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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.

Network202.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
202.0.0.0
Broadcast address
203.255.255.255
First usable
202.0.0.1
Last usable
203.255.255.254
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
C (default /24)
As numbers
Hex CA000000 · Integer 3388997632 to 3422552063
Reverse DNS zones
202.in-addr.arpa
203.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
Address11001010.00000000.00000000.00000000202.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network11001010.00000000.00000000.00000000202.0.0.0
Broadcast11001011.11111111.11111111.11111111203.255.255.255
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)

202.0.0.0/7 makes 4,096 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1202.0.0.0/19202.0.0.1 to 202.0.31.254202.0.31.2558,190
2202.0.32.0/19202.0.32.1 to 202.0.63.254202.0.63.2558,190
3202.0.64.0/19202.0.64.1 to 202.0.95.254202.0.95.2558,190
4202.0.96.0/19202.0.96.1 to 202.0.127.254202.0.127.2558,190
5202.0.128.0/19202.0.128.1 to 202.0.159.254202.0.159.2558,190
6202.0.160.0/19202.0.160.1 to 202.0.191.254202.0.191.2558,190
7202.0.192.0/19202.0.192.1 to 202.0.223.254202.0.223.2558,190
8202.0.224.0/19202.0.224.1 to 202.0.255.254202.0.255.2558,190
9202.1.0.0/19202.1.0.1 to 202.1.31.254202.1.31.2558,190
10202.1.32.0/19202.1.32.1 to 202.1.63.254202.1.63.2558,190
11202.1.64.0/19202.1.64.1 to 202.1.95.254202.1.95.2558,190
12202.1.96.0/19202.1.96.1 to 202.1.127.254202.1.127.2558,190
13202.1.128.0/19202.1.128.1 to 202.1.159.254202.1.159.2558,190
14202.1.160.0/19202.1.160.1 to 202.1.191.254202.1.191.2558,190
15202.1.192.0/19202.1.192.1 to 202.1.223.254202.1.223.2558,190
16202.1.224.0/19202.1.224.1 to 202.1.255.254202.1.255.2558,190
17202.2.0.0/19202.2.0.1 to 202.2.31.254202.2.31.2558,190
18202.2.32.0/19202.2.32.1 to 202.2.63.254202.2.63.2558,190
19202.2.64.0/19202.2.64.1 to 202.2.95.254202.2.95.2558,190
20202.2.96.0/19202.2.96.1 to 202.2.127.254202.2.127.2558,190
21202.2.128.0/19202.2.128.1 to 202.2.159.254202.2.159.2558,190
22202.2.160.0/19202.2.160.1 to 202.2.191.254202.2.191.2558,190
23202.2.192.0/19202.2.192.1 to 202.2.223.254202.2.223.2558,190
24202.2.224.0/19202.2.224.1 to 202.2.255.254202.2.255.2558,190
25202.3.0.0/19202.3.0.1 to 202.3.31.254202.3.31.2558,190
26202.3.32.0/19202.3.32.1 to 202.3.63.254202.3.63.2558,190
27202.3.64.0/19202.3.64.1 to 202.3.95.254202.3.95.2558,190
28202.3.96.0/19202.3.96.1 to 202.3.127.254202.3.127.2558,190
29202.3.128.0/19202.3.128.1 to 202.3.159.254202.3.159.2558,190
30202.3.160.0/19202.3.160.1 to 202.3.191.254202.3.191.2558,190
31202.3.192.0/19202.3.192.1 to 202.3.223.254202.3.223.2558,190
32202.3.224.0/19202.3.224.1 to 202.3.255.254202.3.255.2558,190
33202.4.0.0/19202.4.0.1 to 202.4.31.254202.4.31.2558,190
34202.4.32.0/19202.4.32.1 to 202.4.63.254202.4.63.2558,190
