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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/18
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

202.0.0.0/7 makes 2,048 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1202.0.0.0/18202.0.0.1 to 202.0.63.254202.0.63.25516,382
2202.0.64.0/18202.0.64.1 to 202.0.127.254202.0.127.25516,382
3202.0.128.0/18202.0.128.1 to 202.0.191.254202.0.191.25516,382
4202.0.192.0/18202.0.192.1 to 202.0.255.254202.0.255.25516,382
5202.1.0.0/18202.1.0.1 to 202.1.63.254202.1.63.25516,382
6202.1.64.0/18202.1.64.1 to 202.1.127.254202.1.127.25516,382
7202.1.128.0/18202.1.128.1 to 202.1.191.254202.1.191.25516,382
8202.1.192.0/18202.1.192.1 to 202.1.255.254202.1.255.25516,382
9202.2.0.0/18202.2.0.1 to 202.2.63.254202.2.63.25516,382
10202.2.64.0/18202.2.64.1 to 202.2.127.254202.2.127.25516,382
11202.2.128.0/18202.2.128.1 to 202.2.191.254202.2.191.25516,382
12202.2.192.0/18202.2.192.1 to 202.2.255.254202.2.255.25516,382
13202.3.0.0/18202.3.0.1 to 202.3.63.254202.3.63.25516,382
14202.3.64.0/18202.3.64.1 to 202.3.127.254202.3.127.25516,382
15202.3.128.0/18202.3.128.1 to 202.3.191.254202.3.191.25516,382
16202.3.192.0/18202.3.192.1 to 202.3.255.254202.3.255.25516,382
17202.4.0.0/18202.4.0.1 to 202.4.63.254202.4.63.25516,382
18202.4.64.0/18202.4.64.1 to 202.4.127.254202.4.127.25516,382
19202.4.128.0/18202.4.128.1 to 202.4.191.254202.4.191.25516,382
20202.4.192.0/18202.4.192.1 to 202.4.255.254202.4.255.25516,382
21202.5.0.0/18202.5.0.1 to 202.5.63.254202.5.63.25516,382
22202.5.64.0/18202.5.64.1 to 202.5.127.254202.5.127.25516,382
23202.5.128.0/18202.5.128.1 to 202.5.191.254202.5.191.25516,382
24202.5.192.0/18202.5.192.1 to 202.5.255.254202.5.255.25516,382
25202.6.0.0/18202.6.0.1 to 202.6.63.254202.6.63.25516,382
26202.6.64.0/18202.6.64.1 to 202.6.127.254202.6.127.25516,382
27202.6.128.0/18202.6.128.1 to 202.6.191.254202.6.191.25516,382
28202.6.192.0/18202.6.192.1 to 202.6.255.254202.6.255.25516,382
29202.7.0.0/18202.7.0.1 to 202.7.63.254202.7.63.25516,382
30202.7.64.0/18202.7.64.1 to 202.7.127.254202.7.127.25516,382
31202.7.128.0/18202.7.128.1 to 202.7.191.254202.7.191.25516,382
32202.7.192.0/18202.7.192.1 to 202.7.255.254202.7.255.25516,382
33202.8.0.0/18202.8.0.1 to 202.8.63.254202.8.63.25516,382
34202.8.64.0/18202.8.64.1 to 202.8.127.254202.8.127.25516,382
35202.8.128.0/18202.8.128.1 to 202.8.191.254202.8.191.25516,382
36202.8.192.0/18202.8.192.1 to 202.8.255.254202.8.255.25516,382
37202.9.0.0/18202.9.0.1 to 202.9.63.254202.9.63.25516,382
38202.9.64.0/18202.9.64.1 to 202.9.127.254202.9.127.25516,382
39202.9.128.0/18202.9.128.1 to 202.9.191.254202.9.191.25516,382
40202.9.192.0/18202.9.192.1 to 202.9.255.254202.9.255.25516,382
41202.10.0.0/18202.10.0.1 to 202.10.63.254202.10.63.25516,382
