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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.

Network155.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
155.0.0.0
Broadcast address
155.255.255.255
First usable
155.0.0.1
Last usable
155.255.255.254
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 9B000000 · Integer 2600468480 to 2617245695
Reverse DNS zone
155.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011011..00000000.00000000.00000000155.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10011011..00000000.00000000.00000000155.0.0.0
Broadcast10011011..11111111.11111111.11111111155.255.255.255
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)

155.0.0.0/8 makes 1,024 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1155.0.0.0/18155.0.0.1 to 155.0.63.254155.0.63.25516,382
2155.0.64.0/18155.0.64.1 to 155.0.127.254155.0.127.25516,382
3155.0.128.0/18155.0.128.1 to 155.0.191.254155.0.191.25516,382
4155.0.192.0/18155.0.192.1 to 155.0.255.254155.0.255.25516,382
5155.1.0.0/18155.1.0.1 to 155.1.63.254155.1.63.25516,382
6155.1.64.0/18155.1.64.1 to 155.1.127.254155.1.127.25516,382
7155.1.128.0/18155.1.128.1 to 155.1.191.254155.1.191.25516,382
8155.1.192.0/18155.1.192.1 to 155.1.255.254155.1.255.25516,382
9155.2.0.0/18155.2.0.1 to 155.2.63.254155.2.63.25516,382
10155.2.64.0/18155.2.64.1 to 155.2.127.254155.2.127.25516,382
11155.2.128.0/18155.2.128.1 to 155.2.191.254155.2.191.25516,382
12155.2.192.0/18155.2.192.1 to 155.2.255.254155.2.255.25516,382
13155.3.0.0/18155.3.0.1 to 155.3.63.254155.3.63.25516,382
14155.3.64.0/18155.3.64.1 to 155.3.127.254155.3.127.25516,382
15155.3.128.0/18155.3.128.1 to 155.3.191.254155.3.191.25516,382
16155.3.192.0/18155.3.192.1 to 155.3.255.254155.3.255.25516,382
17155.4.0.0/18155.4.0.1 to 155.4.63.254155.4.63.25516,382
18155.4.64.0/18155.4.64.1 to 155.4.127.254155.4.127.25516,382
19155.4.128.0/18155.4.128.1 to 155.4.191.254155.4.191.25516,382
20155.4.192.0/18155.4.192.1 to 155.4.255.254155.4.255.25516,382
21155.5.0.0/18155.5.0.1 to 155.5.63.254155.5.63.25516,382
22155.5.64.0/18155.5.64.1 to 155.5.127.254155.5.127.25516,382
23155.5.128.0/18155.5.128.1 to 155.5.191.254155.5.191.25516,382
24155.5.192.0/18155.5.192.1 to 155.5.255.254155.5.255.25516,382
25155.6.0.0/18155.6.0.1 to 155.6.63.254155.6.63.25516,382
26155.6.64.0/18155.6.64.1 to 155.6.127.254155.6.127.25516,382
27155.6.128.0/18155.6.128.1 to 155.6.191.254155.6.191.25516,382
28155.6.192.0/18155.6.192.1 to 155.6.255.254155.6.255.25516,382
29155.7.0.0/18155.7.0.1 to 155.7.63.254155.7.63.25516,382
30155.7.64.0/18155.7.64.1 to 155.7.127.254155.7.127.25516,382
31155.7.128.0/18155.7.128.1 to 155.7.191.254155.7.191.25516,382
32155.7.192.0/18155.7.192.1 to 155.7.255.254155.7.255.25516,382
33155.8.0.0/18155.8.0.1 to 155.8.63.254155.8.63.25516,382
34155.8.64.0/18155.8.64.1 to 155.8.127.254155.8.127.25516,382
35155.8.128.0/18155.8.128.1 to 155.8.191.254155.8.191.25516,382
