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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.

Network176.45.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
176.45.0.0
Broadcast address
176.45.127.255
First usable
176.45.0.1
Last usable
176.45.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
B (default /16)
As numbers
Hex B02D0000 · Integer 2955739136 to 2955771903
Reverse DNS zones
0.45.176.in-addr.arpa
1.45.176.in-addr.arpa
2.45.176.in-addr.arpa
3.45.176.in-addr.arpa
4.45.176.in-addr.arpa
5.45.176.in-addr.arpa
6.45.176.in-addr.arpa
7.45.176.in-addr.arpa
8.45.176.in-addr.arpa
9.45.176.in-addr.arpa
10.45.176.in-addr.arpa
11.45.176.in-addr.arpa
12.45.176.in-addr.arpa
13.45.176.in-addr.arpa
14.45.176.in-addr.arpa
15.45.176.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10110000.00101101.00000000.00000000176.45.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network10110000.00101101.00000000.00000000176.45.0.0
Broadcast10110000.00101101.01111111.11111111176.45.127.255
Split into smaller subnets/27
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

176.45.0.0/17 makes 1,024 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1176.45.0.0/27176.45.0.1 to 176.45.0.30176.45.0.3130
2176.45.0.32/27176.45.0.33 to 176.45.0.62176.45.0.6330
3176.45.0.64/27176.45.0.65 to 176.45.0.94176.45.0.9530
4176.45.0.96/27176.45.0.97 to 176.45.0.126176.45.0.12730
5176.45.0.128/27176.45.0.129 to 176.45.0.158176.45.0.15930
6176.45.0.160/27176.45.0.161 to 176.45.0.190176.45.0.19130
7176.45.0.192/27176.45.0.193 to 176.45.0.222176.45.0.22330
8176.45.0.224/27176.45.0.225 to 176.45.0.254176.45.0.25530
9176.45.1.0/27176.45.1.1 to 176.45.1.30176.45.1.3130
10176.45.1.32/27176.45.1.33 to 176.45.1.62176.45.1.6330
11176.45.1.64/27176.45.1.65 to 176.45.1.94176.45.1.9530
12176.45.1.96/27176.45.1.97 to 176.45.1.126176.45.1.12730
13176.45.1.128/27176.45.1.129 to 176.45.1.158176.45.1.15930
14176.45.1.160/27176.45.1.161 to 176.45.1.190176.45.1.19130
15176.45.1.192/27176.45.1.193 to 176.45.1.222176.45.1.22330
16176.45.1.224/27176.45.1.225 to 176.45.1.254176.45.1.25530
17176.45.2.0/27176.45.2.1 to 176.45.2.30176.45.2.3130
18176.45.2.32/27176.45.2.33 to 176.45.2.62176.45.2.6330
19176.45.2.64/27176.45.2.65 to 176.45.2.94176.45.2.9530
20176.45.2.96/27176.45.2.97 to 176.45.2.126176.45.2.12730
21176.45.2.128/27176.45.2.129 to 176.45.2.158176.45.2.15930
22176.45.2.160/27176.45.2.161 to 176.45.2.190176.45.2.19130
23176.45.2.192/27176.45.2.193 to 176.45.2.222176.45.2.22330
24176.45.2.224/27176.45.2.225 to 176.45.2.254176.45.2.25530
25176.45.3.0/27176.45.3.1 to 176.45.3.30176.45.3.3130
26176.45.3.32/27176.45.3.33 to 176.45.3.62176.45.3.6330
27176.45.3.64/27176.45.3.65 to 176.45.3.94176.45.3.9530
28176.45.3.96/27176.45.3.97 to 176.45.3.126176.45.3.12730
29176.45.3.128/27176.45.3.129 to 176.45.3.158176.45.3.15930