42202.10.64.0/18202.10.64.1 to 202.10.127.254202.10.127.25516,382
43202.10.128.0/18202.10.128.1 to 202.10.191.254202.10.191.25516,382
44202.10.192.0/18202.10.192.1 to 202.10.255.254202.10.255.25516,382
45202.11.0.0/18202.11.0.1 to 202.11.63.254202.11.63.25516,382
46202.11.64.0/18202.11.64.1 to 202.11.127.254202.11.127.25516,382
47202.11.128.0/18202.11.128.1 to 202.11.191.254202.11.191.25516,382
48202.11.192.0/18202.11.192.1 to 202.11.255.254202.11.255.25516,382
49202.12.0.0/18202.12.0.1 to 202.12.63.254202.12.63.25516,382
50202.12.64.0/18202.12.64.1 to 202.12.127.254202.12.127.25516,382
51202.12.128.0/18202.12.128.1 to 202.12.191.254202.12.191.25516,382
52202.12.192.0/18202.12.192.1 to 202.12.255.254202.12.255.25516,382
53202.13.0.0/18202.13.0.1 to 202.13.63.254202.13.63.25516,382
54202.13.64.0/18202.13.64.1 to 202.13.127.254202.13.127.25516,382
55202.13.128.0/18202.13.128.1 to 202.13.191.254202.13.191.25516,382
56202.13.192.0/18202.13.192.1 to 202.13.255.254202.13.255.25516,382
57202.14.0.0/18202.14.0.1 to 202.14.63.254202.14.63.25516,382
58202.14.64.0/18202.14.64.1 to 202.14.127.254202.14.127.25516,382
59202.14.128.0/18202.14.128.1 to 202.14.191.254202.14.191.25516,382
60202.14.192.0/18202.14.192.1 to 202.14.255.254202.14.255.25516,382
61202.15.0.0/18202.15.0.1 to 202.15.63.254202.15.63.25516,382
62202.15.64.0/18202.15.64.1 to 202.15.127.254202.15.127.25516,382
63202.15.128.0/18202.15.128.1 to 202.15.191.254202.15.191.25516,382
64202.15.192.0/18202.15.192.1 to 202.15.255.254202.15.255.25516,382
65202.16.0.0/18202.16.0.1 to 202.16.63.254202.16.63.25516,382
66202.16.64.0/18202.16.64.1 to 202.16.127.254202.16.127.25516,382
67202.16.128.0/18202.16.128.1 to 202.16.191.254202.16.191.25516,382
68202.16.192.0/18202.16.192.1 to 202.16.255.254202.16.255.25516,382
69202.17.0.0/18202.17.0.1 to 202.17.63.254202.17.63.25516,382
70202.17.64.0/18202.17.64.1 to 202.17.127.254202.17.127.25516,382
71202.17.128.0/18202.17.128.1 to 202.17.191.254202.17.191.25516,382
72202.17.192.0/18202.17.192.1 to 202.17.255.254202.17.255.25516,382
73202.18.0.0/18202.18.0.1 to 202.18.63.254202.18.63.25516,382
74202.18.64.0/18202.18.64.1 to 202.18.127.254202.18.127.25516,382
75202.18.128.0/18202.18.128.1 to 202.18.191.254202.18.191.25516,382
76202.18.192.0/18202.18.192.1 to 202.18.255.254202.18.255.25516,382
77202.19.0.0/18202.19.0.1 to 202.19.63.254202.19.63.25516,382
78202.19.64.0/18202.19.64.1 to 202.19.127.254202.19.127.25516,382
79202.19.128.0/18202.19.128.1 to 202.19.191.254202.19.191.25516,382
80202.19.192.0/18202.19.192.1 to 202.19.255.254202.19.255.25516,382
81202.20.0.0/18202.20.0.1 to 202.20.63.254202.20.63.25516,382
82202.20.64.0/18202.20.64.1 to 202.20.127.254202.20.127.25516,382
83202.20.128.0/18202.20.128.1 to 202.20.191.254202.20.191.25516,382
