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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.

Network132.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
132.0.0.0
Broadcast address
133.255.255.255
First usable
132.0.0.1
Last usable
133.255.255.254
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
Public public
Old class
B (default /16)
As numbers
Hex 84000000 · Integer 2214592512 to 2248146943
Reverse DNS zones
132.in-addr.arpa
133.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
Address10000100.00000000.00000000.00000000132.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network10000100.00000000.00000000.00000000132.0.0.0
Broadcast10000101.11111111.11111111.11111111133.255.255.255
Split into smaller subnets/19
/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)

132.0.0.0/7 makes 4,096 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1132.0.0.0/19132.0.0.1 to 132.0.31.254132.0.31.2558,190
2132.0.32.0/19132.0.32.1 to 132.0.63.254132.0.63.2558,190
3132.0.64.0/19132.0.64.1 to 132.0.95.254132.0.95.2558,190
4132.0.96.0/19132.0.96.1 to 132.0.127.254132.0.127.2558,190
5132.0.128.0/19132.0.128.1 to 132.0.159.254132.0.159.2558,190
6132.0.160.0/19132.0.160.1 to 132.0.191.254132.0.191.2558,190
7132.0.192.0/19132.0.192.1 to 132.0.223.254132.0.223.2558,190
8132.0.224.0/19132.0.224.1 to 132.0.255.254132.0.255.2558,190
9132.1.0.0/19132.1.0.1 to 132.1.31.254132.1.31.2558,190
10132.1.32.0/19132.1.32.1 to 132.1.63.254132.1.63.2558,190
11132.1.64.0/19132.1.64.1 to 132.1.95.254132.1.95.2558,190
12132.1.96.0/19132.1.96.1 to 132.1.127.254132.1.127.2558,190
13132.1.128.0/19132.1.128.1 to 132.1.159.254132.1.159.2558,190
14132.1.160.0/19132.1.160.1 to 132.1.191.254132.1.191.2558,190
15132.1.192.0/19132.1.192.1 to 132.1.223.254132.1.223.2558,190
16132.1.224.0/19132.1.224.1 to 132.1.255.254132.1.255.2558,190
17132.2.0.0/19132.2.0.1 to 132.2.31.254132.2.31.2558,190
18132.2.32.0/19132.2.32.1 to 132.2.63.254132.2.63.2558,190
19132.2.64.0/19132.2.64.1 to 132.2.95.254132.2.95.2558,190
20132.2.96.0/19132.2.96.1 to 132.2.127.254132.2.127.2558,190
21132.2.128.0/19132.2.128.1 to 132.2.159.254132.2.159.2558,190
22132.2.160.0/19132.2.160.1 to 132.2.191.254132.2.191.2558,190
23132.2.192.0/19132.2.192.1 to 132.2.223.254132.2.223.2558,190
24132.2.224.0/19132.2.224.1 to 132.2.255.254132.2.255.2558,190
25132.3.0.0/19132.3.0.1 to 132.3.31.254132.3.31.2558,190
26132.3.32.0/19132.3.32.1 to 132.3.63.254132.3.63.2558,190
27132.3.64.0/19132.3.64.1 to 132.3.95.254132.3.95.2558,190
28132.3.96.0/19132.3.96.1 to 132.3.127.254132.3.127.2558,190
29132.3.128.0/19132.3.128.1 to 132.3.159.254132.3.159.2558,190
30132.3.160.0/19132.3.160.1 to 132.3.191.254132.3.191.2558,190
31132.3.192.0/19132.3.192.1 to 132.3.223.254132.3.223.2558,190
32132.3.224.0/19132.3.224.1 to 132.3.255.254132.3.255.2558,190
33132.4.0.0/19132.4.0.1 to 132.4.31.254132.4.31.2558,190
