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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.

Network175.136.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
175.136.0.0
Broadcast address
175.137.255.255
First usable
175.136.0.1
Last usable
175.137.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
B (default /16)
As numbers
Hex AF880000 · Integer 2944925696 to 2945056767
Reverse DNS zones
136.175.in-addr.arpa
137.175.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10101111.10001000.00000000.00000000175.136.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network10101111.10001000.00000000.00000000175.136.0.0
Broadcast10101111.10001001.11111111.11111111175.137.255.255
Split into smaller subnets/27
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

175.136.0.0/15 makes 4,096 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1175.136.0.0/27175.136.0.1 to 175.136.0.30175.136.0.3130
2175.136.0.32/27175.136.0.33 to 175.136.0.62175.136.0.6330
3175.136.0.64/27175.136.0.65 to 175.136.0.94175.136.0.9530
4175.136.0.96/27175.136.0.97 to 175.136.0.126175.136.0.12730
5175.136.0.128/27175.136.0.129 to 175.136.0.158175.136.0.15930
6175.136.0.160/27175.136.0.161 to 175.136.0.190175.136.0.19130
7175.136.0.192/27175.136.0.193 to 175.136.0.222175.136.0.22330
8175.136.0.224/27175.136.0.225 to 175.136.0.254175.136.0.25530
9175.136.1.0/27175.136.1.1 to 175.136.1.30175.136.1.3130
10175.136.1.32/27175.136.1.33 to 175.136.1.62175.136.1.6330
11175.136.1.64/27175.136.1.65 to 175.136.1.94175.136.1.9530
12175.136.1.96/27175.136.1.97 to 175.136.1.126175.136.1.12730
13175.136.1.128/27175.136.1.129 to 175.136.1.158175.136.1.15930
14175.136.1.160/27175.136.1.161 to 175.136.1.190175.136.1.19130
15175.136.1.192/27175.136.1.193 to 175.136.1.222175.136.1.22330
16175.136.1.224/27175.136.1.225 to 175.136.1.254175.136.1.25530
17175.136.2.0/27175.136.2.1 to 175.136.2.30175.136.2.3130
18175.136.2.32/27175.136.2.33 to 175.136.2.62175.136.2.6330
19175.136.2.64/27175.136.2.65 to 175.136.2.94175.136.2.9530
20175.136.2.96/27175.136.2.97 to 175.136.2.126175.136.2.12730
21175.136.2.128/27175.136.2.129 to 175.136.2.158175.136.2.15930
22175.136.2.160/27175.136.2.161 to 175.136.2.190175.136.2.19130
23175.136.2.192/27175.136.2.193 to 175.136.2.222175.136.2.22330
24175.136.2.224/27175.136.2.225 to 175.136.2.254175.136.2.25530
25175.136.3.0/27175.136.3.1 to 175.136.3.30175.136.3.3130
26175.136.3.32/27175.136.3.33 to 175.136.3.62175.136.3.6330
27175.136.3.64/27175.136.3.65 to 175.136.3.94175.136.3.9530
28175.136.3.96/27175.136.3.97 to 175.136.3.126175.136.3.12730
29175.136.3.128/27175.136.3.129 to 175.136.3.158175.136.3.15930
30175.136.3.160/27175.136.3.161 to 175.136.3.190175.136.3.19130
31175.136.3.192/27175.136.3.193 to 175.136.3.222175.136.3.22330
32175.136.3.224/27175.136.3.225 to 175.136.3.254175.136.3.25530
33175.136.4.0/27175.136.4.1 to 175.136.4.30175.136.4.3130
34175.136.4.32/27175.136.4.33 to 175.136.4.62175.136.4.6330