84202.20.192.0/18202.20.192.1 to 202.20.255.254202.20.255.25516,382
85202.21.0.0/18202.21.0.1 to 202.21.63.254202.21.63.25516,382
86202.21.64.0/18202.21.64.1 to 202.21.127.254202.21.127.25516,382
87202.21.128.0/18202.21.128.1 to 202.21.191.254202.21.191.25516,382
88202.21.192.0/18202.21.192.1 to 202.21.255.254202.21.255.25516,382
89202.22.0.0/18202.22.0.1 to 202.22.63.254202.22.63.25516,382
90202.22.64.0/18202.22.64.1 to 202.22.127.254202.22.127.25516,382
91202.22.128.0/18202.22.128.1 to 202.22.191.254202.22.191.25516,382
92202.22.192.0/18202.22.192.1 to 202.22.255.254202.22.255.25516,382
93202.23.0.0/18202.23.0.1 to 202.23.63.254202.23.63.25516,382
94202.23.64.0/18202.23.64.1 to 202.23.127.254202.23.127.25516,382
95202.23.128.0/18202.23.128.1 to 202.23.191.254202.23.191.25516,382
96202.23.192.0/18202.23.192.1 to 202.23.255.254202.23.255.25516,382
97202.24.0.0/18202.24.0.1 to 202.24.63.254202.24.63.25516,382
98202.24.64.0/18202.24.64.1 to 202.24.127.254202.24.127.25516,382
99202.24.128.0/18202.24.128.1 to 202.24.191.254202.24.191.25516,382
100202.24.192.0/18202.24.192.1 to 202.24.255.254202.24.255.25516,382
101202.25.0.0/18202.25.0.1 to 202.25.63.254202.25.63.25516,382
102202.25.64.0/18202.25.64.1 to 202.25.127.254202.25.127.25516,382
103202.25.128.0/18202.25.128.1 to 202.25.191.254202.25.191.25516,382
104202.25.192.0/18202.25.192.1 to 202.25.255.254202.25.255.25516,382
105202.26.0.0/18202.26.0.1 to 202.26.63.254202.26.63.25516,382
106202.26.64.0/18202.26.64.1 to 202.26.127.254202.26.127.25516,382
107202.26.128.0/18202.26.128.1 to 202.26.191.254202.26.191.25516,382
108202.26.192.0/18202.26.192.1 to 202.26.255.254202.26.255.25516,382
109202.27.0.0/18202.27.0.1 to 202.27.63.254202.27.63.25516,382
110202.27.64.0/18202.27.64.1 to 202.27.127.254202.27.127.25516,382
111202.27.128.0/18202.27.128.1 to 202.27.191.254202.27.191.25516,382
112202.27.192.0/18202.27.192.1 to 202.27.255.254202.27.255.25516,382
113202.28.0.0/18202.28.0.1 to 202.28.63.254202.28.63.25516,382
114202.28.64.0/18202.28.64.1 to 202.28.127.254202.28.127.25516,382
115202.28.128.0/18202.28.128.1 to 202.28.191.254202.28.191.25516,382
116202.28.192.0/18202.28.192.1 to 202.28.255.254202.28.255.25516,382
117202.29.0.0/18202.29.0.1 to 202.29.63.254202.29.63.25516,382
118202.29.64.0/18202.29.64.1 to 202.29.127.254202.29.127.25516,382
119202.29.128.0/18202.29.128.1 to 202.29.191.254202.29.191.25516,382
120202.29.192.0/18202.29.192.1 to 202.29.255.254202.29.255.25516,382
121202.30.0.0/18202.30.0.1 to 202.30.63.254202.30.63.25516,382
122202.30.64.0/18202.30.64.1 to 202.30.127.254202.30.127.25516,382
123202.30.128.0/18202.30.128.1 to 202.30.191.254202.30.191.25516,382
124202.30.192.0/18202.30.192.1 to 202.30.255.254202.30.255.25516,382
125202.31.0.0/18202.31.0.1 to 202.31.63.254202.31.63.25516,382