35202.4.64.0/19202.4.64.1 to 202.4.95.254202.4.95.2558,190
36202.4.96.0/19202.4.96.1 to 202.4.127.254202.4.127.2558,190
37202.4.128.0/19202.4.128.1 to 202.4.159.254202.4.159.2558,190
38202.4.160.0/19202.4.160.1 to 202.4.191.254202.4.191.2558,190
39202.4.192.0/19202.4.192.1 to 202.4.223.254202.4.223.2558,190
40202.4.224.0/19202.4.224.1 to 202.4.255.254202.4.255.2558,190
41202.5.0.0/19202.5.0.1 to 202.5.31.254202.5.31.2558,190
42202.5.32.0/19202.5.32.1 to 202.5.63.254202.5.63.2558,190
43202.5.64.0/19202.5.64.1 to 202.5.95.254202.5.95.2558,190
44202.5.96.0/19202.5.96.1 to 202.5.127.254202.5.127.2558,190
45202.5.128.0/19202.5.128.1 to 202.5.159.254202.5.159.2558,190
46202.5.160.0/19202.5.160.1 to 202.5.191.254202.5.191.2558,190
47202.5.192.0/19202.5.192.1 to 202.5.223.254202.5.223.2558,190
48202.5.224.0/19202.5.224.1 to 202.5.255.254202.5.255.2558,190
49202.6.0.0/19202.6.0.1 to 202.6.31.254202.6.31.2558,190
50202.6.32.0/19202.6.32.1 to 202.6.63.254202.6.63.2558,190
51202.6.64.0/19202.6.64.1 to 202.6.95.254202.6.95.2558,190
52202.6.96.0/19202.6.96.1 to 202.6.127.254202.6.127.2558,190
53202.6.128.0/19202.6.128.1 to 202.6.159.254202.6.159.2558,190
54202.6.160.0/19202.6.160.1 to 202.6.191.254202.6.191.2558,190
55202.6.192.0/19202.6.192.1 to 202.6.223.254202.6.223.2558,190
56202.6.224.0/19202.6.224.1 to 202.6.255.254202.6.255.2558,190
57202.7.0.0/19202.7.0.1 to 202.7.31.254202.7.31.2558,190
58202.7.32.0/19202.7.32.1 to 202.7.63.254202.7.63.2558,190
59202.7.64.0/19202.7.64.1 to 202.7.95.254202.7.95.2558,190
60202.7.96.0/19202.7.96.1 to 202.7.127.254202.7.127.2558,190
61202.7.128.0/19202.7.128.1 to 202.7.159.254202.7.159.2558,190
62202.7.160.0/19202.7.160.1 to 202.7.191.254202.7.191.2558,190
63202.7.192.0/19202.7.192.1 to 202.7.223.254202.7.223.2558,190
64202.7.224.0/19202.7.224.1 to 202.7.255.254202.7.255.2558,190
65202.8.0.0/19202.8.0.1 to 202.8.31.254202.8.31.2558,190
66202.8.32.0/19202.8.32.1 to 202.8.63.254202.8.63.2558,190
67202.8.64.0/19202.8.64.1 to 202.8.95.254202.8.95.2558,190
68202.8.96.0/19202.8.96.1 to 202.8.127.254202.8.127.2558,190
69202.8.128.0/19202.8.128.1 to 202.8.159.254202.8.159.2558,190
70202.8.160.0/19202.8.160.1 to 202.8.191.254202.8.191.2558,190
71202.8.192.0/19202.8.192.1 to 202.8.223.254202.8.223.2558,190
72202.8.224.0/19202.8.224.1 to 202.8.255.254202.8.255.2558,190
73202.9.0.0/19202.9.0.1 to 202.9.31.254202.9.31.2558,190
74202.9.32.0/19202.9.32.1 to 202.9.63.254202.9.63.2558,190
75202.9.64.0/19202.9.64.1 to 202.9.95.254202.9.95.2558,190
76202.9.96.0/19202.9.96.1 to 202.9.127.254202.9.127.2558,190
77202.9.128.0/19202.9.128.1 to 202.9.159.254202.9.159.2558,190
78202.9.160.0/19202.9.160.1 to 202.9.191.254202.9.191.2558,190
79202.9.192.0/19202.9.192.1 to 202.9.223.254202.9.223.2558,190
80202.9.224.0/19202.9.224.1 to 202.9.255.254202.9.255.2558,190
81202.10.0.0/19202.10.0.1 to 202.10.31.254202.10.31.2558,190
