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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.

Network180.136.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
180.136.0.0
Broadcast address
180.137.255.255
First usable
180.136.0.1
Last usable
180.137.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
B (default /16)
As numbers
Hex B4880000 · Integer 3028811776 to 3028942847
Reverse DNS zones
136.180.in-addr.arpa
137.180.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10110100.10001000.00000000.00000000180.136.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network10110100.10001000.00000000.00000000180.136.0.0
Broadcast10110100.10001001.11111111.11111111180.137.255.255
Split into smaller subnets/26
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

180.136.0.0/15 makes 2,048 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1180.136.0.0/26180.136.0.1 to 180.136.0.62180.136.0.6362
2180.136.0.64/26180.136.0.65 to 180.136.0.126180.136.0.12762
3180.136.0.128/26180.136.0.129 to 180.136.0.190180.136.0.19162
4180.136.0.192/26180.136.0.193 to 180.136.0.254180.136.0.25562
5180.136.1.0/26180.136.1.1 to 180.136.1.62180.136.1.6362
6180.136.1.64/26180.136.1.65 to 180.136.1.126180.136.1.12762
7180.136.1.128/26180.136.1.129 to 180.136.1.190180.136.1.19162
8180.136.1.192/26180.136.1.193 to 180.136.1.254180.136.1.25562
9180.136.2.0/26180.136.2.1 to 180.136.2.62180.136.2.6362
10180.136.2.64/26180.136.2.65 to 180.136.2.126180.136.2.12762
11180.136.2.128/26180.136.2.129 to 180.136.2.190180.136.2.19162
12180.136.2.192/26180.136.2.193 to 180.136.2.254180.136.2.25562
13180.136.3.0/26180.136.3.1 to 180.136.3.62180.136.3.6362
14180.136.3.64/26180.136.3.65 to 180.136.3.126180.136.3.12762
15180.136.3.128/26180.136.3.129 to 180.136.3.190180.136.3.19162
16180.136.3.192/26180.136.3.193 to 180.136.3.254180.136.3.25562
17180.136.4.0/26180.136.4.1 to 180.136.4.62180.136.4.6362
18180.136.4.64/26180.136.4.65 to 180.136.4.126180.136.4.12762
19180.136.4.128/26180.136.4.129 to 180.136.4.190180.136.4.19162
20180.136.4.192/26180.136.4.193 to 180.136.4.254180.136.4.25562
21180.136.5.0/26180.136.5.1 to 180.136.5.62180.136.5.6362
22180.136.5.64/26180.136.5.65 to 180.136.5.126180.136.5.12762
23180.136.5.128/26180.136.5.129 to 180.136.5.190180.136.5.19162
24180.136.5.192/26180.136.5.193 to 180.136.5.254180.136.5.25562
25180.136.6.0/26180.136.6.1 to 180.136.6.62180.136.6.6362
26180.136.6.64/26180.136.6.65 to 180.136.6.126180.136.6.12762
27180.136.6.128/26180.136.6.129 to 180.136.6.190180.136.6.19162
28180.136.6.192/26180.136.6.193 to 180.136.6.254180.136.6.25562
29180.136.7.0/26180.136.7.1 to 180.136.7.62180.136.7.6362
30180.136.7.64/26180.136.7.65 to 180.136.7.126180.136.7.12762
31180.136.7.128/26180.136.7.129 to 180.136.7.190180.136.7.19162
32180.136.7.192/26180.136.7.193 to 180.136.7.254180.136.7.25562
33180.136.8.0/26180.136.8.1 to 180.136.8.62180.136.8.6362
34180.136.8.64/26180.136.8.65 to 180.136.8.126180.136.8.12762
