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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.

Network154.7.0.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
154.7.0.0
Broadcast address
154.7.31.255
First usable
154.7.0.1
Last usable
154.7.31.254
Usable hosts
8,190 (8,192 less the network and broadcast addresses)
Subnet mask
255.255.224.0
Wildcard mask
0.0.31.255 (Cisco ACLs, OSPF)
Prefix length
/19
Type
Public public
Old class
B (default /16)
As numbers
Hex 9A070000 · Integer 2584150016 to 2584158207
Reverse DNS zones
0.7.154.in-addr.arpa
1.7.154.in-addr.arpa
2.7.154.in-addr.arpa
3.7.154.in-addr.arpa
4.7.154.in-addr.arpa
5.7.154.in-addr.arpa
6.7.154.in-addr.arpa
7.7.154.in-addr.arpa
8.7.154.in-addr.arpa
9.7.154.in-addr.arpa
10.7.154.in-addr.arpa
11.7.154.in-addr.arpa
12.7.154.in-addr.arpa
13.7.154.in-addr.arpa
14.7.154.in-addr.arpa
15.7.154.in-addr.arpa
and 16 more
/19 is not on a 8-bit boundary, so it takes 32 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011010.00000111.00000000.00000000154.7.0.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network10011010.00000111.00000000.00000000154.7.0.0
Broadcast10011010.00000111.00011111.11111111154.7.31.255
Split into smaller subnets/27
/20 (2)/21 (4)/22 (8)/23 (16)/24 (32)/25 (64)/26 (128)/27 (256)/28 (512)/29 (1,024)/30 (2,048)/31 (4,096)

154.7.0.0/19 makes 256 subnets of /27.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1154.7.0.0/27154.7.0.1 to 154.7.0.30154.7.0.3130
2154.7.0.32/27154.7.0.33 to 154.7.0.62154.7.0.6330
3154.7.0.64/27154.7.0.65 to 154.7.0.94154.7.0.9530
4154.7.0.96/27154.7.0.97 to 154.7.0.126154.7.0.12730
5154.7.0.128/27154.7.0.129 to 154.7.0.158154.7.0.15930
6154.7.0.160/27154.7.0.161 to 154.7.0.190154.7.0.19130
7154.7.0.192/27154.7.0.193 to 154.7.0.222154.7.0.22330
8154.7.0.224/27154.7.0.225 to 154.7.0.254154.7.0.25530
9154.7.1.0/27154.7.1.1 to 154.7.1.30154.7.1.3130
10154.7.1.32/27154.7.1.33 to 154.7.1.62154.7.1.6330
11154.7.1.64/27154.7.1.65 to 154.7.1.94154.7.1.9530
12154.7.1.96/27154.7.1.97 to 154.7.1.126154.7.1.12730
13154.7.1.128/27154.7.1.129 to 154.7.1.158154.7.1.15930
14154.7.1.160/27154.7.1.161 to 154.7.1.190154.7.1.19130
15154.7.1.192/27154.7.1.193 to 154.7.1.222154.7.1.22330
16154.7.1.224/27154.7.1.225 to 154.7.1.254154.7.1.25530
17154.7.2.0/27154.7.2.1 to 154.7.2.30154.7.2.3130
18154.7.2.32/27154.7.2.33 to 154.7.2.62154.7.2.6330
19154.7.2.64/27154.7.2.65 to 154.7.2.94154.7.2.9530
20154.7.2.96/27154.7.2.97 to 154.7.2.126154.7.2.12730
21154.7.2.128/27154.7.2.129 to 154.7.2.158154.7.2.15930
22154.7.2.160/27154.7.2.161 to 154.7.2.190154.7.2.19130
23154.7.2.192/27154.7.2.193 to 154.7.2.222154.7.2.22330
24154.7.2.224/27154.7.2.225 to 154.7.2.254154.7.2.25530