35175.136.4.64/27175.136.4.65 to 175.136.4.94175.136.4.9530
36175.136.4.96/27175.136.4.97 to 175.136.4.126175.136.4.12730
37175.136.4.128/27175.136.4.129 to 175.136.4.158175.136.4.15930
38175.136.4.160/27175.136.4.161 to 175.136.4.190175.136.4.19130
39175.136.4.192/27175.136.4.193 to 175.136.4.222175.136.4.22330
40175.136.4.224/27175.136.4.225 to 175.136.4.254175.136.4.25530
41175.136.5.0/27175.136.5.1 to 175.136.5.30175.136.5.3130
42175.136.5.32/27175.136.5.33 to 175.136.5.62175.136.5.6330
43175.136.5.64/27175.136.5.65 to 175.136.5.94175.136.5.9530
44175.136.5.96/27175.136.5.97 to 175.136.5.126175.136.5.12730
45175.136.5.128/27175.136.5.129 to 175.136.5.158175.136.5.15930
46175.136.5.160/27175.136.5.161 to 175.136.5.190175.136.5.19130
47175.136.5.192/27175.136.5.193 to 175.136.5.222175.136.5.22330
48175.136.5.224/27175.136.5.225 to 175.136.5.254175.136.5.25530
49175.136.6.0/27175.136.6.1 to 175.136.6.30175.136.6.3130
50175.136.6.32/27175.136.6.33 to 175.136.6.62175.136.6.6330
51175.136.6.64/27175.136.6.65 to 175.136.6.94175.136.6.9530
52175.136.6.96/27175.136.6.97 to 175.136.6.126175.136.6.12730
53175.136.6.128/27175.136.6.129 to 175.136.6.158175.136.6.15930
54175.136.6.160/27175.136.6.161 to 175.136.6.190175.136.6.19130
55175.136.6.192/27175.136.6.193 to 175.136.6.222175.136.6.22330
56175.136.6.224/27175.136.6.225 to 175.136.6.254175.136.6.25530
57175.136.7.0/27175.136.7.1 to 175.136.7.30175.136.7.3130
58175.136.7.32/27175.136.7.33 to 175.136.7.62175.136.7.6330
59175.136.7.64/27175.136.7.65 to 175.136.7.94175.136.7.9530
60175.136.7.96/27175.136.7.97 to 175.136.7.126175.136.7.12730
61175.136.7.128/27175.136.7.129 to 175.136.7.158175.136.7.15930
62175.136.7.160/27175.136.7.161 to 175.136.7.190175.136.7.19130
63175.136.7.192/27175.136.7.193 to 175.136.7.222175.136.7.22330
64175.136.7.224/27175.136.7.225 to 175.136.7.254175.136.7.25530
65175.136.8.0/27175.136.8.1 to 175.136.8.30175.136.8.3130
66175.136.8.32/27175.136.8.33 to 175.136.8.62175.136.8.6330
67175.136.8.64/27175.136.8.65 to 175.136.8.94175.136.8.9530
68175.136.8.96/27175.136.8.97 to 175.136.8.126175.136.8.12730
69175.136.8.128/27175.136.8.129 to 175.136.8.158175.136.8.15930
70175.136.8.160/27175.136.8.161 to 175.136.8.190175.136.8.19130
71175.136.8.192/27175.136.8.193 to 175.136.8.222175.136.8.22330
72175.136.8.224/27175.136.8.225 to 175.136.8.254175.136.8.25530
73175.136.9.0/27175.136.9.1 to 175.136.9.30175.136.9.3130
74175.136.9.32/27175.136.9.33 to 175.136.9.62175.136.9.6330
75175.136.9.64/27175.136.9.65 to 175.136.9.94175.136.9.9530
76175.136.9.96/27175.136.9.97 to 175.136.9.126175.136.9.12730
77175.136.9.128/27175.136.9.129 to 175.136.9.158175.136.9.15930
78175.136.9.160/27175.136.9.161 to 175.136.9.190175.136.9.19130
79175.136.9.192/27175.136.9.193 to 175.136.9.222175.136.9.22330
80175.136.9.224/27175.136.9.225 to 175.136.9.254175.136.9.25530
81175.136.10.0/27175.136.10.1 to 175.136.10.30175.136.10.3130
