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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.

Network153.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
153.0.0.0
Broadcast address
153.255.255.255
First usable
153.0.0.1
Last usable
153.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
B (default /16)
As numbers
Hex 99000000 · Integer 2566914048 to 2583691263
Reverse DNS zone
153.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011001..00000000.00000000.00000000153.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10011001..00000000.00000000.00000000153.0.0.0
Broadcast10011001..11111111.11111111.11111111153.255.255.255
Split into smaller subnets/18
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

153.0.0.0/8 makes 1,024 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1153.0.0.0/18153.0.0.1 to 153.0.63.254153.0.63.25516,382
2153.0.64.0/18153.0.64.1 to 153.0.127.254153.0.127.25516,382
3153.0.128.0/18153.0.128.1 to 153.0.191.254153.0.191.25516,382
4153.0.192.0/18153.0.192.1 to 153.0.255.254153.0.255.25516,382
5153.1.0.0/18153.1.0.1 to 153.1.63.254153.1.63.25516,382
6153.1.64.0/18153.1.64.1 to 153.1.127.254153.1.127.25516,382
7153.1.128.0/18153.1.128.1 to 153.1.191.254153.1.191.25516,382
8153.1.192.0/18153.1.192.1 to 153.1.255.254153.1.255.25516,382
9153.2.0.0/18153.2.0.1 to 153.2.63.254153.2.63.25516,382
10153.2.64.0/18153.2.64.1 to 153.2.127.254153.2.127.25516,382
11153.2.128.0/18153.2.128.1 to 153.2.191.254153.2.191.25516,382
12153.2.192.0/18153.2.192.1 to 153.2.255.254153.2.255.25516,382
13153.3.0.0/18153.3.0.1 to 153.3.63.254153.3.63.25516,382
14153.3.64.0/18153.3.64.1 to 153.3.127.254153.3.127.25516,382
15153.3.128.0/18153.3.128.1 to 153.3.191.254153.3.191.25516,382
16153.3.192.0/18153.3.192.1 to 153.3.255.254153.3.255.25516,382
17153.4.0.0/18153.4.0.1 to 153.4.63.254153.4.63.25516,382
18153.4.64.0/18153.4.64.1 to 153.4.127.254153.4.127.25516,382
19153.4.128.0/18153.4.128.1 to 153.4.191.254153.4.191.25516,382
20153.4.192.0/18153.4.192.1 to 153.4.255.254153.4.255.25516,382
21153.5.0.0/18153.5.0.1 to 153.5.63.254153.5.63.25516,382
22153.5.64.0/18153.5.64.1 to 153.5.127.254153.5.127.25516,382
23153.5.128.0/18153.5.128.1 to 153.5.191.254153.5.191.25516,382
24153.5.192.0/18153.5.192.1 to 153.5.255.254153.5.255.25516,382
25153.6.0.0/18153.6.0.1 to 153.6.63.254153.6.63.25516,382
26153.6.64.0/18153.6.64.1 to 153.6.127.254153.6.127.25516,382
27153.6.128.0/18153.6.128.1 to 153.6.191.254153.6.191.25516,382
28153.6.192.0/18153.6.192.1 to 153.6.255.254153.6.255.25516,382
29153.7.0.0/18153.7.0.1 to 153.7.63.254153.7.63.25516,382
30153.7.64.0/18153.7.64.1 to 153.7.127.254153.7.127.25516,382
31153.7.128.0/18153.7.128.1 to 153.7.191.254153.7.191.25516,382
32153.7.192.0/18153.7.192.1 to 153.7.255.254153.7.255.25516,382
33153.8.0.0/18153.8.0.1 to 153.8.63.254153.8.63.25516,382
34153.8.64.0/18153.8.64.1 to 153.8.127.254153.8.127.25516,382
35153.8.128.0/18153.8.128.1 to 153.8.191.254153.8.191.25516,382
