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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.

Network183.44.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
183.44.0.0
Broadcast address
183.45.255.255
First usable
183.44.0.1
Last usable
183.45.255.254
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 B72C0000 · Integer 3073114112 to 3073245183
Reverse DNS zones
44.183.in-addr.arpa
45.183.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
Address10110111.00101100.00000000.00000000183.44.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network10110111.00101100.00000000.00000000183.44.0.0
Broadcast10110111.00101101.11111111.11111111183.45.255.255
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)

183.44.0.0/15 makes 2,048 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1183.44.0.0/26183.44.0.1 to 183.44.0.62183.44.0.6362
2183.44.0.64/26183.44.0.65 to 183.44.0.126183.44.0.12762
3183.44.0.128/26183.44.0.129 to 183.44.0.190183.44.0.19162
4183.44.0.192/26183.44.0.193 to 183.44.0.254183.44.0.25562
5183.44.1.0/26183.44.1.1 to 183.44.1.62183.44.1.6362
6183.44.1.64/26183.44.1.65 to 183.44.1.126183.44.1.12762
7183.44.1.128/26183.44.1.129 to 183.44.1.190183.44.1.19162
8183.44.1.192/26183.44.1.193 to 183.44.1.254183.44.1.25562
9183.44.2.0/26183.44.2.1 to 183.44.2.62183.44.2.6362
10183.44.2.64/26183.44.2.65 to 183.44.2.126183.44.2.12762
11183.44.2.128/26183.44.2.129 to 183.44.2.190183.44.2.19162
12183.44.2.192/26183.44.2.193 to 183.44.2.254183.44.2.25562
13183.44.3.0/26183.44.3.1 to 183.44.3.62183.44.3.6362
14183.44.3.64/26183.44.3.65 to 183.44.3.126183.44.3.12762
15183.44.3.128/26183.44.3.129 to 183.44.3.190183.44.3.19162
16183.44.3.192/26183.44.3.193 to 183.44.3.254183.44.3.25562
17183.44.4.0/26183.44.4.1 to 183.44.4.62183.44.4.6362
18183.44.4.64/26183.44.4.65 to 183.44.4.126183.44.4.12762
19183.44.4.128/26183.44.4.129 to 183.44.4.190183.44.4.19162
20183.44.4.192/26183.44.4.193 to 183.44.4.254183.44.4.25562
21183.44.5.0/26183.44.5.1 to 183.44.5.62183.44.5.6362
22183.44.5.64/26183.44.5.65 to 183.44.5.126183.44.5.12762
23183.44.5.128/26183.44.5.129 to 183.44.5.190183.44.5.19162
24183.44.5.192/26183.44.5.193 to 183.44.5.254183.44.5.25562
25183.44.6.0/26183.44.6.1 to 183.44.6.62183.44.6.6362
26183.44.6.64/26183.44.6.65 to 183.44.6.126183.44.6.12762
27183.44.6.128/26183.44.6.129 to 183.44.6.190183.44.6.19162
28183.44.6.192/26183.44.6.193 to 183.44.6.254183.44.6.25562
29183.44.7.0/26183.44.7.1 to 183.44.7.62183.44.7.6362
30183.44.7.64/26183.44.7.65 to 183.44.7.126183.44.7.12762
31183.44.7.128/26183.44.7.129 to 183.44.7.190183.44.7.19162
32183.44.7.192/26183.44.7.193 to 183.44.7.254183.44.7.25562
33183.44.8.0/26183.44.8.1 to 183.44.8.62183.44.8.6362
34183.44.8.64/26183.44.8.65 to 183.44.8.126183.44.8.12762