34132.4.32.0/19132.4.32.1 to 132.4.63.254132.4.63.2558,190
35132.4.64.0/19132.4.64.1 to 132.4.95.254132.4.95.2558,190
36132.4.96.0/19132.4.96.1 to 132.4.127.254132.4.127.2558,190
37132.4.128.0/19132.4.128.1 to 132.4.159.254132.4.159.2558,190
38132.4.160.0/19132.4.160.1 to 132.4.191.254132.4.191.2558,190
39132.4.192.0/19132.4.192.1 to 132.4.223.254132.4.223.2558,190
40132.4.224.0/19132.4.224.1 to 132.4.255.254132.4.255.2558,190
41132.5.0.0/19132.5.0.1 to 132.5.31.254132.5.31.2558,190
42132.5.32.0/19132.5.32.1 to 132.5.63.254132.5.63.2558,190
43132.5.64.0/19132.5.64.1 to 132.5.95.254132.5.95.2558,190
44132.5.96.0/19132.5.96.1 to 132.5.127.254132.5.127.2558,190
45132.5.128.0/19132.5.128.1 to 132.5.159.254132.5.159.2558,190
46132.5.160.0/19132.5.160.1 to 132.5.191.254132.5.191.2558,190
47132.5.192.0/19132.5.192.1 to 132.5.223.254132.5.223.2558,190
48132.5.224.0/19132.5.224.1 to 132.5.255.254132.5.255.2558,190
49132.6.0.0/19132.6.0.1 to 132.6.31.254132.6.31.2558,190
50132.6.32.0/19132.6.32.1 to 132.6.63.254132.6.63.2558,190
51132.6.64.0/19132.6.64.1 to 132.6.95.254132.6.95.2558,190
52132.6.96.0/19132.6.96.1 to 132.6.127.254132.6.127.2558,190
53132.6.128.0/19132.6.128.1 to 132.6.159.254132.6.159.2558,190
54132.6.160.0/19132.6.160.1 to 132.6.191.254132.6.191.2558,190
55132.6.192.0/19132.6.192.1 to 132.6.223.254132.6.223.2558,190
56132.6.224.0/19132.6.224.1 to 132.6.255.254132.6.255.2558,190
57132.7.0.0/19132.7.0.1 to 132.7.31.254132.7.31.2558,190
58132.7.32.0/19132.7.32.1 to 132.7.63.254132.7.63.2558,190
59132.7.64.0/19132.7.64.1 to 132.7.95.254132.7.95.2558,190
60132.7.96.0/19132.7.96.1 to 132.7.127.254132.7.127.2558,190
61132.7.128.0/19132.7.128.1 to 132.7.159.254132.7.159.2558,190
62132.7.160.0/19132.7.160.1 to 132.7.191.254132.7.191.2558,190
63132.7.192.0/19132.7.192.1 to 132.7.223.254132.7.223.2558,190
64132.7.224.0/19132.7.224.1 to 132.7.255.254132.7.255.2558,190
65132.8.0.0/19132.8.0.1 to 132.8.31.254132.8.31.2558,190
66132.8.32.0/19132.8.32.1 to 132.8.63.254132.8.63.2558,190
67132.8.64.0/19132.8.64.1 to 132.8.95.254132.8.95.2558,190
68132.8.96.0/19132.8.96.1 to 132.8.127.254132.8.127.2558,190
69132.8.128.0/19132.8.128.1 to 132.8.159.254132.8.159.2558,190
70132.8.160.0/19132.8.160.1 to 132.8.191.254132.8.191.2558,190
71132.8.192.0/19132.8.192.1 to 132.8.223.254132.8.223.2558,190
72132.8.224.0/19132.8.224.1 to 132.8.255.254132.8.255.2558,190
73132.9.0.0/19132.9.0.1 to 132.9.31.254132.9.31.2558,190
74132.9.32.0/19132.9.32.1 to 132.9.63.254132.9.63.2558,190
75132.9.64.0/19132.9.64.1 to 132.9.95.254132.9.95.2558,190
76132.9.96.0/19132.9.96.1 to 132.9.127.254132.9.127.2558,190
77132.9.128.0/19132.9.128.1 to 132.9.159.254132.9.159.2558,190
78132.9.160.0/19132.9.160.1 to 132.9.191.254132.9.191.2558,190
79132.9.192.0/19132.9.192.1 to 132.9.223.254132.9.223.2558,190
80132.9.224.0/19132.9.224.1 to 132.9.255.254132.9.255.2558,190
81132.10.0.0/19132.10.0.1 to 132.10.31.254132.10.31.2558,190
