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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.

Network152.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
152.0.0.0
Broadcast address
155.255.255.255
First usable
152.0.0.1
Last usable
155.255.255.254
Usable hosts
67,108,862 (67,108,864 less the network and broadcast addresses)
Subnet mask
252.0.0.0
Wildcard mask
3.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/6
Type
Public public
Old class
B (default /16)
As numbers
Hex 98000000 · Integer 2550136832 to 2617245695
Reverse DNS zones
152.in-addr.arpa
153.in-addr.arpa
154.in-addr.arpa
155.in-addr.arpa
/6 is not on a 8-bit boundary, so it takes 4 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011000.00000000.00000000.00000000152.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network10011000.00000000.00000000.00000000152.0.0.0
Broadcast10011011.11111111.11111111.11111111155.255.255.255
Split into smaller subnets/18
/7 (2)/8 (4)/9 (8)/10 (16)/11 (32)/12 (64)/13 (128)/14 (256)/15 (512)/16 (1,024)/17 (2,048)/18 (4,096)

152.0.0.0/6 makes 4,096 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1152.0.0.0/18152.0.0.1 to 152.0.63.254152.0.63.25516,382
2152.0.64.0/18152.0.64.1 to 152.0.127.254152.0.127.25516,382
3152.0.128.0/18152.0.128.1 to 152.0.191.254152.0.191.25516,382
4152.0.192.0/18152.0.192.1 to 152.0.255.254152.0.255.25516,382
5152.1.0.0/18152.1.0.1 to 152.1.63.254152.1.63.25516,382
6152.1.64.0/18152.1.64.1 to 152.1.127.254152.1.127.25516,382
7152.1.128.0/18152.1.128.1 to 152.1.191.254152.1.191.25516,382
8152.1.192.0/18152.1.192.1 to 152.1.255.254152.1.255.25516,382
9152.2.0.0/18152.2.0.1 to 152.2.63.254152.2.63.25516,382
10152.2.64.0/18152.2.64.1 to 152.2.127.254152.2.127.25516,382
11152.2.128.0/18152.2.128.1 to 152.2.191.254152.2.191.25516,382
12152.2.192.0/18152.2.192.1 to 152.2.255.254152.2.255.25516,382
13152.3.0.0/18152.3.0.1 to 152.3.63.254152.3.63.25516,382
14152.3.64.0/18152.3.64.1 to 152.3.127.254152.3.127.25516,382
15152.3.128.0/18152.3.128.1 to 152.3.191.254152.3.191.25516,382
16152.3.192.0/18152.3.192.1 to 152.3.255.254152.3.255.25516,382
17152.4.0.0/18152.4.0.1 to 152.4.63.254152.4.63.25516,382
18152.4.64.0/18152.4.64.1 to 152.4.127.254152.4.127.25516,382
19152.4.128.0/18152.4.128.1 to 152.4.191.254152.4.191.25516,382
20152.4.192.0/18152.4.192.1 to 152.4.255.254152.4.255.25516,382
21152.5.0.0/18152.5.0.1 to 152.5.63.254152.5.63.25516,382
22152.5.64.0/18152.5.64.1 to 152.5.127.254152.5.127.25516,382
23152.5.128.0/18152.5.128.1 to 152.5.191.254152.5.191.25516,382
24152.5.192.0/18152.5.192.1 to 152.5.255.254152.5.255.25516,382
25152.6.0.0/18152.6.0.1 to 152.6.63.254152.6.63.25516,382
26152.6.64.0/18152.6.64.1 to 152.6.127.254152.6.127.25516,382
27152.6.128.0/18152.6.128.1 to 152.6.191.254152.6.191.25516,382
28152.6.192.0/18152.6.192.1 to 152.6.255.254152.6.255.25516,382
29152.7.0.0/18152.7.0.1 to 152.7.63.254152.7.63.25516,382
30152.7.64.0/18152.7.64.1 to 152.7.127.254152.7.127.25516,382