36155.8.192.0/18155.8.192.1 to 155.8.255.254155.8.255.25516,382
37155.9.0.0/18155.9.0.1 to 155.9.63.254155.9.63.25516,382
38155.9.64.0/18155.9.64.1 to 155.9.127.254155.9.127.25516,382
39155.9.128.0/18155.9.128.1 to 155.9.191.254155.9.191.25516,382
40155.9.192.0/18155.9.192.1 to 155.9.255.254155.9.255.25516,382
41155.10.0.0/18155.10.0.1 to 155.10.63.254155.10.63.25516,382
42155.10.64.0/18155.10.64.1 to 155.10.127.254155.10.127.25516,382
43155.10.128.0/18155.10.128.1 to 155.10.191.254155.10.191.25516,382
44155.10.192.0/18155.10.192.1 to 155.10.255.254155.10.255.25516,382
45155.11.0.0/18155.11.0.1 to 155.11.63.254155.11.63.25516,382
46155.11.64.0/18155.11.64.1 to 155.11.127.254155.11.127.25516,382
47155.11.128.0/18155.11.128.1 to 155.11.191.254155.11.191.25516,382
48155.11.192.0/18155.11.192.1 to 155.11.255.254155.11.255.25516,382
49155.12.0.0/18155.12.0.1 to 155.12.63.254155.12.63.25516,382
50155.12.64.0/18155.12.64.1 to 155.12.127.254155.12.127.25516,382
51155.12.128.0/18155.12.128.1 to 155.12.191.254155.12.191.25516,382
52155.12.192.0/18155.12.192.1 to 155.12.255.254155.12.255.25516,382
53155.13.0.0/18155.13.0.1 to 155.13.63.254155.13.63.25516,382
54155.13.64.0/18155.13.64.1 to 155.13.127.254155.13.127.25516,382
55155.13.128.0/18155.13.128.1 to 155.13.191.254155.13.191.25516,382
56155.13.192.0/18155.13.192.1 to 155.13.255.254155.13.255.25516,382
57155.14.0.0/18155.14.0.1 to 155.14.63.254155.14.63.25516,382
58155.14.64.0/18155.14.64.1 to 155.14.127.254155.14.127.25516,382
59155.14.128.0/18155.14.128.1 to 155.14.191.254155.14.191.25516,382
60155.14.192.0/18155.14.192.1 to 155.14.255.254155.14.255.25516,382
61155.15.0.0/18155.15.0.1 to 155.15.63.254155.15.63.25516,382
62155.15.64.0/18155.15.64.1 to 155.15.127.254155.15.127.25516,382
63155.15.128.0/18155.15.128.1 to 155.15.191.254155.15.191.25516,382
64155.15.192.0/18155.15.192.1 to 155.15.255.254155.15.255.25516,382
65155.16.0.0/18155.16.0.1 to 155.16.63.254155.16.63.25516,382
66155.16.64.0/18155.16.64.1 to 155.16.127.254155.16.127.25516,382
67155.16.128.0/18155.16.128.1 to 155.16.191.254155.16.191.25516,382
68155.16.192.0/18155.16.192.1 to 155.16.255.254155.16.255.25516,382
69155.17.0.0/18155.17.0.1 to 155.17.63.254155.17.63.25516,382
70155.17.64.0/18155.17.64.1 to 155.17.127.254155.17.127.25516,382
71155.17.128.0/18155.17.128.1 to 155.17.191.254155.17.191.25516,382
72155.17.192.0/18155.17.192.1 to 155.17.255.254155.17.255.25516,382
73155.18.0.0/18155.18.0.1 to 155.18.63.254155.18.63.25516,382
74155.18.64.0/18155.18.64.1 to 155.18.127.254155.18.127.25516,382
75155.18.128.0/18155.18.128.1 to 155.18.191.254155.18.191.25516,382
76155.18.192.0/18155.18.192.1 to 155.18.255.254155.18.255.25516,382
77155.19.0.0/18155.19.0.1 to 155.19.63.254155.19.63.25516,382
78155.19.64.0/18155.19.64.1 to 155.19.127.254155.19.127.25516,382
79155.19.128.0/18155.19.128.1 to 155.19.191.254155.19.191.25516,382
80155.19.192.0/18155.19.192.1 to 155.19.255.254155.19.255.25516,382