82132.10.32.0/19132.10.32.1 to 132.10.63.254132.10.63.2558,190
83132.10.64.0/19132.10.64.1 to 132.10.95.254132.10.95.2558,190
84132.10.96.0/19132.10.96.1 to 132.10.127.254132.10.127.2558,190
85132.10.128.0/19132.10.128.1 to 132.10.159.254132.10.159.2558,190
86132.10.160.0/19132.10.160.1 to 132.10.191.254132.10.191.2558,190
87132.10.192.0/19132.10.192.1 to 132.10.223.254132.10.223.2558,190
88132.10.224.0/19132.10.224.1 to 132.10.255.254132.10.255.2558,190
89132.11.0.0/19132.11.0.1 to 132.11.31.254132.11.31.2558,190
90132.11.32.0/19132.11.32.1 to 132.11.63.254132.11.63.2558,190
91132.11.64.0/19132.11.64.1 to 132.11.95.254132.11.95.2558,190
92132.11.96.0/19132.11.96.1 to 132.11.127.254132.11.127.2558,190
93132.11.128.0/19132.11.128.1 to 132.11.159.254132.11.159.2558,190
94132.11.160.0/19132.11.160.1 to 132.11.191.254132.11.191.2558,190
95132.11.192.0/19132.11.192.1 to 132.11.223.254132.11.223.2558,190
96132.11.224.0/19132.11.224.1 to 132.11.255.254132.11.255.2558,190
97132.12.0.0/19132.12.0.1 to 132.12.31.254132.12.31.2558,190
98132.12.32.0/19132.12.32.1 to 132.12.63.254132.12.63.2558,190
99132.12.64.0/19132.12.64.1 to 132.12.95.254132.12.95.2558,190
100132.12.96.0/19132.12.96.1 to 132.12.127.254132.12.127.2558,190
101132.12.128.0/19132.12.128.1 to 132.12.159.254132.12.159.2558,190
102132.12.160.0/19132.12.160.1 to 132.12.191.254132.12.191.2558,190
103132.12.192.0/19132.12.192.1 to 132.12.223.254132.12.223.2558,190
104132.12.224.0/19132.12.224.1 to 132.12.255.254132.12.255.2558,190
105132.13.0.0/19132.13.0.1 to 132.13.31.254132.13.31.2558,190
106132.13.32.0/19132.13.32.1 to 132.13.63.254132.13.63.2558,190
107132.13.64.0/19132.13.64.1 to 132.13.95.254132.13.95.2558,190
108132.13.96.0/19132.13.96.1 to 132.13.127.254132.13.127.2558,190
109132.13.128.0/19132.13.128.1 to 132.13.159.254132.13.159.2558,190
110132.13.160.0/19132.13.160.1 to 132.13.191.254132.13.191.2558,190
111132.13.192.0/19132.13.192.1 to 132.13.223.254132.13.223.2558,190
112132.13.224.0/19132.13.224.1 to 132.13.255.254132.13.255.2558,190
113132.14.0.0/19132.14.0.1 to 132.14.31.254132.14.31.2558,190
114132.14.32.0/19132.14.32.1 to 132.14.63.254132.14.63.2558,190
115132.14.64.0/19132.14.64.1 to 132.14.95.254132.14.95.2558,190
116132.14.96.0/19132.14.96.1 to 132.14.127.254132.14.127.2558,190
117132.14.128.0/19132.14.128.1 to 132.14.159.254132.14.159.2558,190
118132.14.160.0/19132.14.160.1 to 132.14.191.254132.14.191.2558,190
119132.14.192.0/19132.14.192.1 to 132.14.223.254132.14.223.2558,190
120132.14.224.0/19132.14.224.1 to 132.14.255.254132.14.255.2558,190
121132.15.0.0/19132.15.0.1 to 132.15.31.254132.15.31.2558,190
122132.15.32.0/19132.15.32.1 to 132.15.63.254132.15.63.2558,190
123132.15.64.0/19132.15.64.1 to 132.15.95.254132.15.95.2558,190
124132.15.96.0/19132.15.96.1 to 132.15.127.254132.15.127.2558,190
125132.15.128.0/19132.15.128.1 to 132.15.159.254132.15.159.2558,190
