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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.

Network252.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
252.0.0.0
Broadcast address
253.255.255.255
First usable
252.0.0.1
Last usable
253.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex FC000000 · Integer 4227858432 to 4261412863
Reverse DNS zones
252.in-addr.arpa
253.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11111100.00000000.00000000.00000000252.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network11111100.00000000.00000000.00000000252.0.0.0
Broadcast11111101.11111111.11111111.11111111253.255.255.255
Split into smaller subnets/18
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

252.0.0.0/7 makes 2,048 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1252.0.0.0/18252.0.0.1 to 252.0.63.254252.0.63.25516,382
2252.0.64.0/18252.0.64.1 to 252.0.127.254252.0.127.25516,382
3252.0.128.0/18252.0.128.1 to 252.0.191.254252.0.191.25516,382
4252.0.192.0/18252.0.192.1 to 252.0.255.254252.0.255.25516,382
5252.1.0.0/18252.1.0.1 to 252.1.63.254252.1.63.25516,382
6252.1.64.0/18252.1.64.1 to 252.1.127.254252.1.127.25516,382
7252.1.128.0/18252.1.128.1 to 252.1.191.254252.1.191.25516,382
8252.1.192.0/18252.1.192.1 to 252.1.255.254252.1.255.25516,382
9252.2.0.0/18252.2.0.1 to 252.2.63.254252.2.63.25516,382
10252.2.64.0/18252.2.64.1 to 252.2.127.254252.2.127.25516,382
11252.2.128.0/18252.2.128.1 to 252.2.191.254252.2.191.25516,382
12252.2.192.0/18252.2.192.1 to 252.2.255.254252.2.255.25516,382
13252.3.0.0/18252.3.0.1 to 252.3.63.254252.3.63.25516,382
14252.3.64.0/18252.3.64.1 to 252.3.127.254252.3.127.25516,382
15252.3.128.0/18252.3.128.1 to 252.3.191.254252.3.191.25516,382
16252.3.192.0/18252.3.192.1 to 252.3.255.254252.3.255.25516,382
17252.4.0.0/18252.4.0.1 to 252.4.63.254252.4.63.25516,382
18252.4.64.0/18252.4.64.1 to 252.4.127.254252.4.127.25516,382
19252.4.128.0/18252.4.128.1 to 252.4.191.254252.4.191.25516,382
20252.4.192.0/18252.4.192.1 to 252.4.255.254252.4.255.25516,382
21252.5.0.0/18252.5.0.1 to 252.5.63.254252.5.63.25516,382
22252.5.64.0/18252.5.64.1 to 252.5.127.254252.5.127.25516,382
23252.5.128.0/18252.5.128.1 to 252.5.191.254252.5.191.25516,382
24252.5.192.0/18252.5.192.1 to 252.5.255.254252.5.255.25516,382
25252.6.0.0/18252.6.0.1 to 252.6.63.254252.6.63.25516,382
26252.6.64.0/18252.6.64.1 to 252.6.127.254252.6.127.25516,382
27252.6.128.0/18252.6.128.1 to 252.6.191.254252.6.191.25516,382
28252.6.192.0/18252.6.192.1 to 252.6.255.254252.6.255.25516,382
29252.7.0.0/18252.7.0.1 to 252.7.63.254252.7.63.25516,382
30252.7.64.0/18252.7.64.1 to 252.7.127.254252.7.127.25516,382
31252.7.128.0/18252.7.128.1 to 252.7.191.254252.7.191.25516,382
32252.7.192.0/18252.7.192.1 to 252.7.255.254252.7.255.25516,382
33252.8.0.0/18252.8.0.1 to 252.8.63.254252.8.63.25516,382
34252.8.64.0/18252.8.64.1 to 252.8.127.254252.8.127.25516,382
35252.8.128.0/18252.8.128.1 to 252.8.191.254252.8.191.25516,382
