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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.

Network202.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
202.0.0.0
Broadcast address
202.255.255.255
First usable
202.0.0.1
Last usable
202.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
C (default /24)
As numbers
Hex CA000000 · Integer 3388997632 to 3405774847
Reverse DNS zone
202.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11001010..00000000.00000000.00000000202.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network11001010..00000000.00000000.00000000202.0.0.0
Broadcast11001010..11111111.11111111.11111111202.255.255.255
Split into smaller subnets/20
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

202.0.0.0/8 makes 4,096 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1202.0.0.0/20202.0.0.1 to 202.0.15.254202.0.15.2554,094
2202.0.16.0/20202.0.16.1 to 202.0.31.254202.0.31.2554,094
3202.0.32.0/20202.0.32.1 to 202.0.47.254202.0.47.2554,094
4202.0.48.0/20202.0.48.1 to 202.0.63.254202.0.63.2554,094
5202.0.64.0/20202.0.64.1 to 202.0.79.254202.0.79.2554,094
6202.0.80.0/20202.0.80.1 to 202.0.95.254202.0.95.2554,094
7202.0.96.0/20202.0.96.1 to 202.0.111.254202.0.111.2554,094
8202.0.112.0/20202.0.112.1 to 202.0.127.254202.0.127.2554,094
9202.0.128.0/20202.0.128.1 to 202.0.143.254202.0.143.2554,094
10202.0.144.0/20202.0.144.1 to 202.0.159.254202.0.159.2554,094
11202.0.160.0/20202.0.160.1 to 202.0.175.254202.0.175.2554,094
12202.0.176.0/20202.0.176.1 to 202.0.191.254202.0.191.2554,094
13202.0.192.0/20202.0.192.1 to 202.0.207.254202.0.207.2554,094
14202.0.208.0/20202.0.208.1 to 202.0.223.254202.0.223.2554,094
15202.0.224.0/20202.0.224.1 to 202.0.239.254202.0.239.2554,094
16202.0.240.0/20202.0.240.1 to 202.0.255.254202.0.255.2554,094
17202.1.0.0/20202.1.0.1 to 202.1.15.254202.1.15.2554,094
18202.1.16.0/20202.1.16.1 to 202.1.31.254202.1.31.2554,094
19202.1.32.0/20202.1.32.1 to 202.1.47.254202.1.47.2554,094
20202.1.48.0/20202.1.48.1 to 202.1.63.254202.1.63.2554,094
21202.1.64.0/20202.1.64.1 to 202.1.79.254202.1.79.2554,094
22202.1.80.0/20202.1.80.1 to 202.1.95.254202.1.95.2554,094
23202.1.96.0/20202.1.96.1 to 202.1.111.254202.1.111.2554,094
24202.1.112.0/20202.1.112.1 to 202.1.127.254202.1.127.2554,094
25202.1.128.0/20202.1.128.1 to 202.1.143.254202.1.143.2554,094
26202.1.144.0/20202.1.144.1 to 202.1.159.254202.1.159.2554,094
27202.1.160.0/20202.1.160.1 to 202.1.175.254202.1.175.2554,094
28202.1.176.0/20202.1.176.1 to 202.1.191.254202.1.191.2554,094
29202.1.192.0/20202.1.192.1 to 202.1.207.254202.1.207.2554,094
30202.1.208.0/20202.1.208.1 to 202.1.223.254202.1.223.2554,094
31202.1.224.0/20202.1.224.1 to 202.1.239.254202.1.239.2554,094
32202.1.240.0/20202.1.240.1 to 202.1.255.254202.1.255.2554,094
33202.2.0.0/20202.2.0.1 to 202.2.15.254202.2.15.2554,094