25154.7.3.0/27154.7.3.1 to 154.7.3.30154.7.3.3130
26154.7.3.32/27154.7.3.33 to 154.7.3.62154.7.3.6330
27154.7.3.64/27154.7.3.65 to 154.7.3.94154.7.3.9530
28154.7.3.96/27154.7.3.97 to 154.7.3.126154.7.3.12730
29154.7.3.128/27154.7.3.129 to 154.7.3.158154.7.3.15930
30154.7.3.160/27154.7.3.161 to 154.7.3.190154.7.3.19130
31154.7.3.192/27154.7.3.193 to 154.7.3.222154.7.3.22330
32154.7.3.224/27154.7.3.225 to 154.7.3.254154.7.3.25530
33154.7.4.0/27154.7.4.1 to 154.7.4.30154.7.4.3130
34154.7.4.32/27154.7.4.33 to 154.7.4.62154.7.4.6330
35154.7.4.64/27154.7.4.65 to 154.7.4.94154.7.4.9530
36154.7.4.96/27154.7.4.97 to 154.7.4.126154.7.4.12730
37154.7.4.128/27154.7.4.129 to 154.7.4.158154.7.4.15930
38154.7.4.160/27154.7.4.161 to 154.7.4.190154.7.4.19130
39154.7.4.192/27154.7.4.193 to 154.7.4.222154.7.4.22330
40154.7.4.224/27154.7.4.225 to 154.7.4.254154.7.4.25530
41154.7.5.0/27154.7.5.1 to 154.7.5.30154.7.5.3130
42154.7.5.32/27154.7.5.33 to 154.7.5.62154.7.5.6330
43154.7.5.64/27154.7.5.65 to 154.7.5.94154.7.5.9530
44154.7.5.96/27154.7.5.97 to 154.7.5.126154.7.5.12730
45154.7.5.128/27154.7.5.129 to 154.7.5.158154.7.5.15930
46154.7.5.160/27154.7.5.161 to 154.7.5.190154.7.5.19130
47154.7.5.192/27154.7.5.193 to 154.7.5.222154.7.5.22330
48154.7.5.224/27154.7.5.225 to 154.7.5.254154.7.5.25530
49154.7.6.0/27154.7.6.1 to 154.7.6.30154.7.6.3130
50154.7.6.32/27154.7.6.33 to 154.7.6.62154.7.6.6330
51154.7.6.64/27154.7.6.65 to 154.7.6.94154.7.6.9530
52154.7.6.96/27154.7.6.97 to 154.7.6.126154.7.6.12730
53154.7.6.128/27154.7.6.129 to 154.7.6.158154.7.6.15930
54154.7.6.160/27154.7.6.161 to 154.7.6.190154.7.6.19130
55154.7.6.192/27154.7.6.193 to 154.7.6.222154.7.6.22330
56154.7.6.224/27154.7.6.225 to 154.7.6.254154.7.6.25530
57154.7.7.0/27154.7.7.1 to 154.7.7.30154.7.7.3130
58154.7.7.32/27154.7.7.33 to 154.7.7.62154.7.7.6330
59154.7.7.64/27154.7.7.65 to 154.7.7.94154.7.7.9530
60154.7.7.96/27154.7.7.97 to 154.7.7.126154.7.7.12730
61154.7.7.128/27154.7.7.129 to 154.7.7.158154.7.7.15930
62154.7.7.160/27154.7.7.161 to 154.7.7.190154.7.7.19130
63154.7.7.192/27154.7.7.193 to 154.7.7.222154.7.7.22330
64154.7.7.224/27154.7.7.225 to 154.7.7.254154.7.7.25530
65154.7.8.0/27154.7.8.1 to 154.7.8.30154.7.8.3130
66154.7.8.32/27154.7.8.33 to 154.7.8.62154.7.8.6330
67154.7.8.64/27154.7.8.65 to 154.7.8.94154.7.8.9530
68154.7.8.96/27154.7.8.97 to 154.7.8.126154.7.8.12730
69154.7.8.128/27154.7.8.129 to 154.7.8.158154.7.8.15930
70154.7.8.160/27154.7.8.161 to 154.7.8.190154.7.8.19130
71154.7.8.192/27154.7.8.193 to 154.7.8.222154.7.8.22330
72154.7.8.224/27154.7.8.225 to 154.7.8.254154.7.8.25530
73154.7.9.0/27154.7.9.1 to 154.7.9.30154.7.9.3130
74154.7.9.32/27154.7.9.33 to 154.7.9.62154.7.9.6330