36252.8.192.0/18252.8.192.1 to 252.8.255.254252.8.255.25516,382
37252.9.0.0/18252.9.0.1 to 252.9.63.254252.9.63.25516,382
38252.9.64.0/18252.9.64.1 to 252.9.127.254252.9.127.25516,382
39252.9.128.0/18252.9.128.1 to 252.9.191.254252.9.191.25516,382
40252.9.192.0/18252.9.192.1 to 252.9.255.254252.9.255.25516,382
41252.10.0.0/18252.10.0.1 to 252.10.63.254252.10.63.25516,382
42252.10.64.0/18252.10.64.1 to 252.10.127.254252.10.127.25516,382
43252.10.128.0/18252.10.128.1 to 252.10.191.254252.10.191.25516,382
44252.10.192.0/18252.10.192.1 to 252.10.255.254252.10.255.25516,382
45252.11.0.0/18252.11.0.1 to 252.11.63.254252.11.63.25516,382
46252.11.64.0/18252.11.64.1 to 252.11.127.254252.11.127.25516,382
47252.11.128.0/18252.11.128.1 to 252.11.191.254252.11.191.25516,382
48252.11.192.0/18252.11.192.1 to 252.11.255.254252.11.255.25516,382
49252.12.0.0/18252.12.0.1 to 252.12.63.254252.12.63.25516,382
50252.12.64.0/18252.12.64.1 to 252.12.127.254252.12.127.25516,382
51252.12.128.0/18252.12.128.1 to 252.12.191.254252.12.191.25516,382
52252.12.192.0/18252.12.192.1 to 252.12.255.254252.12.255.25516,382
53252.13.0.0/18252.13.0.1 to 252.13.63.254252.13.63.25516,382
54252.13.64.0/18252.13.64.1 to 252.13.127.254252.13.127.25516,382
55252.13.128.0/18252.13.128.1 to 252.13.191.254252.13.191.25516,382
56252.13.192.0/18252.13.192.1 to 252.13.255.254252.13.255.25516,382
57252.14.0.0/18252.14.0.1 to 252.14.63.254252.14.63.25516,382
58252.14.64.0/18252.14.64.1 to 252.14.127.254252.14.127.25516,382
59252.14.128.0/18252.14.128.1 to 252.14.191.254252.14.191.25516,382
60252.14.192.0/18252.14.192.1 to 252.14.255.254252.14.255.25516,382
61252.15.0.0/18252.15.0.1 to 252.15.63.254252.15.63.25516,382
62252.15.64.0/18252.15.64.1 to 252.15.127.254252.15.127.25516,382
63252.15.128.0/18252.15.128.1 to 252.15.191.254252.15.191.25516,382
64252.15.192.0/18252.15.192.1 to 252.15.255.254252.15.255.25516,382
65252.16.0.0/18252.16.0.1 to 252.16.63.254252.16.63.25516,382
66252.16.64.0/18252.16.64.1 to 252.16.127.254252.16.127.25516,382
67252.16.128.0/18252.16.128.1 to 252.16.191.254252.16.191.25516,382
68252.16.192.0/18252.16.192.1 to 252.16.255.254252.16.255.25516,382
69252.17.0.0/18252.17.0.1 to 252.17.63.254252.17.63.25516,382
70252.17.64.0/18252.17.64.1 to 252.17.127.254252.17.127.25516,382
71252.17.128.0/18252.17.128.1 to 252.17.191.254252.17.191.25516,382
72252.17.192.0/18252.17.192.1 to 252.17.255.254252.17.255.25516,382
73252.18.0.0/18252.18.0.1 to 252.18.63.254252.18.63.25516,382
74252.18.64.0/18252.18.64.1 to 252.18.127.254252.18.127.25516,382
75252.18.128.0/18252.18.128.1 to 252.18.191.254252.18.191.25516,382
76252.18.192.0/18252.18.192.1 to 252.18.255.254252.18.255.25516,382
77252.19.0.0/18252.19.0.1 to 252.19.63.254252.19.63.25516,382
78252.19.64.0/18252.19.64.1 to 252.19.127.254252.19.127.25516,382
79252.19.128.0/18252.19.128.1 to 252.19.191.254252.19.191.25516,382
80252.19.192.0/18252.19.192.1 to 252.19.255.254252.19.255.25516,382
