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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/28
/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 1,024 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1230.167.64.0/28230.167.64.1 to 230.167.64.14230.167.64.1514
2230.167.64.16/28230.167.64.17 to 230.167.64.30230.167.64.3114
3230.167.64.32/28230.167.64.33 to 230.167.64.46230.167.64.4714
4230.167.64.48/28230.167.64.49 to 230.167.64.62230.167.64.6314
5230.167.64.64/28230.167.64.65 to 230.167.64.78230.167.64.7914
6230.167.64.80/28230.167.64.81 to 230.167.64.94230.167.64.9514
7230.167.64.96/28230.167.64.97 to 230.167.64.110230.167.64.11114
8230.167.64.112/28230.167.64.113 to 230.167.64.126230.167.64.12714
9230.167.64.128/28230.167.64.129 to 230.167.64.142230.167.64.14314
10230.167.64.144/28230.167.64.145 to 230.167.64.158230.167.64.15914
11230.167.64.160/28230.167.64.161 to 230.167.64.174230.167.64.17514
12230.167.64.176/28230.167.64.177 to 230.167.64.190230.167.64.19114
13230.167.64.192/28230.167.64.193 to 230.167.64.206230.167.64.20714
14230.167.64.208/28230.167.64.209 to 230.167.64.222230.167.64.22314
15230.167.64.224/28230.167.64.225 to 230.167.64.238230.167.64.23914
16230.167.64.240/28230.167.64.241 to 230.167.64.254230.167.64.25514
17230.167.65.0/28230.167.65.1 to 230.167.65.14230.167.65.1514
18230.167.65.16/28230.167.65.17 to 230.167.65.30230.167.65.3114
19230.167.65.32/28230.167.65.33 to 230.167.65.46230.167.65.4714
20230.167.65.48/28230.167.65.49 to 230.167.65.62230.167.65.6314
21230.167.65.64/28230.167.65.65 to 230.167.65.78230.167.65.7914
22230.167.65.80/28230.167.65.81 to 230.167.65.94230.167.65.9514
23230.167.65.96/28230.167.65.97 to 230.167.65.110230.167.65.11114
24230.167.65.112/28230.167.65.113 to 230.167.65.126230.167.65.12714
25230.167.65.128/28230.167.65.129 to 230.167.65.142230.167.65.14314
26230.167.65.144/28230.167.65.145 to 230.167.65.158230.167.65.15914
27230.167.65.160/28230.167.65.161 to 230.167.65.174230.167.65.17514
28230.167.65.176/28230.167.65.177 to 230.167.65.190230.167.65.19114
29230.167.65.192/28230.167.65.193 to 230.167.65.206230.167.65.20714
30230.167.65.208/28230.167.65.209 to 230.167.65.222230.167.65.22314
31230.167.65.224/28230.167.65.225 to 230.167.65.238230.167.65.23914
32230.167.65.240/28230.167.65.241 to 230.167.65.254230.167.65.25514
33230.167.66.0/28230.167.66.1 to 230.167.66.14230.167.66.1514
34230.167.66.16/28230.167.66.17 to 230.167.66.30230.167.66.3114
35230.167.66.32/28230.167.66.33 to 230.167.66.46230.167.66.4714
36230.167.66.48/28230.167.66.49 to 230.167.66.62230.167.66.6314
37230.167.66.64/28230.167.66.65 to 230.167.66.78230.167.66.7914
38230.167.66.80/28230.167.66.81 to 230.167.66.94230.167.66.9514
39230.167.66.96/28230.167.66.97 to 230.167.66.110230.167.66.11114
40230.167.66.112/28230.167.66.113 to 230.167.66.126230.167.66.12714
41230.167.66.128/28230.167.66.129 to 230.167.66.142230.167.66.14314
