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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.

Network233.167.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
233.167.0.0
Broadcast address
233.167.255.255
First usable
233.167.0.1
Last usable
233.167.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E9A70000 · Integer 3920035840 to 3920101375
Reverse DNS zone
167.233.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11101001.10100111..00000000.00000000233.167.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network11101001.10100111..00000000.00000000233.167.0.0
Broadcast11101001.10100111..11111111.11111111233.167.255.255
Split into smaller subnets/26
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

233.167.0.0/16 makes 1,024 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1233.167.0.0/26233.167.0.1 to 233.167.0.62233.167.0.6362
2233.167.0.64/26233.167.0.65 to 233.167.0.126233.167.0.12762
3233.167.0.128/26233.167.0.129 to 233.167.0.190233.167.0.19162
4233.167.0.192/26233.167.0.193 to 233.167.0.254233.167.0.25562
5233.167.1.0/26233.167.1.1 to 233.167.1.62233.167.1.6362
6233.167.1.64/26233.167.1.65 to 233.167.1.126233.167.1.12762
7233.167.1.128/26233.167.1.129 to 233.167.1.190233.167.1.19162
8233.167.1.192/26233.167.1.193 to 233.167.1.254233.167.1.25562
9233.167.2.0/26233.167.2.1 to 233.167.2.62233.167.2.6362
10233.167.2.64/26233.167.2.65 to 233.167.2.126233.167.2.12762
11233.167.2.128/26233.167.2.129 to 233.167.2.190233.167.2.19162
12233.167.2.192/26233.167.2.193 to 233.167.2.254233.167.2.25562
13233.167.3.0/26233.167.3.1 to 233.167.3.62233.167.3.6362
14233.167.3.64/26233.167.3.65 to 233.167.3.126233.167.3.12762
15233.167.3.128/26233.167.3.129 to 233.167.3.190233.167.3.19162
16233.167.3.192/26233.167.3.193 to 233.167.3.254233.167.3.25562
17233.167.4.0/26233.167.4.1 to 233.167.4.62233.167.4.6362
18233.167.4.64/26233.167.4.65 to 233.167.4.126233.167.4.12762
19233.167.4.128/26233.167.4.129 to 233.167.4.190233.167.4.19162
20233.167.4.192/26233.167.4.193 to 233.167.4.254233.167.4.25562
21233.167.5.0/26233.167.5.1 to 233.167.5.62233.167.5.6362
22233.167.5.64/26233.167.5.65 to 233.167.5.126233.167.5.12762
23233.167.5.128/26233.167.5.129 to 233.167.5.190233.167.5.19162
24233.167.5.192/26233.167.5.193 to 233.167.5.254233.167.5.25562
25233.167.6.0/26233.167.6.1 to 233.167.6.62233.167.6.6362
26233.167.6.64/26233.167.6.65 to 233.167.6.126233.167.6.12762
27233.167.6.128/26233.167.6.129 to 233.167.6.190233.167.6.19162
28233.167.6.192/26233.167.6.193 to 233.167.6.254233.167.6.25562
29233.167.7.0/26233.167.7.1 to 233.167.7.62233.167.7.6362
30233.167.7.64/26233.167.7.65 to 233.167.7.126233.167.7.12762
31233.167.7.128/26233.167.7.129 to 233.167.7.190233.167.7.19162
32233.167.7.192/26233.167.7.193 to 233.167.7.254233.167.7.25562
33233.167.8.0/26233.167.8.1 to 233.167.8.62233.167.8.6362
34233.167.8.64/26233.167.8.65 to 233.167.8.126233.167.8.12762
35233.167.8.128/26233.167.8.129 to 233.167.8.190233.167.8.19162