75154.7.9.64/27154.7.9.65 to 154.7.9.94154.7.9.9530
76154.7.9.96/27154.7.9.97 to 154.7.9.126154.7.9.12730
77154.7.9.128/27154.7.9.129 to 154.7.9.158154.7.9.15930
78154.7.9.160/27154.7.9.161 to 154.7.9.190154.7.9.19130
79154.7.9.192/27154.7.9.193 to 154.7.9.222154.7.9.22330
80154.7.9.224/27154.7.9.225 to 154.7.9.254154.7.9.25530
81154.7.10.0/27154.7.10.1 to 154.7.10.30154.7.10.3130
82154.7.10.32/27154.7.10.33 to 154.7.10.62154.7.10.6330
83154.7.10.64/27154.7.10.65 to 154.7.10.94154.7.10.9530
84154.7.10.96/27154.7.10.97 to 154.7.10.126154.7.10.12730
85154.7.10.128/27154.7.10.129 to 154.7.10.158154.7.10.15930
86154.7.10.160/27154.7.10.161 to 154.7.10.190154.7.10.19130
87154.7.10.192/27154.7.10.193 to 154.7.10.222154.7.10.22330
88154.7.10.224/27154.7.10.225 to 154.7.10.254154.7.10.25530
89154.7.11.0/27154.7.11.1 to 154.7.11.30154.7.11.3130
90154.7.11.32/27154.7.11.33 to 154.7.11.62154.7.11.6330
91154.7.11.64/27154.7.11.65 to 154.7.11.94154.7.11.9530
92154.7.11.96/27154.7.11.97 to 154.7.11.126154.7.11.12730
93154.7.11.128/27154.7.11.129 to 154.7.11.158154.7.11.15930
94154.7.11.160/27154.7.11.161 to 154.7.11.190154.7.11.19130
95154.7.11.192/27154.7.11.193 to 154.7.11.222154.7.11.22330
96154.7.11.224/27154.7.11.225 to 154.7.11.254154.7.11.25530
97154.7.12.0/27154.7.12.1 to 154.7.12.30154.7.12.3130
98154.7.12.32/27154.7.12.33 to 154.7.12.62154.7.12.6330
99154.7.12.64/27154.7.12.65 to 154.7.12.94154.7.12.9530
100154.7.12.96/27154.7.12.97 to 154.7.12.126154.7.12.12730
101154.7.12.128/27154.7.12.129 to 154.7.12.158154.7.12.15930
102154.7.12.160/27154.7.12.161 to 154.7.12.190154.7.12.19130
103154.7.12.192/27154.7.12.193 to 154.7.12.222154.7.12.22330
104154.7.12.224/27154.7.12.225 to 154.7.12.254154.7.12.25530
105154.7.13.0/27154.7.13.1 to 154.7.13.30154.7.13.3130
106154.7.13.32/27154.7.13.33 to 154.7.13.62154.7.13.6330
107154.7.13.64/27154.7.13.65 to 154.7.13.94154.7.13.9530
108154.7.13.96/27154.7.13.97 to 154.7.13.126154.7.13.12730
109154.7.13.128/27154.7.13.129 to 154.7.13.158154.7.13.15930
110154.7.13.160/27154.7.13.161 to 154.7.13.190154.7.13.19130
111154.7.13.192/27154.7.13.193 to 154.7.13.222154.7.13.22330
112154.7.13.224/27154.7.13.225 to 154.7.13.254154.7.13.25530
113154.7.14.0/27154.7.14.1 to 154.7.14.30154.7.14.3130
114154.7.14.32/27154.7.14.33 to 154.7.14.62154.7.14.6330
115154.7.14.64/27154.7.14.65 to 154.7.14.94154.7.14.9530
116154.7.14.96/27154.7.14.97 to 154.7.14.126154.7.14.12730
117154.7.14.128/27154.7.14.129 to 154.7.14.158154.7.14.15930
118154.7.14.160/27154.7.14.161 to 154.7.14.190154.7.14.19130
119154.7.14.192/27154.7.14.193 to 154.7.14.222154.7.14.22330
120154.7.14.224/27154.7.14.225 to 154.7.14.254154.7.14.25530