36153.8.192.0/18153.8.192.1 to 153.8.255.254153.8.255.25516,382
37153.9.0.0/18153.9.0.1 to 153.9.63.254153.9.63.25516,382
38153.9.64.0/18153.9.64.1 to 153.9.127.254153.9.127.25516,382
39153.9.128.0/18153.9.128.1 to 153.9.191.254153.9.191.25516,382
40153.9.192.0/18153.9.192.1 to 153.9.255.254153.9.255.25516,382
41153.10.0.0/18153.10.0.1 to 153.10.63.254153.10.63.25516,382
42153.10.64.0/18153.10.64.1 to 153.10.127.254153.10.127.25516,382
43153.10.128.0/18153.10.128.1 to 153.10.191.254153.10.191.25516,382
44153.10.192.0/18153.10.192.1 to 153.10.255.254153.10.255.25516,382
45153.11.0.0/18153.11.0.1 to 153.11.63.254153.11.63.25516,382
46153.11.64.0/18153.11.64.1 to 153.11.127.254153.11.127.25516,382
47153.11.128.0/18153.11.128.1 to 153.11.191.254153.11.191.25516,382
48153.11.192.0/18153.11.192.1 to 153.11.255.254153.11.255.25516,382
49153.12.0.0/18153.12.0.1 to 153.12.63.254153.12.63.25516,382
50153.12.64.0/18153.12.64.1 to 153.12.127.254153.12.127.25516,382
51153.12.128.0/18153.12.128.1 to 153.12.191.254153.12.191.25516,382
52153.12.192.0/18153.12.192.1 to 153.12.255.254153.12.255.25516,382
53153.13.0.0/18153.13.0.1 to 153.13.63.254153.13.63.25516,382
54153.13.64.0/18153.13.64.1 to 153.13.127.254153.13.127.25516,382
55153.13.128.0/18153.13.128.1 to 153.13.191.254153.13.191.25516,382
56153.13.192.0/18153.13.192.1 to 153.13.255.254153.13.255.25516,382
57153.14.0.0/18153.14.0.1 to 153.14.63.254153.14.63.25516,382
58153.14.64.0/18153.14.64.1 to 153.14.127.254153.14.127.25516,382
59153.14.128.0/18153.14.128.1 to 153.14.191.254153.14.191.25516,382
60153.14.192.0/18153.14.192.1 to 153.14.255.254153.14.255.25516,382
61153.15.0.0/18153.15.0.1 to 153.15.63.254153.15.63.25516,382
62153.15.64.0/18153.15.64.1 to 153.15.127.254153.15.127.25516,382
63153.15.128.0/18153.15.128.1 to 153.15.191.254153.15.191.25516,382
64153.15.192.0/18153.15.192.1 to 153.15.255.254153.15.255.25516,382
65153.16.0.0/18153.16.0.1 to 153.16.63.254153.16.63.25516,382
66153.16.64.0/18153.16.64.1 to 153.16.127.254153.16.127.25516,382
67153.16.128.0/18153.16.128.1 to 153.16.191.254153.16.191.25516,382
68153.16.192.0/18153.16.192.1 to 153.16.255.254153.16.255.25516,382
69153.17.0.0/18153.17.0.1 to 153.17.63.254153.17.63.25516,382
70153.17.64.0/18153.17.64.1 to 153.17.127.254153.17.127.25516,382
71153.17.128.0/18153.17.128.1 to 153.17.191.254153.17.191.25516,382
72153.17.192.0/18153.17.192.1 to 153.17.255.254153.17.255.25516,382
73153.18.0.0/18153.18.0.1 to 153.18.63.254153.18.63.25516,382
74153.18.64.0/18153.18.64.1 to 153.18.127.254153.18.127.25516,382
75153.18.128.0/18153.18.128.1 to 153.18.191.254153.18.191.25516,382
76153.18.192.0/18153.18.192.1 to 153.18.255.254153.18.255.25516,382
77153.19.0.0/18153.19.0.1 to 153.19.63.254153.19.63.25516,382
78153.19.64.0/18153.19.64.1 to 153.19.127.254153.19.127.25516,382
79153.19.128.0/18153.19.128.1 to 153.19.191.254153.19.191.25516,382
80153.19.192.0/18153.19.192.1 to 153.19.255.254153.19.255.25516,382