42230.167.66.144/28230.167.66.145 to 230.167.66.158230.167.66.15914
43230.167.66.160/28230.167.66.161 to 230.167.66.174230.167.66.17514
44230.167.66.176/28230.167.66.177 to 230.167.66.190230.167.66.19114
45230.167.66.192/28230.167.66.193 to 230.167.66.206230.167.66.20714
46230.167.66.208/28230.167.66.209 to 230.167.66.222230.167.66.22314
47230.167.66.224/28230.167.66.225 to 230.167.66.238230.167.66.23914
48230.167.66.240/28230.167.66.241 to 230.167.66.254230.167.66.25514
49230.167.67.0/28230.167.67.1 to 230.167.67.14230.167.67.1514
50230.167.67.16/28230.167.67.17 to 230.167.67.30230.167.67.3114
51230.167.67.32/28230.167.67.33 to 230.167.67.46230.167.67.4714
52230.167.67.48/28230.167.67.49 to 230.167.67.62230.167.67.6314
53230.167.67.64/28230.167.67.65 to 230.167.67.78230.167.67.7914
54230.167.67.80/28230.167.67.81 to 230.167.67.94230.167.67.9514
55230.167.67.96/28230.167.67.97 to 230.167.67.110230.167.67.11114
56230.167.67.112/28230.167.67.113 to 230.167.67.126230.167.67.12714
57230.167.67.128/28230.167.67.129 to 230.167.67.142230.167.67.14314
58230.167.67.144/28230.167.67.145 to 230.167.67.158230.167.67.15914
59230.167.67.160/28230.167.67.161 to 230.167.67.174230.167.67.17514
60230.167.67.176/28230.167.67.177 to 230.167.67.190230.167.67.19114
61230.167.67.192/28230.167.67.193 to 230.167.67.206230.167.67.20714
62230.167.67.208/28230.167.67.209 to 230.167.67.222230.167.67.22314
63230.167.67.224/28230.167.67.225 to 230.167.67.238230.167.67.23914
64230.167.67.240/28230.167.67.241 to 230.167.67.254230.167.67.25514
65230.167.68.0/28230.167.68.1 to 230.167.68.14230.167.68.1514
66230.167.68.16/28230.167.68.17 to 230.167.68.30230.167.68.3114
67230.167.68.32/28230.167.68.33 to 230.167.68.46230.167.68.4714
68230.167.68.48/28230.167.68.49 to 230.167.68.62230.167.68.6314
69230.167.68.64/28230.167.68.65 to 230.167.68.78230.167.68.7914
70230.167.68.80/28230.167.68.81 to 230.167.68.94230.167.68.9514
71230.167.68.96/28230.167.68.97 to 230.167.68.110230.167.68.11114
72230.167.68.112/28230.167.68.113 to 230.167.68.126230.167.68.12714
73230.167.68.128/28230.167.68.129 to 230.167.68.142230.167.68.14314
74230.167.68.144/28230.167.68.145 to 230.167.68.158230.167.68.15914
75230.167.68.160/28230.167.68.161 to 230.167.68.174230.167.68.17514
76230.167.68.176/28230.167.68.177 to 230.167.68.190230.167.68.19114
77230.167.68.192/28230.167.68.193 to 230.167.68.206230.167.68.20714
78230.167.68.208/28230.167.68.209 to 230.167.68.222230.167.68.22314
79230.167.68.224/28230.167.68.225 to 230.167.68.238230.167.68.23914
80230.167.68.240/28230.167.68.241 to 230.167.68.254230.167.68.25514
81230.167.69.0/28230.167.69.1 to 230.167.69.14230.167.69.1514
82230.167.69.16/28230.167.69.17 to 230.167.69.30230.167.69.3114
83230.167.69.32/28230.167.69.33 to 230.167.69.46230.167.69.4714
84230.167.69.48/28230.167.69.49 to 230.167.69.62230.167.69.6314