36233.167.8.192/26233.167.8.193 to 233.167.8.254233.167.8.25562
37233.167.9.0/26233.167.9.1 to 233.167.9.62233.167.9.6362
38233.167.9.64/26233.167.9.65 to 233.167.9.126233.167.9.12762
39233.167.9.128/26233.167.9.129 to 233.167.9.190233.167.9.19162
40233.167.9.192/26233.167.9.193 to 233.167.9.254233.167.9.25562
41233.167.10.0/26233.167.10.1 to 233.167.10.62233.167.10.6362
42233.167.10.64/26233.167.10.65 to 233.167.10.126233.167.10.12762
43233.167.10.128/26233.167.10.129 to 233.167.10.190233.167.10.19162
44233.167.10.192/26233.167.10.193 to 233.167.10.254233.167.10.25562
45233.167.11.0/26233.167.11.1 to 233.167.11.62233.167.11.6362
46233.167.11.64/26233.167.11.65 to 233.167.11.126233.167.11.12762
47233.167.11.128/26233.167.11.129 to 233.167.11.190233.167.11.19162
48233.167.11.192/26233.167.11.193 to 233.167.11.254233.167.11.25562
49233.167.12.0/26233.167.12.1 to 233.167.12.62233.167.12.6362
50233.167.12.64/26233.167.12.65 to 233.167.12.126233.167.12.12762
51233.167.12.128/26233.167.12.129 to 233.167.12.190233.167.12.19162
52233.167.12.192/26233.167.12.193 to 233.167.12.254233.167.12.25562
53233.167.13.0/26233.167.13.1 to 233.167.13.62233.167.13.6362
54233.167.13.64/26233.167.13.65 to 233.167.13.126233.167.13.12762
55233.167.13.128/26233.167.13.129 to 233.167.13.190233.167.13.19162
56233.167.13.192/26233.167.13.193 to 233.167.13.254233.167.13.25562
57233.167.14.0/26233.167.14.1 to 233.167.14.62233.167.14.6362
58233.167.14.64/26233.167.14.65 to 233.167.14.126233.167.14.12762
59233.167.14.128/26233.167.14.129 to 233.167.14.190233.167.14.19162
60233.167.14.192/26233.167.14.193 to 233.167.14.254233.167.14.25562
61233.167.15.0/26233.167.15.1 to 233.167.15.62233.167.15.6362
62233.167.15.64/26233.167.15.65 to 233.167.15.126233.167.15.12762
63233.167.15.128/26233.167.15.129 to 233.167.15.190233.167.15.19162
64233.167.15.192/26233.167.15.193 to 233.167.15.254233.167.15.25562
65233.167.16.0/26233.167.16.1 to 233.167.16.62233.167.16.6362
66233.167.16.64/26233.167.16.65 to 233.167.16.126233.167.16.12762
67233.167.16.128/26233.167.16.129 to 233.167.16.190233.167.16.19162
68233.167.16.192/26233.167.16.193 to 233.167.16.254233.167.16.25562
69233.167.17.0/26233.167.17.1 to 233.167.17.62233.167.17.6362
70233.167.17.64/26233.167.17.65 to 233.167.17.126233.167.17.12762
71233.167.17.128/26233.167.17.129 to 233.167.17.190233.167.17.19162
72233.167.17.192/26233.167.17.193 to 233.167.17.254233.167.17.25562
73233.167.18.0/26233.167.18.1 to 233.167.18.62233.167.18.6362
74233.167.18.64/26233.167.18.65 to 233.167.18.126233.167.18.12762
75233.167.18.128/26233.167.18.129 to 233.167.18.190233.167.18.19162
76233.167.18.192/26233.167.18.193 to 233.167.18.254233.167.18.25562
77233.167.19.0/26233.167.19.1 to 233.167.19.62233.167.19.6362
78233.167.19.64/26233.167.19.65 to 233.167.19.126233.167.19.12762
79233.167.19.128/26233.167.19.129 to 233.167.19.190233.167.19.19162
80233.167.19.192/26233.167.19.193 to 233.167.19.254233.167.19.25562