126202.31.64.0/18202.31.64.1 to 202.31.127.254202.31.127.25516,382
127202.31.128.0/18202.31.128.1 to 202.31.191.254202.31.191.25516,382
128202.31.192.0/18202.31.192.1 to 202.31.255.254202.31.255.25516,382
129202.32.0.0/18202.32.0.1 to 202.32.63.254202.32.63.25516,382
130202.32.64.0/18202.32.64.1 to 202.32.127.254202.32.127.25516,382
131202.32.128.0/18202.32.128.1 to 202.32.191.254202.32.191.25516,382
132202.32.192.0/18202.32.192.1 to 202.32.255.254202.32.255.25516,382
133202.33.0.0/18202.33.0.1 to 202.33.63.254202.33.63.25516,382
134202.33.64.0/18202.33.64.1 to 202.33.127.254202.33.127.25516,382
135202.33.128.0/18202.33.128.1 to 202.33.191.254202.33.191.25516,382
136202.33.192.0/18202.33.192.1 to 202.33.255.254202.33.255.25516,382
137202.34.0.0/18202.34.0.1 to 202.34.63.254202.34.63.25516,382
138202.34.64.0/18202.34.64.1 to 202.34.127.254202.34.127.25516,382
139202.34.128.0/18202.34.128.1 to 202.34.191.254202.34.191.25516,382
140202.34.192.0/18202.34.192.1 to 202.34.255.254202.34.255.25516,382
141202.35.0.0/18202.35.0.1 to 202.35.63.254202.35.63.25516,382
142202.35.64.0/18202.35.64.1 to 202.35.127.254202.35.127.25516,382
143202.35.128.0/18202.35.128.1 to 202.35.191.254202.35.191.25516,382
144202.35.192.0/18202.35.192.1 to 202.35.255.254202.35.255.25516,382
145202.36.0.0/18202.36.0.1 to 202.36.63.254202.36.63.25516,382
146202.36.64.0/18202.36.64.1 to 202.36.127.254202.36.127.25516,382
147202.36.128.0/18202.36.128.1 to 202.36.191.254202.36.191.25516,382
148202.36.192.0/18202.36.192.1 to 202.36.255.254202.36.255.25516,382
149202.37.0.0/18202.37.0.1 to 202.37.63.254202.37.63.25516,382
150202.37.64.0/18202.37.64.1 to 202.37.127.254202.37.127.25516,382
151202.37.128.0/18202.37.128.1 to 202.37.191.254202.37.191.25516,382
152202.37.192.0/18202.37.192.1 to 202.37.255.254202.37.255.25516,382
153202.38.0.0/18202.38.0.1 to 202.38.63.254202.38.63.25516,382
154202.38.64.0/18202.38.64.1 to 202.38.127.254202.38.127.25516,382
155202.38.128.0/18202.38.128.1 to 202.38.191.254202.38.191.25516,382
156202.38.192.0/18202.38.192.1 to 202.38.255.254202.38.255.25516,382
157202.39.0.0/18202.39.0.1 to 202.39.63.254202.39.63.25516,382
158202.39.64.0/18202.39.64.1 to 202.39.127.254202.39.127.25516,382
159202.39.128.0/18202.39.128.1 to 202.39.191.254202.39.191.25516,382
160202.39.192.0/18202.39.192.1 to 202.39.255.254202.39.255.25516,382
161202.40.0.0/18202.40.0.1 to 202.40.63.254202.40.63.25516,382
162202.40.64.0/18202.40.64.1 to 202.40.127.254202.40.127.25516,382
163202.40.128.0/18202.40.128.1 to 202.40.191.254202.40.191.25516,382
164202.40.192.0/18202.40.192.1 to 202.40.255.254202.40.255.25516,382
165202.41.0.0/18202.41.0.1 to 202.41.63.254202.41.63.25516,382
166202.41.64.0/18202.41.64.1 to 202.41.127.254202.41.127.25516,382
167202.41.128.0/18202.41.128.1 to 202.41.191.254202.41.191.25516,382