34202.2.16.0/20202.2.16.1 to 202.2.31.254202.2.31.2554,094
35202.2.32.0/20202.2.32.1 to 202.2.47.254202.2.47.2554,094
36202.2.48.0/20202.2.48.1 to 202.2.63.254202.2.63.2554,094
37202.2.64.0/20202.2.64.1 to 202.2.79.254202.2.79.2554,094
38202.2.80.0/20202.2.80.1 to 202.2.95.254202.2.95.2554,094
39202.2.96.0/20202.2.96.1 to 202.2.111.254202.2.111.2554,094
40202.2.112.0/20202.2.112.1 to 202.2.127.254202.2.127.2554,094
41202.2.128.0/20202.2.128.1 to 202.2.143.254202.2.143.2554,094
42202.2.144.0/20202.2.144.1 to 202.2.159.254202.2.159.2554,094
43202.2.160.0/20202.2.160.1 to 202.2.175.254202.2.175.2554,094
44202.2.176.0/20202.2.176.1 to 202.2.191.254202.2.191.2554,094
45202.2.192.0/20202.2.192.1 to 202.2.207.254202.2.207.2554,094
46202.2.208.0/20202.2.208.1 to 202.2.223.254202.2.223.2554,094
47202.2.224.0/20202.2.224.1 to 202.2.239.254202.2.239.2554,094
48202.2.240.0/20202.2.240.1 to 202.2.255.254202.2.255.2554,094
49202.3.0.0/20202.3.0.1 to 202.3.15.254202.3.15.2554,094
50202.3.16.0/20202.3.16.1 to 202.3.31.254202.3.31.2554,094
51202.3.32.0/20202.3.32.1 to 202.3.47.254202.3.47.2554,094
52202.3.48.0/20202.3.48.1 to 202.3.63.254202.3.63.2554,094
53202.3.64.0/20202.3.64.1 to 202.3.79.254202.3.79.2554,094
54202.3.80.0/20202.3.80.1 to 202.3.95.254202.3.95.2554,094
55202.3.96.0/20202.3.96.1 to 202.3.111.254202.3.111.2554,094
56202.3.112.0/20202.3.112.1 to 202.3.127.254202.3.127.2554,094
57202.3.128.0/20202.3.128.1 to 202.3.143.254202.3.143.2554,094
58202.3.144.0/20202.3.144.1 to 202.3.159.254202.3.159.2554,094
59202.3.160.0/20202.3.160.1 to 202.3.175.254202.3.175.2554,094
60202.3.176.0/20202.3.176.1 to 202.3.191.254202.3.191.2554,094
61202.3.192.0/20202.3.192.1 to 202.3.207.254202.3.207.2554,094
62202.3.208.0/20202.3.208.1 to 202.3.223.254202.3.223.2554,094
63202.3.224.0/20202.3.224.1 to 202.3.239.254202.3.239.2554,094
64202.3.240.0/20202.3.240.1 to 202.3.255.254202.3.255.2554,094
65202.4.0.0/20202.4.0.1 to 202.4.15.254202.4.15.2554,094
66202.4.16.0/20202.4.16.1 to 202.4.31.254202.4.31.2554,094
67202.4.32.0/20202.4.32.1 to 202.4.47.254202.4.47.2554,094
68202.4.48.0/20202.4.48.1 to 202.4.63.254202.4.63.2554,094
69202.4.64.0/20202.4.64.1 to 202.4.79.254202.4.79.2554,094
70202.4.80.0/20202.4.80.1 to 202.4.95.254202.4.95.2554,094
71202.4.96.0/20202.4.96.1 to 202.4.111.254202.4.111.2554,094
72202.4.112.0/20202.4.112.1 to 202.4.127.254202.4.127.2554,094
73202.4.128.0/20202.4.128.1 to 202.4.143.254202.4.143.2554,094
74202.4.144.0/20202.4.144.1 to 202.4.159.254202.4.159.2554,094
75202.4.160.0/20202.4.160.1 to 202.4.175.254202.4.175.2554,094
76202.4.176.0/20202.4.176.1 to 202.4.191.254202.4.191.2554,094
77202.4.192.0/20202.4.192.1 to 202.4.207.254202.4.207.2554,094
78202.4.208.0/20202.4.208.1 to 202.4.223.254202.4.223.2554,094
79202.4.224.0/20202.4.224.1 to 202.4.239.254202.4.239.2554,094
80202.4.240.0/20202.4.240.1 to 202.4.255.254202.4.255.2554,094