31152.7.128.0/18152.7.128.1 to 152.7.191.254152.7.191.25516,382
32152.7.192.0/18152.7.192.1 to 152.7.255.254152.7.255.25516,382
33152.8.0.0/18152.8.0.1 to 152.8.63.254152.8.63.25516,382
34152.8.64.0/18152.8.64.1 to 152.8.127.254152.8.127.25516,382
35152.8.128.0/18152.8.128.1 to 152.8.191.254152.8.191.25516,382
36152.8.192.0/18152.8.192.1 to 152.8.255.254152.8.255.25516,382
37152.9.0.0/18152.9.0.1 to 152.9.63.254152.9.63.25516,382
38152.9.64.0/18152.9.64.1 to 152.9.127.254152.9.127.25516,382
39152.9.128.0/18152.9.128.1 to 152.9.191.254152.9.191.25516,382
40152.9.192.0/18152.9.192.1 to 152.9.255.254152.9.255.25516,382
41152.10.0.0/18152.10.0.1 to 152.10.63.254152.10.63.25516,382
42152.10.64.0/18152.10.64.1 to 152.10.127.254152.10.127.25516,382
43152.10.128.0/18152.10.128.1 to 152.10.191.254152.10.191.25516,382
44152.10.192.0/18152.10.192.1 to 152.10.255.254152.10.255.25516,382
45152.11.0.0/18152.11.0.1 to 152.11.63.254152.11.63.25516,382
46152.11.64.0/18152.11.64.1 to 152.11.127.254152.11.127.25516,382
47152.11.128.0/18152.11.128.1 to 152.11.191.254152.11.191.25516,382
48152.11.192.0/18152.11.192.1 to 152.11.255.254152.11.255.25516,382
49152.12.0.0/18152.12.0.1 to 152.12.63.254152.12.63.25516,382
50152.12.64.0/18152.12.64.1 to 152.12.127.254152.12.127.25516,382
51152.12.128.0/18152.12.128.1 to 152.12.191.254152.12.191.25516,382
52152.12.192.0/18152.12.192.1 to 152.12.255.254152.12.255.25516,382
53152.13.0.0/18152.13.0.1 to 152.13.63.254152.13.63.25516,382
54152.13.64.0/18152.13.64.1 to 152.13.127.254152.13.127.25516,382
55152.13.128.0/18152.13.128.1 to 152.13.191.254152.13.191.25516,382
56152.13.192.0/18152.13.192.1 to 152.13.255.254152.13.255.25516,382
57152.14.0.0/18152.14.0.1 to 152.14.63.254152.14.63.25516,382
58152.14.64.0/18152.14.64.1 to 152.14.127.254152.14.127.25516,382
59152.14.128.0/18152.14.128.1 to 152.14.191.254152.14.191.25516,382
60152.14.192.0/18152.14.192.1 to 152.14.255.254152.14.255.25516,382
61152.15.0.0/18152.15.0.1 to 152.15.63.254152.15.63.25516,382
62152.15.64.0/18152.15.64.1 to 152.15.127.254152.15.127.25516,382
63152.15.128.0/18152.15.128.1 to 152.15.191.254152.15.191.25516,382
64152.15.192.0/18152.15.192.1 to 152.15.255.254152.15.255.25516,382
65152.16.0.0/18152.16.0.1 to 152.16.63.254152.16.63.25516,382
66152.16.64.0/18152.16.64.1 to 152.16.127.254152.16.127.25516,382
67152.16.128.0/18152.16.128.1 to 152.16.191.254152.16.191.25516,382
68152.16.192.0/18152.16.192.1 to 152.16.255.254152.16.255.25516,382
69152.17.0.0/18152.17.0.1 to 152.17.63.254152.17.63.25516,382
70152.17.64.0/18152.17.64.1 to 152.17.127.254152.17.127.25516,382
71152.17.128.0/18152.17.128.1 to 152.17.191.254152.17.191.25516,382
72152.17.192.0/18152.17.192.1 to 152.17.255.254152.17.255.25516,382
73152.18.0.0/18152.18.0.1 to 152.18.63.254152.18.63.25516,382
74152.18.64.0/18152.18.64.1 to 152.18.127.254152.18.127.25516,382
75152.18.128.0/18152.18.128.1 to 152.18.191.254152.18.191.25516,382
76152.18.192.0/18152.18.192.1 to 152.18.255.254152.18.255.25516,382
77152.19.0.0/18152.19.0.1 to 152.19.63.254152.19.63.25516,382