81233.167.20.0/26233.167.20.1 to 233.167.20.62233.167.20.6362
82233.167.20.64/26233.167.20.65 to 233.167.20.126233.167.20.12762
83233.167.20.128/26233.167.20.129 to 233.167.20.190233.167.20.19162
84233.167.20.192/26233.167.20.193 to 233.167.20.254233.167.20.25562
85233.167.21.0/26233.167.21.1 to 233.167.21.62233.167.21.6362
86233.167.21.64/26233.167.21.65 to 233.167.21.126233.167.21.12762
87233.167.21.128/26233.167.21.129 to 233.167.21.190233.167.21.19162
88233.167.21.192/26233.167.21.193 to 233.167.21.254233.167.21.25562
89233.167.22.0/26233.167.22.1 to 233.167.22.62233.167.22.6362
90233.167.22.64/26233.167.22.65 to 233.167.22.126233.167.22.12762
91233.167.22.128/26233.167.22.129 to 233.167.22.190233.167.22.19162
92233.167.22.192/26233.167.22.193 to 233.167.22.254233.167.22.25562
93233.167.23.0/26233.167.23.1 to 233.167.23.62233.167.23.6362
94233.167.23.64/26233.167.23.65 to 233.167.23.126233.167.23.12762
95233.167.23.128/26233.167.23.129 to 233.167.23.190233.167.23.19162
96233.167.23.192/26233.167.23.193 to 233.167.23.254233.167.23.25562
97233.167.24.0/26233.167.24.1 to 233.167.24.62233.167.24.6362
98233.167.24.64/26233.167.24.65 to 233.167.24.126233.167.24.12762
99233.167.24.128/26233.167.24.129 to 233.167.24.190233.167.24.19162
100233.167.24.192/26233.167.24.193 to 233.167.24.254233.167.24.25562
101233.167.25.0/26233.167.25.1 to 233.167.25.62233.167.25.6362
102233.167.25.64/26233.167.25.65 to 233.167.25.126233.167.25.12762
103233.167.25.128/26233.167.25.129 to 233.167.25.190233.167.25.19162
104233.167.25.192/26233.167.25.193 to 233.167.25.254233.167.25.25562
105233.167.26.0/26233.167.26.1 to 233.167.26.62233.167.26.6362
106233.167.26.64/26233.167.26.65 to 233.167.26.126233.167.26.12762
107233.167.26.128/26233.167.26.129 to 233.167.26.190233.167.26.19162
108233.167.26.192/26233.167.26.193 to 233.167.26.254233.167.26.25562
109233.167.27.0/26233.167.27.1 to 233.167.27.62233.167.27.6362
110233.167.27.64/26233.167.27.65 to 233.167.27.126233.167.27.12762
111233.167.27.128/26233.167.27.129 to 233.167.27.190233.167.27.19162
112233.167.27.192/26233.167.27.193 to 233.167.27.254233.167.27.25562
113233.167.28.0/26233.167.28.1 to 233.167.28.62233.167.28.6362
114233.167.28.64/26233.167.28.65 to 233.167.28.126233.167.28.12762
115233.167.28.128/26233.167.28.129 to 233.167.28.190233.167.28.19162
116233.167.28.192/26233.167.28.193 to 233.167.28.254233.167.28.25562
117233.167.29.0/26233.167.29.1 to 233.167.29.62233.167.29.6362
118233.167.29.64/26233.167.29.65 to 233.167.29.126233.167.29.12762
119233.167.29.128/26233.167.29.129 to 233.167.29.190233.167.29.19162
120233.167.29.192/26233.167.29.193 to 233.167.29.254233.167.29.25562
121233.167.30.0/26233.167.30.1 to 233.167.30.62233.167.30.6362
122233.167.30.64/26233.167.30.65 to 233.167.30.126233.167.30.12762
123233.167.30.128/26233.167.30.129 to 233.167.30.190233.167.30.19162
124233.167.30.192/26233.167.30.193 to 233.167.30.254233.167.30.25562
