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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.

Network230.167.64.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
230.167.64.0
Broadcast address
230.167.127.255
First usable
230.167.64.1
Last usable
230.167.127.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E6A74000 · Integer 3869720576 to 3869736959
Reverse DNS zones
64.167.230.in-addr.arpa
65.167.230.in-addr.arpa
66.167.230.in-addr.arpa
67.167.230.in-addr.arpa
68.167.230.in-addr.arpa
69.167.230.in-addr.arpa
70.167.230.in-addr.arpa
71.167.230.in-addr.arpa
72.167.230.in-addr.arpa
73.167.230.in-addr.arpa
74.167.230.in-addr.arpa
75.167.230.in-addr.arpa
76.167.230.in-addr.arpa
77.167.230.in-addr.arpa
78.167.230.in-addr.arpa
79.167.230.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100110.10100111.01000000.00000000230.167.64.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network11100110.10100111.01000000.00000000230.167.64.0
Broadcast11100110.10100111.01111111.11111111230.167.127.255
Split into smaller subnets/27
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

230.167.64.0/18 makes 512 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1230.167.64.0/27230.167.64.1 to 230.167.64.30230.167.64.3130
2230.167.64.32/27230.167.64.33 to 230.167.64.62230.167.64.6330
3230.167.64.64/27230.167.64.65 to 230.167.64.94230.167.64.9530
4230.167.64.96/27230.167.64.97 to 230.167.64.126230.167.64.12730
5230.167.64.128/27230.167.64.129 to 230.167.64.158230.167.64.15930
6230.167.64.160/27230.167.64.161 to 230.167.64.190230.167.64.19130
7230.167.64.192/27230.167.64.193 to 230.167.64.222230.167.64.22330
8230.167.64.224/27230.167.64.225 to 230.167.64.254230.167.64.25530
9230.167.65.0/27230.167.65.1 to 230.167.65.30230.167.65.3130
10230.167.65.32/27230.167.65.33 to 230.167.65.62230.167.65.6330
11230.167.65.64/27230.167.65.65 to 230.167.65.94230.167.65.9530
12230.167.65.96/27230.167.65.97 to 230.167.65.126230.167.65.12730
13230.167.65.128/27230.167.65.129 to 230.167.65.158230.167.65.15930
14230.167.65.160/27230.167.65.161 to 230.167.65.190230.167.65.19130
15230.167.65.192/27230.167.65.193 to 230.167.65.222230.167.65.22330
16230.167.65.224/27230.167.65.225 to 230.167.65.254230.167.65.25530
17230.167.66.0/27230.167.66.1 to 230.167.66.30230.167.66.3130
18230.167.66.32/27230.167.66.33 to 230.167.66.62230.167.66.6330
19230.167.66.64/27230.167.66.65 to 230.167.66.94230.167.66.9530
20230.167.66.96/27230.167.66.97 to 230.167.66.126230.167.66.12730
21230.167.66.128/27230.167.66.129 to 230.167.66.158230.167.66.15930
22230.167.66.160/27230.167.66.161 to 230.167.66.190230.167.66.19130
23230.167.66.192/27230.167.66.193 to 230.167.66.222230.167.66.22330
24230.167.66.224/27230.167.66.225 to 230.167.66.254230.167.66.25530
25230.167.67.0/27230.167.67.1 to 230.167.67.30230.167.67.3130
26230.167.67.32/27230.167.67.33 to 230.167.67.62230.167.67.6330
27230.167.67.64/27230.167.67.65 to 230.167.67.94230.167.67.9530
28230.167.67.96/27230.167.67.97 to 230.167.67.126230.167.67.12730
