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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.

Network229.72.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
229.72.0.0
Broadcast address
229.72.127.255
First usable
229.72.0.1
Last usable
229.72.127.254
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
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E5480000 · Integer 3846701056 to 3846733823
Reverse DNS zones
0.72.229.in-addr.arpa
1.72.229.in-addr.arpa
2.72.229.in-addr.arpa
3.72.229.in-addr.arpa
4.72.229.in-addr.arpa
5.72.229.in-addr.arpa
6.72.229.in-addr.arpa
7.72.229.in-addr.arpa
8.72.229.in-addr.arpa
9.72.229.in-addr.arpa
10.72.229.in-addr.arpa
11.72.229.in-addr.arpa
12.72.229.in-addr.arpa
13.72.229.in-addr.arpa
14.72.229.in-addr.arpa
15.72.229.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
Address11100101.01001000.00000000.00000000229.72.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network11100101.01001000.00000000.00000000229.72.0.0
Broadcast11100101.01001000.01111111.11111111229.72.127.255
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)

229.72.0.0/17 makes 1,024 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1229.72.0.0/27229.72.0.1 to 229.72.0.30229.72.0.3130
2229.72.0.32/27229.72.0.33 to 229.72.0.62229.72.0.6330
3229.72.0.64/27229.72.0.65 to 229.72.0.94229.72.0.9530
4229.72.0.96/27229.72.0.97 to 229.72.0.126229.72.0.12730
5229.72.0.128/27229.72.0.129 to 229.72.0.158229.72.0.15930
6229.72.0.160/27229.72.0.161 to 229.72.0.190229.72.0.19130
7229.72.0.192/27229.72.0.193 to 229.72.0.222229.72.0.22330
8229.72.0.224/27229.72.0.225 to 229.72.0.254229.72.0.25530
9229.72.1.0/27229.72.1.1 to 229.72.1.30229.72.1.3130
10229.72.1.32/27229.72.1.33 to 229.72.1.62229.72.1.6330
11229.72.1.64/27229.72.1.65 to 229.72.1.94229.72.1.9530
12229.72.1.96/27229.72.1.97 to 229.72.1.126229.72.1.12730
13229.72.1.128/27229.72.1.129 to 229.72.1.158229.72.1.15930
14229.72.1.160/27229.72.1.161 to 229.72.1.190229.72.1.19130
15229.72.1.192/27229.72.1.193 to 229.72.1.222229.72.1.22330
16229.72.1.224/27229.72.1.225 to 229.72.1.254229.72.1.25530
17229.72.2.0/27229.72.2.1 to 229.72.2.30229.72.2.3130
18229.72.2.32/27229.72.2.33 to 229.72.2.62229.72.2.6330
19229.72.2.64/27229.72.2.65 to 229.72.2.94229.72.2.9530
20229.72.2.96/27229.72.2.97 to 229.72.2.126229.72.2.12730
21229.72.2.128/27229.72.2.129 to 229.72.2.158229.72.2.15930
22229.72.2.160/27229.72.2.161 to 229.72.2.190229.72.2.19130
23229.72.2.192/27229.72.2.193 to 229.72.2.222229.72.2.22330
24229.72.2.224/27229.72.2.225 to 229.72.2.254229.72.2.25530
25229.72.3.0/27229.72.3.1 to 229.72.3.30229.72.3.3130
26229.72.3.32/27229.72.3.33 to 229.72.3.62229.72.3.6330
27229.72.3.64/27229.72.3.65 to 229.72.3.94229.72.3.9530
28229.72.3.96/27229.72.3.97 to 229.72.3.126229.72.3.12730