121154.7.15.0/27154.7.15.1 to 154.7.15.30154.7.15.3130
122154.7.15.32/27154.7.15.33 to 154.7.15.62154.7.15.6330
123154.7.15.64/27154.7.15.65 to 154.7.15.94154.7.15.9530
124154.7.15.96/27154.7.15.97 to 154.7.15.126154.7.15.12730
125154.7.15.128/27154.7.15.129 to 154.7.15.158154.7.15.15930
126154.7.15.160/27154.7.15.161 to 154.7.15.190154.7.15.19130
127154.7.15.192/27154.7.15.193 to 154.7.15.222154.7.15.22330
128154.7.15.224/27154.7.15.225 to 154.7.15.254154.7.15.25530
129154.7.16.0/27154.7.16.1 to 154.7.16.30154.7.16.3130
130154.7.16.32/27154.7.16.33 to 154.7.16.62154.7.16.6330
131154.7.16.64/27154.7.16.65 to 154.7.16.94154.7.16.9530
132154.7.16.96/27154.7.16.97 to 154.7.16.126154.7.16.12730
133154.7.16.128/27154.7.16.129 to 154.7.16.158154.7.16.15930
134154.7.16.160/27154.7.16.161 to 154.7.16.190154.7.16.19130
135154.7.16.192/27154.7.16.193 to 154.7.16.222154.7.16.22330
136154.7.16.224/27154.7.16.225 to 154.7.16.254154.7.16.25530
137154.7.17.0/27154.7.17.1 to 154.7.17.30154.7.17.3130
138154.7.17.32/27154.7.17.33 to 154.7.17.62154.7.17.6330
139154.7.17.64/27154.7.17.65 to 154.7.17.94154.7.17.9530
140154.7.17.96/27154.7.17.97 to 154.7.17.126154.7.17.12730
141154.7.17.128/27154.7.17.129 to 154.7.17.158154.7.17.15930
142154.7.17.160/27154.7.17.161 to 154.7.17.190154.7.17.19130
143154.7.17.192/27154.7.17.193 to 154.7.17.222154.7.17.22330
144154.7.17.224/27154.7.17.225 to 154.7.17.254154.7.17.25530
145154.7.18.0/27154.7.18.1 to 154.7.18.30154.7.18.3130
146154.7.18.32/27154.7.18.33 to 154.7.18.62154.7.18.6330
147154.7.18.64/27154.7.18.65 to 154.7.18.94154.7.18.9530
148154.7.18.96/27154.7.18.97 to 154.7.18.126154.7.18.12730
149154.7.18.128/27154.7.18.129 to 154.7.18.158154.7.18.15930
150154.7.18.160/27154.7.18.161 to 154.7.18.190154.7.18.19130
151154.7.18.192/27154.7.18.193 to 154.7.18.222154.7.18.22330
152154.7.18.224/27154.7.18.225 to 154.7.18.254154.7.18.25530
153154.7.19.0/27154.7.19.1 to 154.7.19.30154.7.19.3130
154154.7.19.32/27154.7.19.33 to 154.7.19.62154.7.19.6330
155154.7.19.64/27154.7.19.65 to 154.7.19.94154.7.19.9530
156154.7.19.96/27154.7.19.97 to 154.7.19.126154.7.19.12730
157154.7.19.128/27154.7.19.129 to 154.7.19.158154.7.19.15930
158154.7.19.160/27154.7.19.161 to 154.7.19.190154.7.19.19130
159154.7.19.192/27154.7.19.193 to 154.7.19.222154.7.19.22330
160154.7.19.224/27154.7.19.225 to 154.7.19.254154.7.19.25530
161154.7.20.0/27154.7.20.1 to 154.7.20.30154.7.20.3130
162154.7.20.32/27154.7.20.33 to 154.7.20.62154.7.20.6330
163154.7.20.64/27154.7.20.65 to 154.7.20.94154.7.20.9530
164154.7.20.96/27154.7.20.97 to 154.7.20.126154.7.20.12730
165154.7.20.128/27154.7.20.129 to 154.7.20.158154.7.20.15930
166154.7.20.160/27154.7.20.161 to 154.7.20.190154.7.20.19130