81155.20.0.0/18155.20.0.1 to 155.20.63.254155.20.63.25516,382
82155.20.64.0/18155.20.64.1 to 155.20.127.254155.20.127.25516,382
83155.20.128.0/18155.20.128.1 to 155.20.191.254155.20.191.25516,382
84155.20.192.0/18155.20.192.1 to 155.20.255.254155.20.255.25516,382
85155.21.0.0/18155.21.0.1 to 155.21.63.254155.21.63.25516,382
86155.21.64.0/18155.21.64.1 to 155.21.127.254155.21.127.25516,382
87155.21.128.0/18155.21.128.1 to 155.21.191.254155.21.191.25516,382
88155.21.192.0/18155.21.192.1 to 155.21.255.254155.21.255.25516,382
89155.22.0.0/18155.22.0.1 to 155.22.63.254155.22.63.25516,382
90155.22.64.0/18155.22.64.1 to 155.22.127.254155.22.127.25516,382
91155.22.128.0/18155.22.128.1 to 155.22.191.254155.22.191.25516,382
92155.22.192.0/18155.22.192.1 to 155.22.255.254155.22.255.25516,382
93155.23.0.0/18155.23.0.1 to 155.23.63.254155.23.63.25516,382
94155.23.64.0/18155.23.64.1 to 155.23.127.254155.23.127.25516,382
95155.23.128.0/18155.23.128.1 to 155.23.191.254155.23.191.25516,382
96155.23.192.0/18155.23.192.1 to 155.23.255.254155.23.255.25516,382
97155.24.0.0/18155.24.0.1 to 155.24.63.254155.24.63.25516,382
98155.24.64.0/18155.24.64.1 to 155.24.127.254155.24.127.25516,382
99155.24.128.0/18155.24.128.1 to 155.24.191.254155.24.191.25516,382
100155.24.192.0/18155.24.192.1 to 155.24.255.254155.24.255.25516,382
101155.25.0.0/18155.25.0.1 to 155.25.63.254155.25.63.25516,382
102155.25.64.0/18155.25.64.1 to 155.25.127.254155.25.127.25516,382
103155.25.128.0/18155.25.128.1 to 155.25.191.254155.25.191.25516,382
104155.25.192.0/18155.25.192.1 to 155.25.255.254155.25.255.25516,382
105155.26.0.0/18155.26.0.1 to 155.26.63.254155.26.63.25516,382
106155.26.64.0/18155.26.64.1 to 155.26.127.254155.26.127.25516,382
107155.26.128.0/18155.26.128.1 to 155.26.191.254155.26.191.25516,382
108155.26.192.0/18155.26.192.1 to 155.26.255.254155.26.255.25516,382
109155.27.0.0/18155.27.0.1 to 155.27.63.254155.27.63.25516,382
110155.27.64.0/18155.27.64.1 to 155.27.127.254155.27.127.25516,382
111155.27.128.0/18155.27.128.1 to 155.27.191.254155.27.191.25516,382
112155.27.192.0/18155.27.192.1 to 155.27.255.254155.27.255.25516,382
113155.28.0.0/18155.28.0.1 to 155.28.63.254155.28.63.25516,382
114155.28.64.0/18155.28.64.1 to 155.28.127.254155.28.127.25516,382
115155.28.128.0/18155.28.128.1 to 155.28.191.254155.28.191.25516,382
116155.28.192.0/18155.28.192.1 to 155.28.255.254155.28.255.25516,382
117155.29.0.0/18155.29.0.1 to 155.29.63.254155.29.63.25516,382
118155.29.64.0/18155.29.64.1 to 155.29.127.254155.29.127.25516,382
119155.29.128.0/18155.29.128.1 to 155.29.191.254155.29.191.25516,382
120155.29.192.0/18155.29.192.1 to 155.29.255.254155.29.255.25516,382
121155.30.0.0/18155.30.0.1 to 155.30.63.254155.30.63.25516,382
122155.30.64.0/18155.30.64.1 to 155.30.127.254155.30.127.25516,382
123155.30.128.0/18155.30.128.1 to 155.30.191.254155.30.191.25516,382
124155.30.192.0/18155.30.192.1 to 155.30.255.254155.30.255.25516,382
125155.31.0.0/18155.31.0.1 to 155.31.63.254155.31.63.25516,382