35180.136.8.128/26180.136.8.129 to 180.136.8.190180.136.8.19162
36180.136.8.192/26180.136.8.193 to 180.136.8.254180.136.8.25562
37180.136.9.0/26180.136.9.1 to 180.136.9.62180.136.9.6362
38180.136.9.64/26180.136.9.65 to 180.136.9.126180.136.9.12762
39180.136.9.128/26180.136.9.129 to 180.136.9.190180.136.9.19162
40180.136.9.192/26180.136.9.193 to 180.136.9.254180.136.9.25562
41180.136.10.0/26180.136.10.1 to 180.136.10.62180.136.10.6362
42180.136.10.64/26180.136.10.65 to 180.136.10.126180.136.10.12762
43180.136.10.128/26180.136.10.129 to 180.136.10.190180.136.10.19162
44180.136.10.192/26180.136.10.193 to 180.136.10.254180.136.10.25562
45180.136.11.0/26180.136.11.1 to 180.136.11.62180.136.11.6362
46180.136.11.64/26180.136.11.65 to 180.136.11.126180.136.11.12762
47180.136.11.128/26180.136.11.129 to 180.136.11.190180.136.11.19162
48180.136.11.192/26180.136.11.193 to 180.136.11.254180.136.11.25562
49180.136.12.0/26180.136.12.1 to 180.136.12.62180.136.12.6362
50180.136.12.64/26180.136.12.65 to 180.136.12.126180.136.12.12762
51180.136.12.128/26180.136.12.129 to 180.136.12.190180.136.12.19162
52180.136.12.192/26180.136.12.193 to 180.136.12.254180.136.12.25562
53180.136.13.0/26180.136.13.1 to 180.136.13.62180.136.13.6362
54180.136.13.64/26180.136.13.65 to 180.136.13.126180.136.13.12762
55180.136.13.128/26180.136.13.129 to 180.136.13.190180.136.13.19162
56180.136.13.192/26180.136.13.193 to 180.136.13.254180.136.13.25562
57180.136.14.0/26180.136.14.1 to 180.136.14.62180.136.14.6362
58180.136.14.64/26180.136.14.65 to 180.136.14.126180.136.14.12762
59180.136.14.128/26180.136.14.129 to 180.136.14.190180.136.14.19162
60180.136.14.192/26180.136.14.193 to 180.136.14.254180.136.14.25562
61180.136.15.0/26180.136.15.1 to 180.136.15.62180.136.15.6362
62180.136.15.64/26180.136.15.65 to 180.136.15.126180.136.15.12762
63180.136.15.128/26180.136.15.129 to 180.136.15.190180.136.15.19162
64180.136.15.192/26180.136.15.193 to 180.136.15.254180.136.15.25562
65180.136.16.0/26180.136.16.1 to 180.136.16.62180.136.16.6362
66180.136.16.64/26180.136.16.65 to 180.136.16.126180.136.16.12762
67180.136.16.128/26180.136.16.129 to 180.136.16.190180.136.16.19162
68180.136.16.192/26180.136.16.193 to 180.136.16.254180.136.16.25562
69180.136.17.0/26180.136.17.1 to 180.136.17.62180.136.17.6362
70180.136.17.64/26180.136.17.65 to 180.136.17.126180.136.17.12762
71180.136.17.128/26180.136.17.129 to 180.136.17.190180.136.17.19162
72180.136.17.192/26180.136.17.193 to 180.136.17.254180.136.17.25562
73180.136.18.0/26180.136.18.1 to 180.136.18.62180.136.18.6362
74180.136.18.64/26180.136.18.65 to 180.136.18.126180.136.18.12762
75180.136.18.128/26180.136.18.129 to 180.136.18.190180.136.18.19162
76180.136.18.192/26180.136.18.193 to 180.136.18.254180.136.18.25562
77180.136.19.0/26180.136.19.1 to 180.136.19.62180.136.19.6362
78180.136.19.64/26180.136.19.65 to 180.136.19.126180.136.19.12762
79180.136.19.128/26180.136.19.129 to 180.136.19.190180.136.19.19162