167154.7.20.192/27154.7.20.193 to 154.7.20.222154.7.20.22330
168154.7.20.224/27154.7.20.225 to 154.7.20.254154.7.20.25530
169154.7.21.0/27154.7.21.1 to 154.7.21.30154.7.21.3130
170154.7.21.32/27154.7.21.33 to 154.7.21.62154.7.21.6330
171154.7.21.64/27154.7.21.65 to 154.7.21.94154.7.21.9530
172154.7.21.96/27154.7.21.97 to 154.7.21.126154.7.21.12730
173154.7.21.128/27154.7.21.129 to 154.7.21.158154.7.21.15930
174154.7.21.160/27154.7.21.161 to 154.7.21.190154.7.21.19130
175154.7.21.192/27154.7.21.193 to 154.7.21.222154.7.21.22330
176154.7.21.224/27154.7.21.225 to 154.7.21.254154.7.21.25530
177154.7.22.0/27154.7.22.1 to 154.7.22.30154.7.22.3130
178154.7.22.32/27154.7.22.33 to 154.7.22.62154.7.22.6330
179154.7.22.64/27154.7.22.65 to 154.7.22.94154.7.22.9530
180154.7.22.96/27154.7.22.97 to 154.7.22.126154.7.22.12730
181154.7.22.128/27154.7.22.129 to 154.7.22.158154.7.22.15930
182154.7.22.160/27154.7.22.161 to 154.7.22.190154.7.22.19130
183154.7.22.192/27154.7.22.193 to 154.7.22.222154.7.22.22330
184154.7.22.224/27154.7.22.225 to 154.7.22.254154.7.22.25530
185154.7.23.0/27154.7.23.1 to 154.7.23.30154.7.23.3130
186154.7.23.32/27154.7.23.33 to 154.7.23.62154.7.23.6330
187154.7.23.64/27154.7.23.65 to 154.7.23.94154.7.23.9530
188154.7.23.96/27154.7.23.97 to 154.7.23.126154.7.23.12730
189154.7.23.128/27154.7.23.129 to 154.7.23.158154.7.23.15930
190154.7.23.160/27154.7.23.161 to 154.7.23.190154.7.23.19130
191154.7.23.192/27154.7.23.193 to 154.7.23.222154.7.23.22330
192154.7.23.224/27154.7.23.225 to 154.7.23.254154.7.23.25530
193154.7.24.0/27154.7.24.1 to 154.7.24.30154.7.24.3130
194154.7.24.32/27154.7.24.33 to 154.7.24.62154.7.24.6330
195154.7.24.64/27154.7.24.65 to 154.7.24.94154.7.24.9530
196154.7.24.96/27154.7.24.97 to 154.7.24.126154.7.24.12730
197154.7.24.128/27154.7.24.129 to 154.7.24.158154.7.24.15930
198154.7.24.160/27154.7.24.161 to 154.7.24.190154.7.24.19130
199154.7.24.192/27154.7.24.193 to 154.7.24.222154.7.24.22330
200154.7.24.224/27154.7.24.225 to 154.7.24.254154.7.24.25530
201154.7.25.0/27154.7.25.1 to 154.7.25.30154.7.25.3130
202154.7.25.32/27154.7.25.33 to 154.7.25.62154.7.25.6330
203154.7.25.64/27154.7.25.65 to 154.7.25.94154.7.25.9530
204154.7.25.96/27154.7.25.97 to 154.7.25.126154.7.25.12730
205154.7.25.128/27154.7.25.129 to 154.7.25.158154.7.25.15930
206154.7.25.160/27154.7.25.161 to 154.7.25.190154.7.25.19130
207154.7.25.192/27154.7.25.193 to 154.7.25.222154.7.25.22330
208154.7.25.224/27154.7.25.225 to 154.7.25.254154.7.25.25530
209154.7.26.0/27154.7.26.1 to 154.7.26.30154.7.26.3130
210154.7.26.32/27154.7.26.33 to 154.7.26.62154.7.26.6330
211154.7.26.64/27154.7.26.65 to 154.7.26.94154.7.26.9530