82175.136.10.32/27175.136.10.33 to 175.136.10.62175.136.10.6330
83175.136.10.64/27175.136.10.65 to 175.136.10.94175.136.10.9530
84175.136.10.96/27175.136.10.97 to 175.136.10.126175.136.10.12730
85175.136.10.128/27175.136.10.129 to 175.136.10.158175.136.10.15930
86175.136.10.160/27175.136.10.161 to 175.136.10.190175.136.10.19130
87175.136.10.192/27175.136.10.193 to 175.136.10.222175.136.10.22330
88175.136.10.224/27175.136.10.225 to 175.136.10.254175.136.10.25530
89175.136.11.0/27175.136.11.1 to 175.136.11.30175.136.11.3130
90175.136.11.32/27175.136.11.33 to 175.136.11.62175.136.11.6330
91175.136.11.64/27175.136.11.65 to 175.136.11.94175.136.11.9530
92175.136.11.96/27175.136.11.97 to 175.136.11.126175.136.11.12730
93175.136.11.128/27175.136.11.129 to 175.136.11.158175.136.11.15930
94175.136.11.160/27175.136.11.161 to 175.136.11.190175.136.11.19130
95175.136.11.192/27175.136.11.193 to 175.136.11.222175.136.11.22330
96175.136.11.224/27175.136.11.225 to 175.136.11.254175.136.11.25530
97175.136.12.0/27175.136.12.1 to 175.136.12.30175.136.12.3130
98175.136.12.32/27175.136.12.33 to 175.136.12.62175.136.12.6330
99175.136.12.64/27175.136.12.65 to 175.136.12.94175.136.12.9530
100175.136.12.96/27175.136.12.97 to 175.136.12.126175.136.12.12730
101175.136.12.128/27175.136.12.129 to 175.136.12.158175.136.12.15930
102175.136.12.160/27175.136.12.161 to 175.136.12.190175.136.12.19130
103175.136.12.192/27175.136.12.193 to 175.136.12.222175.136.12.22330
104175.136.12.224/27175.136.12.225 to 175.136.12.254175.136.12.25530
105175.136.13.0/27175.136.13.1 to 175.136.13.30175.136.13.3130
106175.136.13.32/27175.136.13.33 to 175.136.13.62175.136.13.6330
107175.136.13.64/27175.136.13.65 to 175.136.13.94175.136.13.9530
108175.136.13.96/27175.136.13.97 to 175.136.13.126175.136.13.12730
109175.136.13.128/27175.136.13.129 to 175.136.13.158175.136.13.15930
110175.136.13.160/27175.136.13.161 to 175.136.13.190175.136.13.19130
111175.136.13.192/27175.136.13.193 to 175.136.13.222175.136.13.22330
112175.136.13.224/27175.136.13.225 to 175.136.13.254175.136.13.25530
113175.136.14.0/27175.136.14.1 to 175.136.14.30175.136.14.3130
114175.136.14.32/27175.136.14.33 to 175.136.14.62175.136.14.6330
115175.136.14.64/27175.136.14.65 to 175.136.14.94175.136.14.9530
116175.136.14.96/27175.136.14.97 to 175.136.14.126175.136.14.12730
117175.136.14.128/27175.136.14.129 to 175.136.14.158175.136.14.15930
118175.136.14.160/27175.136.14.161 to 175.136.14.190175.136.14.19130
119175.136.14.192/27175.136.14.193 to 175.136.14.222175.136.14.22330
120175.136.14.224/27175.136.14.225 to 175.136.14.254175.136.14.25530
121175.136.15.0/27175.136.15.1 to 175.136.15.30175.136.15.3130
122175.136.15.32/27175.136.15.33 to 175.136.15.62175.136.15.6330
123175.136.15.64/27175.136.15.65 to 175.136.15.94175.136.15.9530
124175.136.15.96/27175.136.15.97 to 175.136.15.126175.136.15.12730
125175.136.15.128/27175.136.15.129 to 175.136.15.158175.136.15.15930