82202.10.32.0/19202.10.32.1 to 202.10.63.254202.10.63.2558,190
83202.10.64.0/19202.10.64.1 to 202.10.95.254202.10.95.2558,190
84202.10.96.0/19202.10.96.1 to 202.10.127.254202.10.127.2558,190
85202.10.128.0/19202.10.128.1 to 202.10.159.254202.10.159.2558,190
86202.10.160.0/19202.10.160.1 to 202.10.191.254202.10.191.2558,190
87202.10.192.0/19202.10.192.1 to 202.10.223.254202.10.223.2558,190
88202.10.224.0/19202.10.224.1 to 202.10.255.254202.10.255.2558,190
89202.11.0.0/19202.11.0.1 to 202.11.31.254202.11.31.2558,190
90202.11.32.0/19202.11.32.1 to 202.11.63.254202.11.63.2558,190
91202.11.64.0/19202.11.64.1 to 202.11.95.254202.11.95.2558,190
92202.11.96.0/19202.11.96.1 to 202.11.127.254202.11.127.2558,190
93202.11.128.0/19202.11.128.1 to 202.11.159.254202.11.159.2558,190
94202.11.160.0/19202.11.160.1 to 202.11.191.254202.11.191.2558,190
95202.11.192.0/19202.11.192.1 to 202.11.223.254202.11.223.2558,190
96202.11.224.0/19202.11.224.1 to 202.11.255.254202.11.255.2558,190
97202.12.0.0/19202.12.0.1 to 202.12.31.254202.12.31.2558,190
98202.12.32.0/19202.12.32.1 to 202.12.63.254202.12.63.2558,190
99202.12.64.0/19202.12.64.1 to 202.12.95.254202.12.95.2558,190
100202.12.96.0/19202.12.96.1 to 202.12.127.254202.12.127.2558,190
101202.12.128.0/19202.12.128.1 to 202.12.159.254202.12.159.2558,190
102202.12.160.0/19202.12.160.1 to 202.12.191.254202.12.191.2558,190
103202.12.192.0/19202.12.192.1 to 202.12.223.254202.12.223.2558,190
104202.12.224.0/19202.12.224.1 to 202.12.255.254202.12.255.2558,190
105202.13.0.0/19202.13.0.1 to 202.13.31.254202.13.31.2558,190
106202.13.32.0/19202.13.32.1 to 202.13.63.254202.13.63.2558,190
107202.13.64.0/19202.13.64.1 to 202.13.95.254202.13.95.2558,190
108202.13.96.0/19202.13.96.1 to 202.13.127.254202.13.127.2558,190
109202.13.128.0/19202.13.128.1 to 202.13.159.254202.13.159.2558,190
110202.13.160.0/19202.13.160.1 to 202.13.191.254202.13.191.2558,190
111202.13.192.0/19202.13.192.1 to 202.13.223.254202.13.223.2558,190
112202.13.224.0/19202.13.224.1 to 202.13.255.254202.13.255.2558,190
113202.14.0.0/19202.14.0.1 to 202.14.31.254202.14.31.2558,190
114202.14.32.0/19202.14.32.1 to 202.14.63.254202.14.63.2558,190
115202.14.64.0/19202.14.64.1 to 202.14.95.254202.14.95.2558,190
116202.14.96.0/19202.14.96.1 to 202.14.127.254202.14.127.2558,190
117202.14.128.0/19202.14.128.1 to 202.14.159.254202.14.159.2558,190
118202.14.160.0/19202.14.160.1 to 202.14.191.254202.14.191.2558,190
119202.14.192.0/19202.14.192.1 to 202.14.223.254202.14.223.2558,190
120202.14.224.0/19202.14.224.1 to 202.14.255.254202.14.255.2558,190
121202.15.0.0/19202.15.0.1 to 202.15.31.254202.15.31.2558,190
122202.15.32.0/19202.15.32.1 to 202.15.63.254202.15.63.2558,190
123202.15.64.0/19202.15.64.1 to 202.15.95.254202.15.95.2558,190
124202.15.96.0/19202.15.96.1 to 202.15.127.254202.15.127.2558,190
125202.15.128.0/19202.15.128.1 to 202.15.159.254202.15.159.2558,190
