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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.

Network180.78.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
180.78.0.0
Broadcast address
180.78.127.255
First usable
180.78.0.1
Last usable
180.78.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
B (default /16)
As numbers
Hex B44E0000 · Integer 3025010688 to 3025043455
Reverse DNS zones
0.78.180.in-addr.arpa
1.78.180.in-addr.arpa
2.78.180.in-addr.arpa
3.78.180.in-addr.arpa
4.78.180.in-addr.arpa
5.78.180.in-addr.arpa
6.78.180.in-addr.arpa
7.78.180.in-addr.arpa
8.78.180.in-addr.arpa
9.78.180.in-addr.arpa
10.78.180.in-addr.arpa
11.78.180.in-addr.arpa
12.78.180.in-addr.arpa
13.78.180.in-addr.arpa
14.78.180.in-addr.arpa
15.78.180.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
Address10110100.01001110.00000000.00000000180.78.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network10110100.01001110.00000000.00000000180.78.0.0
Broadcast10110100.01001110.01111111.11111111180.78.127.255
Split into smaller subnets/28
/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)

180.78.0.0/17 makes 2,048 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1180.78.0.0/28180.78.0.1 to 180.78.0.14180.78.0.1514
2180.78.0.16/28180.78.0.17 to 180.78.0.30180.78.0.3114
3180.78.0.32/28180.78.0.33 to 180.78.0.46180.78.0.4714
4180.78.0.48/28180.78.0.49 to 180.78.0.62180.78.0.6314
5180.78.0.64/28180.78.0.65 to 180.78.0.78180.78.0.7914
6180.78.0.80/28180.78.0.81 to 180.78.0.94180.78.0.9514
7180.78.0.96/28180.78.0.97 to 180.78.0.110180.78.0.11114
8180.78.0.112/28180.78.0.113 to 180.78.0.126180.78.0.12714
9180.78.0.128/28180.78.0.129 to 180.78.0.142180.78.0.14314
10180.78.0.144/28180.78.0.145 to 180.78.0.158180.78.0.15914
11180.78.0.160/28180.78.0.161 to 180.78.0.174180.78.0.17514
12180.78.0.176/28180.78.0.177 to 180.78.0.190180.78.0.19114
13180.78.0.192/28180.78.0.193 to 180.78.0.206180.78.0.20714
14180.78.0.208/28180.78.0.209 to 180.78.0.222180.78.0.22314
15180.78.0.224/28180.78.0.225 to 180.78.0.238180.78.0.23914
16180.78.0.240/28180.78.0.241 to 180.78.0.254180.78.0.25514
17180.78.1.0/28180.78.1.1 to 180.78.1.14180.78.1.1514
18180.78.1.16/28180.78.1.17 to 180.78.1.30180.78.1.3114
19180.78.1.32/28180.78.1.33 to 180.78.1.46180.78.1.4714
20180.78.1.48/28180.78.1.49 to 180.78.1.62180.78.1.6314
21180.78.1.64/28180.78.1.65 to 180.78.1.78180.78.1.7914
22180.78.1.80/28180.78.1.81 to 180.78.1.94180.78.1.9514
23180.78.1.96/28180.78.1.97 to 180.78.1.110180.78.1.11114
24180.78.1.112/28180.78.1.113 to 180.78.1.126180.78.1.12714
25180.78.1.128/28180.78.1.129 to 180.78.1.142180.78.1.14314
26180.78.1.144/28180.78.1.145 to 180.78.1.158180.78.1.15914
27180.78.1.160/28180.78.1.161 to 180.78.1.174180.78.1.17514
28180.78.1.176/28180.78.1.177 to 180.78.1.190180.78.1.19114