126175.136.15.160/27175.136.15.161 to 175.136.15.190175.136.15.19130
127175.136.15.192/27175.136.15.193 to 175.136.15.222175.136.15.22330
128175.136.15.224/27175.136.15.225 to 175.136.15.254175.136.15.25530
129175.136.16.0/27175.136.16.1 to 175.136.16.30175.136.16.3130
130175.136.16.32/27175.136.16.33 to 175.136.16.62175.136.16.6330
131175.136.16.64/27175.136.16.65 to 175.136.16.94175.136.16.9530
132175.136.16.96/27175.136.16.97 to 175.136.16.126175.136.16.12730
133175.136.16.128/27175.136.16.129 to 175.136.16.158175.136.16.15930
134175.136.16.160/27175.136.16.161 to 175.136.16.190175.136.16.19130
135175.136.16.192/27175.136.16.193 to 175.136.16.222175.136.16.22330
136175.136.16.224/27175.136.16.225 to 175.136.16.254175.136.16.25530
137175.136.17.0/27175.136.17.1 to 175.136.17.30175.136.17.3130
138175.136.17.32/27175.136.17.33 to 175.136.17.62175.136.17.6330
139175.136.17.64/27175.136.17.65 to 175.136.17.94175.136.17.9530
140175.136.17.96/27175.136.17.97 to 175.136.17.126175.136.17.12730
141175.136.17.128/27175.136.17.129 to 175.136.17.158175.136.17.15930
142175.136.17.160/27175.136.17.161 to 175.136.17.190175.136.17.19130
143175.136.17.192/27175.136.17.193 to 175.136.17.222175.136.17.22330
144175.136.17.224/27175.136.17.225 to 175.136.17.254175.136.17.25530
145175.136.18.0/27175.136.18.1 to 175.136.18.30175.136.18.3130
146175.136.18.32/27175.136.18.33 to 175.136.18.62175.136.18.6330
147175.136.18.64/27175.136.18.65 to 175.136.18.94175.136.18.9530
148175.136.18.96/27175.136.18.97 to 175.136.18.126175.136.18.12730
149175.136.18.128/27175.136.18.129 to 175.136.18.158175.136.18.15930
150175.136.18.160/27175.136.18.161 to 175.136.18.190175.136.18.19130
151175.136.18.192/27175.136.18.193 to 175.136.18.222175.136.18.22330
152175.136.18.224/27175.136.18.225 to 175.136.18.254175.136.18.25530
153175.136.19.0/27175.136.19.1 to 175.136.19.30175.136.19.3130
154175.136.19.32/27175.136.19.33 to 175.136.19.62175.136.19.6330
155175.136.19.64/27175.136.19.65 to 175.136.19.94175.136.19.9530
156175.136.19.96/27175.136.19.97 to 175.136.19.126175.136.19.12730
157175.136.19.128/27175.136.19.129 to 175.136.19.158175.136.19.15930
158175.136.19.160/27175.136.19.161 to 175.136.19.190175.136.19.19130
159175.136.19.192/27175.136.19.193 to 175.136.19.222175.136.19.22330
160175.136.19.224/27175.136.19.225 to 175.136.19.254175.136.19.25530
161175.136.20.0/27175.136.20.1 to 175.136.20.30175.136.20.3130
162175.136.20.32/27175.136.20.33 to 175.136.20.62175.136.20.6330
163175.136.20.64/27175.136.20.65 to 175.136.20.94175.136.20.9530
164175.136.20.96/27175.136.20.97 to 175.136.20.126175.136.20.12730
165175.136.20.128/27175.136.20.129 to 175.136.20.158175.136.20.15930
166175.136.20.160/27175.136.20.161 to 175.136.20.190175.136.20.19130
167175.136.20.192/27175.136.20.193 to 175.136.20.222175.136.20.22330
168175.136.20.224/27175.136.20.225 to 175.136.20.254175.136.20.25530
169175.136.21.0/27175.136.21.1 to 175.136.21.30175.136.21.3130