85230.167.69.64/28230.167.69.65 to 230.167.69.78230.167.69.7914
86230.167.69.80/28230.167.69.81 to 230.167.69.94230.167.69.9514
87230.167.69.96/28230.167.69.97 to 230.167.69.110230.167.69.11114
88230.167.69.112/28230.167.69.113 to 230.167.69.126230.167.69.12714
89230.167.69.128/28230.167.69.129 to 230.167.69.142230.167.69.14314
90230.167.69.144/28230.167.69.145 to 230.167.69.158230.167.69.15914
91230.167.69.160/28230.167.69.161 to 230.167.69.174230.167.69.17514
92230.167.69.176/28230.167.69.177 to 230.167.69.190230.167.69.19114
93230.167.69.192/28230.167.69.193 to 230.167.69.206230.167.69.20714
94230.167.69.208/28230.167.69.209 to 230.167.69.222230.167.69.22314
95230.167.69.224/28230.167.69.225 to 230.167.69.238230.167.69.23914
96230.167.69.240/28230.167.69.241 to 230.167.69.254230.167.69.25514
97230.167.70.0/28230.167.70.1 to 230.167.70.14230.167.70.1514
98230.167.70.16/28230.167.70.17 to 230.167.70.30230.167.70.3114
99230.167.70.32/28230.167.70.33 to 230.167.70.46230.167.70.4714
100230.167.70.48/28230.167.70.49 to 230.167.70.62230.167.70.6314
101230.167.70.64/28230.167.70.65 to 230.167.70.78230.167.70.7914
102230.167.70.80/28230.167.70.81 to 230.167.70.94230.167.70.9514
103230.167.70.96/28230.167.70.97 to 230.167.70.110230.167.70.11114
104230.167.70.112/28230.167.70.113 to 230.167.70.126230.167.70.12714
105230.167.70.128/28230.167.70.129 to 230.167.70.142230.167.70.14314
106230.167.70.144/28230.167.70.145 to 230.167.70.158230.167.70.15914
107230.167.70.160/28230.167.70.161 to 230.167.70.174230.167.70.17514
108230.167.70.176/28230.167.70.177 to 230.167.70.190230.167.70.19114
109230.167.70.192/28230.167.70.193 to 230.167.70.206230.167.70.20714
110230.167.70.208/28230.167.70.209 to 230.167.70.222230.167.70.22314
111230.167.70.224/28230.167.70.225 to 230.167.70.238230.167.70.23914
112230.167.70.240/28230.167.70.241 to 230.167.70.254230.167.70.25514
113230.167.71.0/28230.167.71.1 to 230.167.71.14230.167.71.1514
114230.167.71.16/28230.167.71.17 to 230.167.71.30230.167.71.3114
115230.167.71.32/28230.167.71.33 to 230.167.71.46230.167.71.4714
116230.167.71.48/28230.167.71.49 to 230.167.71.62230.167.71.6314
117230.167.71.64/28230.167.71.65 to 230.167.71.78230.167.71.7914
118230.167.71.80/28230.167.71.81 to 230.167.71.94230.167.71.9514
119230.167.71.96/28230.167.71.97 to 230.167.71.110230.167.71.11114
120230.167.71.112/28230.167.71.113 to 230.167.71.126230.167.71.12714
121230.167.71.128/28230.167.71.129 to 230.167.71.142230.167.71.14314
122230.167.71.144/28230.167.71.145 to 230.167.71.158230.167.71.15914
123230.167.71.160/28230.167.71.161 to 230.167.71.174230.167.71.17514
124230.167.71.176/28230.167.71.177 to 230.167.71.190230.167.71.19114
125230.167.71.192/28230.167.71.193 to 230.167.71.206230.167.71.20714
126230.167.71.208/28230.167.71.209 to 230.167.71.222230.167.71.22314
127230.167.71.224/28230.167.71.225 to 230.167.71.238230.167.71.23914
128230.167.71.240/28230.167.71.241 to 230.167.71.254230.167.71.25514