29229.72.3.128/27229.72.3.129 to 229.72.3.158229.72.3.15930
30229.72.3.160/27229.72.3.161 to 229.72.3.190229.72.3.19130
31229.72.3.192/27229.72.3.193 to 229.72.3.222229.72.3.22330
32229.72.3.224/27229.72.3.225 to 229.72.3.254229.72.3.25530
33229.72.4.0/27229.72.4.1 to 229.72.4.30229.72.4.3130
34229.72.4.32/27229.72.4.33 to 229.72.4.62229.72.4.6330
35229.72.4.64/27229.72.4.65 to 229.72.4.94229.72.4.9530
36229.72.4.96/27229.72.4.97 to 229.72.4.126229.72.4.12730
37229.72.4.128/27229.72.4.129 to 229.72.4.158229.72.4.15930
38229.72.4.160/27229.72.4.161 to 229.72.4.190229.72.4.19130
39229.72.4.192/27229.72.4.193 to 229.72.4.222229.72.4.22330
40229.72.4.224/27229.72.4.225 to 229.72.4.254229.72.4.25530
41229.72.5.0/27229.72.5.1 to 229.72.5.30229.72.5.3130
42229.72.5.32/27229.72.5.33 to 229.72.5.62229.72.5.6330
43229.72.5.64/27229.72.5.65 to 229.72.5.94229.72.5.9530
44229.72.5.96/27229.72.5.97 to 229.72.5.126229.72.5.12730
45229.72.5.128/27229.72.5.129 to 229.72.5.158229.72.5.15930
46229.72.5.160/27229.72.5.161 to 229.72.5.190229.72.5.19130
47229.72.5.192/27229.72.5.193 to 229.72.5.222229.72.5.22330
48229.72.5.224/27229.72.5.225 to 229.72.5.254229.72.5.25530
49229.72.6.0/27229.72.6.1 to 229.72.6.30229.72.6.3130
50229.72.6.32/27229.72.6.33 to 229.72.6.62229.72.6.6330
51229.72.6.64/27229.72.6.65 to 229.72.6.94229.72.6.9530
52229.72.6.96/27229.72.6.97 to 229.72.6.126229.72.6.12730
53229.72.6.128/27229.72.6.129 to 229.72.6.158229.72.6.15930
54229.72.6.160/27229.72.6.161 to 229.72.6.190229.72.6.19130
55229.72.6.192/27229.72.6.193 to 229.72.6.222229.72.6.22330
56229.72.6.224/27229.72.6.225 to 229.72.6.254229.72.6.25530
57229.72.7.0/27229.72.7.1 to 229.72.7.30229.72.7.3130
58229.72.7.32/27229.72.7.33 to 229.72.7.62229.72.7.6330
59229.72.7.64/27229.72.7.65 to 229.72.7.94229.72.7.9530
60229.72.7.96/27229.72.7.97 to 229.72.7.126229.72.7.12730
61229.72.7.128/27229.72.7.129 to 229.72.7.158229.72.7.15930
62229.72.7.160/27229.72.7.161 to 229.72.7.190229.72.7.19130
63229.72.7.192/27229.72.7.193 to 229.72.7.222229.72.7.22330
64229.72.7.224/27229.72.7.225 to 229.72.7.254229.72.7.25530
65229.72.8.0/27229.72.8.1 to 229.72.8.30229.72.8.3130
66229.72.8.32/27229.72.8.33 to 229.72.8.62229.72.8.6330
67229.72.8.64/27229.72.8.65 to 229.72.8.94229.72.8.9530
68229.72.8.96/27229.72.8.97 to 229.72.8.126229.72.8.12730
69229.72.8.128/27229.72.8.129 to 229.72.8.158229.72.8.15930
70229.72.8.160/27229.72.8.161 to 229.72.8.190229.72.8.19130
71229.72.8.192/27229.72.8.193 to 229.72.8.222229.72.8.22330
72229.72.8.224/27229.72.8.225 to 229.72.8.254229.72.8.25530
73229.72.9.0/27229.72.9.1 to 229.72.9.30229.72.9.3130
74229.72.9.32/27229.72.9.33 to 229.72.9.62229.72.9.6330
75229.72.9.64/27229.72.9.65 to 229.72.9.94229.72.9.9530
76229.72.9.96/27229.72.9.97 to 229.72.9.126229.72.9.12730
77229.72.9.128/27229.72.9.129 to 229.72.9.158229.72.9.15930