81153.20.0.0/18153.20.0.1 to 153.20.63.254153.20.63.25516,382
82153.20.64.0/18153.20.64.1 to 153.20.127.254153.20.127.25516,382
83153.20.128.0/18153.20.128.1 to 153.20.191.254153.20.191.25516,382
84153.20.192.0/18153.20.192.1 to 153.20.255.254153.20.255.25516,382
85153.21.0.0/18153.21.0.1 to 153.21.63.254153.21.63.25516,382
86153.21.64.0/18153.21.64.1 to 153.21.127.254153.21.127.25516,382
87153.21.128.0/18153.21.128.1 to 153.21.191.254153.21.191.25516,382
88153.21.192.0/18153.21.192.1 to 153.21.255.254153.21.255.25516,382
89153.22.0.0/18153.22.0.1 to 153.22.63.254153.22.63.25516,382
90153.22.64.0/18153.22.64.1 to 153.22.127.254153.22.127.25516,382
91153.22.128.0/18153.22.128.1 to 153.22.191.254153.22.191.25516,382
92153.22.192.0/18153.22.192.1 to 153.22.255.254153.22.255.25516,382
93153.23.0.0/18153.23.0.1 to 153.23.63.254153.23.63.25516,382
94153.23.64.0/18153.23.64.1 to 153.23.127.254153.23.127.25516,382
95153.23.128.0/18153.23.128.1 to 153.23.191.254153.23.191.25516,382
96153.23.192.0/18153.23.192.1 to 153.23.255.254153.23.255.25516,382
97153.24.0.0/18153.24.0.1 to 153.24.63.254153.24.63.25516,382
98153.24.64.0/18153.24.64.1 to 153.24.127.254153.24.127.25516,382
99153.24.128.0/18153.24.128.1 to 153.24.191.254153.24.191.25516,382
100153.24.192.0/18153.24.192.1 to 153.24.255.254153.24.255.25516,382
101153.25.0.0/18153.25.0.1 to 153.25.63.254153.25.63.25516,382
102153.25.64.0/18153.25.64.1 to 153.25.127.254153.25.127.25516,382
103153.25.128.0/18153.25.128.1 to 153.25.191.254153.25.191.25516,382
104153.25.192.0/18153.25.192.1 to 153.25.255.254153.25.255.25516,382
105153.26.0.0/18153.26.0.1 to 153.26.63.254153.26.63.25516,382
106153.26.64.0/18153.26.64.1 to 153.26.127.254153.26.127.25516,382
107153.26.128.0/18153.26.128.1 to 153.26.191.254153.26.191.25516,382
108153.26.192.0/18153.26.192.1 to 153.26.255.254153.26.255.25516,382
109153.27.0.0/18153.27.0.1 to 153.27.63.254153.27.63.25516,382
110153.27.64.0/18153.27.64.1 to 153.27.127.254153.27.127.25516,382
111153.27.128.0/18153.27.128.1 to 153.27.191.254153.27.191.25516,382
112153.27.192.0/18153.27.192.1 to 153.27.255.254153.27.255.25516,382
113153.28.0.0/18153.28.0.1 to 153.28.63.254153.28.63.25516,382
114153.28.64.0/18153.28.64.1 to 153.28.127.254153.28.127.25516,382
115153.28.128.0/18153.28.128.1 to 153.28.191.254153.28.191.25516,382
116153.28.192.0/18153.28.192.1 to 153.28.255.254153.28.255.25516,382
117153.29.0.0/18153.29.0.1 to 153.29.63.254153.29.63.25516,382
118153.29.64.0/18153.29.64.1 to 153.29.127.254153.29.127.25516,382
119153.29.128.0/18153.29.128.1 to 153.29.191.254153.29.191.25516,382
120153.29.192.0/18153.29.192.1 to 153.29.255.254153.29.255.25516,382
121153.30.0.0/18153.30.0.1 to 153.30.63.254153.30.63.25516,382
122153.30.64.0/18153.30.64.1 to 153.30.127.254153.30.127.25516,382
123153.30.128.0/18153.30.128.1 to 153.30.191.254153.30.191.25516,382
124153.30.192.0/18153.30.192.1 to 153.30.255.254153.30.255.25516,382