168202.41.192.0/18202.41.192.1 to 202.41.255.254202.41.255.25516,382
169202.42.0.0/18202.42.0.1 to 202.42.63.254202.42.63.25516,382
170202.42.64.0/18202.42.64.1 to 202.42.127.254202.42.127.25516,382
171202.42.128.0/18202.42.128.1 to 202.42.191.254202.42.191.25516,382
172202.42.192.0/18202.42.192.1 to 202.42.255.254202.42.255.25516,382
173202.43.0.0/18202.43.0.1 to 202.43.63.254202.43.63.25516,382
174202.43.64.0/18202.43.64.1 to 202.43.127.254202.43.127.25516,382
175202.43.128.0/18202.43.128.1 to 202.43.191.254202.43.191.25516,382
176202.43.192.0/18202.43.192.1 to 202.43.255.254202.43.255.25516,382
177202.44.0.0/18202.44.0.1 to 202.44.63.254202.44.63.25516,382
178202.44.64.0/18202.44.64.1 to 202.44.127.254202.44.127.25516,382
179202.44.128.0/18202.44.128.1 to 202.44.191.254202.44.191.25516,382
180202.44.192.0/18202.44.192.1 to 202.44.255.254202.44.255.25516,382
181202.45.0.0/18202.45.0.1 to 202.45.63.254202.45.63.25516,382
182202.45.64.0/18202.45.64.1 to 202.45.127.254202.45.127.25516,382
183202.45.128.0/18202.45.128.1 to 202.45.191.254202.45.191.25516,382
184202.45.192.0/18202.45.192.1 to 202.45.255.254202.45.255.25516,382
185202.46.0.0/18202.46.0.1 to 202.46.63.254202.46.63.25516,382
186202.46.64.0/18202.46.64.1 to 202.46.127.254202.46.127.25516,382
187202.46.128.0/18202.46.128.1 to 202.46.191.254202.46.191.25516,382
188202.46.192.0/18202.46.192.1 to 202.46.255.254202.46.255.25516,382
189202.47.0.0/18202.47.0.1 to 202.47.63.254202.47.63.25516,382
190202.47.64.0/18202.47.64.1 to 202.47.127.254202.47.127.25516,382
191202.47.128.0/18202.47.128.1 to 202.47.191.254202.47.191.25516,382
192202.47.192.0/18202.47.192.1 to 202.47.255.254202.47.255.25516,382
193202.48.0.0/18202.48.0.1 to 202.48.63.254202.48.63.25516,382
194202.48.64.0/18202.48.64.1 to 202.48.127.254202.48.127.25516,382
195202.48.128.0/18202.48.128.1 to 202.48.191.254202.48.191.25516,382
196202.48.192.0/18202.48.192.1 to 202.48.255.254202.48.255.25516,382
197202.49.0.0/18202.49.0.1 to 202.49.63.254202.49.63.25516,382
198202.49.64.0/18202.49.64.1 to 202.49.127.254202.49.127.25516,382
199202.49.128.0/18202.49.128.1 to 202.49.191.254202.49.191.25516,382
200202.49.192.0/18202.49.192.1 to 202.49.255.254202.49.255.25516,382
201202.50.0.0/18202.50.0.1 to 202.50.63.254202.50.63.25516,382
202202.50.64.0/18202.50.64.1 to 202.50.127.254202.50.127.25516,382
203202.50.128.0/18202.50.128.1 to 202.50.191.254202.50.191.25516,382
204202.50.192.0/18202.50.192.1 to 202.50.255.254202.50.255.25516,382
205202.51.0.0/18202.51.0.1 to 202.51.63.254202.51.63.25516,382
206202.51.64.0/18202.51.64.1 to 202.51.127.254202.51.127.25516,382
207202.51.128.0/18202.51.128.1 to 202.51.191.254202.51.191.25516,382
208202.51.192.0/18202.51.192.1 to 202.51.255.254202.51.255.25516,382