78229.72.9.160/27229.72.9.161 to 229.72.9.190229.72.9.19130
79229.72.9.192/27229.72.9.193 to 229.72.9.222229.72.9.22330
80229.72.9.224/27229.72.9.225 to 229.72.9.254229.72.9.25530
81229.72.10.0/27229.72.10.1 to 229.72.10.30229.72.10.3130
82229.72.10.32/27229.72.10.33 to 229.72.10.62229.72.10.6330
83229.72.10.64/27229.72.10.65 to 229.72.10.94229.72.10.9530
84229.72.10.96/27229.72.10.97 to 229.72.10.126229.72.10.12730
85229.72.10.128/27229.72.10.129 to 229.72.10.158229.72.10.15930
86229.72.10.160/27229.72.10.161 to 229.72.10.190229.72.10.19130
87229.72.10.192/27229.72.10.193 to 229.72.10.222229.72.10.22330
88229.72.10.224/27229.72.10.225 to 229.72.10.254229.72.10.25530
89229.72.11.0/27229.72.11.1 to 229.72.11.30229.72.11.3130
90229.72.11.32/27229.72.11.33 to 229.72.11.62229.72.11.6330
91229.72.11.64/27229.72.11.65 to 229.72.11.94229.72.11.9530
92229.72.11.96/27229.72.11.97 to 229.72.11.126229.72.11.12730
93229.72.11.128/27229.72.11.129 to 229.72.11.158229.72.11.15930
94229.72.11.160/27229.72.11.161 to 229.72.11.190229.72.11.19130
95229.72.11.192/27229.72.11.193 to 229.72.11.222229.72.11.22330
96229.72.11.224/27229.72.11.225 to 229.72.11.254229.72.11.25530
97229.72.12.0/27229.72.12.1 to 229.72.12.30229.72.12.3130
98229.72.12.32/27229.72.12.33 to 229.72.12.62229.72.12.6330
99229.72.12.64/27229.72.12.65 to 229.72.12.94229.72.12.9530
100229.72.12.96/27229.72.12.97 to 229.72.12.126229.72.12.12730
101229.72.12.128/27229.72.12.129 to 229.72.12.158229.72.12.15930
102229.72.12.160/27229.72.12.161 to 229.72.12.190229.72.12.19130
103229.72.12.192/27229.72.12.193 to 229.72.12.222229.72.12.22330
104229.72.12.224/27229.72.12.225 to 229.72.12.254229.72.12.25530
105229.72.13.0/27229.72.13.1 to 229.72.13.30229.72.13.3130
106229.72.13.32/27229.72.13.33 to 229.72.13.62229.72.13.6330
107229.72.13.64/27229.72.13.65 to 229.72.13.94229.72.13.9530
108229.72.13.96/27229.72.13.97 to 229.72.13.126229.72.13.12730
109229.72.13.128/27229.72.13.129 to 229.72.13.158229.72.13.15930
110229.72.13.160/27229.72.13.161 to 229.72.13.190229.72.13.19130
111229.72.13.192/27229.72.13.193 to 229.72.13.222229.72.13.22330
112229.72.13.224/27229.72.13.225 to 229.72.13.254229.72.13.25530
113229.72.14.0/27229.72.14.1 to 229.72.14.30229.72.14.3130
114229.72.14.32/27229.72.14.33 to 229.72.14.62229.72.14.6330
115229.72.14.64/27229.72.14.65 to 229.72.14.94229.72.14.9530
116229.72.14.96/27229.72.14.97 to 229.72.14.126229.72.14.12730
117229.72.14.128/27229.72.14.129 to 229.72.14.158229.72.14.15930
118229.72.14.160/27229.72.14.161 to 229.72.14.190229.72.14.19130
119229.72.14.192/27229.72.14.193 to 229.72.14.222229.72.14.22330
120229.72.14.224/27229.72.14.225 to 229.72.14.254229.72.14.25530
121229.72.15.0/27229.72.15.1 to 229.72.15.30229.72.15.3130
122229.72.15.32/27229.72.15.33 to 229.72.15.62229.72.15.6330
123229.72.15.64/27229.72.15.65 to 229.72.15.94229.72.15.9530