125153.31.0.0/18153.31.0.1 to 153.31.63.254153.31.63.25516,382
126153.31.64.0/18153.31.64.1 to 153.31.127.254153.31.127.25516,382
127153.31.128.0/18153.31.128.1 to 153.31.191.254153.31.191.25516,382
128153.31.192.0/18153.31.192.1 to 153.31.255.254153.31.255.25516,382
129153.32.0.0/18153.32.0.1 to 153.32.63.254153.32.63.25516,382
130153.32.64.0/18153.32.64.1 to 153.32.127.254153.32.127.25516,382
131153.32.128.0/18153.32.128.1 to 153.32.191.254153.32.191.25516,382
132153.32.192.0/18153.32.192.1 to 153.32.255.254153.32.255.25516,382
133153.33.0.0/18153.33.0.1 to 153.33.63.254153.33.63.25516,382
134153.33.64.0/18153.33.64.1 to 153.33.127.254153.33.127.25516,382
135153.33.128.0/18153.33.128.1 to 153.33.191.254153.33.191.25516,382
136153.33.192.0/18153.33.192.1 to 153.33.255.254153.33.255.25516,382
137153.34.0.0/18153.34.0.1 to 153.34.63.254153.34.63.25516,382
138153.34.64.0/18153.34.64.1 to 153.34.127.254153.34.127.25516,382
139153.34.128.0/18153.34.128.1 to 153.34.191.254153.34.191.25516,382
140153.34.192.0/18153.34.192.1 to 153.34.255.254153.34.255.25516,382
141153.35.0.0/18153.35.0.1 to 153.35.63.254153.35.63.25516,382
142153.35.64.0/18153.35.64.1 to 153.35.127.254153.35.127.25516,382
143153.35.128.0/18153.35.128.1 to 153.35.191.254153.35.191.25516,382
144153.35.192.0/18153.35.192.1 to 153.35.255.254153.35.255.25516,382
145153.36.0.0/18153.36.0.1 to 153.36.63.254153.36.63.25516,382
146153.36.64.0/18153.36.64.1 to 153.36.127.254153.36.127.25516,382
147153.36.128.0/18153.36.128.1 to 153.36.191.254153.36.191.25516,382
148153.36.192.0/18153.36.192.1 to 153.36.255.254153.36.255.25516,382
149153.37.0.0/18153.37.0.1 to 153.37.63.254153.37.63.25516,382
150153.37.64.0/18153.37.64.1 to 153.37.127.254153.37.127.25516,382
151153.37.128.0/18153.37.128.1 to 153.37.191.254153.37.191.25516,382
152153.37.192.0/18153.37.192.1 to 153.37.255.254153.37.255.25516,382
153153.38.0.0/18153.38.0.1 to 153.38.63.254153.38.63.25516,382
154153.38.64.0/18153.38.64.1 to 153.38.127.254153.38.127.25516,382
155153.38.128.0/18153.38.128.1 to 153.38.191.254153.38.191.25516,382
156153.38.192.0/18153.38.192.1 to 153.38.255.254153.38.255.25516,382
157153.39.0.0/18153.39.0.1 to 153.39.63.254153.39.63.25516,382
158153.39.64.0/18153.39.64.1 to 153.39.127.254153.39.127.25516,382
159153.39.128.0/18153.39.128.1 to 153.39.191.254153.39.191.25516,382
160153.39.192.0/18153.39.192.1 to 153.39.255.254153.39.255.25516,382
161153.40.0.0/18153.40.0.1 to 153.40.63.254153.40.63.25516,382
162153.40.64.0/18153.40.64.1 to 153.40.127.254153.40.127.25516,382
163153.40.128.0/18153.40.128.1 to 153.40.191.254153.40.191.25516,382
164153.40.192.0/18153.40.192.1 to 153.40.255.254153.40.255.25516,382
165153.41.0.0/18153.41.0.1 to 153.41.63.254153.41.63.25516,382
166153.41.64.0/18153.41.64.1 to 153.41.127.254153.41.127.25516,382
167153.41.128.0/18153.41.128.1 to 153.41.191.254153.41.191.25516,382
168153.41.192.0/18153.41.192.1 to 153.41.255.254153.41.255.25516,382