129230.167.72.0/28230.167.72.1 to 230.167.72.14230.167.72.1514
130230.167.72.16/28230.167.72.17 to 230.167.72.30230.167.72.3114
131230.167.72.32/28230.167.72.33 to 230.167.72.46230.167.72.4714
132230.167.72.48/28230.167.72.49 to 230.167.72.62230.167.72.6314
133230.167.72.64/28230.167.72.65 to 230.167.72.78230.167.72.7914
134230.167.72.80/28230.167.72.81 to 230.167.72.94230.167.72.9514
135230.167.72.96/28230.167.72.97 to 230.167.72.110230.167.72.11114
136230.167.72.112/28230.167.72.113 to 230.167.72.126230.167.72.12714
137230.167.72.128/28230.167.72.129 to 230.167.72.142230.167.72.14314
138230.167.72.144/28230.167.72.145 to 230.167.72.158230.167.72.15914
139230.167.72.160/28230.167.72.161 to 230.167.72.174230.167.72.17514
140230.167.72.176/28230.167.72.177 to 230.167.72.190230.167.72.19114
141230.167.72.192/28230.167.72.193 to 230.167.72.206230.167.72.20714
142230.167.72.208/28230.167.72.209 to 230.167.72.222230.167.72.22314
143230.167.72.224/28230.167.72.225 to 230.167.72.238230.167.72.23914
144230.167.72.240/28230.167.72.241 to 230.167.72.254230.167.72.25514
145230.167.73.0/28230.167.73.1 to 230.167.73.14230.167.73.1514
146230.167.73.16/28230.167.73.17 to 230.167.73.30230.167.73.3114
147230.167.73.32/28230.167.73.33 to 230.167.73.46230.167.73.4714
148230.167.73.48/28230.167.73.49 to 230.167.73.62230.167.73.6314
149230.167.73.64/28230.167.73.65 to 230.167.73.78230.167.73.7914
150230.167.73.80/28230.167.73.81 to 230.167.73.94230.167.73.9514
151230.167.73.96/28230.167.73.97 to 230.167.73.110230.167.73.11114
152230.167.73.112/28230.167.73.113 to 230.167.73.126230.167.73.12714
153230.167.73.128/28230.167.73.129 to 230.167.73.142230.167.73.14314
154230.167.73.144/28230.167.73.145 to 230.167.73.158230.167.73.15914
155230.167.73.160/28230.167.73.161 to 230.167.73.174230.167.73.17514
156230.167.73.176/28230.167.73.177 to 230.167.73.190230.167.73.19114
157230.167.73.192/28230.167.73.193 to 230.167.73.206230.167.73.20714
158230.167.73.208/28230.167.73.209 to 230.167.73.222230.167.73.22314
159230.167.73.224/28230.167.73.225 to 230.167.73.238230.167.73.23914
160230.167.73.240/28230.167.73.241 to 230.167.73.254230.167.73.25514
161230.167.74.0/28230.167.74.1 to 230.167.74.14230.167.74.1514
162230.167.74.16/28230.167.74.17 to 230.167.74.30230.167.74.3114
163230.167.74.32/28230.167.74.33 to 230.167.74.46230.167.74.4714
164230.167.74.48/28230.167.74.49 to 230.167.74.62230.167.74.6314
165230.167.74.64/28230.167.74.65 to 230.167.74.78230.167.74.7914
166230.167.74.80/28230.167.74.81 to 230.167.74.94230.167.74.9514
167230.167.74.96/28230.167.74.97 to 230.167.74.110230.167.74.11114
168230.167.74.112/28230.167.74.113 to 230.167.74.126230.167.74.12714
169230.167.74.128/28230.167.74.129 to 230.167.74.142230.167.74.14314
170230.167.74.144/28230.167.74.145 to 230.167.74.158230.167.74.15914
171230.167.74.160/28230.167.74.161 to 230.167.74.174230.167.74.17514