78152.19.64.0/18152.19.64.1 to 152.19.127.254152.19.127.25516,382
79152.19.128.0/18152.19.128.1 to 152.19.191.254152.19.191.25516,382
80152.19.192.0/18152.19.192.1 to 152.19.255.254152.19.255.25516,382
81152.20.0.0/18152.20.0.1 to 152.20.63.254152.20.63.25516,382
82152.20.64.0/18152.20.64.1 to 152.20.127.254152.20.127.25516,382
83152.20.128.0/18152.20.128.1 to 152.20.191.254152.20.191.25516,382
84152.20.192.0/18152.20.192.1 to 152.20.255.254152.20.255.25516,382
85152.21.0.0/18152.21.0.1 to 152.21.63.254152.21.63.25516,382
86152.21.64.0/18152.21.64.1 to 152.21.127.254152.21.127.25516,382
87152.21.128.0/18152.21.128.1 to 152.21.191.254152.21.191.25516,382
88152.21.192.0/18152.21.192.1 to 152.21.255.254152.21.255.25516,382
89152.22.0.0/18152.22.0.1 to 152.22.63.254152.22.63.25516,382
90152.22.64.0/18152.22.64.1 to 152.22.127.254152.22.127.25516,382
91152.22.128.0/18152.22.128.1 to 152.22.191.254152.22.191.25516,382
92152.22.192.0/18152.22.192.1 to 152.22.255.254152.22.255.25516,382
93152.23.0.0/18152.23.0.1 to 152.23.63.254152.23.63.25516,382
94152.23.64.0/18152.23.64.1 to 152.23.127.254152.23.127.25516,382
95152.23.128.0/18152.23.128.1 to 152.23.191.254152.23.191.25516,382
96152.23.192.0/18152.23.192.1 to 152.23.255.254152.23.255.25516,382
97152.24.0.0/18152.24.0.1 to 152.24.63.254152.24.63.25516,382
98152.24.64.0/18152.24.64.1 to 152.24.127.254152.24.127.25516,382
99152.24.128.0/18152.24.128.1 to 152.24.191.254152.24.191.25516,382
100152.24.192.0/18152.24.192.1 to 152.24.255.254152.24.255.25516,382
101152.25.0.0/18152.25.0.1 to 152.25.63.254152.25.63.25516,382
102152.25.64.0/18152.25.64.1 to 152.25.127.254152.25.127.25516,382
103152.25.128.0/18152.25.128.1 to 152.25.191.254152.25.191.25516,382
104152.25.192.0/18152.25.192.1 to 152.25.255.254152.25.255.25516,382
105152.26.0.0/18152.26.0.1 to 152.26.63.254152.26.63.25516,382
106152.26.64.0/18152.26.64.1 to 152.26.127.254152.26.127.25516,382
107152.26.128.0/18152.26.128.1 to 152.26.191.254152.26.191.25516,382
108152.26.192.0/18152.26.192.1 to 152.26.255.254152.26.255.25516,382
109152.27.0.0/18152.27.0.1 to 152.27.63.254152.27.63.25516,382
110152.27.64.0/18152.27.64.1 to 152.27.127.254152.27.127.25516,382
111152.27.128.0/18152.27.128.1 to 152.27.191.254152.27.191.25516,382
112152.27.192.0/18152.27.192.1 to 152.27.255.254152.27.255.25516,382
113152.28.0.0/18152.28.0.1 to 152.28.63.254152.28.63.25516,382
114152.28.64.0/18152.28.64.1 to 152.28.127.254152.28.127.25516,382
115152.28.128.0/18152.28.128.1 to 152.28.191.254152.28.191.25516,382
116152.28.192.0/18152.28.192.1 to 152.28.255.254152.28.255.25516,382
117152.29.0.0/18152.29.0.1 to 152.29.63.254152.29.63.25516,382
118152.29.64.0/18152.29.64.1 to 152.29.127.254152.29.127.25516,382
119152.29.128.0/18152.29.128.1 to 152.29.191.254152.29.191.25516,382
120152.29.192.0/18152.29.192.1 to 152.29.255.254152.29.255.25516,382
121152.30.0.0/18152.30.0.1 to 152.30.63.254152.30.63.25516,382
122152.30.64.0/18152.30.64.1 to 152.30.127.254152.30.127.25516,382