29180.78.1.192/28180.78.1.193 to 180.78.1.206180.78.1.20714
30180.78.1.208/28180.78.1.209 to 180.78.1.222180.78.1.22314
31180.78.1.224/28180.78.1.225 to 180.78.1.238180.78.1.23914
32180.78.1.240/28180.78.1.241 to 180.78.1.254180.78.1.25514
33180.78.2.0/28180.78.2.1 to 180.78.2.14180.78.2.1514
34180.78.2.16/28180.78.2.17 to 180.78.2.30180.78.2.3114
35180.78.2.32/28180.78.2.33 to 180.78.2.46180.78.2.4714
36180.78.2.48/28180.78.2.49 to 180.78.2.62180.78.2.6314
37180.78.2.64/28180.78.2.65 to 180.78.2.78180.78.2.7914
38180.78.2.80/28180.78.2.81 to 180.78.2.94180.78.2.9514
39180.78.2.96/28180.78.2.97 to 180.78.2.110180.78.2.11114
40180.78.2.112/28180.78.2.113 to 180.78.2.126180.78.2.12714
41180.78.2.128/28180.78.2.129 to 180.78.2.142180.78.2.14314
42180.78.2.144/28180.78.2.145 to 180.78.2.158180.78.2.15914
43180.78.2.160/28180.78.2.161 to 180.78.2.174180.78.2.17514
44180.78.2.176/28180.78.2.177 to 180.78.2.190180.78.2.19114
45180.78.2.192/28180.78.2.193 to 180.78.2.206180.78.2.20714
46180.78.2.208/28180.78.2.209 to 180.78.2.222180.78.2.22314
47180.78.2.224/28180.78.2.225 to 180.78.2.238180.78.2.23914
48180.78.2.240/28180.78.2.241 to 180.78.2.254180.78.2.25514
49180.78.3.0/28180.78.3.1 to 180.78.3.14180.78.3.1514
50180.78.3.16/28180.78.3.17 to 180.78.3.30180.78.3.3114
51180.78.3.32/28180.78.3.33 to 180.78.3.46180.78.3.4714
52180.78.3.48/28180.78.3.49 to 180.78.3.62180.78.3.6314
53180.78.3.64/28180.78.3.65 to 180.78.3.78180.78.3.7914
54180.78.3.80/28180.78.3.81 to 180.78.3.94180.78.3.9514
55180.78.3.96/28180.78.3.97 to 180.78.3.110180.78.3.11114
56180.78.3.112/28180.78.3.113 to 180.78.3.126180.78.3.12714
57180.78.3.128/28180.78.3.129 to 180.78.3.142180.78.3.14314
58180.78.3.144/28180.78.3.145 to 180.78.3.158180.78.3.15914
59180.78.3.160/28180.78.3.161 to 180.78.3.174180.78.3.17514
60180.78.3.176/28180.78.3.177 to 180.78.3.190180.78.3.19114
61180.78.3.192/28180.78.3.193 to 180.78.3.206180.78.3.20714
62180.78.3.208/28180.78.3.209 to 180.78.3.222180.78.3.22314
63180.78.3.224/28180.78.3.225 to 180.78.3.238180.78.3.23914
64180.78.3.240/28180.78.3.241 to 180.78.3.254180.78.3.25514
65180.78.4.0/28180.78.4.1 to 180.78.4.14180.78.4.1514
66180.78.4.16/28180.78.4.17 to 180.78.4.30180.78.4.3114
67180.78.4.32/28180.78.4.33 to 180.78.4.46180.78.4.4714
68180.78.4.48/28180.78.4.49 to 180.78.4.62180.78.4.6314
69180.78.4.64/28180.78.4.65 to 180.78.4.78180.78.4.7914
70180.78.4.80/28180.78.4.81 to 180.78.4.94180.78.4.9514
71180.78.4.96/28180.78.4.97 to 180.78.4.110180.78.4.11114
72180.78.4.112/28180.78.4.113 to 180.78.4.126180.78.4.12714
73180.78.4.128/28180.78.4.129 to 180.78.4.142180.78.4.14314
74180.78.4.144/28180.78.4.145 to 180.78.4.158180.78.4.15914
75180.78.4.160/28180.78.4.161 to 180.78.4.174180.78.4.17514