81252.20.0.0/18252.20.0.1 to 252.20.63.254252.20.63.25516,382
82252.20.64.0/18252.20.64.1 to 252.20.127.254252.20.127.25516,382
83252.20.128.0/18252.20.128.1 to 252.20.191.254252.20.191.25516,382
84252.20.192.0/18252.20.192.1 to 252.20.255.254252.20.255.25516,382
85252.21.0.0/18252.21.0.1 to 252.21.63.254252.21.63.25516,382
86252.21.64.0/18252.21.64.1 to 252.21.127.254252.21.127.25516,382
87252.21.128.0/18252.21.128.1 to 252.21.191.254252.21.191.25516,382
88252.21.192.0/18252.21.192.1 to 252.21.255.254252.21.255.25516,382
89252.22.0.0/18252.22.0.1 to 252.22.63.254252.22.63.25516,382
90252.22.64.0/18252.22.64.1 to 252.22.127.254252.22.127.25516,382
91252.22.128.0/18252.22.128.1 to 252.22.191.254252.22.191.25516,382
92252.22.192.0/18252.22.192.1 to 252.22.255.254252.22.255.25516,382
93252.23.0.0/18252.23.0.1 to 252.23.63.254252.23.63.25516,382
94252.23.64.0/18252.23.64.1 to 252.23.127.254252.23.127.25516,382
95252.23.128.0/18252.23.128.1 to 252.23.191.254252.23.191.25516,382
96252.23.192.0/18252.23.192.1 to 252.23.255.254252.23.255.25516,382
97252.24.0.0/18252.24.0.1 to 252.24.63.254252.24.63.25516,382
98252.24.64.0/18252.24.64.1 to 252.24.127.254252.24.127.25516,382
99252.24.128.0/18252.24.128.1 to 252.24.191.254252.24.191.25516,382
100252.24.192.0/18252.24.192.1 to 252.24.255.254252.24.255.25516,382
101252.25.0.0/18252.25.0.1 to 252.25.63.254252.25.63.25516,382
102252.25.64.0/18252.25.64.1 to 252.25.127.254252.25.127.25516,382
103252.25.128.0/18252.25.128.1 to 252.25.191.254252.25.191.25516,382
104252.25.192.0/18252.25.192.1 to 252.25.255.254252.25.255.25516,382
105252.26.0.0/18252.26.0.1 to 252.26.63.254252.26.63.25516,382
106252.26.64.0/18252.26.64.1 to 252.26.127.254252.26.127.25516,382
107252.26.128.0/18252.26.128.1 to 252.26.191.254252.26.191.25516,382
108252.26.192.0/18252.26.192.1 to 252.26.255.254252.26.255.25516,382
109252.27.0.0/18252.27.0.1 to 252.27.63.254252.27.63.25516,382
110252.27.64.0/18252.27.64.1 to 252.27.127.254252.27.127.25516,382
111252.27.128.0/18252.27.128.1 to 252.27.191.254252.27.191.25516,382
112252.27.192.0/18252.27.192.1 to 252.27.255.254252.27.255.25516,382
113252.28.0.0/18252.28.0.1 to 252.28.63.254252.28.63.25516,382
114252.28.64.0/18252.28.64.1 to 252.28.127.254252.28.127.25516,382
115252.28.128.0/18252.28.128.1 to 252.28.191.254252.28.191.25516,382
116252.28.192.0/18252.28.192.1 to 252.28.255.254252.28.255.25516,382
117252.29.0.0/18252.29.0.1 to 252.29.63.254252.29.63.25516,382
118252.29.64.0/18252.29.64.1 to 252.29.127.254252.29.127.25516,382
119252.29.128.0/18252.29.128.1 to 252.29.191.254252.29.191.25516,382
120252.29.192.0/18252.29.192.1 to 252.29.255.254252.29.255.25516,382
121252.30.0.0/18252.30.0.1 to 252.30.63.254252.30.63.25516,382
122252.30.64.0/18252.30.64.1 to 252.30.127.254252.30.127.25516,382
123252.30.128.0/18252.30.128.1 to 252.30.191.254252.30.191.25516,382
124252.30.192.0/18252.30.192.1 to 252.30.255.254252.30.255.25516,382