30176.45.3.160/27176.45.3.161 to 176.45.3.190176.45.3.19130
31176.45.3.192/27176.45.3.193 to 176.45.3.222176.45.3.22330
32176.45.3.224/27176.45.3.225 to 176.45.3.254176.45.3.25530
33176.45.4.0/27176.45.4.1 to 176.45.4.30176.45.4.3130
34176.45.4.32/27176.45.4.33 to 176.45.4.62176.45.4.6330
35176.45.4.64/27176.45.4.65 to 176.45.4.94176.45.4.9530
36176.45.4.96/27176.45.4.97 to 176.45.4.126176.45.4.12730
37176.45.4.128/27176.45.4.129 to 176.45.4.158176.45.4.15930
38176.45.4.160/27176.45.4.161 to 176.45.4.190176.45.4.19130
39176.45.4.192/27176.45.4.193 to 176.45.4.222176.45.4.22330
40176.45.4.224/27176.45.4.225 to 176.45.4.254176.45.4.25530
41176.45.5.0/27176.45.5.1 to 176.45.5.30176.45.5.3130
42176.45.5.32/27176.45.5.33 to 176.45.5.62176.45.5.6330
43176.45.5.64/27176.45.5.65 to 176.45.5.94176.45.5.9530
44176.45.5.96/27176.45.5.97 to 176.45.5.126176.45.5.12730
45176.45.5.128/27176.45.5.129 to 176.45.5.158176.45.5.15930
46176.45.5.160/27176.45.5.161 to 176.45.5.190176.45.5.19130
47176.45.5.192/27176.45.5.193 to 176.45.5.222176.45.5.22330
48176.45.5.224/27176.45.5.225 to 176.45.5.254176.45.5.25530
49176.45.6.0/27176.45.6.1 to 176.45.6.30176.45.6.3130
50176.45.6.32/27176.45.6.33 to 176.45.6.62176.45.6.6330
51176.45.6.64/27176.45.6.65 to 176.45.6.94176.45.6.9530
52176.45.6.96/27176.45.6.97 to 176.45.6.126176.45.6.12730
53176.45.6.128/27176.45.6.129 to 176.45.6.158176.45.6.15930
54176.45.6.160/27176.45.6.161 to 176.45.6.190176.45.6.19130
55176.45.6.192/27176.45.6.193 to 176.45.6.222176.45.6.22330
56176.45.6.224/27176.45.6.225 to 176.45.6.254176.45.6.25530
57176.45.7.0/27176.45.7.1 to 176.45.7.30176.45.7.3130
58176.45.7.32/27176.45.7.33 to 176.45.7.62176.45.7.6330
59176.45.7.64/27176.45.7.65 to 176.45.7.94176.45.7.9530
60176.45.7.96/27176.45.7.97 to 176.45.7.126176.45.7.12730
61176.45.7.128/27176.45.7.129 to 176.45.7.158176.45.7.15930
62176.45.7.160/27176.45.7.161 to 176.45.7.190176.45.7.19130
63176.45.7.192/27176.45.7.193 to 176.45.7.222176.45.7.22330
64176.45.7.224/27176.45.7.225 to 176.45.7.254176.45.7.25530
65176.45.8.0/27176.45.8.1 to 176.45.8.30176.45.8.3130
66176.45.8.32/27176.45.8.33 to 176.45.8.62176.45.8.6330
67176.45.8.64/27176.45.8.65 to 176.45.8.94176.45.8.9530
68176.45.8.96/27176.45.8.97 to 176.45.8.126176.45.8.12730
69176.45.8.128/27176.45.8.129 to 176.45.8.158176.45.8.15930
70176.45.8.160/27176.45.8.161 to 176.45.8.190176.45.8.19130
71176.45.8.192/27176.45.8.193 to 176.45.8.222176.45.8.22330
72176.45.8.224/27176.45.8.225 to 176.45.8.254176.45.8.25530
73176.45.9.0/27176.45.9.1 to 176.45.9.30176.45.9.3130
74176.45.9.32/27176.45.9.33 to 176.45.9.62176.45.9.6330
75176.45.9.64/27176.45.9.65 to 176.45.9.94176.45.9.9530
76176.45.9.96/27176.45.9.97 to 176.45.9.126176.45.9.12730
77176.45.9.128/27176.45.9.129 to 176.45.9.158176.45.9.15930