123152.30.128.0/18152.30.128.1 to 152.30.191.254152.30.191.25516,382
124152.30.192.0/18152.30.192.1 to 152.30.255.254152.30.255.25516,382
125152.31.0.0/18152.31.0.1 to 152.31.63.254152.31.63.25516,382
126152.31.64.0/18152.31.64.1 to 152.31.127.254152.31.127.25516,382
127152.31.128.0/18152.31.128.1 to 152.31.191.254152.31.191.25516,382
128152.31.192.0/18152.31.192.1 to 152.31.255.254152.31.255.25516,382
129152.32.0.0/18152.32.0.1 to 152.32.63.254152.32.63.25516,382
130152.32.64.0/18152.32.64.1 to 152.32.127.254152.32.127.25516,382
131152.32.128.0/18152.32.128.1 to 152.32.191.254152.32.191.25516,382
132152.32.192.0/18152.32.192.1 to 152.32.255.254152.32.255.25516,382
133152.33.0.0/18152.33.0.1 to 152.33.63.254152.33.63.25516,382
134152.33.64.0/18152.33.64.1 to 152.33.127.254152.33.127.25516,382
135152.33.128.0/18152.33.128.1 to 152.33.191.254152.33.191.25516,382
136152.33.192.0/18152.33.192.1 to 152.33.255.254152.33.255.25516,382
137152.34.0.0/18152.34.0.1 to 152.34.63.254152.34.63.25516,382
138152.34.64.0/18152.34.64.1 to 152.34.127.254152.34.127.25516,382
139152.34.128.0/18152.34.128.1 to 152.34.191.254152.34.191.25516,382
140152.34.192.0/18152.34.192.1 to 152.34.255.254152.34.255.25516,382
141152.35.0.0/18152.35.0.1 to 152.35.63.254152.35.63.25516,382
142152.35.64.0/18152.35.64.1 to 152.35.127.254152.35.127.25516,382
143152.35.128.0/18152.35.128.1 to 152.35.191.254152.35.191.25516,382
144152.35.192.0/18152.35.192.1 to 152.35.255.254152.35.255.25516,382
145152.36.0.0/18152.36.0.1 to 152.36.63.254152.36.63.25516,382
146152.36.64.0/18152.36.64.1 to 152.36.127.254152.36.127.25516,382
147152.36.128.0/18152.36.128.1 to 152.36.191.254152.36.191.25516,382
148152.36.192.0/18152.36.192.1 to 152.36.255.254152.36.255.25516,382
149152.37.0.0/18152.37.0.1 to 152.37.63.254152.37.63.25516,382
150152.37.64.0/18152.37.64.1 to 152.37.127.254152.37.127.25516,382
151152.37.128.0/18152.37.128.1 to 152.37.191.254152.37.191.25516,382
152152.37.192.0/18152.37.192.1 to 152.37.255.254152.37.255.25516,382
153152.38.0.0/18152.38.0.1 to 152.38.63.254152.38.63.25516,382
154152.38.64.0/18152.38.64.1 to 152.38.127.254152.38.127.25516,382
155152.38.128.0/18152.38.128.1 to 152.38.191.254152.38.191.25516,382
156152.38.192.0/18152.38.192.1 to 152.38.255.254152.38.255.25516,382
157152.39.0.0/18152.39.0.1 to 152.39.63.254152.39.63.25516,382
158152.39.64.0/18152.39.64.1 to 152.39.127.254152.39.127.25516,382
159152.39.128.0/18152.39.128.1 to 152.39.191.254152.39.191.25516,382
160152.39.192.0/18152.39.192.1 to 152.39.255.254152.39.255.25516,382
161152.40.0.0/18152.40.0.1 to 152.40.63.254152.40.63.25516,382
162152.40.64.0/18152.40.64.1 to 152.40.127.254152.40.127.25516,382
163152.40.128.0/18152.40.128.1 to 152.40.191.254152.40.191.25516,382
164152.40.192.0/18152.40.192.1 to 152.40.255.254152.40.255.25516,382
165152.41.0.0/18152.41.0.1 to 152.41.63.254152.41.63.25516,382
166152.41.64.0/18152.41.64.1 to 152.41.127.254152.41.127.25516,382
167152.41.128.0/18152.41.128.1 to 152.41.191.254152.41.191.25516,382