172230.167.74.176/28230.167.74.177 to 230.167.74.190230.167.74.19114
173230.167.74.192/28230.167.74.193 to 230.167.74.206230.167.74.20714
174230.167.74.208/28230.167.74.209 to 230.167.74.222230.167.74.22314
175230.167.74.224/28230.167.74.225 to 230.167.74.238230.167.74.23914
176230.167.74.240/28230.167.74.241 to 230.167.74.254230.167.74.25514
177230.167.75.0/28230.167.75.1 to 230.167.75.14230.167.75.1514
178230.167.75.16/28230.167.75.17 to 230.167.75.30230.167.75.3114
179230.167.75.32/28230.167.75.33 to 230.167.75.46230.167.75.4714
180230.167.75.48/28230.167.75.49 to 230.167.75.62230.167.75.6314
181230.167.75.64/28230.167.75.65 to 230.167.75.78230.167.75.7914
182230.167.75.80/28230.167.75.81 to 230.167.75.94230.167.75.9514
183230.167.75.96/28230.167.75.97 to 230.167.75.110230.167.75.11114
184230.167.75.112/28230.167.75.113 to 230.167.75.126230.167.75.12714
185230.167.75.128/28230.167.75.129 to 230.167.75.142230.167.75.14314
186230.167.75.144/28230.167.75.145 to 230.167.75.158230.167.75.15914
187230.167.75.160/28230.167.75.161 to 230.167.75.174230.167.75.17514
188230.167.75.176/28230.167.75.177 to 230.167.75.190230.167.75.19114
189230.167.75.192/28230.167.75.193 to 230.167.75.206230.167.75.20714
190230.167.75.208/28230.167.75.209 to 230.167.75.222230.167.75.22314
191230.167.75.224/28230.167.75.225 to 230.167.75.238230.167.75.23914
192230.167.75.240/28230.167.75.241 to 230.167.75.254230.167.75.25514
193230.167.76.0/28230.167.76.1 to 230.167.76.14230.167.76.1514
194230.167.76.16/28230.167.76.17 to 230.167.76.30230.167.76.3114
195230.167.76.32/28230.167.76.33 to 230.167.76.46230.167.76.4714
196230.167.76.48/28230.167.76.49 to 230.167.76.62230.167.76.6314
197230.167.76.64/28230.167.76.65 to 230.167.76.78230.167.76.7914
198230.167.76.80/28230.167.76.81 to 230.167.76.94230.167.76.9514
199230.167.76.96/28230.167.76.97 to 230.167.76.110230.167.76.11114
200230.167.76.112/28230.167.76.113 to 230.167.76.126230.167.76.12714
201230.167.76.128/28230.167.76.129 to 230.167.76.142230.167.76.14314
202230.167.76.144/28230.167.76.145 to 230.167.76.158230.167.76.15914
203230.167.76.160/28230.167.76.161 to 230.167.76.174230.167.76.17514
204230.167.76.176/28230.167.76.177 to 230.167.76.190230.167.76.19114
205230.167.76.192/28230.167.76.193 to 230.167.76.206230.167.76.20714
206230.167.76.208/28230.167.76.209 to 230.167.76.222230.167.76.22314
207230.167.76.224/28230.167.76.225 to 230.167.76.238230.167.76.23914
208230.167.76.240/28230.167.76.241 to 230.167.76.254230.167.76.25514
209230.167.77.0/28230.167.77.1 to 230.167.77.14230.167.77.1514
210230.167.77.16/28230.167.77.17 to 230.167.77.30230.167.77.3114
211230.167.77.32/28230.167.77.33 to 230.167.77.46230.167.77.4714
212230.167.77.48/28230.167.77.49 to 230.167.77.62230.167.77.6314
213230.167.77.64/28230.167.77.65 to 230.167.77.78230.167.77.7914
214230.167.77.80/28230.167.77.81 to 230.167.77.94230.167.77.9514