169153.42.0.0/18153.42.0.1 to 153.42.63.254153.42.63.25516,382
170153.42.64.0/18153.42.64.1 to 153.42.127.254153.42.127.25516,382
171153.42.128.0/18153.42.128.1 to 153.42.191.254153.42.191.25516,382
172153.42.192.0/18153.42.192.1 to 153.42.255.254153.42.255.25516,382
173153.43.0.0/18153.43.0.1 to 153.43.63.254153.43.63.25516,382
174153.43.64.0/18153.43.64.1 to 153.43.127.254153.43.127.25516,382
175153.43.128.0/18153.43.128.1 to 153.43.191.254153.43.191.25516,382
176153.43.192.0/18153.43.192.1 to 153.43.255.254153.43.255.25516,382
177153.44.0.0/18153.44.0.1 to 153.44.63.254153.44.63.25516,382
178153.44.64.0/18153.44.64.1 to 153.44.127.254153.44.127.25516,382
179153.44.128.0/18153.44.128.1 to 153.44.191.254153.44.191.25516,382
180153.44.192.0/18153.44.192.1 to 153.44.255.254153.44.255.25516,382
181153.45.0.0/18153.45.0.1 to 153.45.63.254153.45.63.25516,382
182153.45.64.0/18153.45.64.1 to 153.45.127.254153.45.127.25516,382
183153.45.128.0/18153.45.128.1 to 153.45.191.254153.45.191.25516,382
184153.45.192.0/18153.45.192.1 to 153.45.255.254153.45.255.25516,382
185153.46.0.0/18153.46.0.1 to 153.46.63.254153.46.63.25516,382
186153.46.64.0/18153.46.64.1 to 153.46.127.254153.46.127.25516,382
187153.46.128.0/18153.46.128.1 to 153.46.191.254153.46.191.25516,382
188153.46.192.0/18153.46.192.1 to 153.46.255.254153.46.255.25516,382
189153.47.0.0/18153.47.0.1 to 153.47.63.254153.47.63.25516,382
190153.47.64.0/18153.47.64.1 to 153.47.127.254153.47.127.25516,382
191153.47.128.0/18153.47.128.1 to 153.47.191.254153.47.191.25516,382
192153.47.192.0/18153.47.192.1 to 153.47.255.254153.47.255.25516,382
193153.48.0.0/18153.48.0.1 to 153.48.63.254153.48.63.25516,382
194153.48.64.0/18153.48.64.1 to 153.48.127.254153.48.127.25516,382
195153.48.128.0/18153.48.128.1 to 153.48.191.254153.48.191.25516,382
196153.48.192.0/18153.48.192.1 to 153.48.255.254153.48.255.25516,382
197153.49.0.0/18153.49.0.1 to 153.49.63.254153.49.63.25516,382
198153.49.64.0/18153.49.64.1 to 153.49.127.254153.49.127.25516,382
199153.49.128.0/18153.49.128.1 to 153.49.191.254153.49.191.25516,382
200153.49.192.0/18153.49.192.1 to 153.49.255.254153.49.255.25516,382
201153.50.0.0/18153.50.0.1 to 153.50.63.254153.50.63.25516,382
202153.50.64.0/18153.50.64.1 to 153.50.127.254153.50.127.25516,382
203153.50.128.0/18153.50.128.1 to 153.50.191.254153.50.191.25516,382
204153.50.192.0/18153.50.192.1 to 153.50.255.254153.50.255.25516,382
205153.51.0.0/18153.51.0.1 to 153.51.63.254153.51.63.25516,382
206153.51.64.0/18153.51.64.1 to 153.51.127.254153.51.127.25516,382
207153.51.128.0/18153.51.128.1 to 153.51.191.254153.51.191.25516,382
208153.51.192.0/18153.51.192.1 to 153.51.255.254153.51.255.25516,382
209153.52.0.0/18153.52.0.1 to 153.52.63.254153.52.63.25516,382
210153.52.64.0/18153.52.64.1 to 153.52.127.254153.52.127.25516,382
211153.52.128.0/18153.52.128.1 to 153.52.191.254153.52.191.25516,382
212153.52.192.0/18153.52.192.1 to 153.52.255.254153.52.255.25516,382
213153.53.0.0/18153.53.0.1 to 153.53.63.254153.53.63.25516,382