212154.7.26.96/27154.7.26.97 to 154.7.26.126154.7.26.12730
213154.7.26.128/27154.7.26.129 to 154.7.26.158154.7.26.15930
214154.7.26.160/27154.7.26.161 to 154.7.26.190154.7.26.19130
215154.7.26.192/27154.7.26.193 to 154.7.26.222154.7.26.22330
216154.7.26.224/27154.7.26.225 to 154.7.26.254154.7.26.25530
217154.7.27.0/27154.7.27.1 to 154.7.27.30154.7.27.3130
218154.7.27.32/27154.7.27.33 to 154.7.27.62154.7.27.6330
219154.7.27.64/27154.7.27.65 to 154.7.27.94154.7.27.9530
220154.7.27.96/27154.7.27.97 to 154.7.27.126154.7.27.12730
221154.7.27.128/27154.7.27.129 to 154.7.27.158154.7.27.15930
222154.7.27.160/27154.7.27.161 to 154.7.27.190154.7.27.19130
223154.7.27.192/27154.7.27.193 to 154.7.27.222154.7.27.22330
224154.7.27.224/27154.7.27.225 to 154.7.27.254154.7.27.25530
225154.7.28.0/27154.7.28.1 to 154.7.28.30154.7.28.3130
226154.7.28.32/27154.7.28.33 to 154.7.28.62154.7.28.6330
227154.7.28.64/27154.7.28.65 to 154.7.28.94154.7.28.9530
228154.7.28.96/27154.7.28.97 to 154.7.28.126154.7.28.12730
229154.7.28.128/27154.7.28.129 to 154.7.28.158154.7.28.15930
230154.7.28.160/27154.7.28.161 to 154.7.28.190154.7.28.19130
231154.7.28.192/27154.7.28.193 to 154.7.28.222154.7.28.22330
232154.7.28.224/27154.7.28.225 to 154.7.28.254154.7.28.25530
233154.7.29.0/27154.7.29.1 to 154.7.29.30154.7.29.3130
234154.7.29.32/27154.7.29.33 to 154.7.29.62154.7.29.6330
235154.7.29.64/27154.7.29.65 to 154.7.29.94154.7.29.9530
236154.7.29.96/27154.7.29.97 to 154.7.29.126154.7.29.12730
237154.7.29.128/27154.7.29.129 to 154.7.29.158154.7.29.15930
238154.7.29.160/27154.7.29.161 to 154.7.29.190154.7.29.19130
239154.7.29.192/27154.7.29.193 to 154.7.29.222154.7.29.22330
240154.7.29.224/27154.7.29.225 to 154.7.29.254154.7.29.25530
241154.7.30.0/27154.7.30.1 to 154.7.30.30154.7.30.3130
242154.7.30.32/27154.7.30.33 to 154.7.30.62154.7.30.6330
243154.7.30.64/27154.7.30.65 to 154.7.30.94154.7.30.9530
244154.7.30.96/27154.7.30.97 to 154.7.30.126154.7.30.12730
245154.7.30.128/27154.7.30.129 to 154.7.30.158154.7.30.15930
246154.7.30.160/27154.7.30.161 to 154.7.30.190154.7.30.19130
247154.7.30.192/27154.7.30.193 to 154.7.30.222154.7.30.22330
248154.7.30.224/27154.7.30.225 to 154.7.30.254154.7.30.25530
249154.7.31.0/27154.7.31.1 to 154.7.31.30154.7.31.3130
250154.7.31.32/27154.7.31.33 to 154.7.31.62154.7.31.6330
251154.7.31.64/27154.7.31.65 to 154.7.31.94154.7.31.9530
252154.7.31.96/27154.7.31.97 to 154.7.31.126154.7.31.12730
253154.7.31.128/27154.7.31.129 to 154.7.31.158154.7.31.15930
254154.7.31.160/27154.7.31.161 to 154.7.31.190154.7.31.19130
255154.7.31.192/27154.7.31.193 to 154.7.31.222154.7.31.22330
256154.7.31.224/27154.7.31.225 to 154.7.31.254154.7.31.25530

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.