126155.31.64.0/18155.31.64.1 to 155.31.127.254155.31.127.25516,382
127155.31.128.0/18155.31.128.1 to 155.31.191.254155.31.191.25516,382
128155.31.192.0/18155.31.192.1 to 155.31.255.254155.31.255.25516,382
129155.32.0.0/18155.32.0.1 to 155.32.63.254155.32.63.25516,382
130155.32.64.0/18155.32.64.1 to 155.32.127.254155.32.127.25516,382
131155.32.128.0/18155.32.128.1 to 155.32.191.254155.32.191.25516,382
132155.32.192.0/18155.32.192.1 to 155.32.255.254155.32.255.25516,382
133155.33.0.0/18155.33.0.1 to 155.33.63.254155.33.63.25516,382
134155.33.64.0/18155.33.64.1 to 155.33.127.254155.33.127.25516,382
135155.33.128.0/18155.33.128.1 to 155.33.191.254155.33.191.25516,382
136155.33.192.0/18155.33.192.1 to 155.33.255.254155.33.255.25516,382
137155.34.0.0/18155.34.0.1 to 155.34.63.254155.34.63.25516,382
138155.34.64.0/18155.34.64.1 to 155.34.127.254155.34.127.25516,382
139155.34.128.0/18155.34.128.1 to 155.34.191.254155.34.191.25516,382
140155.34.192.0/18155.34.192.1 to 155.34.255.254155.34.255.25516,382
141155.35.0.0/18155.35.0.1 to 155.35.63.254155.35.63.25516,382
142155.35.64.0/18155.35.64.1 to 155.35.127.254155.35.127.25516,382
143155.35.128.0/18155.35.128.1 to 155.35.191.254155.35.191.25516,382
144155.35.192.0/18155.35.192.1 to 155.35.255.254155.35.255.25516,382
145155.36.0.0/18155.36.0.1 to 155.36.63.254155.36.63.25516,382
146155.36.64.0/18155.36.64.1 to 155.36.127.254155.36.127.25516,382
147155.36.128.0/18155.36.128.1 to 155.36.191.254155.36.191.25516,382
148155.36.192.0/18155.36.192.1 to 155.36.255.254155.36.255.25516,382
149155.37.0.0/18155.37.0.1 to 155.37.63.254155.37.63.25516,382
150155.37.64.0/18155.37.64.1 to 155.37.127.254155.37.127.25516,382
151155.37.128.0/18155.37.128.1 to 155.37.191.254155.37.191.25516,382
152155.37.192.0/18155.37.192.1 to 155.37.255.254155.37.255.25516,382
153155.38.0.0/18155.38.0.1 to 155.38.63.254155.38.63.25516,382
154155.38.64.0/18155.38.64.1 to 155.38.127.254155.38.127.25516,382
155155.38.128.0/18155.38.128.1 to 155.38.191.254155.38.191.25516,382
156155.38.192.0/18155.38.192.1 to 155.38.255.254155.38.255.25516,382
157155.39.0.0/18155.39.0.1 to 155.39.63.254155.39.63.25516,382
158155.39.64.0/18155.39.64.1 to 155.39.127.254155.39.127.25516,382
159155.39.128.0/18155.39.128.1 to 155.39.191.254155.39.191.25516,382
160155.39.192.0/18155.39.192.1 to 155.39.255.254155.39.255.25516,382
161155.40.0.0/18155.40.0.1 to 155.40.63.254155.40.63.25516,382
162155.40.64.0/18155.40.64.1 to 155.40.127.254155.40.127.25516,382
163155.40.128.0/18155.40.128.1 to 155.40.191.254155.40.191.25516,382
164155.40.192.0/18155.40.192.1 to 155.40.255.254155.40.255.25516,382
165155.41.0.0/18155.41.0.1 to 155.41.63.254155.41.63.25516,382
166155.41.64.0/18155.41.64.1 to 155.41.127.254155.41.127.25516,382
167155.41.128.0/18155.41.128.1 to 155.41.191.254155.41.191.25516,382
168155.41.192.0/18155.41.192.1 to 155.41.255.254155.41.255.25516,382
169155.42.0.0/18155.42.0.1 to 155.42.63.254155.42.63.25516,382