76180.78.4.176/28180.78.4.177 to 180.78.4.190180.78.4.19114
77180.78.4.192/28180.78.4.193 to 180.78.4.206180.78.4.20714
78180.78.4.208/28180.78.4.209 to 180.78.4.222180.78.4.22314
79180.78.4.224/28180.78.4.225 to 180.78.4.238180.78.4.23914
80180.78.4.240/28180.78.4.241 to 180.78.4.254180.78.4.25514
81180.78.5.0/28180.78.5.1 to 180.78.5.14180.78.5.1514
82180.78.5.16/28180.78.5.17 to 180.78.5.30180.78.5.3114
83180.78.5.32/28180.78.5.33 to 180.78.5.46180.78.5.4714
84180.78.5.48/28180.78.5.49 to 180.78.5.62180.78.5.6314
85180.78.5.64/28180.78.5.65 to 180.78.5.78180.78.5.7914
86180.78.5.80/28180.78.5.81 to 180.78.5.94180.78.5.9514
87180.78.5.96/28180.78.5.97 to 180.78.5.110180.78.5.11114
88180.78.5.112/28180.78.5.113 to 180.78.5.126180.78.5.12714
89180.78.5.128/28180.78.5.129 to 180.78.5.142180.78.5.14314
90180.78.5.144/28180.78.5.145 to 180.78.5.158180.78.5.15914
91180.78.5.160/28180.78.5.161 to 180.78.5.174180.78.5.17514
92180.78.5.176/28180.78.5.177 to 180.78.5.190180.78.5.19114
93180.78.5.192/28180.78.5.193 to 180.78.5.206180.78.5.20714
94180.78.5.208/28180.78.5.209 to 180.78.5.222180.78.5.22314
95180.78.5.224/28180.78.5.225 to 180.78.5.238180.78.5.23914
96180.78.5.240/28180.78.5.241 to 180.78.5.254180.78.5.25514
97180.78.6.0/28180.78.6.1 to 180.78.6.14180.78.6.1514
98180.78.6.16/28180.78.6.17 to 180.78.6.30180.78.6.3114
99180.78.6.32/28180.78.6.33 to 180.78.6.46180.78.6.4714
100180.78.6.48/28180.78.6.49 to 180.78.6.62180.78.6.6314
101180.78.6.64/28180.78.6.65 to 180.78.6.78180.78.6.7914
102180.78.6.80/28180.78.6.81 to 180.78.6.94180.78.6.9514
103180.78.6.96/28180.78.6.97 to 180.78.6.110180.78.6.11114
104180.78.6.112/28180.78.6.113 to 180.78.6.126180.78.6.12714
105180.78.6.128/28180.78.6.129 to 180.78.6.142180.78.6.14314
106180.78.6.144/28180.78.6.145 to 180.78.6.158180.78.6.15914
107180.78.6.160/28180.78.6.161 to 180.78.6.174180.78.6.17514
108180.78.6.176/28180.78.6.177 to 180.78.6.190180.78.6.19114
109180.78.6.192/28180.78.6.193 to 180.78.6.206180.78.6.20714
110180.78.6.208/28180.78.6.209 to 180.78.6.222180.78.6.22314
111180.78.6.224/28180.78.6.225 to 180.78.6.238180.78.6.23914
112180.78.6.240/28180.78.6.241 to 180.78.6.254180.78.6.25514
113180.78.7.0/28180.78.7.1 to 180.78.7.14180.78.7.1514
114180.78.7.16/28180.78.7.17 to 180.78.7.30180.78.7.3114
115180.78.7.32/28180.78.7.33 to 180.78.7.46180.78.7.4714
116180.78.7.48/28180.78.7.49 to 180.78.7.62180.78.7.6314
117180.78.7.64/28180.78.7.65 to 180.78.7.78180.78.7.7914
118180.78.7.80/28180.78.7.81 to 180.78.7.94180.78.7.9514
119180.78.7.96/28180.78.7.97 to 180.78.7.110180.78.7.11114
120180.78.7.112/28180.78.7.113 to 180.78.7.126180.78.7.12714
121180.78.7.128/28180.78.7.129 to 180.78.7.142180.78.7.14314
122180.78.7.144/28180.78.7.145 to 180.78.7.158180.78.7.15914
123180.78.7.160/28180.78.7.161 to 180.78.7.174180.78.7.17514