126132.15.160.0/19132.15.160.1 to 132.15.191.254132.15.191.2558,190
127132.15.192.0/19132.15.192.1 to 132.15.223.254132.15.223.2558,190
128132.15.224.0/19132.15.224.1 to 132.15.255.254132.15.255.2558,190
129132.16.0.0/19132.16.0.1 to 132.16.31.254132.16.31.2558,190
130132.16.32.0/19132.16.32.1 to 132.16.63.254132.16.63.2558,190
131132.16.64.0/19132.16.64.1 to 132.16.95.254132.16.95.2558,190
132132.16.96.0/19132.16.96.1 to 132.16.127.254132.16.127.2558,190
133132.16.128.0/19132.16.128.1 to 132.16.159.254132.16.159.2558,190
134132.16.160.0/19132.16.160.1 to 132.16.191.254132.16.191.2558,190
135132.16.192.0/19132.16.192.1 to 132.16.223.254132.16.223.2558,190
136132.16.224.0/19132.16.224.1 to 132.16.255.254132.16.255.2558,190
137132.17.0.0/19132.17.0.1 to 132.17.31.254132.17.31.2558,190
138132.17.32.0/19132.17.32.1 to 132.17.63.254132.17.63.2558,190
139132.17.64.0/19132.17.64.1 to 132.17.95.254132.17.95.2558,190
140132.17.96.0/19132.17.96.1 to 132.17.127.254132.17.127.2558,190
141132.17.128.0/19132.17.128.1 to 132.17.159.254132.17.159.2558,190
142132.17.160.0/19132.17.160.1 to 132.17.191.254132.17.191.2558,190
143132.17.192.0/19132.17.192.1 to 132.17.223.254132.17.223.2558,190
144132.17.224.0/19132.17.224.1 to 132.17.255.254132.17.255.2558,190
145132.18.0.0/19132.18.0.1 to 132.18.31.254132.18.31.2558,190
146132.18.32.0/19132.18.32.1 to 132.18.63.254132.18.63.2558,190
147132.18.64.0/19132.18.64.1 to 132.18.95.254132.18.95.2558,190
148132.18.96.0/19132.18.96.1 to 132.18.127.254132.18.127.2558,190
149132.18.128.0/19132.18.128.1 to 132.18.159.254132.18.159.2558,190
150132.18.160.0/19132.18.160.1 to 132.18.191.254132.18.191.2558,190
151132.18.192.0/19132.18.192.1 to 132.18.223.254132.18.223.2558,190
152132.18.224.0/19132.18.224.1 to 132.18.255.254132.18.255.2558,190
153132.19.0.0/19132.19.0.1 to 132.19.31.254132.19.31.2558,190
154132.19.32.0/19132.19.32.1 to 132.19.63.254132.19.63.2558,190
155132.19.64.0/19132.19.64.1 to 132.19.95.254132.19.95.2558,190
156132.19.96.0/19132.19.96.1 to 132.19.127.254132.19.127.2558,190
157132.19.128.0/19132.19.128.1 to 132.19.159.254132.19.159.2558,190
158132.19.160.0/19132.19.160.1 to 132.19.191.254132.19.191.2558,190
159132.19.192.0/19132.19.192.1 to 132.19.223.254132.19.223.2558,190
160132.19.224.0/19132.19.224.1 to 132.19.255.254132.19.255.2558,190
161132.20.0.0/19132.20.0.1 to 132.20.31.254132.20.31.2558,190
162132.20.32.0/19132.20.32.1 to 132.20.63.254132.20.63.2558,190
163132.20.64.0/19132.20.64.1 to 132.20.95.254132.20.95.2558,190
164132.20.96.0/19132.20.96.1 to 132.20.127.254132.20.127.2558,190
165132.20.128.0/19132.20.128.1 to 132.20.159.254132.20.159.2558,190
166132.20.160.0/19132.20.160.1 to 132.20.191.254132.20.191.2558,190
167132.20.192.0/19132.20.192.1 to 132.20.223.254132.20.223.2558,190
168132.20.224.0/19132.20.224.1 to 132.20.255.254132.20.255.2558,190
169132.21.0.0/19132.21.0.1 to 132.21.31.254132.21.31.2558,190