78176.45.9.160/27176.45.9.161 to 176.45.9.190176.45.9.19130
79176.45.9.192/27176.45.9.193 to 176.45.9.222176.45.9.22330
80176.45.9.224/27176.45.9.225 to 176.45.9.254176.45.9.25530
81176.45.10.0/27176.45.10.1 to 176.45.10.30176.45.10.3130
82176.45.10.32/27176.45.10.33 to 176.45.10.62176.45.10.6330
83176.45.10.64/27176.45.10.65 to 176.45.10.94176.45.10.9530
84176.45.10.96/27176.45.10.97 to 176.45.10.126176.45.10.12730
85176.45.10.128/27176.45.10.129 to 176.45.10.158176.45.10.15930
86176.45.10.160/27176.45.10.161 to 176.45.10.190176.45.10.19130
87176.45.10.192/27176.45.10.193 to 176.45.10.222176.45.10.22330
88176.45.10.224/27176.45.10.225 to 176.45.10.254176.45.10.25530
89176.45.11.0/27176.45.11.1 to 176.45.11.30176.45.11.3130
90176.45.11.32/27176.45.11.33 to 176.45.11.62176.45.11.6330
91176.45.11.64/27176.45.11.65 to 176.45.11.94176.45.11.9530
92176.45.11.96/27176.45.11.97 to 176.45.11.126176.45.11.12730
93176.45.11.128/27176.45.11.129 to 176.45.11.158176.45.11.15930
94176.45.11.160/27176.45.11.161 to 176.45.11.190176.45.11.19130
95176.45.11.192/27176.45.11.193 to 176.45.11.222176.45.11.22330
96176.45.11.224/27176.45.11.225 to 176.45.11.254176.45.11.25530
97176.45.12.0/27176.45.12.1 to 176.45.12.30176.45.12.3130
98176.45.12.32/27176.45.12.33 to 176.45.12.62176.45.12.6330
99176.45.12.64/27176.45.12.65 to 176.45.12.94176.45.12.9530
100176.45.12.96/27176.45.12.97 to 176.45.12.126176.45.12.12730
101176.45.12.128/27176.45.12.129 to 176.45.12.158176.45.12.15930
102176.45.12.160/27176.45.12.161 to 176.45.12.190176.45.12.19130
103176.45.12.192/27176.45.12.193 to 176.45.12.222176.45.12.22330
104176.45.12.224/27176.45.12.225 to 176.45.12.254176.45.12.25530
105176.45.13.0/27176.45.13.1 to 176.45.13.30176.45.13.3130
106176.45.13.32/27176.45.13.33 to 176.45.13.62176.45.13.6330
107176.45.13.64/27176.45.13.65 to 176.45.13.94176.45.13.9530
108176.45.13.96/27176.45.13.97 to 176.45.13.126176.45.13.12730
109176.45.13.128/27176.45.13.129 to 176.45.13.158176.45.13.15930
110176.45.13.160/27176.45.13.161 to 176.45.13.190176.45.13.19130
111176.45.13.192/27176.45.13.193 to 176.45.13.222176.45.13.22330
112176.45.13.224/27176.45.13.225 to 176.45.13.254176.45.13.25530
113176.45.14.0/27176.45.14.1 to 176.45.14.30176.45.14.3130
114176.45.14.32/27176.45.14.33 to 176.45.14.62176.45.14.6330
115176.45.14.64/27176.45.14.65 to 176.45.14.94176.45.14.9530
116176.45.14.96/27176.45.14.97 to 176.45.14.126176.45.14.12730
117176.45.14.128/27176.45.14.129 to 176.45.14.158176.45.14.15930
118176.45.14.160/27176.45.14.161 to 176.45.14.190176.45.14.19130
119176.45.14.192/27176.45.14.193 to 176.45.14.222176.45.14.22330
120176.45.14.224/27176.45.14.225 to 176.45.14.254176.45.14.25530
121176.45.15.0/27176.45.15.1 to 176.45.15.30176.45.15.3130
122176.45.15.32/27176.45.15.33 to 176.45.15.62176.45.15.6330
123176.45.15.64/27176.45.15.65 to 176.45.15.94176.45.15.9530