125252.31.0.0/18252.31.0.1 to 252.31.63.254252.31.63.25516,382
126252.31.64.0/18252.31.64.1 to 252.31.127.254252.31.127.25516,382
127252.31.128.0/18252.31.128.1 to 252.31.191.254252.31.191.25516,382
128252.31.192.0/18252.31.192.1 to 252.31.255.254252.31.255.25516,382
129252.32.0.0/18252.32.0.1 to 252.32.63.254252.32.63.25516,382
130252.32.64.0/18252.32.64.1 to 252.32.127.254252.32.127.25516,382
131252.32.128.0/18252.32.128.1 to 252.32.191.254252.32.191.25516,382
132252.32.192.0/18252.32.192.1 to 252.32.255.254252.32.255.25516,382
133252.33.0.0/18252.33.0.1 to 252.33.63.254252.33.63.25516,382
134252.33.64.0/18252.33.64.1 to 252.33.127.254252.33.127.25516,382
135252.33.128.0/18252.33.128.1 to 252.33.191.254252.33.191.25516,382
136252.33.192.0/18252.33.192.1 to 252.33.255.254252.33.255.25516,382
137252.34.0.0/18252.34.0.1 to 252.34.63.254252.34.63.25516,382
138252.34.64.0/18252.34.64.1 to 252.34.127.254252.34.127.25516,382
139252.34.128.0/18252.34.128.1 to 252.34.191.254252.34.191.25516,382
140252.34.192.0/18252.34.192.1 to 252.34.255.254252.34.255.25516,382
141252.35.0.0/18252.35.0.1 to 252.35.63.254252.35.63.25516,382
142252.35.64.0/18252.35.64.1 to 252.35.127.254252.35.127.25516,382
143252.35.128.0/18252.35.128.1 to 252.35.191.254252.35.191.25516,382
144252.35.192.0/18252.35.192.1 to 252.35.255.254252.35.255.25516,382
145252.36.0.0/18252.36.0.1 to 252.36.63.254252.36.63.25516,382
146252.36.64.0/18252.36.64.1 to 252.36.127.254252.36.127.25516,382
147252.36.128.0/18252.36.128.1 to 252.36.191.254252.36.191.25516,382
148252.36.192.0/18252.36.192.1 to 252.36.255.254252.36.255.25516,382
149252.37.0.0/18252.37.0.1 to 252.37.63.254252.37.63.25516,382
150252.37.64.0/18252.37.64.1 to 252.37.127.254252.37.127.25516,382
151252.37.128.0/18252.37.128.1 to 252.37.191.254252.37.191.25516,382
152252.37.192.0/18252.37.192.1 to 252.37.255.254252.37.255.25516,382
153252.38.0.0/18252.38.0.1 to 252.38.63.254252.38.63.25516,382
154252.38.64.0/18252.38.64.1 to 252.38.127.254252.38.127.25516,382
155252.38.128.0/18252.38.128.1 to 252.38.191.254252.38.191.25516,382
156252.38.192.0/18252.38.192.1 to 252.38.255.254252.38.255.25516,382
157252.39.0.0/18252.39.0.1 to 252.39.63.254252.39.63.25516,382
158252.39.64.0/18252.39.64.1 to 252.39.127.254252.39.127.25516,382
159252.39.128.0/18252.39.128.1 to 252.39.191.254252.39.191.25516,382
160252.39.192.0/18252.39.192.1 to 252.39.255.254252.39.255.25516,382
161252.40.0.0/18252.40.0.1 to 252.40.63.254252.40.63.25516,382
162252.40.64.0/18252.40.64.1 to 252.40.127.254252.40.127.25516,382
163252.40.128.0/18252.40.128.1 to 252.40.191.254252.40.191.25516,382
164252.40.192.0/18252.40.192.1 to 252.40.255.254252.40.255.25516,382
165252.41.0.0/18252.41.0.1 to 252.41.63.254252.41.63.25516,382
166252.41.64.0/18252.41.64.1 to 252.41.127.254252.41.127.25516,382
167252.41.128.0/18252.41.128.1 to 252.41.191.254252.41.191.25516,382
168252.41.192.0/18252.41.192.1 to 252.41.255.254252.41.255.25516,382
169252.42.0.0/18252.42.0.1 to 252.42.63.254252.42.63.25516,382