170132.21.32.0/19132.21.32.1 to 132.21.63.254132.21.63.2558,190
171132.21.64.0/19132.21.64.1 to 132.21.95.254132.21.95.2558,190
172132.21.96.0/19132.21.96.1 to 132.21.127.254132.21.127.2558,190
173132.21.128.0/19132.21.128.1 to 132.21.159.254132.21.159.2558,190
174132.21.160.0/19132.21.160.1 to 132.21.191.254132.21.191.2558,190
175132.21.192.0/19132.21.192.1 to 132.21.223.254132.21.223.2558,190
176132.21.224.0/19132.21.224.1 to 132.21.255.254132.21.255.2558,190
177132.22.0.0/19132.22.0.1 to 132.22.31.254132.22.31.2558,190
178132.22.32.0/19132.22.32.1 to 132.22.63.254132.22.63.2558,190
179132.22.64.0/19132.22.64.1 to 132.22.95.254132.22.95.2558,190
180132.22.96.0/19132.22.96.1 to 132.22.127.254132.22.127.2558,190
181132.22.128.0/19132.22.128.1 to 132.22.159.254132.22.159.2558,190
182132.22.160.0/19132.22.160.1 to 132.22.191.254132.22.191.2558,190
183132.22.192.0/19132.22.192.1 to 132.22.223.254132.22.223.2558,190
184132.22.224.0/19132.22.224.1 to 132.22.255.254132.22.255.2558,190
185132.23.0.0/19132.23.0.1 to 132.23.31.254132.23.31.2558,190
186132.23.32.0/19132.23.32.1 to 132.23.63.254132.23.63.2558,190
187132.23.64.0/19132.23.64.1 to 132.23.95.254132.23.95.2558,190
188132.23.96.0/19132.23.96.1 to 132.23.127.254132.23.127.2558,190
189132.23.128.0/19132.23.128.1 to 132.23.159.254132.23.159.2558,190
190132.23.160.0/19132.23.160.1 to 132.23.191.254132.23.191.2558,190
191132.23.192.0/19132.23.192.1 to 132.23.223.254132.23.223.2558,190
192132.23.224.0/19132.23.224.1 to 132.23.255.254132.23.255.2558,190
193132.24.0.0/19132.24.0.1 to 132.24.31.254132.24.31.2558,190
194132.24.32.0/19132.24.32.1 to 132.24.63.254132.24.63.2558,190
195132.24.64.0/19132.24.64.1 to 132.24.95.254132.24.95.2558,190
196132.24.96.0/19132.24.96.1 to 132.24.127.254132.24.127.2558,190
197132.24.128.0/19132.24.128.1 to 132.24.159.254132.24.159.2558,190
198132.24.160.0/19132.24.160.1 to 132.24.191.254132.24.191.2558,190
199132.24.192.0/19132.24.192.1 to 132.24.223.254132.24.223.2558,190
200132.24.224.0/19132.24.224.1 to 132.24.255.254132.24.255.2558,190
201132.25.0.0/19132.25.0.1 to 132.25.31.254132.25.31.2558,190
202132.25.32.0/19132.25.32.1 to 132.25.63.254132.25.63.2558,190
203132.25.64.0/19132.25.64.1 to 132.25.95.254132.25.95.2558,190
204132.25.96.0/19132.25.96.1 to 132.25.127.254132.25.127.2558,190
205132.25.128.0/19132.25.128.1 to 132.25.159.254132.25.159.2558,190
206132.25.160.0/19132.25.160.1 to 132.25.191.254132.25.191.2558,190
207132.25.192.0/19132.25.192.1 to 132.25.223.254132.25.223.2558,190
208132.25.224.0/19132.25.224.1 to 132.25.255.254132.25.255.2558,190
209132.26.0.0/19132.26.0.1 to 132.26.31.254132.26.31.2558,190
210132.26.32.0/19132.26.32.1 to 132.26.63.254132.26.63.2558,190
211132.26.64.0/19132.26.64.1 to 132.26.95.254132.26.95.2558,190
212132.26.96.0/19132.26.96.1 to 132.26.127.254132.26.127.2558,190
213132.26.128.0/19132.26.128.1 to 132.26.159.254132.26.159.2558,190