81202.5.0.0/20202.5.0.1 to 202.5.15.254202.5.15.2554,094
82202.5.16.0/20202.5.16.1 to 202.5.31.254202.5.31.2554,094
83202.5.32.0/20202.5.32.1 to 202.5.47.254202.5.47.2554,094
84202.5.48.0/20202.5.48.1 to 202.5.63.254202.5.63.2554,094
85202.5.64.0/20202.5.64.1 to 202.5.79.254202.5.79.2554,094
86202.5.80.0/20202.5.80.1 to 202.5.95.254202.5.95.2554,094
87202.5.96.0/20202.5.96.1 to 202.5.111.254202.5.111.2554,094
88202.5.112.0/20202.5.112.1 to 202.5.127.254202.5.127.2554,094
89202.5.128.0/20202.5.128.1 to 202.5.143.254202.5.143.2554,094
90202.5.144.0/20202.5.144.1 to 202.5.159.254202.5.159.2554,094
91202.5.160.0/20202.5.160.1 to 202.5.175.254202.5.175.2554,094
92202.5.176.0/20202.5.176.1 to 202.5.191.254202.5.191.2554,094
93202.5.192.0/20202.5.192.1 to 202.5.207.254202.5.207.2554,094
94202.5.208.0/20202.5.208.1 to 202.5.223.254202.5.223.2554,094
95202.5.224.0/20202.5.224.1 to 202.5.239.254202.5.239.2554,094
96202.5.240.0/20202.5.240.1 to 202.5.255.254202.5.255.2554,094
97202.6.0.0/20202.6.0.1 to 202.6.15.254202.6.15.2554,094
98202.6.16.0/20202.6.16.1 to 202.6.31.254202.6.31.2554,094
99202.6.32.0/20202.6.32.1 to 202.6.47.254202.6.47.2554,094
100202.6.48.0/20202.6.48.1 to 202.6.63.254202.6.63.2554,094
101202.6.64.0/20202.6.64.1 to 202.6.79.254202.6.79.2554,094
102202.6.80.0/20202.6.80.1 to 202.6.95.254202.6.95.2554,094
103202.6.96.0/20202.6.96.1 to 202.6.111.254202.6.111.2554,094
104202.6.112.0/20202.6.112.1 to 202.6.127.254202.6.127.2554,094
105202.6.128.0/20202.6.128.1 to 202.6.143.254202.6.143.2554,094
106202.6.144.0/20202.6.144.1 to 202.6.159.254202.6.159.2554,094
107202.6.160.0/20202.6.160.1 to 202.6.175.254202.6.175.2554,094
108202.6.176.0/20202.6.176.1 to 202.6.191.254202.6.191.2554,094
109202.6.192.0/20202.6.192.1 to 202.6.207.254202.6.207.2554,094
110202.6.208.0/20202.6.208.1 to 202.6.223.254202.6.223.2554,094
111202.6.224.0/20202.6.224.1 to 202.6.239.254202.6.239.2554,094
112202.6.240.0/20202.6.240.1 to 202.6.255.254202.6.255.2554,094
113202.7.0.0/20202.7.0.1 to 202.7.15.254202.7.15.2554,094
114202.7.16.0/20202.7.16.1 to 202.7.31.254202.7.31.2554,094
115202.7.32.0/20202.7.32.1 to 202.7.47.254202.7.47.2554,094
116202.7.48.0/20202.7.48.1 to 202.7.63.254202.7.63.2554,094
117202.7.64.0/20202.7.64.1 to 202.7.79.254202.7.79.2554,094
118202.7.80.0/20202.7.80.1 to 202.7.95.254202.7.95.2554,094
119202.7.96.0/20202.7.96.1 to 202.7.111.254202.7.111.2554,094
120202.7.112.0/20202.7.112.1 to 202.7.127.254202.7.127.2554,094
121202.7.128.0/20202.7.128.1 to 202.7.143.254202.7.143.2554,094
122202.7.144.0/20202.7.144.1 to 202.7.159.254202.7.159.2554,094
123202.7.160.0/20202.7.160.1 to 202.7.175.254202.7.175.2554,094
124202.7.176.0/20202.7.176.1 to 202.7.191.254202.7.191.2554,094
125202.7.192.0/20202.7.192.1 to 202.7.207.254202.7.207.2554,094
126202.7.208.0/20202.7.208.1 to 202.7.223.254202.7.223.2554,094