170252.42.64.0/18252.42.64.1 to 252.42.127.254252.42.127.25516,382
171252.42.128.0/18252.42.128.1 to 252.42.191.254252.42.191.25516,382
172252.42.192.0/18252.42.192.1 to 252.42.255.254252.42.255.25516,382
173252.43.0.0/18252.43.0.1 to 252.43.63.254252.43.63.25516,382
174252.43.64.0/18252.43.64.1 to 252.43.127.254252.43.127.25516,382
175252.43.128.0/18252.43.128.1 to 252.43.191.254252.43.191.25516,382
176252.43.192.0/18252.43.192.1 to 252.43.255.254252.43.255.25516,382
177252.44.0.0/18252.44.0.1 to 252.44.63.254252.44.63.25516,382
178252.44.64.0/18252.44.64.1 to 252.44.127.254252.44.127.25516,382
179252.44.128.0/18252.44.128.1 to 252.44.191.254252.44.191.25516,382
180252.44.192.0/18252.44.192.1 to 252.44.255.254252.44.255.25516,382
181252.45.0.0/18252.45.0.1 to 252.45.63.254252.45.63.25516,382
182252.45.64.0/18252.45.64.1 to 252.45.127.254252.45.127.25516,382
183252.45.128.0/18252.45.128.1 to 252.45.191.254252.45.191.25516,382
184252.45.192.0/18252.45.192.1 to 252.45.255.254252.45.255.25516,382
185252.46.0.0/18252.46.0.1 to 252.46.63.254252.46.63.25516,382
186252.46.64.0/18252.46.64.1 to 252.46.127.254252.46.127.25516,382
187252.46.128.0/18252.46.128.1 to 252.46.191.254252.46.191.25516,382
188252.46.192.0/18252.46.192.1 to 252.46.255.254252.46.255.25516,382
189252.47.0.0/18252.47.0.1 to 252.47.63.254252.47.63.25516,382
190252.47.64.0/18252.47.64.1 to 252.47.127.254252.47.127.25516,382
191252.47.128.0/18252.47.128.1 to 252.47.191.254252.47.191.25516,382
192252.47.192.0/18252.47.192.1 to 252.47.255.254252.47.255.25516,382
193252.48.0.0/18252.48.0.1 to 252.48.63.254252.48.63.25516,382
194252.48.64.0/18252.48.64.1 to 252.48.127.254252.48.127.25516,382
195252.48.128.0/18252.48.128.1 to 252.48.191.254252.48.191.25516,382
196252.48.192.0/18252.48.192.1 to 252.48.255.254252.48.255.25516,382
197252.49.0.0/18252.49.0.1 to 252.49.63.254252.49.63.25516,382
198252.49.64.0/18252.49.64.1 to 252.49.127.254252.49.127.25516,382
199252.49.128.0/18252.49.128.1 to 252.49.191.254252.49.191.25516,382
200252.49.192.0/18252.49.192.1 to 252.49.255.254252.49.255.25516,382
201252.50.0.0/18252.50.0.1 to 252.50.63.254252.50.63.25516,382
202252.50.64.0/18252.50.64.1 to 252.50.127.254252.50.127.25516,382
203252.50.128.0/18252.50.128.1 to 252.50.191.254252.50.191.25516,382
204252.50.192.0/18252.50.192.1 to 252.50.255.254252.50.255.25516,382
205252.51.0.0/18252.51.0.1 to 252.51.63.254252.51.63.25516,382
206252.51.64.0/18252.51.64.1 to 252.51.127.254252.51.127.25516,382
207252.51.128.0/18252.51.128.1 to 252.51.191.254252.51.191.25516,382
208252.51.192.0/18252.51.192.1 to 252.51.255.254252.51.255.25516,382
209252.52.0.0/18252.52.0.1 to 252.52.63.254252.52.63.25516,382
210252.52.64.0/18252.52.64.1 to 252.52.127.254252.52.127.25516,382
211252.52.128.0/18252.52.128.1 to 252.52.191.254252.52.191.25516,382
212252.52.192.0/18252.52.192.1 to 252.52.255.254252.52.255.25516,382
213252.53.0.0/18252.53.0.1 to 252.53.63.254252.53.63.25516,382