80180.136.19.192/26180.136.19.193 to 180.136.19.254180.136.19.25562
81180.136.20.0/26180.136.20.1 to 180.136.20.62180.136.20.6362
82180.136.20.64/26180.136.20.65 to 180.136.20.126180.136.20.12762
83180.136.20.128/26180.136.20.129 to 180.136.20.190180.136.20.19162
84180.136.20.192/26180.136.20.193 to 180.136.20.254180.136.20.25562
85180.136.21.0/26180.136.21.1 to 180.136.21.62180.136.21.6362
86180.136.21.64/26180.136.21.65 to 180.136.21.126180.136.21.12762
87180.136.21.128/26180.136.21.129 to 180.136.21.190180.136.21.19162
88180.136.21.192/26180.136.21.193 to 180.136.21.254180.136.21.25562
89180.136.22.0/26180.136.22.1 to 180.136.22.62180.136.22.6362
90180.136.22.64/26180.136.22.65 to 180.136.22.126180.136.22.12762
91180.136.22.128/26180.136.22.129 to 180.136.22.190180.136.22.19162
92180.136.22.192/26180.136.22.193 to 180.136.22.254180.136.22.25562
93180.136.23.0/26180.136.23.1 to 180.136.23.62180.136.23.6362
94180.136.23.64/26180.136.23.65 to 180.136.23.126180.136.23.12762
95180.136.23.128/26180.136.23.129 to 180.136.23.190180.136.23.19162
96180.136.23.192/26180.136.23.193 to 180.136.23.254180.136.23.25562
97180.136.24.0/26180.136.24.1 to 180.136.24.62180.136.24.6362
98180.136.24.64/26180.136.24.65 to 180.136.24.126180.136.24.12762
99180.136.24.128/26180.136.24.129 to 180.136.24.190180.136.24.19162
100180.136.24.192/26180.136.24.193 to 180.136.24.254180.136.24.25562
101180.136.25.0/26180.136.25.1 to 180.136.25.62180.136.25.6362
102180.136.25.64/26180.136.25.65 to 180.136.25.126180.136.25.12762
103180.136.25.128/26180.136.25.129 to 180.136.25.190180.136.25.19162
104180.136.25.192/26180.136.25.193 to 180.136.25.254180.136.25.25562
105180.136.26.0/26180.136.26.1 to 180.136.26.62180.136.26.6362
106180.136.26.64/26180.136.26.65 to 180.136.26.126180.136.26.12762
107180.136.26.128/26180.136.26.129 to 180.136.26.190180.136.26.19162
108180.136.26.192/26180.136.26.193 to 180.136.26.254180.136.26.25562
109180.136.27.0/26180.136.27.1 to 180.136.27.62180.136.27.6362
110180.136.27.64/26180.136.27.65 to 180.136.27.126180.136.27.12762
111180.136.27.128/26180.136.27.129 to 180.136.27.190180.136.27.19162
112180.136.27.192/26180.136.27.193 to 180.136.27.254180.136.27.25562
113180.136.28.0/26180.136.28.1 to 180.136.28.62180.136.28.6362
114180.136.28.64/26180.136.28.65 to 180.136.28.126180.136.28.12762
115180.136.28.128/26180.136.28.129 to 180.136.28.190180.136.28.19162
116180.136.28.192/26180.136.28.193 to 180.136.28.254180.136.28.25562
117180.136.29.0/26180.136.29.1 to 180.136.29.62180.136.29.6362
118180.136.29.64/26180.136.29.65 to 180.136.29.126180.136.29.12762
119180.136.29.128/26180.136.29.129 to 180.136.29.190180.136.29.19162
120180.136.29.192/26180.136.29.193 to 180.136.29.254180.136.29.25562
121180.136.30.0/26180.136.30.1 to 180.136.30.62180.136.30.6362
122180.136.30.64/26180.136.30.65 to 180.136.30.126180.136.30.12762
123180.136.30.128/26180.136.30.129 to 180.136.30.190180.136.30.19162
124180.136.30.192/26180.136.30.193 to 180.136.30.254180.136.30.25562