127202.7.224.0/20202.7.224.1 to 202.7.239.254202.7.239.2554,094
128202.7.240.0/20202.7.240.1 to 202.7.255.254202.7.255.2554,094
129202.8.0.0/20202.8.0.1 to 202.8.15.254202.8.15.2554,094
130202.8.16.0/20202.8.16.1 to 202.8.31.254202.8.31.2554,094
131202.8.32.0/20202.8.32.1 to 202.8.47.254202.8.47.2554,094
132202.8.48.0/20202.8.48.1 to 202.8.63.254202.8.63.2554,094
133202.8.64.0/20202.8.64.1 to 202.8.79.254202.8.79.2554,094
134202.8.80.0/20202.8.80.1 to 202.8.95.254202.8.95.2554,094
135202.8.96.0/20202.8.96.1 to 202.8.111.254202.8.111.2554,094
136202.8.112.0/20202.8.112.1 to 202.8.127.254202.8.127.2554,094
137202.8.128.0/20202.8.128.1 to 202.8.143.254202.8.143.2554,094
138202.8.144.0/20202.8.144.1 to 202.8.159.254202.8.159.2554,094
139202.8.160.0/20202.8.160.1 to 202.8.175.254202.8.175.2554,094
140202.8.176.0/20202.8.176.1 to 202.8.191.254202.8.191.2554,094
141202.8.192.0/20202.8.192.1 to 202.8.207.254202.8.207.2554,094
142202.8.208.0/20202.8.208.1 to 202.8.223.254202.8.223.2554,094
143202.8.224.0/20202.8.224.1 to 202.8.239.254202.8.239.2554,094
144202.8.240.0/20202.8.240.1 to 202.8.255.254202.8.255.2554,094
145202.9.0.0/20202.9.0.1 to 202.9.15.254202.9.15.2554,094
146202.9.16.0/20202.9.16.1 to 202.9.31.254202.9.31.2554,094
147202.9.32.0/20202.9.32.1 to 202.9.47.254202.9.47.2554,094
148202.9.48.0/20202.9.48.1 to 202.9.63.254202.9.63.2554,094
149202.9.64.0/20202.9.64.1 to 202.9.79.254202.9.79.2554,094
150202.9.80.0/20202.9.80.1 to 202.9.95.254202.9.95.2554,094
151202.9.96.0/20202.9.96.1 to 202.9.111.254202.9.111.2554,094
152202.9.112.0/20202.9.112.1 to 202.9.127.254202.9.127.2554,094
153202.9.128.0/20202.9.128.1 to 202.9.143.254202.9.143.2554,094
154202.9.144.0/20202.9.144.1 to 202.9.159.254202.9.159.2554,094
155202.9.160.0/20202.9.160.1 to 202.9.175.254202.9.175.2554,094
156202.9.176.0/20202.9.176.1 to 202.9.191.254202.9.191.2554,094
157202.9.192.0/20202.9.192.1 to 202.9.207.254202.9.207.2554,094
158202.9.208.0/20202.9.208.1 to 202.9.223.254202.9.223.2554,094
159202.9.224.0/20202.9.224.1 to 202.9.239.254202.9.239.2554,094
160202.9.240.0/20202.9.240.1 to 202.9.255.254202.9.255.2554,094
161202.10.0.0/20202.10.0.1 to 202.10.15.254202.10.15.2554,094
162202.10.16.0/20202.10.16.1 to 202.10.31.254202.10.31.2554,094
163202.10.32.0/20202.10.32.1 to 202.10.47.254202.10.47.2554,094
164202.10.48.0/20202.10.48.1 to 202.10.63.254202.10.63.2554,094
165202.10.64.0/20202.10.64.1 to 202.10.79.254202.10.79.2554,094
166202.10.80.0/20202.10.80.1 to 202.10.95.254202.10.95.2554,094
167202.10.96.0/20202.10.96.1 to 202.10.111.254202.10.111.2554,094
168202.10.112.0/20202.10.112.1 to 202.10.127.254202.10.127.2554,094
169202.10.128.0/20202.10.128.1 to 202.10.143.254202.10.143.2554,094
170202.10.144.0/20202.10.144.1 to 202.10.159.254202.10.159.2554,094
171202.10.160.0/20202.10.160.1 to 202.10.175.254202.10.175.2554,094