170175.136.21.32/27175.136.21.33 to 175.136.21.62175.136.21.6330
171175.136.21.64/27175.136.21.65 to 175.136.21.94175.136.21.9530
172175.136.21.96/27175.136.21.97 to 175.136.21.126175.136.21.12730
173175.136.21.128/27175.136.21.129 to 175.136.21.158175.136.21.15930
174175.136.21.160/27175.136.21.161 to 175.136.21.190175.136.21.19130
175175.136.21.192/27175.136.21.193 to 175.136.21.222175.136.21.22330
176175.136.21.224/27175.136.21.225 to 175.136.21.254175.136.21.25530
177175.136.22.0/27175.136.22.1 to 175.136.22.30175.136.22.3130
178175.136.22.32/27175.136.22.33 to 175.136.22.62175.136.22.6330
179175.136.22.64/27175.136.22.65 to 175.136.22.94175.136.22.9530
180175.136.22.96/27175.136.22.97 to 175.136.22.126175.136.22.12730
181175.136.22.128/27175.136.22.129 to 175.136.22.158175.136.22.15930
182175.136.22.160/27175.136.22.161 to 175.136.22.190175.136.22.19130
183175.136.22.192/27175.136.22.193 to 175.136.22.222175.136.22.22330
184175.136.22.224/27175.136.22.225 to 175.136.22.254175.136.22.25530
185175.136.23.0/27175.136.23.1 to 175.136.23.30175.136.23.3130
186175.136.23.32/27175.136.23.33 to 175.136.23.62175.136.23.6330
187175.136.23.64/27175.136.23.65 to 175.136.23.94175.136.23.9530
188175.136.23.96/27175.136.23.97 to 175.136.23.126175.136.23.12730
189175.136.23.128/27175.136.23.129 to 175.136.23.158175.136.23.15930
190175.136.23.160/27175.136.23.161 to 175.136.23.190175.136.23.19130
191175.136.23.192/27175.136.23.193 to 175.136.23.222175.136.23.22330
192175.136.23.224/27175.136.23.225 to 175.136.23.254175.136.23.25530
193175.136.24.0/27175.136.24.1 to 175.136.24.30175.136.24.3130
194175.136.24.32/27175.136.24.33 to 175.136.24.62175.136.24.6330
195175.136.24.64/27175.136.24.65 to 175.136.24.94175.136.24.9530
196175.136.24.96/27175.136.24.97 to 175.136.24.126175.136.24.12730
197175.136.24.128/27175.136.24.129 to 175.136.24.158175.136.24.15930
198175.136.24.160/27175.136.24.161 to 175.136.24.190175.136.24.19130
199175.136.24.192/27175.136.24.193 to 175.136.24.222175.136.24.22330
200175.136.24.224/27175.136.24.225 to 175.136.24.254175.136.24.25530
201175.136.25.0/27175.136.25.1 to 175.136.25.30175.136.25.3130
202175.136.25.32/27175.136.25.33 to 175.136.25.62175.136.25.6330
203175.136.25.64/27175.136.25.65 to 175.136.25.94175.136.25.9530
204175.136.25.96/27175.136.25.97 to 175.136.25.126175.136.25.12730
205175.136.25.128/27175.136.25.129 to 175.136.25.158175.136.25.15930
206175.136.25.160/27175.136.25.161 to 175.136.25.190175.136.25.19130
207175.136.25.192/27175.136.25.193 to 175.136.25.222175.136.25.22330
208175.136.25.224/27175.136.25.225 to 175.136.25.254175.136.25.25530
209175.136.26.0/27175.136.26.1 to 175.136.26.30175.136.26.3130
210175.136.26.32/27175.136.26.33 to 175.136.26.62175.136.26.6330
211175.136.26.64/27175.136.26.65 to 175.136.26.94175.136.26.9530
212175.136.26.96/27175.136.26.97 to 175.136.26.126175.136.26.12730
213175.136.26.128/27175.136.26.129 to 175.136.26.158175.136.26.15930