29230.167.67.128/27230.167.67.129 to 230.167.67.158230.167.67.15930
30230.167.67.160/27230.167.67.161 to 230.167.67.190230.167.67.19130
31230.167.67.192/27230.167.67.193 to 230.167.67.222230.167.67.22330
32230.167.67.224/27230.167.67.225 to 230.167.67.254230.167.67.25530
33230.167.68.0/27230.167.68.1 to 230.167.68.30230.167.68.3130
34230.167.68.32/27230.167.68.33 to 230.167.68.62230.167.68.6330
35230.167.68.64/27230.167.68.65 to 230.167.68.94230.167.68.9530
36230.167.68.96/27230.167.68.97 to 230.167.68.126230.167.68.12730
37230.167.68.128/27230.167.68.129 to 230.167.68.158230.167.68.15930
38230.167.68.160/27230.167.68.161 to 230.167.68.190230.167.68.19130
39230.167.68.192/27230.167.68.193 to 230.167.68.222230.167.68.22330
40230.167.68.224/27230.167.68.225 to 230.167.68.254230.167.68.25530
41230.167.69.0/27230.167.69.1 to 230.167.69.30230.167.69.3130
42230.167.69.32/27230.167.69.33 to 230.167.69.62230.167.69.6330
43230.167.69.64/27230.167.69.65 to 230.167.69.94230.167.69.9530
44230.167.69.96/27230.167.69.97 to 230.167.69.126230.167.69.12730
45230.167.69.128/27230.167.69.129 to 230.167.69.158230.167.69.15930
46230.167.69.160/27230.167.69.161 to 230.167.69.190230.167.69.19130
47230.167.69.192/27230.167.69.193 to 230.167.69.222230.167.69.22330
48230.167.69.224/27230.167.69.225 to 230.167.69.254230.167.69.25530
49230.167.70.0/27230.167.70.1 to 230.167.70.30230.167.70.3130
50230.167.70.32/27230.167.70.33 to 230.167.70.62230.167.70.6330
51230.167.70.64/27230.167.70.65 to 230.167.70.94230.167.70.9530
52230.167.70.96/27230.167.70.97 to 230.167.70.126230.167.70.12730
53230.167.70.128/27230.167.70.129 to 230.167.70.158230.167.70.15930
54230.167.70.160/27230.167.70.161 to 230.167.70.190230.167.70.19130
55230.167.70.192/27230.167.70.193 to 230.167.70.222230.167.70.22330
56230.167.70.224/27230.167.70.225 to 230.167.70.254230.167.70.25530
57230.167.71.0/27230.167.71.1 to 230.167.71.30230.167.71.3130
58230.167.71.32/27230.167.71.33 to 230.167.71.62230.167.71.6330
59230.167.71.64/27230.167.71.65 to 230.167.71.94230.167.71.9530
60230.167.71.96/27230.167.71.97 to 230.167.71.126230.167.71.12730
61230.167.71.128/27230.167.71.129 to 230.167.71.158230.167.71.15930
62230.167.71.160/27230.167.71.161 to 230.167.71.190230.167.71.19130
63230.167.71.192/27230.167.71.193 to 230.167.71.222230.167.71.22330
64230.167.71.224/27230.167.71.225 to 230.167.71.254230.167.71.25530
65230.167.72.0/27230.167.72.1 to 230.167.72.30230.167.72.3130
66230.167.72.32/27230.167.72.33 to 230.167.72.62230.167.72.6330
67230.167.72.64/27230.167.72.65 to 230.167.72.94230.167.72.9530
68230.167.72.96/27230.167.72.97 to 230.167.72.126230.167.72.12730
69230.167.72.128/27230.167.72.129 to 230.167.72.158230.167.72.15930
70230.167.72.160/27230.167.72.161 to 230.167.72.190230.167.72.19130
71230.167.72.192/27230.167.72.193 to 230.167.72.222230.167.72.22330
72230.167.72.224/27230.167.72.225 to 230.167.72.254230.167.72.25530
73230.167.73.0/27230.167.73.1 to 230.167.73.30230.167.73.3130
74230.167.73.32/27230.167.73.33 to 230.167.73.62230.167.73.6330
75230.167.73.64/27230.167.73.65 to 230.167.73.94230.167.73.9530