126202.15.160.0/19202.15.160.1 to 202.15.191.254202.15.191.2558,190
127202.15.192.0/19202.15.192.1 to 202.15.223.254202.15.223.2558,190
128202.15.224.0/19202.15.224.1 to 202.15.255.254202.15.255.2558,190
129202.16.0.0/19202.16.0.1 to 202.16.31.254202.16.31.2558,190
130202.16.32.0/19202.16.32.1 to 202.16.63.254202.16.63.2558,190
131202.16.64.0/19202.16.64.1 to 202.16.95.254202.16.95.2558,190
132202.16.96.0/19202.16.96.1 to 202.16.127.254202.16.127.2558,190
133202.16.128.0/19202.16.128.1 to 202.16.159.254202.16.159.2558,190
134202.16.160.0/19202.16.160.1 to 202.16.191.254202.16.191.2558,190
135202.16.192.0/19202.16.192.1 to 202.16.223.254202.16.223.2558,190
136202.16.224.0/19202.16.224.1 to 202.16.255.254202.16.255.2558,190
137202.17.0.0/19202.17.0.1 to 202.17.31.254202.17.31.2558,190
138202.17.32.0/19202.17.32.1 to 202.17.63.254202.17.63.2558,190
139202.17.64.0/19202.17.64.1 to 202.17.95.254202.17.95.2558,190
140202.17.96.0/19202.17.96.1 to 202.17.127.254202.17.127.2558,190
141202.17.128.0/19202.17.128.1 to 202.17.159.254202.17.159.2558,190
142202.17.160.0/19202.17.160.1 to 202.17.191.254202.17.191.2558,190
143202.17.192.0/19202.17.192.1 to 202.17.223.254202.17.223.2558,190
144202.17.224.0/19202.17.224.1 to 202.17.255.254202.17.255.2558,190
145202.18.0.0/19202.18.0.1 to 202.18.31.254202.18.31.2558,190
146202.18.32.0/19202.18.32.1 to 202.18.63.254202.18.63.2558,190
147202.18.64.0/19202.18.64.1 to 202.18.95.254202.18.95.2558,190
148202.18.96.0/19202.18.96.1 to 202.18.127.254202.18.127.2558,190
149202.18.128.0/19202.18.128.1 to 202.18.159.254202.18.159.2558,190
150202.18.160.0/19202.18.160.1 to 202.18.191.254202.18.191.2558,190
151202.18.192.0/19202.18.192.1 to 202.18.223.254202.18.223.2558,190
152202.18.224.0/19202.18.224.1 to 202.18.255.254202.18.255.2558,190
153202.19.0.0/19202.19.0.1 to 202.19.31.254202.19.31.2558,190
154202.19.32.0/19202.19.32.1 to 202.19.63.254202.19.63.2558,190
155202.19.64.0/19202.19.64.1 to 202.19.95.254202.19.95.2558,190
156202.19.96.0/19202.19.96.1 to 202.19.127.254202.19.127.2558,190
157202.19.128.0/19202.19.128.1 to 202.19.159.254202.19.159.2558,190
158202.19.160.0/19202.19.160.1 to 202.19.191.254202.19.191.2558,190
159202.19.192.0/19202.19.192.1 to 202.19.223.254202.19.223.2558,190
160202.19.224.0/19202.19.224.1 to 202.19.255.254202.19.255.2558,190
161202.20.0.0/19202.20.0.1 to 202.20.31.254202.20.31.2558,190
162202.20.32.0/19202.20.32.1 to 202.20.63.254202.20.63.2558,190
163202.20.64.0/19202.20.64.1 to 202.20.95.254202.20.95.2558,190
164202.20.96.0/19202.20.96.1 to 202.20.127.254202.20.127.2558,190
165202.20.128.0/19202.20.128.1 to 202.20.159.254202.20.159.2558,190
166202.20.160.0/19202.20.160.1 to 202.20.191.254202.20.191.2558,190
167202.20.192.0/19202.20.192.1 to 202.20.223.254202.20.223.2558,190
168202.20.224.0/19202.20.224.1 to 202.20.255.254202.20.255.2558,190
169202.21.0.0/19202.21.0.1 to 202.21.31.254202.21.31.2558,190