35183.44.8.128/26183.44.8.129 to 183.44.8.190183.44.8.19162
36183.44.8.192/26183.44.8.193 to 183.44.8.254183.44.8.25562
37183.44.9.0/26183.44.9.1 to 183.44.9.62183.44.9.6362
38183.44.9.64/26183.44.9.65 to 183.44.9.126183.44.9.12762
39183.44.9.128/26183.44.9.129 to 183.44.9.190183.44.9.19162
40183.44.9.192/26183.44.9.193 to 183.44.9.254183.44.9.25562
41183.44.10.0/26183.44.10.1 to 183.44.10.62183.44.10.6362
42183.44.10.64/26183.44.10.65 to 183.44.10.126183.44.10.12762
43183.44.10.128/26183.44.10.129 to 183.44.10.190183.44.10.19162
44183.44.10.192/26183.44.10.193 to 183.44.10.254183.44.10.25562
45183.44.11.0/26183.44.11.1 to 183.44.11.62183.44.11.6362
46183.44.11.64/26183.44.11.65 to 183.44.11.126183.44.11.12762
47183.44.11.128/26183.44.11.129 to 183.44.11.190183.44.11.19162
48183.44.11.192/26183.44.11.193 to 183.44.11.254183.44.11.25562
49183.44.12.0/26183.44.12.1 to 183.44.12.62183.44.12.6362
50183.44.12.64/26183.44.12.65 to 183.44.12.126183.44.12.12762
51183.44.12.128/26183.44.12.129 to 183.44.12.190183.44.12.19162
52183.44.12.192/26183.44.12.193 to 183.44.12.254183.44.12.25562
53183.44.13.0/26183.44.13.1 to 183.44.13.62183.44.13.6362
54183.44.13.64/26183.44.13.65 to 183.44.13.126183.44.13.12762
55183.44.13.128/26183.44.13.129 to 183.44.13.190183.44.13.19162
56183.44.13.192/26183.44.13.193 to 183.44.13.254183.44.13.25562
57183.44.14.0/26183.44.14.1 to 183.44.14.62183.44.14.6362
58183.44.14.64/26183.44.14.65 to 183.44.14.126183.44.14.12762
59183.44.14.128/26183.44.14.129 to 183.44.14.190183.44.14.19162
60183.44.14.192/26183.44.14.193 to 183.44.14.254183.44.14.25562
61183.44.15.0/26183.44.15.1 to 183.44.15.62183.44.15.6362
62183.44.15.64/26183.44.15.65 to 183.44.15.126183.44.15.12762
63183.44.15.128/26183.44.15.129 to 183.44.15.190183.44.15.19162
64183.44.15.192/26183.44.15.193 to 183.44.15.254183.44.15.25562
65183.44.16.0/26183.44.16.1 to 183.44.16.62183.44.16.6362
66183.44.16.64/26183.44.16.65 to 183.44.16.126183.44.16.12762
67183.44.16.128/26183.44.16.129 to 183.44.16.190183.44.16.19162
68183.44.16.192/26183.44.16.193 to 183.44.16.254183.44.16.25562
69183.44.17.0/26183.44.17.1 to 183.44.17.62183.44.17.6362
70183.44.17.64/26183.44.17.65 to 183.44.17.126183.44.17.12762
71183.44.17.128/26183.44.17.129 to 183.44.17.190183.44.17.19162
72183.44.17.192/26183.44.17.193 to 183.44.17.254183.44.17.25562
73183.44.18.0/26183.44.18.1 to 183.44.18.62183.44.18.6362
74183.44.18.64/26183.44.18.65 to 183.44.18.126183.44.18.12762
75183.44.18.128/26183.44.18.129 to 183.44.18.190183.44.18.19162
76183.44.18.192/26183.44.18.193 to 183.44.18.254183.44.18.25562
77183.44.19.0/26183.44.19.1 to 183.44.19.62183.44.19.6362
78183.44.19.64/26183.44.19.65 to 183.44.19.126183.44.19.12762
79183.44.19.128/26183.44.19.129 to 183.44.19.190183.44.19.19162
80183.44.19.192/26183.44.19.193 to 183.44.19.254183.44.19.25562