124180.78.7.176/28180.78.7.177 to 180.78.7.190180.78.7.19114
125180.78.7.192/28180.78.7.193 to 180.78.7.206180.78.7.20714
126180.78.7.208/28180.78.7.209 to 180.78.7.222180.78.7.22314
127180.78.7.224/28180.78.7.225 to 180.78.7.238180.78.7.23914
128180.78.7.240/28180.78.7.241 to 180.78.7.254180.78.7.25514
129180.78.8.0/28180.78.8.1 to 180.78.8.14180.78.8.1514
130180.78.8.16/28180.78.8.17 to 180.78.8.30180.78.8.3114
131180.78.8.32/28180.78.8.33 to 180.78.8.46180.78.8.4714
132180.78.8.48/28180.78.8.49 to 180.78.8.62180.78.8.6314
133180.78.8.64/28180.78.8.65 to 180.78.8.78180.78.8.7914
134180.78.8.80/28180.78.8.81 to 180.78.8.94180.78.8.9514
135180.78.8.96/28180.78.8.97 to 180.78.8.110180.78.8.11114
136180.78.8.112/28180.78.8.113 to 180.78.8.126180.78.8.12714
137180.78.8.128/28180.78.8.129 to 180.78.8.142180.78.8.14314
138180.78.8.144/28180.78.8.145 to 180.78.8.158180.78.8.15914
139180.78.8.160/28180.78.8.161 to 180.78.8.174180.78.8.17514
140180.78.8.176/28180.78.8.177 to 180.78.8.190180.78.8.19114
141180.78.8.192/28180.78.8.193 to 180.78.8.206180.78.8.20714
142180.78.8.208/28180.78.8.209 to 180.78.8.222180.78.8.22314
143180.78.8.224/28180.78.8.225 to 180.78.8.238180.78.8.23914
144180.78.8.240/28180.78.8.241 to 180.78.8.254180.78.8.25514
145180.78.9.0/28180.78.9.1 to 180.78.9.14180.78.9.1514
146180.78.9.16/28180.78.9.17 to 180.78.9.30180.78.9.3114
147180.78.9.32/28180.78.9.33 to 180.78.9.46180.78.9.4714
148180.78.9.48/28180.78.9.49 to 180.78.9.62180.78.9.6314
149180.78.9.64/28180.78.9.65 to 180.78.9.78180.78.9.7914
150180.78.9.80/28180.78.9.81 to 180.78.9.94180.78.9.9514
151180.78.9.96/28180.78.9.97 to 180.78.9.110180.78.9.11114
152180.78.9.112/28180.78.9.113 to 180.78.9.126180.78.9.12714
153180.78.9.128/28180.78.9.129 to 180.78.9.142180.78.9.14314
154180.78.9.144/28180.78.9.145 to 180.78.9.158180.78.9.15914
155180.78.9.160/28180.78.9.161 to 180.78.9.174180.78.9.17514
156180.78.9.176/28180.78.9.177 to 180.78.9.190180.78.9.19114
157180.78.9.192/28180.78.9.193 to 180.78.9.206180.78.9.20714
158180.78.9.208/28180.78.9.209 to 180.78.9.222180.78.9.22314
159180.78.9.224/28180.78.9.225 to 180.78.9.238180.78.9.23914
160180.78.9.240/28180.78.9.241 to 180.78.9.254180.78.9.25514
161180.78.10.0/28180.78.10.1 to 180.78.10.14180.78.10.1514
162180.78.10.16/28180.78.10.17 to 180.78.10.30180.78.10.3114
163180.78.10.32/28180.78.10.33 to 180.78.10.46180.78.10.4714
164180.78.10.48/28180.78.10.49 to 180.78.10.62180.78.10.6314
165180.78.10.64/28180.78.10.65 to 180.78.10.78180.78.10.7914
166180.78.10.80/28180.78.10.81 to 180.78.10.94180.78.10.9514
167180.78.10.96/28180.78.10.97 to 180.78.10.110180.78.10.11114
168180.78.10.112/28180.78.10.113 to 180.78.10.126180.78.10.12714
169180.78.10.128/28180.78.10.129 to 180.78.10.142180.78.10.14314