214153.53.64.0/18153.53.64.1 to 153.53.127.254153.53.127.25516,382
215153.53.128.0/18153.53.128.1 to 153.53.191.254153.53.191.25516,382
216153.53.192.0/18153.53.192.1 to 153.53.255.254153.53.255.25516,382
217153.54.0.0/18153.54.0.1 to 153.54.63.254153.54.63.25516,382
218153.54.64.0/18153.54.64.1 to 153.54.127.254153.54.127.25516,382
219153.54.128.0/18153.54.128.1 to 153.54.191.254153.54.191.25516,382
220153.54.192.0/18153.54.192.1 to 153.54.255.254153.54.255.25516,382
221153.55.0.0/18153.55.0.1 to 153.55.63.254153.55.63.25516,382
222153.55.64.0/18153.55.64.1 to 153.55.127.254153.55.127.25516,382
223153.55.128.0/18153.55.128.1 to 153.55.191.254153.55.191.25516,382
224153.55.192.0/18153.55.192.1 to 153.55.255.254153.55.255.25516,382
225153.56.0.0/18153.56.0.1 to 153.56.63.254153.56.63.25516,382
226153.56.64.0/18153.56.64.1 to 153.56.127.254153.56.127.25516,382
227153.56.128.0/18153.56.128.1 to 153.56.191.254153.56.191.25516,382
228153.56.192.0/18153.56.192.1 to 153.56.255.254153.56.255.25516,382
229153.57.0.0/18153.57.0.1 to 153.57.63.254153.57.63.25516,382
230153.57.64.0/18153.57.64.1 to 153.57.127.254153.57.127.25516,382
231153.57.128.0/18153.57.128.1 to 153.57.191.254153.57.191.25516,382
232153.57.192.0/18153.57.192.1 to 153.57.255.254153.57.255.25516,382
233153.58.0.0/18153.58.0.1 to 153.58.63.254153.58.63.25516,382
234153.58.64.0/18153.58.64.1 to 153.58.127.254153.58.127.25516,382
235153.58.128.0/18153.58.128.1 to 153.58.191.254153.58.191.25516,382
236153.58.192.0/18153.58.192.1 to 153.58.255.254153.58.255.25516,382
237153.59.0.0/18153.59.0.1 to 153.59.63.254153.59.63.25516,382
238153.59.64.0/18153.59.64.1 to 153.59.127.254153.59.127.25516,382
239153.59.128.0/18153.59.128.1 to 153.59.191.254153.59.191.25516,382
240153.59.192.0/18153.59.192.1 to 153.59.255.254153.59.255.25516,382
241153.60.0.0/18153.60.0.1 to 153.60.63.254153.60.63.25516,382
242153.60.64.0/18153.60.64.1 to 153.60.127.254153.60.127.25516,382
243153.60.128.0/18153.60.128.1 to 153.60.191.254153.60.191.25516,382
244153.60.192.0/18153.60.192.1 to 153.60.255.254153.60.255.25516,382
245153.61.0.0/18153.61.0.1 to 153.61.63.254153.61.63.25516,382
246153.61.64.0/18153.61.64.1 to 153.61.127.254153.61.127.25516,382
247153.61.128.0/18153.61.128.1 to 153.61.191.254153.61.191.25516,382
248153.61.192.0/18153.61.192.1 to 153.61.255.254153.61.255.25516,382
249153.62.0.0/18153.62.0.1 to 153.62.63.254153.62.63.25516,382
250153.62.64.0/18153.62.64.1 to 153.62.127.254153.62.127.25516,382
251153.62.128.0/18153.62.128.1 to 153.62.191.254153.62.191.25516,382
252153.62.192.0/18153.62.192.1 to 153.62.255.254153.62.255.25516,382
253153.63.0.0/18153.63.0.1 to 153.63.63.254153.63.63.25516,382
254153.63.64.0/18153.63.64.1 to 153.63.127.254153.63.127.25516,382
255153.63.128.0/18153.63.128.1 to 153.63.191.254153.63.191.25516,382
256153.63.192.0/18153.63.192.1 to 153.63.255.254153.63.255.25516,382

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.