81183.44.20.0/26183.44.20.1 to 183.44.20.62183.44.20.6362
82183.44.20.64/26183.44.20.65 to 183.44.20.126183.44.20.12762
83183.44.20.128/26183.44.20.129 to 183.44.20.190183.44.20.19162
84183.44.20.192/26183.44.20.193 to 183.44.20.254183.44.20.25562
85183.44.21.0/26183.44.21.1 to 183.44.21.62183.44.21.6362
86183.44.21.64/26183.44.21.65 to 183.44.21.126183.44.21.12762
87183.44.21.128/26183.44.21.129 to 183.44.21.190183.44.21.19162
88183.44.21.192/26183.44.21.193 to 183.44.21.254183.44.21.25562
89183.44.22.0/26183.44.22.1 to 183.44.22.62183.44.22.6362
90183.44.22.64/26183.44.22.65 to 183.44.22.126183.44.22.12762
91183.44.22.128/26183.44.22.129 to 183.44.22.190183.44.22.19162
92183.44.22.192/26183.44.22.193 to 183.44.22.254183.44.22.25562
93183.44.23.0/26183.44.23.1 to 183.44.23.62183.44.23.6362
94183.44.23.64/26183.44.23.65 to 183.44.23.126183.44.23.12762
95183.44.23.128/26183.44.23.129 to 183.44.23.190183.44.23.19162
96183.44.23.192/26183.44.23.193 to 183.44.23.254183.44.23.25562
97183.44.24.0/26183.44.24.1 to 183.44.24.62183.44.24.6362
98183.44.24.64/26183.44.24.65 to 183.44.24.126183.44.24.12762
99183.44.24.128/26183.44.24.129 to 183.44.24.190183.44.24.19162
100183.44.24.192/26183.44.24.193 to 183.44.24.254183.44.24.25562
101183.44.25.0/26183.44.25.1 to 183.44.25.62183.44.25.6362
102183.44.25.64/26183.44.25.65 to 183.44.25.126183.44.25.12762
103183.44.25.128/26183.44.25.129 to 183.44.25.190183.44.25.19162
104183.44.25.192/26183.44.25.193 to 183.44.25.254183.44.25.25562
105183.44.26.0/26183.44.26.1 to 183.44.26.62183.44.26.6362
106183.44.26.64/26183.44.26.65 to 183.44.26.126183.44.26.12762
107183.44.26.128/26183.44.26.129 to 183.44.26.190183.44.26.19162
108183.44.26.192/26183.44.26.193 to 183.44.26.254183.44.26.25562
109183.44.27.0/26183.44.27.1 to 183.44.27.62183.44.27.6362
110183.44.27.64/26183.44.27.65 to 183.44.27.126183.44.27.12762
111183.44.27.128/26183.44.27.129 to 183.44.27.190183.44.27.19162
112183.44.27.192/26183.44.27.193 to 183.44.27.254183.44.27.25562
113183.44.28.0/26183.44.28.1 to 183.44.28.62183.44.28.6362
114183.44.28.64/26183.44.28.65 to 183.44.28.126183.44.28.12762
115183.44.28.128/26183.44.28.129 to 183.44.28.190183.44.28.19162
116183.44.28.192/26183.44.28.193 to 183.44.28.254183.44.28.25562
117183.44.29.0/26183.44.29.1 to 183.44.29.62183.44.29.6362
118183.44.29.64/26183.44.29.65 to 183.44.29.126183.44.29.12762
119183.44.29.128/26183.44.29.129 to 183.44.29.190183.44.29.19162
120183.44.29.192/26183.44.29.193 to 183.44.29.254183.44.29.25562
121183.44.30.0/26183.44.30.1 to 183.44.30.62183.44.30.6362
122183.44.30.64/26183.44.30.65 to 183.44.30.126183.44.30.12762
123183.44.30.128/26183.44.30.129 to 183.44.30.190183.44.30.19162
124183.44.30.192/26183.44.30.193 to 183.44.30.254183.44.30.25562