76230.167.73.96/27230.167.73.97 to 230.167.73.126230.167.73.12730
77230.167.73.128/27230.167.73.129 to 230.167.73.158230.167.73.15930
78230.167.73.160/27230.167.73.161 to 230.167.73.190230.167.73.19130
79230.167.73.192/27230.167.73.193 to 230.167.73.222230.167.73.22330
80230.167.73.224/27230.167.73.225 to 230.167.73.254230.167.73.25530
81230.167.74.0/27230.167.74.1 to 230.167.74.30230.167.74.3130
82230.167.74.32/27230.167.74.33 to 230.167.74.62230.167.74.6330
83230.167.74.64/27230.167.74.65 to 230.167.74.94230.167.74.9530
84230.167.74.96/27230.167.74.97 to 230.167.74.126230.167.74.12730
85230.167.74.128/27230.167.74.129 to 230.167.74.158230.167.74.15930
86230.167.74.160/27230.167.74.161 to 230.167.74.190230.167.74.19130
87230.167.74.192/27230.167.74.193 to 230.167.74.222230.167.74.22330
88230.167.74.224/27230.167.74.225 to 230.167.74.254230.167.74.25530
89230.167.75.0/27230.167.75.1 to 230.167.75.30230.167.75.3130
90230.167.75.32/27230.167.75.33 to 230.167.75.62230.167.75.6330
91230.167.75.64/27230.167.75.65 to 230.167.75.94230.167.75.9530
92230.167.75.96/27230.167.75.97 to 230.167.75.126230.167.75.12730
93230.167.75.128/27230.167.75.129 to 230.167.75.158230.167.75.15930
94230.167.75.160/27230.167.75.161 to 230.167.75.190230.167.75.19130
95230.167.75.192/27230.167.75.193 to 230.167.75.222230.167.75.22330
96230.167.75.224/27230.167.75.225 to 230.167.75.254230.167.75.25530
97230.167.76.0/27230.167.76.1 to 230.167.76.30230.167.76.3130
98230.167.76.32/27230.167.76.33 to 230.167.76.62230.167.76.6330
99230.167.76.64/27230.167.76.65 to 230.167.76.94230.167.76.9530
100230.167.76.96/27230.167.76.97 to 230.167.76.126230.167.76.12730
101230.167.76.128/27230.167.76.129 to 230.167.76.158230.167.76.15930
102230.167.76.160/27230.167.76.161 to 230.167.76.190230.167.76.19130
103230.167.76.192/27230.167.76.193 to 230.167.76.222230.167.76.22330
104230.167.76.224/27230.167.76.225 to 230.167.76.254230.167.76.25530
105230.167.77.0/27230.167.77.1 to 230.167.77.30230.167.77.3130
106230.167.77.32/27230.167.77.33 to 230.167.77.62230.167.77.6330
107230.167.77.64/27230.167.77.65 to 230.167.77.94230.167.77.9530
108230.167.77.96/27230.167.77.97 to 230.167.77.126230.167.77.12730
109230.167.77.128/27230.167.77.129 to 230.167.77.158230.167.77.15930
110230.167.77.160/27230.167.77.161 to 230.167.77.190230.167.77.19130
111230.167.77.192/27230.167.77.193 to 230.167.77.222230.167.77.22330
112230.167.77.224/27230.167.77.225 to 230.167.77.254230.167.77.25530
113230.167.78.0/27230.167.78.1 to 230.167.78.30230.167.78.3130
114230.167.78.32/27230.167.78.33 to 230.167.78.62230.167.78.6330
115230.167.78.64/27230.167.78.65 to 230.167.78.94230.167.78.9530
116230.167.78.96/27230.167.78.97 to 230.167.78.126230.167.78.12730
117230.167.78.128/27230.167.78.129 to 230.167.78.158230.167.78.15930
118230.167.78.160/27230.167.78.161 to 230.167.78.190230.167.78.19130
119230.167.78.192/27230.167.78.193 to 230.167.78.222230.167.78.22330
120230.167.78.224/27230.167.78.225 to 230.167.78.254230.167.78.25530