170180.78.10.144/28180.78.10.145 to 180.78.10.158180.78.10.15914
171180.78.10.160/28180.78.10.161 to 180.78.10.174180.78.10.17514
172180.78.10.176/28180.78.10.177 to 180.78.10.190180.78.10.19114
173180.78.10.192/28180.78.10.193 to 180.78.10.206180.78.10.20714
174180.78.10.208/28180.78.10.209 to 180.78.10.222180.78.10.22314
175180.78.10.224/28180.78.10.225 to 180.78.10.238180.78.10.23914
176180.78.10.240/28180.78.10.241 to 180.78.10.254180.78.10.25514
177180.78.11.0/28180.78.11.1 to 180.78.11.14180.78.11.1514
178180.78.11.16/28180.78.11.17 to 180.78.11.30180.78.11.3114
179180.78.11.32/28180.78.11.33 to 180.78.11.46180.78.11.4714
180180.78.11.48/28180.78.11.49 to 180.78.11.62180.78.11.6314
181180.78.11.64/28180.78.11.65 to 180.78.11.78180.78.11.7914
182180.78.11.80/28180.78.11.81 to 180.78.11.94180.78.11.9514
183180.78.11.96/28180.78.11.97 to 180.78.11.110180.78.11.11114
184180.78.11.112/28180.78.11.113 to 180.78.11.126180.78.11.12714
185180.78.11.128/28180.78.11.129 to 180.78.11.142180.78.11.14314
186180.78.11.144/28180.78.11.145 to 180.78.11.158180.78.11.15914
187180.78.11.160/28180.78.11.161 to 180.78.11.174180.78.11.17514
188180.78.11.176/28180.78.11.177 to 180.78.11.190180.78.11.19114
189180.78.11.192/28180.78.11.193 to 180.78.11.206180.78.11.20714
190180.78.11.208/28180.78.11.209 to 180.78.11.222180.78.11.22314
191180.78.11.224/28180.78.11.225 to 180.78.11.238180.78.11.23914
192180.78.11.240/28180.78.11.241 to 180.78.11.254180.78.11.25514
193180.78.12.0/28180.78.12.1 to 180.78.12.14180.78.12.1514
194180.78.12.16/28180.78.12.17 to 180.78.12.30180.78.12.3114
195180.78.12.32/28180.78.12.33 to 180.78.12.46180.78.12.4714
196180.78.12.48/28180.78.12.49 to 180.78.12.62180.78.12.6314
197180.78.12.64/28180.78.12.65 to 180.78.12.78180.78.12.7914
198180.78.12.80/28180.78.12.81 to 180.78.12.94180.78.12.9514
199180.78.12.96/28180.78.12.97 to 180.78.12.110180.78.12.11114
200180.78.12.112/28180.78.12.113 to 180.78.12.126180.78.12.12714
201180.78.12.128/28180.78.12.129 to 180.78.12.142180.78.12.14314
202180.78.12.144/28180.78.12.145 to 180.78.12.158180.78.12.15914
203180.78.12.160/28180.78.12.161 to 180.78.12.174180.78.12.17514
204180.78.12.176/28180.78.12.177 to 180.78.12.190180.78.12.19114
205180.78.12.192/28180.78.12.193 to 180.78.12.206180.78.12.20714
206180.78.12.208/28180.78.12.209 to 180.78.12.222180.78.12.22314
207180.78.12.224/28180.78.12.225 to 180.78.12.238180.78.12.23914
208180.78.12.240/28180.78.12.241 to 180.78.12.254180.78.12.25514
209180.78.13.0/28180.78.13.1 to 180.78.13.14180.78.13.1514
210180.78.13.16/28180.78.13.17 to 180.78.13.30180.78.13.3114
211180.78.13.32/28180.78.13.33 to 180.78.13.46180.78.13.4714
212180.78.13.48/28180.78.13.49 to 180.78.13.62180.78.13.6314
213180.78.13.64/28180.78.13.65 to 180.78.13.78180.78.13.7914