170155.42.64.0/18155.42.64.1 to 155.42.127.254155.42.127.25516,382
171155.42.128.0/18155.42.128.1 to 155.42.191.254155.42.191.25516,382
172155.42.192.0/18155.42.192.1 to 155.42.255.254155.42.255.25516,382
173155.43.0.0/18155.43.0.1 to 155.43.63.254155.43.63.25516,382
174155.43.64.0/18155.43.64.1 to 155.43.127.254155.43.127.25516,382
175155.43.128.0/18155.43.128.1 to 155.43.191.254155.43.191.25516,382
176155.43.192.0/18155.43.192.1 to 155.43.255.254155.43.255.25516,382
177155.44.0.0/18155.44.0.1 to 155.44.63.254155.44.63.25516,382
178155.44.64.0/18155.44.64.1 to 155.44.127.254155.44.127.25516,382
179155.44.128.0/18155.44.128.1 to 155.44.191.254155.44.191.25516,382
180155.44.192.0/18155.44.192.1 to 155.44.255.254155.44.255.25516,382
181155.45.0.0/18155.45.0.1 to 155.45.63.254155.45.63.25516,382
182155.45.64.0/18155.45.64.1 to 155.45.127.254155.45.127.25516,382
183155.45.128.0/18155.45.128.1 to 155.45.191.254155.45.191.25516,382
184155.45.192.0/18155.45.192.1 to 155.45.255.254155.45.255.25516,382
185155.46.0.0/18155.46.0.1 to 155.46.63.254155.46.63.25516,382
186155.46.64.0/18155.46.64.1 to 155.46.127.254155.46.127.25516,382
187155.46.128.0/18155.46.128.1 to 155.46.191.254155.46.191.25516,382
188155.46.192.0/18155.46.192.1 to 155.46.255.254155.46.255.25516,382
189155.47.0.0/18155.47.0.1 to 155.47.63.254155.47.63.25516,382
190155.47.64.0/18155.47.64.1 to 155.47.127.254155.47.127.25516,382
191155.47.128.0/18155.47.128.1 to 155.47.191.254155.47.191.25516,382
192155.47.192.0/18155.47.192.1 to 155.47.255.254155.47.255.25516,382
193155.48.0.0/18155.48.0.1 to 155.48.63.254155.48.63.25516,382
194155.48.64.0/18155.48.64.1 to 155.48.127.254155.48.127.25516,382
195155.48.128.0/18155.48.128.1 to 155.48.191.254155.48.191.25516,382
196155.48.192.0/18155.48.192.1 to 155.48.255.254155.48.255.25516,382
197155.49.0.0/18155.49.0.1 to 155.49.63.254155.49.63.25516,382
198155.49.64.0/18155.49.64.1 to 155.49.127.254155.49.127.25516,382
199155.49.128.0/18155.49.128.1 to 155.49.191.254155.49.191.25516,382
200155.49.192.0/18155.49.192.1 to 155.49.255.254155.49.255.25516,382
201155.50.0.0/18155.50.0.1 to 155.50.63.254155.50.63.25516,382
202155.50.64.0/18155.50.64.1 to 155.50.127.254155.50.127.25516,382
203155.50.128.0/18155.50.128.1 to 155.50.191.254155.50.191.25516,382
204155.50.192.0/18155.50.192.1 to 155.50.255.254155.50.255.25516,382
205155.51.0.0/18155.51.0.1 to 155.51.63.254155.51.63.25516,382
206155.51.64.0/18155.51.64.1 to 155.51.127.254155.51.127.25516,382
207155.51.128.0/18155.51.128.1 to 155.51.191.254155.51.191.25516,382
208155.51.192.0/18155.51.192.1 to 155.51.255.254155.51.255.25516,382
209155.52.0.0/18155.52.0.1 to 155.52.63.254155.52.63.25516,382
210155.52.64.0/18155.52.64.1 to 155.52.127.254155.52.127.25516,382
211155.52.128.0/18155.52.128.1 to 155.52.191.254155.52.191.25516,382
212155.52.192.0/18155.52.192.1 to 155.52.255.254155.52.255.25516,382
213155.53.0.0/18155.53.0.1 to 155.53.63.254155.53.63.25516,382