124176.45.15.96/27176.45.15.97 to 176.45.15.126176.45.15.12730
125176.45.15.128/27176.45.15.129 to 176.45.15.158176.45.15.15930
126176.45.15.160/27176.45.15.161 to 176.45.15.190176.45.15.19130
127176.45.15.192/27176.45.15.193 to 176.45.15.222176.45.15.22330
128176.45.15.224/27176.45.15.225 to 176.45.15.254176.45.15.25530
129176.45.16.0/27176.45.16.1 to 176.45.16.30176.45.16.3130
130176.45.16.32/27176.45.16.33 to 176.45.16.62176.45.16.6330
131176.45.16.64/27176.45.16.65 to 176.45.16.94176.45.16.9530
132176.45.16.96/27176.45.16.97 to 176.45.16.126176.45.16.12730
133176.45.16.128/27176.45.16.129 to 176.45.16.158176.45.16.15930
134176.45.16.160/27176.45.16.161 to 176.45.16.190176.45.16.19130
135176.45.16.192/27176.45.16.193 to 176.45.16.222176.45.16.22330
136176.45.16.224/27176.45.16.225 to 176.45.16.254176.45.16.25530
137176.45.17.0/27176.45.17.1 to 176.45.17.30176.45.17.3130
138176.45.17.32/27176.45.17.33 to 176.45.17.62176.45.17.6330
139176.45.17.64/27176.45.17.65 to 176.45.17.94176.45.17.9530
140176.45.17.96/27176.45.17.97 to 176.45.17.126176.45.17.12730
141176.45.17.128/27176.45.17.129 to 176.45.17.158176.45.17.15930
142176.45.17.160/27176.45.17.161 to 176.45.17.190176.45.17.19130
143176.45.17.192/27176.45.17.193 to 176.45.17.222176.45.17.22330
144176.45.17.224/27176.45.17.225 to 176.45.17.254176.45.17.25530
145176.45.18.0/27176.45.18.1 to 176.45.18.30176.45.18.3130
146176.45.18.32/27176.45.18.33 to 176.45.18.62176.45.18.6330
147176.45.18.64/27176.45.18.65 to 176.45.18.94176.45.18.9530
148176.45.18.96/27176.45.18.97 to 176.45.18.126176.45.18.12730
149176.45.18.128/27176.45.18.129 to 176.45.18.158176.45.18.15930
150176.45.18.160/27176.45.18.161 to 176.45.18.190176.45.18.19130
151176.45.18.192/27176.45.18.193 to 176.45.18.222176.45.18.22330
152176.45.18.224/27176.45.18.225 to 176.45.18.254176.45.18.25530
153176.45.19.0/27176.45.19.1 to 176.45.19.30176.45.19.3130
154176.45.19.32/27176.45.19.33 to 176.45.19.62176.45.19.6330
155176.45.19.64/27176.45.19.65 to 176.45.19.94176.45.19.9530
156176.45.19.96/27176.45.19.97 to 176.45.19.126176.45.19.12730
157176.45.19.128/27176.45.19.129 to 176.45.19.158176.45.19.15930
158176.45.19.160/27176.45.19.161 to 176.45.19.190176.45.19.19130
159176.45.19.192/27176.45.19.193 to 176.45.19.222176.45.19.22330
160176.45.19.224/27176.45.19.225 to 176.45.19.254176.45.19.25530
161176.45.20.0/27176.45.20.1 to 176.45.20.30176.45.20.3130
162176.45.20.32/27176.45.20.33 to 176.45.20.62176.45.20.6330
163176.45.20.64/27176.45.20.65 to 176.45.20.94176.45.20.9530
164176.45.20.96/27176.45.20.97 to 176.45.20.126176.45.20.12730
165176.45.20.128/27176.45.20.129 to 176.45.20.158176.45.20.15930
166176.45.20.160/27176.45.20.161 to 176.45.20.190176.45.20.19130
167176.45.20.192/27176.45.20.193 to 176.45.20.222176.45.20.22330