172202.10.176.0/20202.10.176.1 to 202.10.191.254202.10.191.2554,094
173202.10.192.0/20202.10.192.1 to 202.10.207.254202.10.207.2554,094
174202.10.208.0/20202.10.208.1 to 202.10.223.254202.10.223.2554,094
175202.10.224.0/20202.10.224.1 to 202.10.239.254202.10.239.2554,094
176202.10.240.0/20202.10.240.1 to 202.10.255.254202.10.255.2554,094
177202.11.0.0/20202.11.0.1 to 202.11.15.254202.11.15.2554,094
178202.11.16.0/20202.11.16.1 to 202.11.31.254202.11.31.2554,094
179202.11.32.0/20202.11.32.1 to 202.11.47.254202.11.47.2554,094
180202.11.48.0/20202.11.48.1 to 202.11.63.254202.11.63.2554,094
181202.11.64.0/20202.11.64.1 to 202.11.79.254202.11.79.2554,094
182202.11.80.0/20202.11.80.1 to 202.11.95.254202.11.95.2554,094
183202.11.96.0/20202.11.96.1 to 202.11.111.254202.11.111.2554,094
184202.11.112.0/20202.11.112.1 to 202.11.127.254202.11.127.2554,094
185202.11.128.0/20202.11.128.1 to 202.11.143.254202.11.143.2554,094
186202.11.144.0/20202.11.144.1 to 202.11.159.254202.11.159.2554,094
187202.11.160.0/20202.11.160.1 to 202.11.175.254202.11.175.2554,094
188202.11.176.0/20202.11.176.1 to 202.11.191.254202.11.191.2554,094
189202.11.192.0/20202.11.192.1 to 202.11.207.254202.11.207.2554,094
190202.11.208.0/20202.11.208.1 to 202.11.223.254202.11.223.2554,094
191202.11.224.0/20202.11.224.1 to 202.11.239.254202.11.239.2554,094
192202.11.240.0/20202.11.240.1 to 202.11.255.254202.11.255.2554,094
193202.12.0.0/20202.12.0.1 to 202.12.15.254202.12.15.2554,094
194202.12.16.0/20202.12.16.1 to 202.12.31.254202.12.31.2554,094
195202.12.32.0/20202.12.32.1 to 202.12.47.254202.12.47.2554,094
196202.12.48.0/20202.12.48.1 to 202.12.63.254202.12.63.2554,094
197202.12.64.0/20202.12.64.1 to 202.12.79.254202.12.79.2554,094
198202.12.80.0/20202.12.80.1 to 202.12.95.254202.12.95.2554,094
199202.12.96.0/20202.12.96.1 to 202.12.111.254202.12.111.2554,094
200202.12.112.0/20202.12.112.1 to 202.12.127.254202.12.127.2554,094
201202.12.128.0/20202.12.128.1 to 202.12.143.254202.12.143.2554,094
202202.12.144.0/20202.12.144.1 to 202.12.159.254202.12.159.2554,094
203202.12.160.0/20202.12.160.1 to 202.12.175.254202.12.175.2554,094
204202.12.176.0/20202.12.176.1 to 202.12.191.254202.12.191.2554,094
205202.12.192.0/20202.12.192.1 to 202.12.207.254202.12.207.2554,094
206202.12.208.0/20202.12.208.1 to 202.12.223.254202.12.223.2554,094
207202.12.224.0/20202.12.224.1 to 202.12.239.254202.12.239.2554,094
208202.12.240.0/20202.12.240.1 to 202.12.255.254202.12.255.2554,094
209202.13.0.0/20202.13.0.1 to 202.13.15.254202.13.15.2554,094
210202.13.16.0/20202.13.16.1 to 202.13.31.254202.13.31.2554,094
211202.13.32.0/20202.13.32.1 to 202.13.47.254202.13.47.2554,094
212202.13.48.0/20202.13.48.1 to 202.13.63.254202.13.63.2554,094
213202.13.64.0/20202.13.64.1 to 202.13.79.254202.13.79.2554,094
214202.13.80.0/20202.13.80.1 to 202.13.95.254202.13.95.2554,094