170202.21.32.0/19202.21.32.1 to 202.21.63.254202.21.63.2558,190
171202.21.64.0/19202.21.64.1 to 202.21.95.254202.21.95.2558,190
172202.21.96.0/19202.21.96.1 to 202.21.127.254202.21.127.2558,190
173202.21.128.0/19202.21.128.1 to 202.21.159.254202.21.159.2558,190
174202.21.160.0/19202.21.160.1 to 202.21.191.254202.21.191.2558,190
175202.21.192.0/19202.21.192.1 to 202.21.223.254202.21.223.2558,190
176202.21.224.0/19202.21.224.1 to 202.21.255.254202.21.255.2558,190
177202.22.0.0/19202.22.0.1 to 202.22.31.254202.22.31.2558,190
178202.22.32.0/19202.22.32.1 to 202.22.63.254202.22.63.2558,190
179202.22.64.0/19202.22.64.1 to 202.22.95.254202.22.95.2558,190
180202.22.96.0/19202.22.96.1 to 202.22.127.254202.22.127.2558,190
181202.22.128.0/19202.22.128.1 to 202.22.159.254202.22.159.2558,190
182202.22.160.0/19202.22.160.1 to 202.22.191.254202.22.191.2558,190
183202.22.192.0/19202.22.192.1 to 202.22.223.254202.22.223.2558,190
184202.22.224.0/19202.22.224.1 to 202.22.255.254202.22.255.2558,190
185202.23.0.0/19202.23.0.1 to 202.23.31.254202.23.31.2558,190
186202.23.32.0/19202.23.32.1 to 202.23.63.254202.23.63.2558,190
187202.23.64.0/19202.23.64.1 to 202.23.95.254202.23.95.2558,190
188202.23.96.0/19202.23.96.1 to 202.23.127.254202.23.127.2558,190
189202.23.128.0/19202.23.128.1 to 202.23.159.254202.23.159.2558,190
190202.23.160.0/19202.23.160.1 to 202.23.191.254202.23.191.2558,190
191202.23.192.0/19202.23.192.1 to 202.23.223.254202.23.223.2558,190
192202.23.224.0/19202.23.224.1 to 202.23.255.254202.23.255.2558,190
193202.24.0.0/19202.24.0.1 to 202.24.31.254202.24.31.2558,190
194202.24.32.0/19202.24.32.1 to 202.24.63.254202.24.63.2558,190
195202.24.64.0/19202.24.64.1 to 202.24.95.254202.24.95.2558,190
196202.24.96.0/19202.24.96.1 to 202.24.127.254202.24.127.2558,190
197202.24.128.0/19202.24.128.1 to 202.24.159.254202.24.159.2558,190
198202.24.160.0/19202.24.160.1 to 202.24.191.254202.24.191.2558,190
199202.24.192.0/19202.24.192.1 to 202.24.223.254202.24.223.2558,190
200202.24.224.0/19202.24.224.1 to 202.24.255.254202.24.255.2558,190
201202.25.0.0/19202.25.0.1 to 202.25.31.254202.25.31.2558,190
202202.25.32.0/19202.25.32.1 to 202.25.63.254202.25.63.2558,190
203202.25.64.0/19202.25.64.1 to 202.25.95.254202.25.95.2558,190
204202.25.96.0/19202.25.96.1 to 202.25.127.254202.25.127.2558,190
205202.25.128.0/19202.25.128.1 to 202.25.159.254202.25.159.2558,190
206202.25.160.0/19202.25.160.1 to 202.25.191.254202.25.191.2558,190
207202.25.192.0/19202.25.192.1 to 202.25.223.254202.25.223.2558,190
208202.25.224.0/19202.25.224.1 to 202.25.255.254202.25.255.2558,190
209202.26.0.0/19202.26.0.1 to 202.26.31.254202.26.31.2558,190
210202.26.32.0/19202.26.32.1 to 202.26.63.254202.26.63.2558,190
211202.26.64.0/19202.26.64.1 to 202.26.95.254202.26.95.2558,190
212202.26.96.0/19202.26.96.1 to 202.26.127.254202.26.127.2558,190
213202.26.128.0/19202.26.128.1 to 202.26.159.254202.26.159.2558,190