168176.45.20.224/27176.45.20.225 to 176.45.20.254176.45.20.25530
169176.45.21.0/27176.45.21.1 to 176.45.21.30176.45.21.3130
170176.45.21.32/27176.45.21.33 to 176.45.21.62176.45.21.6330
171176.45.21.64/27176.45.21.65 to 176.45.21.94176.45.21.9530
172176.45.21.96/27176.45.21.97 to 176.45.21.126176.45.21.12730
173176.45.21.128/27176.45.21.129 to 176.45.21.158176.45.21.15930
174176.45.21.160/27176.45.21.161 to 176.45.21.190176.45.21.19130
175176.45.21.192/27176.45.21.193 to 176.45.21.222176.45.21.22330
176176.45.21.224/27176.45.21.225 to 176.45.21.254176.45.21.25530
177176.45.22.0/27176.45.22.1 to 176.45.22.30176.45.22.3130
178176.45.22.32/27176.45.22.33 to 176.45.22.62176.45.22.6330
179176.45.22.64/27176.45.22.65 to 176.45.22.94176.45.22.9530
180176.45.22.96/27176.45.22.97 to 176.45.22.126176.45.22.12730
181176.45.22.128/27176.45.22.129 to 176.45.22.158176.45.22.15930
182176.45.22.160/27176.45.22.161 to 176.45.22.190176.45.22.19130
183176.45.22.192/27176.45.22.193 to 176.45.22.222176.45.22.22330
184176.45.22.224/27176.45.22.225 to 176.45.22.254176.45.22.25530
185176.45.23.0/27176.45.23.1 to 176.45.23.30176.45.23.3130
186176.45.23.32/27176.45.23.33 to 176.45.23.62176.45.23.6330
187176.45.23.64/27176.45.23.65 to 176.45.23.94176.45.23.9530
188176.45.23.96/27176.45.23.97 to 176.45.23.126176.45.23.12730
189176.45.23.128/27176.45.23.129 to 176.45.23.158176.45.23.15930
190176.45.23.160/27176.45.23.161 to 176.45.23.190176.45.23.19130
191176.45.23.192/27176.45.23.193 to 176.45.23.222176.45.23.22330
192176.45.23.224/27176.45.23.225 to 176.45.23.254176.45.23.25530
193176.45.24.0/27176.45.24.1 to 176.45.24.30176.45.24.3130
194176.45.24.32/27176.45.24.33 to 176.45.24.62176.45.24.6330
195176.45.24.64/27176.45.24.65 to 176.45.24.94176.45.24.9530
196176.45.24.96/27176.45.24.97 to 176.45.24.126176.45.24.12730
197176.45.24.128/27176.45.24.129 to 176.45.24.158176.45.24.15930
198176.45.24.160/27176.45.24.161 to 176.45.24.190176.45.24.19130
199176.45.24.192/27176.45.24.193 to 176.45.24.222176.45.24.22330
200176.45.24.224/27176.45.24.225 to 176.45.24.254176.45.24.25530
201176.45.25.0/27176.45.25.1 to 176.45.25.30176.45.25.3130
202176.45.25.32/27176.45.25.33 to 176.45.25.62176.45.25.6330
203176.45.25.64/27176.45.25.65 to 176.45.25.94176.45.25.9530
204176.45.25.96/27176.45.25.97 to 176.45.25.126176.45.25.12730
205176.45.25.128/27176.45.25.129 to 176.45.25.158176.45.25.15930
206176.45.25.160/27176.45.25.161 to 176.45.25.190176.45.25.19130
207176.45.25.192/27176.45.25.193 to 176.45.25.222176.45.25.22330
208176.45.25.224/27176.45.25.225 to 176.45.25.254176.45.25.25530
209176.45.26.0/27176.45.26.1 to 176.45.26.30176.45.26.3130
210176.45.26.32/27176.45.26.33 to 176.45.26.62176.45.26.6330
211176.45.26.64/27176.45.26.65 to 176.45.26.94176.45.26.9530
212176.45.26.96/27176.45.26.97 to 176.45.26.126176.45.26.12730