214132.26.160.0/19132.26.160.1 to 132.26.191.254132.26.191.2558,190
215132.26.192.0/19132.26.192.1 to 132.26.223.254132.26.223.2558,190
216132.26.224.0/19132.26.224.1 to 132.26.255.254132.26.255.2558,190
217132.27.0.0/19132.27.0.1 to 132.27.31.254132.27.31.2558,190
218132.27.32.0/19132.27.32.1 to 132.27.63.254132.27.63.2558,190
219132.27.64.0/19132.27.64.1 to 132.27.95.254132.27.95.2558,190
220132.27.96.0/19132.27.96.1 to 132.27.127.254132.27.127.2558,190
221132.27.128.0/19132.27.128.1 to 132.27.159.254132.27.159.2558,190
222132.27.160.0/19132.27.160.1 to 132.27.191.254132.27.191.2558,190
223132.27.192.0/19132.27.192.1 to 132.27.223.254132.27.223.2558,190
224132.27.224.0/19132.27.224.1 to 132.27.255.254132.27.255.2558,190
225132.28.0.0/19132.28.0.1 to 132.28.31.254132.28.31.2558,190
226132.28.32.0/19132.28.32.1 to 132.28.63.254132.28.63.2558,190
227132.28.64.0/19132.28.64.1 to 132.28.95.254132.28.95.2558,190
228132.28.96.0/19132.28.96.1 to 132.28.127.254132.28.127.2558,190
229132.28.128.0/19132.28.128.1 to 132.28.159.254132.28.159.2558,190
230132.28.160.0/19132.28.160.1 to 132.28.191.254132.28.191.2558,190
231132.28.192.0/19132.28.192.1 to 132.28.223.254132.28.223.2558,190
232132.28.224.0/19132.28.224.1 to 132.28.255.254132.28.255.2558,190
233132.29.0.0/19132.29.0.1 to 132.29.31.254132.29.31.2558,190
234132.29.32.0/19132.29.32.1 to 132.29.63.254132.29.63.2558,190
235132.29.64.0/19132.29.64.1 to 132.29.95.254132.29.95.2558,190
236132.29.96.0/19132.29.96.1 to 132.29.127.254132.29.127.2558,190
237132.29.128.0/19132.29.128.1 to 132.29.159.254132.29.159.2558,190
238132.29.160.0/19132.29.160.1 to 132.29.191.254132.29.191.2558,190
239132.29.192.0/19132.29.192.1 to 132.29.223.254132.29.223.2558,190
240132.29.224.0/19132.29.224.1 to 132.29.255.254132.29.255.2558,190
241132.30.0.0/19132.30.0.1 to 132.30.31.254132.30.31.2558,190
242132.30.32.0/19132.30.32.1 to 132.30.63.254132.30.63.2558,190
243132.30.64.0/19132.30.64.1 to 132.30.95.254132.30.95.2558,190
244132.30.96.0/19132.30.96.1 to 132.30.127.254132.30.127.2558,190
245132.30.128.0/19132.30.128.1 to 132.30.159.254132.30.159.2558,190
246132.30.160.0/19132.30.160.1 to 132.30.191.254132.30.191.2558,190
247132.30.192.0/19132.30.192.1 to 132.30.223.254132.30.223.2558,190
248132.30.224.0/19132.30.224.1 to 132.30.255.254132.30.255.2558,190
249132.31.0.0/19132.31.0.1 to 132.31.31.254132.31.31.2558,190
250132.31.32.0/19132.31.32.1 to 132.31.63.254132.31.63.2558,190
251132.31.64.0/19132.31.64.1 to 132.31.95.254132.31.95.2558,190
252132.31.96.0/19132.31.96.1 to 132.31.127.254132.31.127.2558,190
253132.31.128.0/19132.31.128.1 to 132.31.159.254132.31.159.2558,190
254132.31.160.0/19132.31.160.1 to 132.31.191.254132.31.191.2558,190
255132.31.192.0/19132.31.192.1 to 132.31.223.254132.31.223.2558,190
256132.31.224.0/19132.31.224.1 to 132.31.255.254132.31.255.2558,190

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.