125233.167.31.0/26233.167.31.1 to 233.167.31.62233.167.31.6362
126233.167.31.64/26233.167.31.65 to 233.167.31.126233.167.31.12762
127233.167.31.128/26233.167.31.129 to 233.167.31.190233.167.31.19162
128233.167.31.192/26233.167.31.193 to 233.167.31.254233.167.31.25562
129233.167.32.0/26233.167.32.1 to 233.167.32.62233.167.32.6362
130233.167.32.64/26233.167.32.65 to 233.167.32.126233.167.32.12762
131233.167.32.128/26233.167.32.129 to 233.167.32.190233.167.32.19162
132233.167.32.192/26233.167.32.193 to 233.167.32.254233.167.32.25562
133233.167.33.0/26233.167.33.1 to 233.167.33.62233.167.33.6362
134233.167.33.64/26233.167.33.65 to 233.167.33.126233.167.33.12762
135233.167.33.128/26233.167.33.129 to 233.167.33.190233.167.33.19162
136233.167.33.192/26233.167.33.193 to 233.167.33.254233.167.33.25562
137233.167.34.0/26233.167.34.1 to 233.167.34.62233.167.34.6362
138233.167.34.64/26233.167.34.65 to 233.167.34.126233.167.34.12762
139233.167.34.128/26233.167.34.129 to 233.167.34.190233.167.34.19162
140233.167.34.192/26233.167.34.193 to 233.167.34.254233.167.34.25562
141233.167.35.0/26233.167.35.1 to 233.167.35.62233.167.35.6362
142233.167.35.64/26233.167.35.65 to 233.167.35.126233.167.35.12762
143233.167.35.128/26233.167.35.129 to 233.167.35.190233.167.35.19162
144233.167.35.192/26233.167.35.193 to 233.167.35.254233.167.35.25562
145233.167.36.0/26233.167.36.1 to 233.167.36.62233.167.36.6362
146233.167.36.64/26233.167.36.65 to 233.167.36.126233.167.36.12762
147233.167.36.128/26233.167.36.129 to 233.167.36.190233.167.36.19162
148233.167.36.192/26233.167.36.193 to 233.167.36.254233.167.36.25562
149233.167.37.0/26233.167.37.1 to 233.167.37.62233.167.37.6362
150233.167.37.64/26233.167.37.65 to 233.167.37.126233.167.37.12762
151233.167.37.128/26233.167.37.129 to 233.167.37.190233.167.37.19162
152233.167.37.192/26233.167.37.193 to 233.167.37.254233.167.37.25562
153233.167.38.0/26233.167.38.1 to 233.167.38.62233.167.38.6362
154233.167.38.64/26233.167.38.65 to 233.167.38.126233.167.38.12762
155233.167.38.128/26233.167.38.129 to 233.167.38.190233.167.38.19162
156233.167.38.192/26233.167.38.193 to 233.167.38.254233.167.38.25562
157233.167.39.0/26233.167.39.1 to 233.167.39.62233.167.39.6362
158233.167.39.64/26233.167.39.65 to 233.167.39.126233.167.39.12762
159233.167.39.128/26233.167.39.129 to 233.167.39.190233.167.39.19162
160233.167.39.192/26233.167.39.193 to 233.167.39.254233.167.39.25562
161233.167.40.0/26233.167.40.1 to 233.167.40.62233.167.40.6362
162233.167.40.64/26233.167.40.65 to 233.167.40.126233.167.40.12762
163233.167.40.128/26233.167.40.129 to 233.167.40.190233.167.40.19162
164233.167.40.192/26233.167.40.193 to 233.167.40.254233.167.40.25562
165233.167.41.0/26233.167.41.1 to 233.167.41.62233.167.41.6362
166233.167.41.64/26233.167.41.65 to 233.167.41.126233.167.41.12762
167233.167.41.128/26233.167.41.129 to 233.167.41.190233.167.41.19162
168233.167.41.192/26233.167.41.193 to 233.167.41.254233.167.41.25562