124229.72.15.96/27229.72.15.97 to 229.72.15.126229.72.15.12730
125229.72.15.128/27229.72.15.129 to 229.72.15.158229.72.15.15930
126229.72.15.160/27229.72.15.161 to 229.72.15.190229.72.15.19130
127229.72.15.192/27229.72.15.193 to 229.72.15.222229.72.15.22330
128229.72.15.224/27229.72.15.225 to 229.72.15.254229.72.15.25530
129229.72.16.0/27229.72.16.1 to 229.72.16.30229.72.16.3130
130229.72.16.32/27229.72.16.33 to 229.72.16.62229.72.16.6330
131229.72.16.64/27229.72.16.65 to 229.72.16.94229.72.16.9530
132229.72.16.96/27229.72.16.97 to 229.72.16.126229.72.16.12730
133229.72.16.128/27229.72.16.129 to 229.72.16.158229.72.16.15930
134229.72.16.160/27229.72.16.161 to 229.72.16.190229.72.16.19130
135229.72.16.192/27229.72.16.193 to 229.72.16.222229.72.16.22330
136229.72.16.224/27229.72.16.225 to 229.72.16.254229.72.16.25530
137229.72.17.0/27229.72.17.1 to 229.72.17.30229.72.17.3130
138229.72.17.32/27229.72.17.33 to 229.72.17.62229.72.17.6330
139229.72.17.64/27229.72.17.65 to 229.72.17.94229.72.17.9530
140229.72.17.96/27229.72.17.97 to 229.72.17.126229.72.17.12730
141229.72.17.128/27229.72.17.129 to 229.72.17.158229.72.17.15930
142229.72.17.160/27229.72.17.161 to 229.72.17.190229.72.17.19130
143229.72.17.192/27229.72.17.193 to 229.72.17.222229.72.17.22330
144229.72.17.224/27229.72.17.225 to 229.72.17.254229.72.17.25530
145229.72.18.0/27229.72.18.1 to 229.72.18.30229.72.18.3130
146229.72.18.32/27229.72.18.33 to 229.72.18.62229.72.18.6330
147229.72.18.64/27229.72.18.65 to 229.72.18.94229.72.18.9530
148229.72.18.96/27229.72.18.97 to 229.72.18.126229.72.18.12730
149229.72.18.128/27229.72.18.129 to 229.72.18.158229.72.18.15930
150229.72.18.160/27229.72.18.161 to 229.72.18.190229.72.18.19130
151229.72.18.192/27229.72.18.193 to 229.72.18.222229.72.18.22330
152229.72.18.224/27229.72.18.225 to 229.72.18.254229.72.18.25530
153229.72.19.0/27229.72.19.1 to 229.72.19.30229.72.19.3130
154229.72.19.32/27229.72.19.33 to 229.72.19.62229.72.19.6330
155229.72.19.64/27229.72.19.65 to 229.72.19.94229.72.19.9530
156229.72.19.96/27229.72.19.97 to 229.72.19.126229.72.19.12730
157229.72.19.128/27229.72.19.129 to 229.72.19.158229.72.19.15930
158229.72.19.160/27229.72.19.161 to 229.72.19.190229.72.19.19130
159229.72.19.192/27229.72.19.193 to 229.72.19.222229.72.19.22330
160229.72.19.224/27229.72.19.225 to 229.72.19.254229.72.19.25530
161229.72.20.0/27229.72.20.1 to 229.72.20.30229.72.20.3130
162229.72.20.32/27229.72.20.33 to 229.72.20.62229.72.20.6330
163229.72.20.64/27229.72.20.65 to 229.72.20.94229.72.20.9530
164229.72.20.96/27229.72.20.97 to 229.72.20.126229.72.20.12730
165229.72.20.128/27229.72.20.129 to 229.72.20.158229.72.20.15930
166229.72.20.160/27229.72.20.161 to 229.72.20.190229.72.20.19130
167229.72.20.192/27229.72.20.193 to 229.72.20.222229.72.20.22330