213176.45.26.128/27176.45.26.129 to 176.45.26.158176.45.26.15930
214176.45.26.160/27176.45.26.161 to 176.45.26.190176.45.26.19130
215176.45.26.192/27176.45.26.193 to 176.45.26.222176.45.26.22330
216176.45.26.224/27176.45.26.225 to 176.45.26.254176.45.26.25530
217176.45.27.0/27176.45.27.1 to 176.45.27.30176.45.27.3130
218176.45.27.32/27176.45.27.33 to 176.45.27.62176.45.27.6330
219176.45.27.64/27176.45.27.65 to 176.45.27.94176.45.27.9530
220176.45.27.96/27176.45.27.97 to 176.45.27.126176.45.27.12730
221176.45.27.128/27176.45.27.129 to 176.45.27.158176.45.27.15930
222176.45.27.160/27176.45.27.161 to 176.45.27.190176.45.27.19130
223176.45.27.192/27176.45.27.193 to 176.45.27.222176.45.27.22330
224176.45.27.224/27176.45.27.225 to 176.45.27.254176.45.27.25530
225176.45.28.0/27176.45.28.1 to 176.45.28.30176.45.28.3130
226176.45.28.32/27176.45.28.33 to 176.45.28.62176.45.28.6330
227176.45.28.64/27176.45.28.65 to 176.45.28.94176.45.28.9530
228176.45.28.96/27176.45.28.97 to 176.45.28.126176.45.28.12730
229176.45.28.128/27176.45.28.129 to 176.45.28.158176.45.28.15930
230176.45.28.160/27176.45.28.161 to 176.45.28.190176.45.28.19130
231176.45.28.192/27176.45.28.193 to 176.45.28.222176.45.28.22330
232176.45.28.224/27176.45.28.225 to 176.45.28.254176.45.28.25530
233176.45.29.0/27176.45.29.1 to 176.45.29.30176.45.29.3130
234176.45.29.32/27176.45.29.33 to 176.45.29.62176.45.29.6330
235176.45.29.64/27176.45.29.65 to 176.45.29.94176.45.29.9530
236176.45.29.96/27176.45.29.97 to 176.45.29.126176.45.29.12730
237176.45.29.128/27176.45.29.129 to 176.45.29.158176.45.29.15930
238176.45.29.160/27176.45.29.161 to 176.45.29.190176.45.29.19130
239176.45.29.192/27176.45.29.193 to 176.45.29.222176.45.29.22330
240176.45.29.224/27176.45.29.225 to 176.45.29.254176.45.29.25530
241176.45.30.0/27176.45.30.1 to 176.45.30.30176.45.30.3130
242176.45.30.32/27176.45.30.33 to 176.45.30.62176.45.30.6330
243176.45.30.64/27176.45.30.65 to 176.45.30.94176.45.30.9530
244176.45.30.96/27176.45.30.97 to 176.45.30.126176.45.30.12730
245176.45.30.128/27176.45.30.129 to 176.45.30.158176.45.30.15930
246176.45.30.160/27176.45.30.161 to 176.45.30.190176.45.30.19130
247176.45.30.192/27176.45.30.193 to 176.45.30.222176.45.30.22330
248176.45.30.224/27176.45.30.225 to 176.45.30.254176.45.30.25530
249176.45.31.0/27176.45.31.1 to 176.45.31.30176.45.31.3130
250176.45.31.32/27176.45.31.33 to 176.45.31.62176.45.31.6330
251176.45.31.64/27176.45.31.65 to 176.45.31.94176.45.31.9530
252176.45.31.96/27176.45.31.97 to 176.45.31.126176.45.31.12730
253176.45.31.128/27176.45.31.129 to 176.45.31.158176.45.31.15930
254176.45.31.160/27176.45.31.161 to 176.45.31.190176.45.31.19130
255176.45.31.192/27176.45.31.193 to 176.45.31.222176.45.31.22330
256176.45.31.224/27176.45.31.225 to 176.45.31.254176.45.31.25530

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.