169233.167.42.0/26233.167.42.1 to 233.167.42.62233.167.42.6362
170233.167.42.64/26233.167.42.65 to 233.167.42.126233.167.42.12762
171233.167.42.128/26233.167.42.129 to 233.167.42.190233.167.42.19162
172233.167.42.192/26233.167.42.193 to 233.167.42.254233.167.42.25562
173233.167.43.0/26233.167.43.1 to 233.167.43.62233.167.43.6362
174233.167.43.64/26233.167.43.65 to 233.167.43.126233.167.43.12762
175233.167.43.128/26233.167.43.129 to 233.167.43.190233.167.43.19162
176233.167.43.192/26233.167.43.193 to 233.167.43.254233.167.43.25562
177233.167.44.0/26233.167.44.1 to 233.167.44.62233.167.44.6362
178233.167.44.64/26233.167.44.65 to 233.167.44.126233.167.44.12762
179233.167.44.128/26233.167.44.129 to 233.167.44.190233.167.44.19162
180233.167.44.192/26233.167.44.193 to 233.167.44.254233.167.44.25562
181233.167.45.0/26233.167.45.1 to 233.167.45.62233.167.45.6362
182233.167.45.64/26233.167.45.65 to 233.167.45.126233.167.45.12762
183233.167.45.128/26233.167.45.129 to 233.167.45.190233.167.45.19162
184233.167.45.192/26233.167.45.193 to 233.167.45.254233.167.45.25562
185233.167.46.0/26233.167.46.1 to 233.167.46.62233.167.46.6362
186233.167.46.64/26233.167.46.65 to 233.167.46.126233.167.46.12762
187233.167.46.128/26233.167.46.129 to 233.167.46.190233.167.46.19162
188233.167.46.192/26233.167.46.193 to 233.167.46.254233.167.46.25562
189233.167.47.0/26233.167.47.1 to 233.167.47.62233.167.47.6362
190233.167.47.64/26233.167.47.65 to 233.167.47.126233.167.47.12762
191233.167.47.128/26233.167.47.129 to 233.167.47.190233.167.47.19162
192233.167.47.192/26233.167.47.193 to 233.167.47.254233.167.47.25562
193233.167.48.0/26233.167.48.1 to 233.167.48.62233.167.48.6362
194233.167.48.64/26233.167.48.65 to 233.167.48.126233.167.48.12762
195233.167.48.128/26233.167.48.129 to 233.167.48.190233.167.48.19162
196233.167.48.192/26233.167.48.193 to 233.167.48.254233.167.48.25562
197233.167.49.0/26233.167.49.1 to 233.167.49.62233.167.49.6362
198233.167.49.64/26233.167.49.65 to 233.167.49.126233.167.49.12762
199233.167.49.128/26233.167.49.129 to 233.167.49.190233.167.49.19162
200233.167.49.192/26233.167.49.193 to 233.167.49.254233.167.49.25562
201233.167.50.0/26233.167.50.1 to 233.167.50.62233.167.50.6362
202233.167.50.64/26233.167.50.65 to 233.167.50.126233.167.50.12762
203233.167.50.128/26233.167.50.129 to 233.167.50.190233.167.50.19162
204233.167.50.192/26233.167.50.193 to 233.167.50.254233.167.50.25562
205233.167.51.0/26233.167.51.1 to 233.167.51.62233.167.51.6362
206233.167.51.64/26233.167.51.65 to 233.167.51.126233.167.51.12762
207233.167.51.128/26233.167.51.129 to 233.167.51.190233.167.51.19162
208233.167.51.192/26233.167.51.193 to 233.167.51.254233.167.51.25562
209233.167.52.0/26233.167.52.1 to 233.167.52.62233.167.52.6362
210233.167.52.64/26233.167.52.65 to 233.167.52.126233.167.52.12762
211233.167.52.128/26233.167.52.129 to 233.167.52.190233.167.52.19162
212233.167.52.192/26233.167.52.193 to 233.167.52.254233.167.52.25562
213233.167.53.0/26233.167.53.1 to 233.167.53.62233.167.53.6362