168152.41.192.0/18152.41.192.1 to 152.41.255.254152.41.255.25516,382
169152.42.0.0/18152.42.0.1 to 152.42.63.254152.42.63.25516,382
170152.42.64.0/18152.42.64.1 to 152.42.127.254152.42.127.25516,382
171152.42.128.0/18152.42.128.1 to 152.42.191.254152.42.191.25516,382
172152.42.192.0/18152.42.192.1 to 152.42.255.254152.42.255.25516,382
173152.43.0.0/18152.43.0.1 to 152.43.63.254152.43.63.25516,382
174152.43.64.0/18152.43.64.1 to 152.43.127.254152.43.127.25516,382
175152.43.128.0/18152.43.128.1 to 152.43.191.254152.43.191.25516,382
176152.43.192.0/18152.43.192.1 to 152.43.255.254152.43.255.25516,382
177152.44.0.0/18152.44.0.1 to 152.44.63.254152.44.63.25516,382
178152.44.64.0/18152.44.64.1 to 152.44.127.254152.44.127.25516,382
179152.44.128.0/18152.44.128.1 to 152.44.191.254152.44.191.25516,382
180152.44.192.0/18152.44.192.1 to 152.44.255.254152.44.255.25516,382
181152.45.0.0/18152.45.0.1 to 152.45.63.254152.45.63.25516,382
182152.45.64.0/18152.45.64.1 to 152.45.127.254152.45.127.25516,382
183152.45.128.0/18152.45.128.1 to 152.45.191.254152.45.191.25516,382
184152.45.192.0/18152.45.192.1 to 152.45.255.254152.45.255.25516,382
185152.46.0.0/18152.46.0.1 to 152.46.63.254152.46.63.25516,382
186152.46.64.0/18152.46.64.1 to 152.46.127.254152.46.127.25516,382
187152.46.128.0/18152.46.128.1 to 152.46.191.254152.46.191.25516,382
188152.46.192.0/18152.46.192.1 to 152.46.255.254152.46.255.25516,382
189152.47.0.0/18152.47.0.1 to 152.47.63.254152.47.63.25516,382
190152.47.64.0/18152.47.64.1 to 152.47.127.254152.47.127.25516,382
191152.47.128.0/18152.47.128.1 to 152.47.191.254152.47.191.25516,382
192152.47.192.0/18152.47.192.1 to 152.47.255.254152.47.255.25516,382
193152.48.0.0/18152.48.0.1 to 152.48.63.254152.48.63.25516,382
194152.48.64.0/18152.48.64.1 to 152.48.127.254152.48.127.25516,382
195152.48.128.0/18152.48.128.1 to 152.48.191.254152.48.191.25516,382
196152.48.192.0/18152.48.192.1 to 152.48.255.254152.48.255.25516,382
197152.49.0.0/18152.49.0.1 to 152.49.63.254152.49.63.25516,382
198152.49.64.0/18152.49.64.1 to 152.49.127.254152.49.127.25516,382
199152.49.128.0/18152.49.128.1 to 152.49.191.254152.49.191.25516,382
200152.49.192.0/18152.49.192.1 to 152.49.255.254152.49.255.25516,382
201152.50.0.0/18152.50.0.1 to 152.50.63.254152.50.63.25516,382
202152.50.64.0/18152.50.64.1 to 152.50.127.254152.50.127.25516,382
203152.50.128.0/18152.50.128.1 to 152.50.191.254152.50.191.25516,382
204152.50.192.0/18152.50.192.1 to 152.50.255.254152.50.255.25516,382
205152.51.0.0/18152.51.0.1 to 152.51.63.254152.51.63.25516,382
206152.51.64.0/18152.51.64.1 to 152.51.127.254152.51.127.25516,382
207152.51.128.0/18152.51.128.1 to 152.51.191.254152.51.191.25516,382
208152.51.192.0/18152.51.192.1 to 152.51.255.254152.51.255.25516,382
209152.52.0.0/18152.52.0.1 to 152.52.63.254152.52.63.25516,382
210152.52.64.0/18152.52.64.1 to 152.52.127.254152.52.127.25516,382
211152.52.128.0/18152.52.128.1 to 152.52.191.254152.52.191.25516,382
212152.52.192.0/18152.52.192.1 to 152.52.255.254152.52.255.25516,382