214202.26.160.0/19202.26.160.1 to 202.26.191.254202.26.191.2558,190
215202.26.192.0/19202.26.192.1 to 202.26.223.254202.26.223.2558,190
216202.26.224.0/19202.26.224.1 to 202.26.255.254202.26.255.2558,190
217202.27.0.0/19202.27.0.1 to 202.27.31.254202.27.31.2558,190
218202.27.32.0/19202.27.32.1 to 202.27.63.254202.27.63.2558,190
219202.27.64.0/19202.27.64.1 to 202.27.95.254202.27.95.2558,190
220202.27.96.0/19202.27.96.1 to 202.27.127.254202.27.127.2558,190
221202.27.128.0/19202.27.128.1 to 202.27.159.254202.27.159.2558,190
222202.27.160.0/19202.27.160.1 to 202.27.191.254202.27.191.2558,190
223202.27.192.0/19202.27.192.1 to 202.27.223.254202.27.223.2558,190
224202.27.224.0/19202.27.224.1 to 202.27.255.254202.27.255.2558,190
225202.28.0.0/19202.28.0.1 to 202.28.31.254202.28.31.2558,190
226202.28.32.0/19202.28.32.1 to 202.28.63.254202.28.63.2558,190
227202.28.64.0/19202.28.64.1 to 202.28.95.254202.28.95.2558,190
228202.28.96.0/19202.28.96.1 to 202.28.127.254202.28.127.2558,190
229202.28.128.0/19202.28.128.1 to 202.28.159.254202.28.159.2558,190
230202.28.160.0/19202.28.160.1 to 202.28.191.254202.28.191.2558,190
231202.28.192.0/19202.28.192.1 to 202.28.223.254202.28.223.2558,190
232202.28.224.0/19202.28.224.1 to 202.28.255.254202.28.255.2558,190
233202.29.0.0/19202.29.0.1 to 202.29.31.254202.29.31.2558,190
234202.29.32.0/19202.29.32.1 to 202.29.63.254202.29.63.2558,190
235202.29.64.0/19202.29.64.1 to 202.29.95.254202.29.95.2558,190
236202.29.96.0/19202.29.96.1 to 202.29.127.254202.29.127.2558,190
237202.29.128.0/19202.29.128.1 to 202.29.159.254202.29.159.2558,190
238202.29.160.0/19202.29.160.1 to 202.29.191.254202.29.191.2558,190
239202.29.192.0/19202.29.192.1 to 202.29.223.254202.29.223.2558,190
240202.29.224.0/19202.29.224.1 to 202.29.255.254202.29.255.2558,190
241202.30.0.0/19202.30.0.1 to 202.30.31.254202.30.31.2558,190
242202.30.32.0/19202.30.32.1 to 202.30.63.254202.30.63.2558,190
243202.30.64.0/19202.30.64.1 to 202.30.95.254202.30.95.2558,190
244202.30.96.0/19202.30.96.1 to 202.30.127.254202.30.127.2558,190
245202.30.128.0/19202.30.128.1 to 202.30.159.254202.30.159.2558,190
246202.30.160.0/19202.30.160.1 to 202.30.191.254202.30.191.2558,190
247202.30.192.0/19202.30.192.1 to 202.30.223.254202.30.223.2558,190
248202.30.224.0/19202.30.224.1 to 202.30.255.254202.30.255.2558,190
249202.31.0.0/19202.31.0.1 to 202.31.31.254202.31.31.2558,190
250202.31.32.0/19202.31.32.1 to 202.31.63.254202.31.63.2558,190
251202.31.64.0/19202.31.64.1 to 202.31.95.254202.31.95.2558,190
252202.31.96.0/19202.31.96.1 to 202.31.127.254202.31.127.2558,190
253202.31.128.0/19202.31.128.1 to 202.31.159.254202.31.159.2558,190
254202.31.160.0/19202.31.160.1 to 202.31.191.254202.31.191.2558,190
255202.31.192.0/19202.31.192.1 to 202.31.223.254202.31.223.2558,190
256202.31.224.0/19202.31.224.1 to 202.31.255.254202.31.255.2558,190

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.