214175.136.26.160/27175.136.26.161 to 175.136.26.190175.136.26.19130
215175.136.26.192/27175.136.26.193 to 175.136.26.222175.136.26.22330
216175.136.26.224/27175.136.26.225 to 175.136.26.254175.136.26.25530
217175.136.27.0/27175.136.27.1 to 175.136.27.30175.136.27.3130
218175.136.27.32/27175.136.27.33 to 175.136.27.62175.136.27.6330
219175.136.27.64/27175.136.27.65 to 175.136.27.94175.136.27.9530
220175.136.27.96/27175.136.27.97 to 175.136.27.126175.136.27.12730
221175.136.27.128/27175.136.27.129 to 175.136.27.158175.136.27.15930
222175.136.27.160/27175.136.27.161 to 175.136.27.190175.136.27.19130
223175.136.27.192/27175.136.27.193 to 175.136.27.222175.136.27.22330
224175.136.27.224/27175.136.27.225 to 175.136.27.254175.136.27.25530
225175.136.28.0/27175.136.28.1 to 175.136.28.30175.136.28.3130
226175.136.28.32/27175.136.28.33 to 175.136.28.62175.136.28.6330
227175.136.28.64/27175.136.28.65 to 175.136.28.94175.136.28.9530
228175.136.28.96/27175.136.28.97 to 175.136.28.126175.136.28.12730
229175.136.28.128/27175.136.28.129 to 175.136.28.158175.136.28.15930
230175.136.28.160/27175.136.28.161 to 175.136.28.190175.136.28.19130
231175.136.28.192/27175.136.28.193 to 175.136.28.222175.136.28.22330
232175.136.28.224/27175.136.28.225 to 175.136.28.254175.136.28.25530
233175.136.29.0/27175.136.29.1 to 175.136.29.30175.136.29.3130
234175.136.29.32/27175.136.29.33 to 175.136.29.62175.136.29.6330
235175.136.29.64/27175.136.29.65 to 175.136.29.94175.136.29.9530
236175.136.29.96/27175.136.29.97 to 175.136.29.126175.136.29.12730
237175.136.29.128/27175.136.29.129 to 175.136.29.158175.136.29.15930
238175.136.29.160/27175.136.29.161 to 175.136.29.190175.136.29.19130
239175.136.29.192/27175.136.29.193 to 175.136.29.222175.136.29.22330
240175.136.29.224/27175.136.29.225 to 175.136.29.254175.136.29.25530
241175.136.30.0/27175.136.30.1 to 175.136.30.30175.136.30.3130
242175.136.30.32/27175.136.30.33 to 175.136.30.62175.136.30.6330
243175.136.30.64/27175.136.30.65 to 175.136.30.94175.136.30.9530
244175.136.30.96/27175.136.30.97 to 175.136.30.126175.136.30.12730
245175.136.30.128/27175.136.30.129 to 175.136.30.158175.136.30.15930
246175.136.30.160/27175.136.30.161 to 175.136.30.190175.136.30.19130
247175.136.30.192/27175.136.30.193 to 175.136.30.222175.136.30.22330
248175.136.30.224/27175.136.30.225 to 175.136.30.254175.136.30.25530
249175.136.31.0/27175.136.31.1 to 175.136.31.30175.136.31.3130
250175.136.31.32/27175.136.31.33 to 175.136.31.62175.136.31.6330
251175.136.31.64/27175.136.31.65 to 175.136.31.94175.136.31.9530
252175.136.31.96/27175.136.31.97 to 175.136.31.126175.136.31.12730
253175.136.31.128/27175.136.31.129 to 175.136.31.158175.136.31.15930
254175.136.31.160/27175.136.31.161 to 175.136.31.190175.136.31.19130
255175.136.31.192/27175.136.31.193 to 175.136.31.222175.136.31.22330
256175.136.31.224/27175.136.31.225 to 175.136.31.254175.136.31.25530

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.