213152.53.0.0/18152.53.0.1 to 152.53.63.254152.53.63.25516,382
214152.53.64.0/18152.53.64.1 to 152.53.127.254152.53.127.25516,382
215152.53.128.0/18152.53.128.1 to 152.53.191.254152.53.191.25516,382
216152.53.192.0/18152.53.192.1 to 152.53.255.254152.53.255.25516,382
217152.54.0.0/18152.54.0.1 to 152.54.63.254152.54.63.25516,382
218152.54.64.0/18152.54.64.1 to 152.54.127.254152.54.127.25516,382
219152.54.128.0/18152.54.128.1 to 152.54.191.254152.54.191.25516,382
220152.54.192.0/18152.54.192.1 to 152.54.255.254152.54.255.25516,382
221152.55.0.0/18152.55.0.1 to 152.55.63.254152.55.63.25516,382
222152.55.64.0/18152.55.64.1 to 152.55.127.254152.55.127.25516,382
223152.55.128.0/18152.55.128.1 to 152.55.191.254152.55.191.25516,382
224152.55.192.0/18152.55.192.1 to 152.55.255.254152.55.255.25516,382
225152.56.0.0/18152.56.0.1 to 152.56.63.254152.56.63.25516,382
226152.56.64.0/18152.56.64.1 to 152.56.127.254152.56.127.25516,382
227152.56.128.0/18152.56.128.1 to 152.56.191.254152.56.191.25516,382
228152.56.192.0/18152.56.192.1 to 152.56.255.254152.56.255.25516,382
229152.57.0.0/18152.57.0.1 to 152.57.63.254152.57.63.25516,382
230152.57.64.0/18152.57.64.1 to 152.57.127.254152.57.127.25516,382
231152.57.128.0/18152.57.128.1 to 152.57.191.254152.57.191.25516,382
232152.57.192.0/18152.57.192.1 to 152.57.255.254152.57.255.25516,382
233152.58.0.0/18152.58.0.1 to 152.58.63.254152.58.63.25516,382
234152.58.64.0/18152.58.64.1 to 152.58.127.254152.58.127.25516,382
235152.58.128.0/18152.58.128.1 to 152.58.191.254152.58.191.25516,382
236152.58.192.0/18152.58.192.1 to 152.58.255.254152.58.255.25516,382
237152.59.0.0/18152.59.0.1 to 152.59.63.254152.59.63.25516,382
238152.59.64.0/18152.59.64.1 to 152.59.127.254152.59.127.25516,382
239152.59.128.0/18152.59.128.1 to 152.59.191.254152.59.191.25516,382
240152.59.192.0/18152.59.192.1 to 152.59.255.254152.59.255.25516,382
241152.60.0.0/18152.60.0.1 to 152.60.63.254152.60.63.25516,382
242152.60.64.0/18152.60.64.1 to 152.60.127.254152.60.127.25516,382
243152.60.128.0/18152.60.128.1 to 152.60.191.254152.60.191.25516,382
244152.60.192.0/18152.60.192.1 to 152.60.255.254152.60.255.25516,382
245152.61.0.0/18152.61.0.1 to 152.61.63.254152.61.63.25516,382
246152.61.64.0/18152.61.64.1 to 152.61.127.254152.61.127.25516,382
247152.61.128.0/18152.61.128.1 to 152.61.191.254152.61.191.25516,382
248152.61.192.0/18152.61.192.1 to 152.61.255.254152.61.255.25516,382
249152.62.0.0/18152.62.0.1 to 152.62.63.254152.62.63.25516,382
250152.62.64.0/18152.62.64.1 to 152.62.127.254152.62.127.25516,382
251152.62.128.0/18152.62.128.1 to 152.62.191.254152.62.191.25516,382
252152.62.192.0/18152.62.192.1 to 152.62.255.254152.62.255.25516,382
253152.63.0.0/18152.63.0.1 to 152.63.63.254152.63.63.25516,382
254152.63.64.0/18152.63.64.1 to 152.63.127.254152.63.127.25516,382
255152.63.128.0/18152.63.128.1 to 152.63.191.254152.63.191.25516,382
256152.63.192.0/18152.63.192.1 to 152.63.255.254152.63.255.25516,382

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.