125183.44.31.0/26183.44.31.1 to 183.44.31.62183.44.31.6362
126183.44.31.64/26183.44.31.65 to 183.44.31.126183.44.31.12762
127183.44.31.128/26183.44.31.129 to 183.44.31.190183.44.31.19162
128183.44.31.192/26183.44.31.193 to 183.44.31.254183.44.31.25562
129183.44.32.0/26183.44.32.1 to 183.44.32.62183.44.32.6362
130183.44.32.64/26183.44.32.65 to 183.44.32.126183.44.32.12762
131183.44.32.128/26183.44.32.129 to 183.44.32.190183.44.32.19162
132183.44.32.192/26183.44.32.193 to 183.44.32.254183.44.32.25562
133183.44.33.0/26183.44.33.1 to 183.44.33.62183.44.33.6362
134183.44.33.64/26183.44.33.65 to 183.44.33.126183.44.33.12762
135183.44.33.128/26183.44.33.129 to 183.44.33.190183.44.33.19162
136183.44.33.192/26183.44.33.193 to 183.44.33.254183.44.33.25562
137183.44.34.0/26183.44.34.1 to 183.44.34.62183.44.34.6362
138183.44.34.64/26183.44.34.65 to 183.44.34.126183.44.34.12762
139183.44.34.128/26183.44.34.129 to 183.44.34.190183.44.34.19162
140183.44.34.192/26183.44.34.193 to 183.44.34.254183.44.34.25562
141183.44.35.0/26183.44.35.1 to 183.44.35.62183.44.35.6362
142183.44.35.64/26183.44.35.65 to 183.44.35.126183.44.35.12762
143183.44.35.128/26183.44.35.129 to 183.44.35.190183.44.35.19162
144183.44.35.192/26183.44.35.193 to 183.44.35.254183.44.35.25562
145183.44.36.0/26183.44.36.1 to 183.44.36.62183.44.36.6362
146183.44.36.64/26183.44.36.65 to 183.44.36.126183.44.36.12762
147183.44.36.128/26183.44.36.129 to 183.44.36.190183.44.36.19162
148183.44.36.192/26183.44.36.193 to 183.44.36.254183.44.36.25562
149183.44.37.0/26183.44.37.1 to 183.44.37.62183.44.37.6362
150183.44.37.64/26183.44.37.65 to 183.44.37.126183.44.37.12762
151183.44.37.128/26183.44.37.129 to 183.44.37.190183.44.37.19162
152183.44.37.192/26183.44.37.193 to 183.44.37.254183.44.37.25562
153183.44.38.0/26183.44.38.1 to 183.44.38.62183.44.38.6362
154183.44.38.64/26183.44.38.65 to 183.44.38.126183.44.38.12762
155183.44.38.128/26183.44.38.129 to 183.44.38.190183.44.38.19162
156183.44.38.192/26183.44.38.193 to 183.44.38.254183.44.38.25562
157183.44.39.0/26183.44.39.1 to 183.44.39.62183.44.39.6362
158183.44.39.64/26183.44.39.65 to 183.44.39.126183.44.39.12762
159183.44.39.128/26183.44.39.129 to 183.44.39.190183.44.39.19162
160183.44.39.192/26183.44.39.193 to 183.44.39.254183.44.39.25562
161183.44.40.0/26183.44.40.1 to 183.44.40.62183.44.40.6362
162183.44.40.64/26183.44.40.65 to 183.44.40.126183.44.40.12762
163183.44.40.128/26183.44.40.129 to 183.44.40.190183.44.40.19162
164183.44.40.192/26183.44.40.193 to 183.44.40.254183.44.40.25562
165183.44.41.0/26183.44.41.1 to 183.44.41.62183.44.41.6362
166183.44.41.64/26183.44.41.65 to 183.44.41.126183.44.41.12762
167183.44.41.128/26183.44.41.129 to 183.44.41.190183.44.41.19162
168183.44.41.192/26183.44.41.193 to 183.44.41.254183.44.41.25562