125180.136.31.0/26180.136.31.1 to 180.136.31.62180.136.31.6362
126180.136.31.64/26180.136.31.65 to 180.136.31.126180.136.31.12762
127180.136.31.128/26180.136.31.129 to 180.136.31.190180.136.31.19162
128180.136.31.192/26180.136.31.193 to 180.136.31.254180.136.31.25562
129180.136.32.0/26180.136.32.1 to 180.136.32.62180.136.32.6362
130180.136.32.64/26180.136.32.65 to 180.136.32.126180.136.32.12762
131180.136.32.128/26180.136.32.129 to 180.136.32.190180.136.32.19162
132180.136.32.192/26180.136.32.193 to 180.136.32.254180.136.32.25562
133180.136.33.0/26180.136.33.1 to 180.136.33.62180.136.33.6362
134180.136.33.64/26180.136.33.65 to 180.136.33.126180.136.33.12762
135180.136.33.128/26180.136.33.129 to 180.136.33.190180.136.33.19162
136180.136.33.192/26180.136.33.193 to 180.136.33.254180.136.33.25562
137180.136.34.0/26180.136.34.1 to 180.136.34.62180.136.34.6362
138180.136.34.64/26180.136.34.65 to 180.136.34.126180.136.34.12762
139180.136.34.128/26180.136.34.129 to 180.136.34.190180.136.34.19162
140180.136.34.192/26180.136.34.193 to 180.136.34.254180.136.34.25562
141180.136.35.0/26180.136.35.1 to 180.136.35.62180.136.35.6362
142180.136.35.64/26180.136.35.65 to 180.136.35.126180.136.35.12762
143180.136.35.128/26180.136.35.129 to 180.136.35.190180.136.35.19162
144180.136.35.192/26180.136.35.193 to 180.136.35.254180.136.35.25562
145180.136.36.0/26180.136.36.1 to 180.136.36.62180.136.36.6362
146180.136.36.64/26180.136.36.65 to 180.136.36.126180.136.36.12762
147180.136.36.128/26180.136.36.129 to 180.136.36.190180.136.36.19162
148180.136.36.192/26180.136.36.193 to 180.136.36.254180.136.36.25562
149180.136.37.0/26180.136.37.1 to 180.136.37.62180.136.37.6362
150180.136.37.64/26180.136.37.65 to 180.136.37.126180.136.37.12762
151180.136.37.128/26180.136.37.129 to 180.136.37.190180.136.37.19162
152180.136.37.192/26180.136.37.193 to 180.136.37.254180.136.37.25562
153180.136.38.0/26180.136.38.1 to 180.136.38.62180.136.38.6362
154180.136.38.64/26180.136.38.65 to 180.136.38.126180.136.38.12762
155180.136.38.128/26180.136.38.129 to 180.136.38.190180.136.38.19162
156180.136.38.192/26180.136.38.193 to 180.136.38.254180.136.38.25562
157180.136.39.0/26180.136.39.1 to 180.136.39.62180.136.39.6362
158180.136.39.64/26180.136.39.65 to 180.136.39.126180.136.39.12762
159180.136.39.128/26180.136.39.129 to 180.136.39.190180.136.39.19162
160180.136.39.192/26180.136.39.193 to 180.136.39.254180.136.39.25562
161180.136.40.0/26180.136.40.1 to 180.136.40.62180.136.40.6362
162180.136.40.64/26180.136.40.65 to 180.136.40.126180.136.40.12762
163180.136.40.128/26180.136.40.129 to 180.136.40.190180.136.40.19162
164180.136.40.192/26180.136.40.193 to 180.136.40.254180.136.40.25562
165180.136.41.0/26180.136.41.1 to 180.136.41.62180.136.41.6362
166180.136.41.64/26180.136.41.65 to 180.136.41.126180.136.41.12762
167180.136.41.128/26180.136.41.129 to 180.136.41.190180.136.41.19162
168180.136.41.192/26180.136.41.193 to 180.136.41.254180.136.41.25562