214252.53.64.0/18252.53.64.1 to 252.53.127.254252.53.127.25516,382
215252.53.128.0/18252.53.128.1 to 252.53.191.254252.53.191.25516,382
216252.53.192.0/18252.53.192.1 to 252.53.255.254252.53.255.25516,382
217252.54.0.0/18252.54.0.1 to 252.54.63.254252.54.63.25516,382
218252.54.64.0/18252.54.64.1 to 252.54.127.254252.54.127.25516,382
219252.54.128.0/18252.54.128.1 to 252.54.191.254252.54.191.25516,382
220252.54.192.0/18252.54.192.1 to 252.54.255.254252.54.255.25516,382
221252.55.0.0/18252.55.0.1 to 252.55.63.254252.55.63.25516,382
222252.55.64.0/18252.55.64.1 to 252.55.127.254252.55.127.25516,382
223252.55.128.0/18252.55.128.1 to 252.55.191.254252.55.191.25516,382
224252.55.192.0/18252.55.192.1 to 252.55.255.254252.55.255.25516,382
225252.56.0.0/18252.56.0.1 to 252.56.63.254252.56.63.25516,382
226252.56.64.0/18252.56.64.1 to 252.56.127.254252.56.127.25516,382
227252.56.128.0/18252.56.128.1 to 252.56.191.254252.56.191.25516,382
228252.56.192.0/18252.56.192.1 to 252.56.255.254252.56.255.25516,382
229252.57.0.0/18252.57.0.1 to 252.57.63.254252.57.63.25516,382
230252.57.64.0/18252.57.64.1 to 252.57.127.254252.57.127.25516,382
231252.57.128.0/18252.57.128.1 to 252.57.191.254252.57.191.25516,382
232252.57.192.0/18252.57.192.1 to 252.57.255.254252.57.255.25516,382
233252.58.0.0/18252.58.0.1 to 252.58.63.254252.58.63.25516,382
234252.58.64.0/18252.58.64.1 to 252.58.127.254252.58.127.25516,382
235252.58.128.0/18252.58.128.1 to 252.58.191.254252.58.191.25516,382
236252.58.192.0/18252.58.192.1 to 252.58.255.254252.58.255.25516,382
237252.59.0.0/18252.59.0.1 to 252.59.63.254252.59.63.25516,382
238252.59.64.0/18252.59.64.1 to 252.59.127.254252.59.127.25516,382
239252.59.128.0/18252.59.128.1 to 252.59.191.254252.59.191.25516,382
240252.59.192.0/18252.59.192.1 to 252.59.255.254252.59.255.25516,382
241252.60.0.0/18252.60.0.1 to 252.60.63.254252.60.63.25516,382
242252.60.64.0/18252.60.64.1 to 252.60.127.254252.60.127.25516,382
243252.60.128.0/18252.60.128.1 to 252.60.191.254252.60.191.25516,382
244252.60.192.0/18252.60.192.1 to 252.60.255.254252.60.255.25516,382
245252.61.0.0/18252.61.0.1 to 252.61.63.254252.61.63.25516,382
246252.61.64.0/18252.61.64.1 to 252.61.127.254252.61.127.25516,382
247252.61.128.0/18252.61.128.1 to 252.61.191.254252.61.191.25516,382
248252.61.192.0/18252.61.192.1 to 252.61.255.254252.61.255.25516,382
249252.62.0.0/18252.62.0.1 to 252.62.63.254252.62.63.25516,382
250252.62.64.0/18252.62.64.1 to 252.62.127.254252.62.127.25516,382
251252.62.128.0/18252.62.128.1 to 252.62.191.254252.62.191.25516,382
252252.62.192.0/18252.62.192.1 to 252.62.255.254252.62.255.25516,382
253252.63.0.0/18252.63.0.1 to 252.63.63.254252.63.63.25516,382
254252.63.64.0/18252.63.64.1 to 252.63.127.254252.63.127.25516,382
255252.63.128.0/18252.63.128.1 to 252.63.191.254252.63.191.25516,382
256252.63.192.0/18252.63.192.1 to 252.63.255.254252.63.255.25516,382

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.