 to 135.31.31.254135.31.31.2558,190
250135.31.32.0/19135.31.32.1 to 135.31.63.254135.31.63.2558,190
251135.31.64.0/19135.31.64.1 to 135.31.95.254135.31.95.2558,190
252135.31.96.0/19135.31.96.1 to 135.31.127.254135.31.127.2558,190
253135.31.128.0/19135.31.128.1 to 135.31.159.254135.31.159.2558,190
254135.31.160.0/19135.31.160.1 to 135.31.191.254135.31.191.2558,190
255135.31.192.0/19135.31.192.1 to 135.31.223.254135.31.223.2558,190
256135.31.224.0/19135.31.224.1 to 135.31.255.254135.31.255.2558,190

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.