121230.167.79.0/27230.167.79.1 to 230.167.79.30230.167.79.3130
122230.167.79.32/27230.167.79.33 to 230.167.79.62230.167.79.6330
123230.167.79.64/27230.167.79.65 to 230.167.79.94230.167.79.9530
124230.167.79.96/27230.167.79.97 to 230.167.79.126230.167.79.12730
125230.167.79.128/27230.167.79.129 to 230.167.79.158230.167.79.15930
126230.167.79.160/27230.167.79.161 to 230.167.79.190230.167.79.19130
127230.167.79.192/27230.167.79.193 to 230.167.79.222230.167.79.22330
128230.167.79.224/27230.167.79.225 to 230.167.79.254230.167.79.25530
129230.167.80.0/27230.167.80.1 to 230.167.80.30230.167.80.3130
130230.167.80.32/27230.167.80.33 to 230.167.80.62230.167.80.6330
131230.167.80.64/27230.167.80.65 to 230.167.80.94230.167.80.9530
132230.167.80.96/27230.167.80.97 to 230.167.80.126230.167.80.12730
133230.167.80.128/27230.167.80.129 to 230.167.80.158230.167.80.15930
134230.167.80.160/27230.167.80.161 to 230.167.80.190230.167.80.19130
135230.167.80.192/27230.167.80.193 to 230.167.80.222230.167.80.22330
136230.167.80.224/27230.167.80.225 to 230.167.80.254230.167.80.25530
137230.167.81.0/27230.167.81.1 to 230.167.81.30230.167.81.3130
138230.167.81.32/27230.167.81.33 to 230.167.81.62230.167.81.6330
139230.167.81.64/27230.167.81.65 to 230.167.81.94230.167.81.9530
140230.167.81.96/27230.167.81.97 to 230.167.81.126230.167.81.12730
141230.167.81.128/27230.167.81.129 to 230.167.81.158230.167.81.15930
142230.167.81.160/27230.167.81.161 to 230.167.81.190230.167.81.19130
143230.167.81.192/27230.167.81.193 to 230.167.81.222230.167.81.22330
144230.167.81.224/27230.167.81.225 to 230.167.81.254230.167.81.25530
145230.167.82.0/27230.167.82.1 to 230.167.82.30230.167.82.3130
146230.167.82.32/27230.167.82.33 to 230.167.82.62230.167.82.6330
147230.167.82.64/27230.167.82.65 to 230.167.82.94230.167.82.9530
148230.167.82.96/27230.167.82.97 to 230.167.82.126230.167.82.12730
149230.167.82.128/27230.167.82.129 to 230.167.82.158230.167.82.15930
150230.167.82.160/27230.167.82.161 to 230.167.82.190230.167.82.19130
151230.167.82.192/27230.167.82.193 to 230.167.82.222230.167.82.22330
152230.167.82.224/27230.167.82.225 to 230.167.82.254230.167.82.25530
153230.167.83.0/27230.167.83.1 to 230.167.83.30230.167.83.3130
154230.167.83.32/27230.167.83.33 to 230.167.83.62230.167.83.6330
155230.167.83.64/27230.167.83.65 to 230.167.83.94230.167.83.9530
156230.167.83.96/27230.167.83.97 to 230.167.83.126230.167.83.12730
157230.167.83.128/27230.167.83.129 to 230.167.83.158230.167.83.15930
158230.167.83.160/27230.167.83.161 to 230.167.83.190230.167.83.19130
159230.167.83.192/27230.167.83.193 to 230.167.83.222230.167.83.22330
160230.167.83.224/27230.167.83.225 to 230.167.83.254230.167.83.25530
161230.167.84.0/27230.167.84.1 to 230.167.84.30230.167.84.3130
162230.167.84.32/27230.167.84.33 to 230.167.84.62230.167.84.6330
163230.167.84.64/27230.167.84.65 to 230.167.84.94230.167.84.9530
164230.167.84.96/27230.167.84.97 to 230.167.84.126230.167.84.12730
165230.167.84.128/27230.167.84.129 to 230.167.84.158230.167.84.15930
166230.167.84.160/27230.167.84.161 to 230.167.84.190230.167.84.19130