169183.44.42.0/26183.44.42.1 to 183.44.42.62183.44.42.6362
170183.44.42.64/26183.44.42.65 to 183.44.42.126183.44.42.12762
171183.44.42.128/26183.44.42.129 to 183.44.42.190183.44.42.19162
172183.44.42.192/26183.44.42.193 to 183.44.42.254183.44.42.25562
173183.44.43.0/26183.44.43.1 to 183.44.43.62183.44.43.6362
174183.44.43.64/26183.44.43.65 to 183.44.43.126183.44.43.12762
175183.44.43.128/26183.44.43.129 to 183.44.43.190183.44.43.19162
176183.44.43.192/26183.44.43.193 to 183.44.43.254183.44.43.25562
177183.44.44.0/26183.44.44.1 to 183.44.44.62183.44.44.6362
178183.44.44.64/26183.44.44.65 to 183.44.44.126183.44.44.12762
179183.44.44.128/26183.44.44.129 to 183.44.44.190183.44.44.19162
180183.44.44.192/26183.44.44.193 to 183.44.44.254183.44.44.25562
181183.44.45.0/26183.44.45.1 to 183.44.45.62183.44.45.6362
182183.44.45.64/26183.44.45.65 to 183.44.45.126183.44.45.12762
183183.44.45.128/26183.44.45.129 to 183.44.45.190183.44.45.19162
184183.44.45.192/26183.44.45.193 to 183.44.45.254183.44.45.25562
185183.44.46.0/26183.44.46.1 to 183.44.46.62183.44.46.6362
186183.44.46.64/26183.44.46.65 to 183.44.46.126183.44.46.12762
187183.44.46.128/26183.44.46.129 to 183.44.46.190183.44.46.19162
188183.44.46.192/26183.44.46.193 to 183.44.46.254183.44.46.25562
189183.44.47.0/26183.44.47.1 to 183.44.47.62183.44.47.6362
190183.44.47.64/26183.44.47.65 to 183.44.47.126183.44.47.12762
191183.44.47.128/26183.44.47.129 to 183.44.47.190183.44.47.19162
192183.44.47.192/26183.44.47.193 to 183.44.47.254183.44.47.25562
193183.44.48.0/26183.44.48.1 to 183.44.48.62183.44.48.6362
194183.44.48.64/26183.44.48.65 to 183.44.48.126183.44.48.12762
195183.44.48.128/26183.44.48.129 to 183.44.48.190183.44.48.19162
196183.44.48.192/26183.44.48.193 to 183.44.48.254183.44.48.25562
197183.44.49.0/26183.44.49.1 to 183.44.49.62183.44.49.6362
198183.44.49.64/26183.44.49.65 to 183.44.49.126183.44.49.12762
199183.44.49.128/26183.44.49.129 to 183.44.49.190183.44.49.19162
200183.44.49.192/26183.44.49.193 to 183.44.49.254183.44.49.25562
201183.44.50.0/26183.44.50.1 to 183.44.50.62183.44.50.6362
202183.44.50.64/26183.44.50.65 to 183.44.50.126183.44.50.12762
203183.44.50.128/26183.44.50.129 to 183.44.50.190183.44.50.19162
204183.44.50.192/26183.44.50.193 to 183.44.50.254183.44.50.25562
205183.44.51.0/26183.44.51.1 to 183.44.51.62183.44.51.6362
206183.44.51.64/26183.44.51.65 to 183.44.51.126183.44.51.12762
207183.44.51.128/26183.44.51.129 to 183.44.51.190183.44.51.19162
208183.44.51.192/26183.44.51.193 to 183.44.51.254183.44.51.25562
209183.44.52.0/26183.44.52.1 to 183.44.52.62183.44.52.6362
210183.44.52.64/26183.44.52.65 to 183.44.52.126183.44.52.12762
211183.44.52.128/26183.44.52.129 to 183.44.52.190183.44.52.19162
212183.44.52.192/26183.44.52.193 to 183.44.52.254183.44.52.25562
213183.44.53.0/26183.44.53.1 to 183.44.53.62183.44.53.6362