169180.136.42.0/26180.136.42.1 to 180.136.42.62180.136.42.6362
170180.136.42.64/26180.136.42.65 to 180.136.42.126180.136.42.12762
171180.136.42.128/26180.136.42.129 to 180.136.42.190180.136.42.19162
172180.136.42.192/26180.136.42.193 to 180.136.42.254180.136.42.25562
173180.136.43.0/26180.136.43.1 to 180.136.43.62180.136.43.6362
174180.136.43.64/26180.136.43.65 to 180.136.43.126180.136.43.12762
175180.136.43.128/26180.136.43.129 to 180.136.43.190180.136.43.19162
176180.136.43.192/26180.136.43.193 to 180.136.43.254180.136.43.25562
177180.136.44.0/26180.136.44.1 to 180.136.44.62180.136.44.6362
178180.136.44.64/26180.136.44.65 to 180.136.44.126180.136.44.12762
179180.136.44.128/26180.136.44.129 to 180.136.44.190180.136.44.19162
180180.136.44.192/26180.136.44.193 to 180.136.44.254180.136.44.25562
181180.136.45.0/26180.136.45.1 to 180.136.45.62180.136.45.6362
182180.136.45.64/26180.136.45.65 to 180.136.45.126180.136.45.12762
183180.136.45.128/26180.136.45.129 to 180.136.45.190180.136.45.19162
184180.136.45.192/26180.136.45.193 to 180.136.45.254180.136.45.25562
185180.136.46.0/26180.136.46.1 to 180.136.46.62180.136.46.6362
186180.136.46.64/26180.136.46.65 to 180.136.46.126180.136.46.12762
187180.136.46.128/26180.136.46.129 to 180.136.46.190180.136.46.19162
188180.136.46.192/26180.136.46.193 to 180.136.46.254180.136.46.25562
189180.136.47.0/26180.136.47.1 to 180.136.47.62180.136.47.6362
190180.136.47.64/26180.136.47.65 to 180.136.47.126180.136.47.12762
191180.136.47.128/26180.136.47.129 to 180.136.47.190180.136.47.19162
192180.136.47.192/26180.136.47.193 to 180.136.47.254180.136.47.25562
193180.136.48.0/26180.136.48.1 to 180.136.48.62180.136.48.6362
194180.136.48.64/26180.136.48.65 to 180.136.48.126180.136.48.12762
195180.136.48.128/26180.136.48.129 to 180.136.48.190180.136.48.19162
196180.136.48.192/26180.136.48.193 to 180.136.48.254180.136.48.25562
197180.136.49.0/26180.136.49.1 to 180.136.49.62180.136.49.6362
198180.136.49.64/26180.136.49.65 to 180.136.49.126180.136.49.12762
199180.136.49.128/26180.136.49.129 to 180.136.49.190180.136.49.19162
200180.136.49.192/26180.136.49.193 to 180.136.49.254180.136.49.25562
201180.136.50.0/26180.136.50.1 to 180.136.50.62180.136.50.6362
202180.136.50.64/26180.136.50.65 to 180.136.50.126180.136.50.12762
203180.136.50.128/26180.136.50.129 to 180.136.50.190180.136.50.19162
204180.136.50.192/26180.136.50.193 to 180.136.50.254180.136.50.25562
205180.136.51.0/26180.136.51.1 to 180.136.51.62180.136.51.6362
206180.136.51.64/26180.136.51.65 to 180.136.51.126180.136.51.12762
207180.136.51.128/26180.136.51.129 to 180.136.51.190180.136.51.19162
208180.136.51.192/26180.136.51.193 to 180.136.51.254180.136.51.25562
209180.136.52.0/26180.136.52.1 to 180.136.52.62180.136.52.6362
210180.136.52.64/26180.136.52.65 to 180.136.52.126180.136.52.12762
211180.136.52.128/26180.136.52.129 to 180.136.52.190180.136.52.19162
212180.136.52.192/26180.136.52.193 to 180.136.52.254180.136.52.25562
213180.136.53.0/26180.136.53.1 to 180.136.53.62180.136.53.6362