214233.167.53.64/26233.167.53.65 to 233.167.53.126233.167.53.12762
215233.167.53.128/26233.167.53.129 to 233.167.53.190233.167.53.19162
216233.167.53.192/26233.167.53.193 to 233.167.53.254233.167.53.25562
217233.167.54.0/26233.167.54.1 to 233.167.54.62233.167.54.6362
218233.167.54.64/26233.167.54.65 to 233.167.54.126233.167.54.12762
219233.167.54.128/26233.167.54.129 to 233.167.54.190233.167.54.19162
220233.167.54.192/26233.167.54.193 to 233.167.54.254233.167.54.25562
221233.167.55.0/26233.167.55.1 to 233.167.55.62233.167.55.6362
222233.167.55.64/26233.167.55.65 to 233.167.55.126233.167.55.12762
223233.167.55.128/26233.167.55.129 to 233.167.55.190233.167.55.19162
224233.167.55.192/26233.167.55.193 to 233.167.55.254233.167.55.25562
225233.167.56.0/26233.167.56.1 to 233.167.56.62233.167.56.6362
226233.167.56.64/26233.167.56.65 to 233.167.56.126233.167.56.12762
227233.167.56.128/26233.167.56.129 to 233.167.56.190233.167.56.19162
228233.167.56.192/26233.167.56.193 to 233.167.56.254233.167.56.25562
229233.167.57.0/26233.167.57.1 to 233.167.57.62233.167.57.6362
230233.167.57.64/26233.167.57.65 to 233.167.57.126233.167.57.12762
231233.167.57.128/26233.167.57.129 to 233.167.57.190233.167.57.19162
232233.167.57.192/26233.167.57.193 to 233.167.57.254233.167.57.25562
233233.167.58.0/26233.167.58.1 to 233.167.58.62233.167.58.6362
234233.167.58.64/26233.167.58.65 to 233.167.58.126233.167.58.12762
235233.167.58.128/26233.167.58.129 to 233.167.58.190233.167.58.19162
236233.167.58.192/26233.167.58.193 to 233.167.58.254233.167.58.25562
237233.167.59.0/26233.167.59.1 to 233.167.59.62233.167.59.6362
238233.167.59.64/26233.167.59.65 to 233.167.59.126233.167.59.12762
239233.167.59.128/26233.167.59.129 to 233.167.59.190233.167.59.19162
240233.167.59.192/26233.167.59.193 to 233.167.59.254233.167.59.25562
241233.167.60.0/26233.167.60.1 to 233.167.60.62233.167.60.6362
242233.167.60.64/26233.167.60.65 to 233.167.60.126233.167.60.12762
243233.167.60.128/26233.167.60.129 to 233.167.60.190233.167.60.19162
244233.167.60.192/26233.167.60.193 to 233.167.60.254233.167.60.25562
245233.167.61.0/26233.167.61.1 to 233.167.61.62233.167.61.6362
246233.167.61.64/26233.167.61.65 to 233.167.61.126233.167.61.12762
247233.167.61.128/26233.167.61.129 to 233.167.61.190233.167.61.19162
248233.167.61.192/26233.167.61.193 to 233.167.61.254233.167.61.25562
249233.167.62.0/26233.167.62.1 to 233.167.62.62233.167.62.6362
250233.167.62.64/26233.167.62.65 to 233.167.62.126233.167.62.12762
251233.167.62.128/26233.167.62.129 to 233.167.62.190233.167.62.19162
252233.167.62.192/26233.167.62.193 to 233.167.62.254233.167.62.25562
253233.167.63.0/26233.167.63.1 to 233.167.63.62233.167.63.6362
254233.167.63.64/26233.167.63.65 to 233.167.63.126233.167.63.12762
255233.167.63.128/26233.167.63.129 to 233.167.63.190233.167.63.19162
256233.167.63.192/26233.167.63.193 to 233.167.63.254233.167.63.25562

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.