168229.72.20.224/27229.72.20.225 to 229.72.20.254229.72.20.25530
169229.72.21.0/27229.72.21.1 to 229.72.21.30229.72.21.3130
170229.72.21.32/27229.72.21.33 to 229.72.21.62229.72.21.6330
171229.72.21.64/27229.72.21.65 to 229.72.21.94229.72.21.9530
172229.72.21.96/27229.72.21.97 to 229.72.21.126229.72.21.12730
173229.72.21.128/27229.72.21.129 to 229.72.21.158229.72.21.15930
174229.72.21.160/27229.72.21.161 to 229.72.21.190229.72.21.19130
175229.72.21.192/27229.72.21.193 to 229.72.21.222229.72.21.22330
176229.72.21.224/27229.72.21.225 to 229.72.21.254229.72.21.25530
177229.72.22.0/27229.72.22.1 to 229.72.22.30229.72.22.3130
178229.72.22.32/27229.72.22.33 to 229.72.22.62229.72.22.6330
179229.72.22.64/27229.72.22.65 to 229.72.22.94229.72.22.9530
180229.72.22.96/27229.72.22.97 to 229.72.22.126229.72.22.12730
181229.72.22.128/27229.72.22.129 to 229.72.22.158229.72.22.15930
182229.72.22.160/27229.72.22.161 to 229.72.22.190229.72.22.19130
183229.72.22.192/27229.72.22.193 to 229.72.22.222229.72.22.22330
184229.72.22.224/27229.72.22.225 to 229.72.22.254229.72.22.25530
185229.72.23.0/27229.72.23.1 to 229.72.23.30229.72.23.3130
186229.72.23.32/27229.72.23.33 to 229.72.23.62229.72.23.6330
187229.72.23.64/27229.72.23.65 to 229.72.23.94229.72.23.9530
188229.72.23.96/27229.72.23.97 to 229.72.23.126229.72.23.12730
189229.72.23.128/27229.72.23.129 to 229.72.23.158229.72.23.15930
190229.72.23.160/27229.72.23.161 to 229.72.23.190229.72.23.19130
191229.72.23.192/27229.72.23.193 to 229.72.23.222229.72.23.22330
192229.72.23.224/27229.72.23.225 to 229.72.23.254229.72.23.25530
193229.72.24.0/27229.72.24.1 to 229.72.24.30229.72.24.3130
194229.72.24.32/27229.72.24.33 to 229.72.24.62229.72.24.6330
195229.72.24.64/27229.72.24.65 to 229.72.24.94229.72.24.9530
196229.72.24.96/27229.72.24.97 to 229.72.24.126229.72.24.12730
197229.72.24.128/27229.72.24.129 to 229.72.24.158229.72.24.15930
198229.72.24.160/27229.72.24.161 to 229.72.24.190229.72.24.19130
199229.72.24.192/27229.72.24.193 to 229.72.24.222229.72.24.22330
200229.72.24.224/27229.72.24.225 to 229.72.24.254229.72.24.25530
201229.72.25.0/27229.72.25.1 to 229.72.25.30229.72.25.3130
202229.72.25.32/27229.72.25.33 to 229.72.25.62229.72.25.6330
203229.72.25.64/27229.72.25.65 to 229.72.25.94229.72.25.9530
204229.72.25.96/27229.72.25.97 to 229.72.25.126229.72.25.12730
205229.72.25.128/27229.72.25.129 to 229.72.25.158229.72.25.15930
206229.72.25.160/27229.72.25.161 to 229.72.25.190229.72.25.19130
207229.72.25.192/27229.72.25.193 to 229.72.25.222229.72.25.22330
208229.72.25.224/27229.72.25.225 to 229.72.25.254229.72.25.25530
209229.72.26.0/27229.72.26.1 to 229.72.26.30229.72.26.3130
210229.72.26.32/27229.72.26.33 to 229.72.26.62229.72.26.6330
211229.72.26.64/27229.72.26.65 to 229.72.26.94229.72.26.9530
212229.72.26.96/27229.72.26.97 to 229.72.26.126229.72.26.12730