214180.136.53.64/26180.136.53.65 to 180.136.53.126180.136.53.12762
215180.136.53.128/26180.136.53.129 to 180.136.53.190180.136.53.19162
216180.136.53.192/26180.136.53.193 to 180.136.53.254180.136.53.25562
217180.136.54.0/26180.136.54.1 to 180.136.54.62180.136.54.6362
218180.136.54.64/26180.136.54.65 to 180.136.54.126180.136.54.12762
219180.136.54.128/26180.136.54.129 to 180.136.54.190180.136.54.19162
220180.136.54.192/26180.136.54.193 to 180.136.54.254180.136.54.25562
221180.136.55.0/26180.136.55.1 to 180.136.55.62180.136.55.6362
222180.136.55.64/26180.136.55.65 to 180.136.55.126180.136.55.12762
223180.136.55.128/26180.136.55.129 to 180.136.55.190180.136.55.19162
224180.136.55.192/26180.136.55.193 to 180.136.55.254180.136.55.25562
225180.136.56.0/26180.136.56.1 to 180.136.56.62180.136.56.6362
226180.136.56.64/26180.136.56.65 to 180.136.56.126180.136.56.12762
227180.136.56.128/26180.136.56.129 to 180.136.56.190180.136.56.19162
228180.136.56.192/26180.136.56.193 to 180.136.56.254180.136.56.25562
229180.136.57.0/26180.136.57.1 to 180.136.57.62180.136.57.6362
230180.136.57.64/26180.136.57.65 to 180.136.57.126180.136.57.12762
231180.136.57.128/26180.136.57.129 to 180.136.57.190180.136.57.19162
232180.136.57.192/26180.136.57.193 to 180.136.57.254180.136.57.25562
233180.136.58.0/26180.136.58.1 to 180.136.58.62180.136.58.6362
234180.136.58.64/26180.136.58.65 to 180.136.58.126180.136.58.12762
235180.136.58.128/26180.136.58.129 to 180.136.58.190180.136.58.19162
236180.136.58.192/26180.136.58.193 to 180.136.58.254180.136.58.25562
237180.136.59.0/26180.136.59.1 to 180.136.59.62180.136.59.6362
238180.136.59.64/26180.136.59.65 to 180.136.59.126180.136.59.12762
239180.136.59.128/26180.136.59.129 to 180.136.59.190180.136.59.19162
240180.136.59.192/26180.136.59.193 to 180.136.59.254180.136.59.25562
241180.136.60.0/26180.136.60.1 to 180.136.60.62180.136.60.6362
242180.136.60.64/26180.136.60.65 to 180.136.60.126180.136.60.12762
243180.136.60.128/26180.136.60.129 to 180.136.60.190180.136.60.19162
244180.136.60.192/26180.136.60.193 to 180.136.60.254180.136.60.25562
245180.136.61.0/26180.136.61.1 to 180.136.61.62180.136.61.6362
246180.136.61.64/26180.136.61.65 to 180.136.61.126180.136.61.12762
247180.136.61.128/26180.136.61.129 to 180.136.61.190180.136.61.19162
248180.136.61.192/26180.136.61.193 to 180.136.61.254180.136.61.25562
249180.136.62.0/26180.136.62.1 to 180.136.62.62180.136.62.6362
250180.136.62.64/26180.136.62.65 to 180.136.62.126180.136.62.12762
251180.136.62.128/26180.136.62.129 to 180.136.62.190180.136.62.19162
252180.136.62.192/26180.136.62.193 to 180.136.62.254180.136.62.25562
253180.136.63.0/26180.136.63.1 to 180.136.63.62180.136.63.6362
254180.136.63.64/26180.136.63.65 to 180.136.63.126180.136.63.12762
255180.136.63.128/26180.136.63.129 to 180.136.63.190180.136.63.19162
256180.136.63.192/26180.136.63.193 to 180.136.63.254180.136.63.25562

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.