214155.53.64.0/18155.53.64.1 to 155.53.127.254155.53.127.25516,382
215155.53.128.0/18155.53.128.1 to 155.53.191.254155.53.191.25516,382
216155.53.192.0/18155.53.192.1 to 155.53.255.254155.53.255.25516,382
217155.54.0.0/18155.54.0.1 to 155.54.63.254155.54.63.25516,382
218155.54.64.0/18155.54.64.1 to 155.54.127.254155.54.127.25516,382
219155.54.128.0/18155.54.128.1 to 155.54.191.254155.54.191.25516,382
220155.54.192.0/18155.54.192.1 to 155.54.255.254155.54.255.25516,382
221155.55.0.0/18155.55.0.1 to 155.55.63.254155.55.63.25516,382
222155.55.64.0/18155.55.64.1 to 155.55.127.254155.55.127.25516,382
223155.55.128.0/18155.55.128.1 to 155.55.191.254155.55.191.25516,382
224155.55.192.0/18155.55.192.1 to 155.55.255.254155.55.255.25516,382
225155.56.0.0/18155.56.0.1 to 155.56.63.254155.56.63.25516,382
226155.56.64.0/18155.56.64.1 to 155.56.127.254155.56.127.25516,382
227155.56.128.0/18155.56.128.1 to 155.56.191.254155.56.191.25516,382
228155.56.192.0/18155.56.192.1 to 155.56.255.254155.56.255.25516,382
229155.57.0.0/18155.57.0.1 to 155.57.63.254155.57.63.25516,382
230155.57.64.0/18155.57.64.1 to 155.57.127.254155.57.127.25516,382
231155.57.128.0/18155.57.128.1 to 155.57.191.254155.57.191.25516,382
232155.57.192.0/18155.57.192.1 to 155.57.255.254155.57.255.25516,382
233155.58.0.0/18155.58.0.1 to 155.58.63.254155.58.63.25516,382
234155.58.64.0/18155.58.64.1 to 155.58.127.254155.58.127.25516,382
235155.58.128.0/18155.58.128.1 to 155.58.191.254155.58.191.25516,382
236155.58.192.0/18155.58.192.1 to 155.58.255.254155.58.255.25516,382
237155.59.0.0/18155.59.0.1 to 155.59.63.254155.59.63.25516,382
238155.59.64.0/18155.59.64.1 to 155.59.127.254155.59.127.25516,382
239155.59.128.0/18155.59.128.1 to 155.59.191.254155.59.191.25516,382
240155.59.192.0/18155.59.192.1 to 155.59.255.254155.59.255.25516,382
241155.60.0.0/18155.60.0.1 to 155.60.63.254155.60.63.25516,382
242155.60.64.0/18155.60.64.1 to 155.60.127.254155.60.127.25516,382
243155.60.128.0/18155.60.128.1 to 155.60.191.254155.60.191.25516,382
244155.60.192.0/18155.60.192.1 to 155.60.255.254155.60.255.25516,382
245155.61.0.0/18155.61.0.1 to 155.61.63.254155.61.63.25516,382
246155.61.64.0/18155.61.64.1 to 155.61.127.254155.61.127.25516,382
247155.61.128.0/18155.61.128.1 to 155.61.191.254155.61.191.25516,382
248155.61.192.0/18155.61.192.1 to 155.61.255.254155.61.255.25516,382
249155.62.0.0/18155.62.0.1 to 155.62.63.254155.62.63.25516,382
250155.62.64.0/18155.62.64.1 to 155.62.127.254155.62.127.25516,382
251155.62.128.0/18155.62.128.1 to 155.62.191.254155.62.191.25516,382
252155.62.192.0/18155.62.192.1 to 155.62.255.254155.62.255.25516,382
253155.63.0.0/18155.63.0.1 to 155.63.63.254155.63.63.25516,382
254155.63.64.0/18155.63.64.1 to 155.63.127.254155.63.127.25516,382
255155.63.128.0/18155.63.128.1 to 155.63.191.254155.63.191.25516,382
256155.63.192.0/18155.63.192.1 to 155.63.255.254155.63.255.25516,382

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.