167230.167.84.192/27230.167.84.193 to 230.167.84.222230.167.84.22330
168230.167.84.224/27230.167.84.225 to 230.167.84.254230.167.84.25530
169230.167.85.0/27230.167.85.1 to 230.167.85.30230.167.85.3130
170230.167.85.32/27230.167.85.33 to 230.167.85.62230.167.85.6330
171230.167.85.64/27230.167.85.65 to 230.167.85.94230.167.85.9530
172230.167.85.96/27230.167.85.97 to 230.167.85.126230.167.85.12730
173230.167.85.128/27230.167.85.129 to 230.167.85.158230.167.85.15930
174230.167.85.160/27230.167.85.161 to 230.167.85.190230.167.85.19130
175230.167.85.192/27230.167.85.193 to 230.167.85.222230.167.85.22330
176230.167.85.224/27230.167.85.225 to 230.167.85.254230.167.85.25530
177230.167.86.0/27230.167.86.1 to 230.167.86.30230.167.86.3130
178230.167.86.32/27230.167.86.33 to 230.167.86.62230.167.86.6330
179230.167.86.64/27230.167.86.65 to 230.167.86.94230.167.86.9530
180230.167.86.96/27230.167.86.97 to 230.167.86.126230.167.86.12730
181230.167.86.128/27230.167.86.129 to 230.167.86.158230.167.86.15930
182230.167.86.160/27230.167.86.161 to 230.167.86.190230.167.86.19130
183230.167.86.192/27230.167.86.193 to 230.167.86.222230.167.86.22330
184230.167.86.224/27230.167.86.225 to 230.167.86.254230.167.86.25530
185230.167.87.0/27230.167.87.1 to 230.167.87.30230.167.87.3130
186230.167.87.32/27230.167.87.33 to 230.167.87.62230.167.87.6330
187230.167.87.64/27230.167.87.65 to 230.167.87.94230.167.87.9530
188230.167.87.96/27230.167.87.97 to 230.167.87.126230.167.87.12730
189230.167.87.128/27230.167.87.129 to 230.167.87.158230.167.87.15930
190230.167.87.160/27230.167.87.161 to 230.167.87.190230.167.87.19130
191230.167.87.192/27230.167.87.193 to 230.167.87.222230.167.87.22330
192230.167.87.224/27230.167.87.225 to 230.167.87.254230.167.87.25530
193230.167.88.0/27230.167.88.1 to 230.167.88.30230.167.88.3130
194230.167.88.32/27230.167.88.33 to 230.167.88.62230.167.88.6330
195230.167.88.64/27230.167.88.65 to 230.167.88.94230.167.88.9530
196230.167.88.96/27230.167.88.97 to 230.167.88.126230.167.88.12730
197230.167.88.128/27230.167.88.129 to 230.167.88.158230.167.88.15930
198230.167.88.160/27230.167.88.161 to 230.167.88.190230.167.88.19130
199230.167.88.192/27230.167.88.193 to 230.167.88.222230.167.88.22330
200230.167.88.224/27230.167.88.225 to 230.167.88.254230.167.88.25530
201230.167.89.0/27230.167.89.1 to 230.167.89.30230.167.89.3130
202230.167.89.32/27230.167.89.33 to 230.167.89.62230.167.89.6330
203230.167.89.64/27230.167.89.65 to 230.167.89.94230.167.89.9530
204230.167.89.96/27230.167.89.97 to 230.167.89.126230.167.89.12730
205230.167.89.128/27230.167.89.129 to 230.167.89.158230.167.89.15930
206230.167.89.160/27230.167.89.161 to 230.167.89.190230.167.89.19130
207230.167.89.192/27230.167.89.193 to 230.167.89.222230.167.89.22330
208230.167.89.224/27230.167.89.225 to 230.167.89.254230.167.89.25530
209230.167.90.0/27230.167.90.1 to 230.167.90.30230.167.90.3130
210230.167.90.32/27230.167.90.33 to 230.167.90.62230.167.90.6330
211230.167.90.64/27230.167.90.65 to 230.167.90.94230.167.90.9530