213229.72.26.128/27229.72.26.129 to 229.72.26.158229.72.26.15930
214229.72.26.160/27229.72.26.161 to 229.72.26.190229.72.26.19130
215229.72.26.192/27229.72.26.193 to 229.72.26.222229.72.26.22330
216229.72.26.224/27229.72.26.225 to 229.72.26.254229.72.26.25530
217229.72.27.0/27229.72.27.1 to 229.72.27.30229.72.27.3130
218229.72.27.32/27229.72.27.33 to 229.72.27.62229.72.27.6330
219229.72.27.64/27229.72.27.65 to 229.72.27.94229.72.27.9530
220229.72.27.96/27229.72.27.97 to 229.72.27.126229.72.27.12730
221229.72.27.128/27229.72.27.129 to 229.72.27.158229.72.27.15930
222229.72.27.160/27229.72.27.161 to 229.72.27.190229.72.27.19130
223229.72.27.192/27229.72.27.193 to 229.72.27.222229.72.27.22330
224229.72.27.224/27229.72.27.225 to 229.72.27.254229.72.27.25530
225229.72.28.0/27229.72.28.1 to 229.72.28.30229.72.28.3130
226229.72.28.32/27229.72.28.33 to 229.72.28.62229.72.28.6330
227229.72.28.64/27229.72.28.65 to 229.72.28.94229.72.28.9530
228229.72.28.96/27229.72.28.97 to 229.72.28.126229.72.28.12730
229229.72.28.128/27229.72.28.129 to 229.72.28.158229.72.28.15930
230229.72.28.160/27229.72.28.161 to 229.72.28.190229.72.28.19130
231229.72.28.192/27229.72.28.193 to 229.72.28.222229.72.28.22330
232229.72.28.224/27229.72.28.225 to 229.72.28.254229.72.28.25530
233229.72.29.0/27229.72.29.1 to 229.72.29.30229.72.29.3130
234229.72.29.32/27229.72.29.33 to 229.72.29.62229.72.29.6330
235229.72.29.64/27229.72.29.65 to 229.72.29.94229.72.29.9530
236229.72.29.96/27229.72.29.97 to 229.72.29.126229.72.29.12730
237229.72.29.128/27229.72.29.129 to 229.72.29.158229.72.29.15930
238229.72.29.160/27229.72.29.161 to 229.72.29.190229.72.29.19130
239229.72.29.192/27229.72.29.193 to 229.72.29.222229.72.29.22330
240229.72.29.224/27229.72.29.225 to 229.72.29.254229.72.29.25530
241229.72.30.0/27229.72.30.1 to 229.72.30.30229.72.30.3130
242229.72.30.32/27229.72.30.33 to 229.72.30.62229.72.30.6330
243229.72.30.64/27229.72.30.65 to 229.72.30.94229.72.30.9530
244229.72.30.96/27229.72.30.97 to 229.72.30.126229.72.30.12730
245229.72.30.128/27229.72.30.129 to 229.72.30.158229.72.30.15930
246229.72.30.160/27229.72.30.161 to 229.72.30.190229.72.30.19130
247229.72.30.192/27229.72.30.193 to 229.72.30.222229.72.30.22330
248229.72.30.224/27229.72.30.225 to 229.72.30.254229.72.30.25530
249229.72.31.0/27229.72.31.1 to 229.72.31.30229.72.31.3130
250229.72.31.32/27229.72.31.33 to 229.72.31.62229.72.31.6330
251229.72.31.64/27229.72.31.65 to 229.72.31.94229.72.31.9530
252229.72.31.96/27229.72.31.97 to 229.72.31.126229.72.31.12730
253229.72.31.128/27229.72.31.129 to 229.72.31.158229.72.31.15930
254229.72.31.160/27229.72.31.161 to 229.72.31.190229.72.31.19130
255229.72.31.192/27229.72.31.193 to 229.72.31.222229.72.31.22330
256229.72.31.224/27229.72.31.225 to 229.72.31.254229.72.31.25530

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.