214180.78.13.80/28180.78.13.81 to 180.78.13.94180.78.13.9514
215180.78.13.96/28180.78.13.97 to 180.78.13.110180.78.13.11114
216180.78.13.112/28180.78.13.113 to 180.78.13.126180.78.13.12714
217180.78.13.128/28180.78.13.129 to 180.78.13.142180.78.13.14314
218180.78.13.144/28180.78.13.145 to 180.78.13.158180.78.13.15914
219180.78.13.160/28180.78.13.161 to 180.78.13.174180.78.13.17514
220180.78.13.176/28180.78.13.177 to 180.78.13.190180.78.13.19114
221180.78.13.192/28180.78.13.193 to 180.78.13.206180.78.13.20714
222180.78.13.208/28180.78.13.209 to 180.78.13.222180.78.13.22314
223180.78.13.224/28180.78.13.225 to 180.78.13.238180.78.13.23914
224180.78.13.240/28180.78.13.241 to 180.78.13.254180.78.13.25514
225180.78.14.0/28180.78.14.1 to 180.78.14.14180.78.14.1514
226180.78.14.16/28180.78.14.17 to 180.78.14.30180.78.14.3114
227180.78.14.32/28180.78.14.33 to 180.78.14.46180.78.14.4714
228180.78.14.48/28180.78.14.49 to 180.78.14.62180.78.14.6314
229180.78.14.64/28180.78.14.65 to 180.78.14.78180.78.14.7914
230180.78.14.80/28180.78.14.81 to 180.78.14.94180.78.14.9514
231180.78.14.96/28180.78.14.97 to 180.78.14.110180.78.14.11114
232180.78.14.112/28180.78.14.113 to 180.78.14.126180.78.14.12714
233180.78.14.128/28180.78.14.129 to 180.78.14.142180.78.14.14314
234180.78.14.144/28180.78.14.145 to 180.78.14.158180.78.14.15914
235180.78.14.160/28180.78.14.161 to 180.78.14.174180.78.14.17514
236180.78.14.176/28180.78.14.177 to 180.78.14.190180.78.14.19114
237180.78.14.192/28180.78.14.193 to 180.78.14.206180.78.14.20714
238180.78.14.208/28180.78.14.209 to 180.78.14.222180.78.14.22314
239180.78.14.224/28180.78.14.225 to 180.78.14.238180.78.14.23914
240180.78.14.240/28180.78.14.241 to 180.78.14.254180.78.14.25514
241180.78.15.0/28180.78.15.1 to 180.78.15.14180.78.15.1514
242180.78.15.16/28180.78.15.17 to 180.78.15.30180.78.15.3114
243180.78.15.32/28180.78.15.33 to 180.78.15.46180.78.15.4714
244180.78.15.48/28180.78.15.49 to 180.78.15.62180.78.15.6314
245180.78.15.64/28180.78.15.65 to 180.78.15.78180.78.15.7914
246180.78.15.80/28180.78.15.81 to 180.78.15.94180.78.15.9514
247180.78.15.96/28180.78.15.97 to 180.78.15.110180.78.15.11114
248180.78.15.112/28180.78.15.113 to 180.78.15.126180.78.15.12714
249180.78.15.128/28180.78.15.129 to 180.78.15.142180.78.15.14314
250180.78.15.144/28180.78.15.145 to 180.78.15.158180.78.15.15914
251180.78.15.160/28180.78.15.161 to 180.78.15.174180.78.15.17514
252180.78.15.176/28180.78.15.177 to 180.78.15.190180.78.15.19114
253180.78.15.192/28180.78.15.193 to 180.78.15.206180.78.15.20714
254180.78.15.208/28180.78.15.209 to 180.78.15.222180.78.15.22314
255180.78.15.224/28180.78.15.225 to 180.78.15.238180.78.15.23914
256180.78.15.240/28180.78.15.241 to 180.78.15.254180.78.15.25514

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.