214183.44.53.64/26183.44.53.65 to 183.44.53.126183.44.53.12762
215183.44.53.128/26183.44.53.129 to 183.44.53.190183.44.53.19162
216183.44.53.192/26183.44.53.193 to 183.44.53.254183.44.53.25562
217183.44.54.0/26183.44.54.1 to 183.44.54.62183.44.54.6362
218183.44.54.64/26183.44.54.65 to 183.44.54.126183.44.54.12762
219183.44.54.128/26183.44.54.129 to 183.44.54.190183.44.54.19162
220183.44.54.192/26183.44.54.193 to 183.44.54.254183.44.54.25562
221183.44.55.0/26183.44.55.1 to 183.44.55.62183.44.55.6362
222183.44.55.64/26183.44.55.65 to 183.44.55.126183.44.55.12762
223183.44.55.128/26183.44.55.129 to 183.44.55.190183.44.55.19162
224183.44.55.192/26183.44.55.193 to 183.44.55.254183.44.55.25562
225183.44.56.0/26183.44.56.1 to 183.44.56.62183.44.56.6362
226183.44.56.64/26183.44.56.65 to 183.44.56.126183.44.56.12762
227183.44.56.128/26183.44.56.129 to 183.44.56.190183.44.56.19162
228183.44.56.192/26183.44.56.193 to 183.44.56.254183.44.56.25562
229183.44.57.0/26183.44.57.1 to 183.44.57.62183.44.57.6362
230183.44.57.64/26183.44.57.65 to 183.44.57.126183.44.57.12762
231183.44.57.128/26183.44.57.129 to 183.44.57.190183.44.57.19162
232183.44.57.192/26183.44.57.193 to 183.44.57.254183.44.57.25562
233183.44.58.0/26183.44.58.1 to 183.44.58.62183.44.58.6362
234183.44.58.64/26183.44.58.65 to 183.44.58.126183.44.58.12762
235183.44.58.128/26183.44.58.129 to 183.44.58.190183.44.58.19162
236183.44.58.192/26183.44.58.193 to 183.44.58.254183.44.58.25562
237183.44.59.0/26183.44.59.1 to 183.44.59.62183.44.59.6362
238183.44.59.64/26183.44.59.65 to 183.44.59.126183.44.59.12762
239183.44.59.128/26183.44.59.129 to 183.44.59.190183.44.59.19162
240183.44.59.192/26183.44.59.193 to 183.44.59.254183.44.59.25562
241183.44.60.0/26183.44.60.1 to 183.44.60.62183.44.60.6362
242183.44.60.64/26183.44.60.65 to 183.44.60.126183.44.60.12762
243183.44.60.128/26183.44.60.129 to 183.44.60.190183.44.60.19162
244183.44.60.192/26183.44.60.193 to 183.44.60.254183.44.60.25562
245183.44.61.0/26183.44.61.1 to 183.44.61.62183.44.61.6362
246183.44.61.64/26183.44.61.65 to 183.44.61.126183.44.61.12762
247183.44.61.128/26183.44.61.129 to 183.44.61.190183.44.61.19162
248183.44.61.192/26183.44.61.193 to 183.44.61.254183.44.61.25562
249183.44.62.0/26183.44.62.1 to 183.44.62.62183.44.62.6362
250183.44.62.64/26183.44.62.65 to 183.44.62.126183.44.62.12762
251183.44.62.128/26183.44.62.129 to 183.44.62.190183.44.62.19162
252183.44.62.192/26183.44.62.193 to 183.44.62.254183.44.62.25562
253183.44.63.0/26183.44.63.1 to 183.44.63.62183.44.63.6362
254183.44.63.64/26183.44.63.65 to 183.44.63.126183.44.63.12762
255183.44.63.128/26183.44.63.129 to 183.44.63.190183.44.63.19162
256183.44.63.192/26183.44.63.193 to 183.44.63.254183.44.63.25562

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.