215202.13.96.0/20202.13.96.1 to 202.13.111.254202.13.111.2554,094
216202.13.112.0/20202.13.112.1 to 202.13.127.254202.13.127.2554,094
217202.13.128.0/20202.13.128.1 to 202.13.143.254202.13.143.2554,094
218202.13.144.0/20202.13.144.1 to 202.13.159.254202.13.159.2554,094
219202.13.160.0/20202.13.160.1 to 202.13.175.254202.13.175.2554,094
220202.13.176.0/20202.13.176.1 to 202.13.191.254202.13.191.2554,094
221202.13.192.0/20202.13.192.1 to 202.13.207.254202.13.207.2554,094
222202.13.208.0/20202.13.208.1 to 202.13.223.254202.13.223.2554,094
223202.13.224.0/20202.13.224.1 to 202.13.239.254202.13.239.2554,094
224202.13.240.0/20202.13.240.1 to 202.13.255.254202.13.255.2554,094
225202.14.0.0/20202.14.0.1 to 202.14.15.254202.14.15.2554,094
226202.14.16.0/20202.14.16.1 to 202.14.31.254202.14.31.2554,094
227202.14.32.0/20202.14.32.1 to 202.14.47.254202.14.47.2554,094
228202.14.48.0/20202.14.48.1 to 202.14.63.254202.14.63.2554,094
229202.14.64.0/20202.14.64.1 to 202.14.79.254202.14.79.2554,094
230202.14.80.0/20202.14.80.1 to 202.14.95.254202.14.95.2554,094
231202.14.96.0/20202.14.96.1 to 202.14.111.254202.14.111.2554,094
232202.14.112.0/20202.14.112.1 to 202.14.127.254202.14.127.2554,094
233202.14.128.0/20202.14.128.1 to 202.14.143.254202.14.143.2554,094
234202.14.144.0/20202.14.144.1 to 202.14.159.254202.14.159.2554,094
235202.14.160.0/20202.14.160.1 to 202.14.175.254202.14.175.2554,094
236202.14.176.0/20202.14.176.1 to 202.14.191.254202.14.191.2554,094
237202.14.192.0/20202.14.192.1 to 202.14.207.254202.14.207.2554,094
238202.14.208.0/20202.14.208.1 to 202.14.223.254202.14.223.2554,094
239202.14.224.0/20202.14.224.1 to 202.14.239.254202.14.239.2554,094
240202.14.240.0/20202.14.240.1 to 202.14.255.254202.14.255.2554,094
241202.15.0.0/20202.15.0.1 to 202.15.15.254202.15.15.2554,094
242202.15.16.0/20202.15.16.1 to 202.15.31.254202.15.31.2554,094
243202.15.32.0/20202.15.32.1 to 202.15.47.254202.15.47.2554,094
244202.15.48.0/20202.15.48.1 to 202.15.63.254202.15.63.2554,094
245202.15.64.0/20202.15.64.1 to 202.15.79.254202.15.79.2554,094
246202.15.80.0/20202.15.80.1 to 202.15.95.254202.15.95.2554,094
247202.15.96.0/20202.15.96.1 to 202.15.111.254202.15.111.2554,094
248202.15.112.0/20202.15.112.1 to 202.15.127.254202.15.127.2554,094
249202.15.128.0/20202.15.128.1 to 202.15.143.254202.15.143.2554,094
250202.15.144.0/20202.15.144.1 to 202.15.159.254202.15.159.2554,094
251202.15.160.0/20202.15.160.1 to 202.15.175.254202.15.175.2554,094
252202.15.176.0/20202.15.176.1 to 202.15.191.254202.15.191.2554,094
253202.15.192.0/20202.15.192.1 to 202.15.207.254202.15.207.2554,094
254202.15.208.0/20202.15.208.1 to 202.15.223.254202.15.223.2554,094
255202.15.224.0/20202.15.224.1 to 202.15.239.254202.15.239.2554,094
256202.15.240.0/20202.15.240.1 to 202.15.255.254202.15.255.2554,094

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.