212230.167.90.96/27230.167.90.97 to 230.167.90.126230.167.90.12730
213230.167.90.128/27230.167.90.129 to 230.167.90.158230.167.90.15930
214230.167.90.160/27230.167.90.161 to 230.167.90.190230.167.90.19130
215230.167.90.192/27230.167.90.193 to 230.167.90.222230.167.90.22330
216230.167.90.224/27230.167.90.225 to 230.167.90.254230.167.90.25530
217230.167.91.0/27230.167.91.1 to 230.167.91.30230.167.91.3130
218230.167.91.32/27230.167.91.33 to 230.167.91.62230.167.91.6330
219230.167.91.64/27230.167.91.65 to 230.167.91.94230.167.91.9530
220230.167.91.96/27230.167.91.97 to 230.167.91.126230.167.91.12730
221230.167.91.128/27230.167.91.129 to 230.167.91.158230.167.91.15930
222230.167.91.160/27230.167.91.161 to 230.167.91.190230.167.91.19130
223230.167.91.192/27230.167.91.193 to 230.167.91.222230.167.91.22330
224230.167.91.224/27230.167.91.225 to 230.167.91.254230.167.91.25530
225230.167.92.0/27230.167.92.1 to 230.167.92.30230.167.92.3130
226230.167.92.32/27230.167.92.33 to 230.167.92.62230.167.92.6330
227230.167.92.64/27230.167.92.65 to 230.167.92.94230.167.92.9530
228230.167.92.96/27230.167.92.97 to 230.167.92.126230.167.92.12730
229230.167.92.128/27230.167.92.129 to 230.167.92.158230.167.92.15930
230230.167.92.160/27230.167.92.161 to 230.167.92.190230.167.92.19130
231230.167.92.192/27230.167.92.193 to 230.167.92.222230.167.92.22330
232230.167.92.224/27230.167.92.225 to 230.167.92.254230.167.92.25530
233230.167.93.0/27230.167.93.1 to 230.167.93.30230.167.93.3130
234230.167.93.32/27230.167.93.33 to 230.167.93.62230.167.93.6330
235230.167.93.64/27230.167.93.65 to 230.167.93.94230.167.93.9530
236230.167.93.96/27230.167.93.97 to 230.167.93.126230.167.93.12730
237230.167.93.128/27230.167.93.129 to 230.167.93.158230.167.93.15930
238230.167.93.160/27230.167.93.161 to 230.167.93.190230.167.93.19130
239230.167.93.192/27230.167.93.193 to 230.167.93.222230.167.93.22330
240230.167.93.224/27230.167.93.225 to 230.167.93.254230.167.93.25530
241230.167.94.0/27230.167.94.1 to 230.167.94.30230.167.94.3130
242230.167.94.32/27230.167.94.33 to 230.167.94.62230.167.94.6330
243230.167.94.64/27230.167.94.65 to 230.167.94.94230.167.94.9530
244230.167.94.96/27230.167.94.97 to 230.167.94.126230.167.94.12730
245230.167.94.128/27230.167.94.129 to 230.167.94.158230.167.94.15930
246230.167.94.160/27230.167.94.161 to 230.167.94.190230.167.94.19130
247230.167.94.192/27230.167.94.193 to 230.167.94.222230.167.94.22330
248230.167.94.224/27230.167.94.225 to 230.167.94.254230.167.94.25530
249230.167.95.0/27230.167.95.1 to 230.167.95.30230.167.95.3130
250230.167.95.32/27230.167.95.33 to 230.167.95.62230.167.95.6330
251230.167.95.64/27230.167.95.65 to 230.167.95.94230.167.95.9530
252230.167.95.96/27230.167.95.97 to 230.167.95.126230.167.95.12730
253230.167.95.128/27230.167.95.129 to 230.167.95.158230.167.95.15930
254230.167.95.160/27230.167.95.161 to 230.167.95.190230.167.95.19130
255230.167.95.192/27230.167.95.193 to 230.167.95.222230.167.95.22330
256230.167.95.224/27230.167.95.225 to 230.167.95.254230.167.95.25530

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.