215230.167.77.96/28230.167.77.97 to 230.167.77.110230.167.77.11114
216230.167.77.112/28230.167.77.113 to 230.167.77.126230.167.77.12714
217230.167.77.128/28230.167.77.129 to 230.167.77.142230.167.77.14314
218230.167.77.144/28230.167.77.145 to 230.167.77.158230.167.77.15914
219230.167.77.160/28230.167.77.161 to 230.167.77.174230.167.77.17514
220230.167.77.176/28230.167.77.177 to 230.167.77.190230.167.77.19114
221230.167.77.192/28230.167.77.193 to 230.167.77.206230.167.77.20714
222230.167.77.208/28230.167.77.209 to 230.167.77.222230.167.77.22314
223230.167.77.224/28230.167.77.225 to 230.167.77.238230.167.77.23914
224230.167.77.240/28230.167.77.241 to 230.167.77.254230.167.77.25514
225230.167.78.0/28230.167.78.1 to 230.167.78.14230.167.78.1514
226230.167.78.16/28230.167.78.17 to 230.167.78.30230.167.78.3114
227230.167.78.32/28230.167.78.33 to 230.167.78.46230.167.78.4714
228230.167.78.48/28230.167.78.49 to 230.167.78.62230.167.78.6314
229230.167.78.64/28230.167.78.65 to 230.167.78.78230.167.78.7914
230230.167.78.80/28230.167.78.81 to 230.167.78.94230.167.78.9514
231230.167.78.96/28230.167.78.97 to 230.167.78.110230.167.78.11114
232230.167.78.112/28230.167.78.113 to 230.167.78.126230.167.78.12714
233230.167.78.128/28230.167.78.129 to 230.167.78.142230.167.78.14314
234230.167.78.144/28230.167.78.145 to 230.167.78.158230.167.78.15914
235230.167.78.160/28230.167.78.161 to 230.167.78.174230.167.78.17514
236230.167.78.176/28230.167.78.177 to 230.167.78.190230.167.78.19114
237230.167.78.192/28230.167.78.193 to 230.167.78.206230.167.78.20714
238230.167.78.208/28230.167.78.209 to 230.167.78.222230.167.78.22314
239230.167.78.224/28230.167.78.225 to 230.167.78.238230.167.78.23914
240230.167.78.240/28230.167.78.241 to 230.167.78.254230.167.78.25514
241230.167.79.0/28230.167.79.1 to 230.167.79.14230.167.79.1514
242230.167.79.16/28230.167.79.17 to 230.167.79.30230.167.79.3114
243230.167.79.32/28230.167.79.33 to 230.167.79.46230.167.79.4714
244230.167.79.48/28230.167.79.49 to 230.167.79.62230.167.79.6314
245230.167.79.64/28230.167.79.65 to 230.167.79.78230.167.79.7914
246230.167.79.80/28230.167.79.81 to 230.167.79.94230.167.79.9514
247230.167.79.96/28230.167.79.97 to 230.167.79.110230.167.79.11114
248230.167.79.112/28230.167.79.113 to 230.167.79.126230.167.79.12714
249230.167.79.128/28230.167.79.129 to 230.167.79.142230.167.79.14314
250230.167.79.144/28230.167.79.145 to 230.167.79.158230.167.79.15914
251230.167.79.160/28230.167.79.161 to 230.167.79.174230.167.79.17514
252230.167.79.176/28230.167.79.177 to 230.167.79.190230.167.79.19114
253230.167.79.192/28230.167.79.193 to 230.167.79.206230.167.79.20714
254230.167.79.208/28230.167.79.209 to 230.167.79.222230.167.79.22314
255230.167.79.224/28230.167.79.225 to 230.167.79.238230.167.79.23914
256230.167.79.240/28230.167.79.241 to 230.167.79.254230.167.79.25514

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.