209202.52.0.0/18202.52.0.1 to 202.52.63.254202.52.63.25516,382
210202.52.64.0/18202.52.64.1 to 202.52.127.254202.52.127.25516,382
211202.52.128.0/18202.52.128.1 to 202.52.191.254202.52.191.25516,382
212202.52.192.0/18202.52.192.1 to 202.52.255.254202.52.255.25516,382
213202.53.0.0/18202.53.0.1 to 202.53.63.254202.53.63.25516,382
214202.53.64.0/18202.53.64.1 to 202.53.127.254202.53.127.25516,382
215202.53.128.0/18202.53.128.1 to 202.53.191.254202.53.191.25516,382
216202.53.192.0/18202.53.192.1 to 202.53.255.254202.53.255.25516,382
217202.54.0.0/18202.54.0.1 to 202.54.63.254202.54.63.25516,382
218202.54.64.0/18202.54.64.1 to 202.54.127.254202.54.127.25516,382
219202.54.128.0/18202.54.128.1 to 202.54.191.254202.54.191.25516,382
220202.54.192.0/18202.54.192.1 to 202.54.255.254202.54.255.25516,382
221202.55.0.0/18202.55.0.1 to 202.55.63.254202.55.63.25516,382
222202.55.64.0/18202.55.64.1 to 202.55.127.254202.55.127.25516,382
223202.55.128.0/18202.55.128.1 to 202.55.191.254202.55.191.25516,382
224202.55.192.0/18202.55.192.1 to 202.55.255.254202.55.255.25516,382
225202.56.0.0/18202.56.0.1 to 202.56.63.254202.56.63.25516,382
226202.56.64.0/18202.56.64.1 to 202.56.127.254202.56.127.25516,382
227202.56.128.0/18202.56.128.1 to 202.56.191.254202.56.191.25516,382
228202.56.192.0/18202.56.192.1 to 202.56.255.254202.56.255.25516,382
229202.57.0.0/18202.57.0.1 to 202.57.63.254202.57.63.25516,382
230202.57.64.0/18202.57.64.1 to 202.57.127.254202.57.127.25516,382
231202.57.128.0/18202.57.128.1 to 202.57.191.254202.57.191.25516,382
232202.57.192.0/18202.57.192.1 to 202.57.255.254202.57.255.25516,382
233202.58.0.0/18202.58.0.1 to 202.58.63.254202.58.63.25516,382
234202.58.64.0/18202.58.64.1 to 202.58.127.254202.58.127.25516,382
235202.58.128.0/18202.58.128.1 to 202.58.191.254202.58.191.25516,382
236202.58.192.0/18202.58.192.1 to 202.58.255.254202.58.255.25516,382
237202.59.0.0/18202.59.0.1 to 202.59.63.254202.59.63.25516,382
238202.59.64.0/18202.59.64.1 to 202.59.127.254202.59.127.25516,382
239202.59.128.0/18202.59.128.1 to 202.59.191.254202.59.191.25516,382
240202.59.192.0/18202.59.192.1 to 202.59.255.254202.59.255.25516,382
241202.60.0.0/18202.60.0.1 to 202.60.63.254202.60.63.25516,382
242202.60.64.0/18202.60.64.1 to 202.60.127.254202.60.127.25516,382
243202.60.128.0/18202.60.128.1 to 202.60.191.254202.60.191.25516,382
244202.60.192.0/18202.60.192.1 to 202.60.255.254202.60.255.25516,382
245202.61.0.0/18202.61.0.1 to 202.61.63.254202.61.63.25516,382
246202.61.64.0/18202.61.64.1 to 202.61.127.254202.61.127.25516,382
247202.61.128.0/18202.61.128.1 to 202.61.191.254202.61.191.25516,382
248202.61.192.0/18202.61.192.1 to 202.61.255.254202.61.255.25516,382
249202.62.0.0/18202.62.0.1 to 202.62.63.254202.62.63.25516,382
250202.62.64.0/18202.62.64.1 to 202.62.127.254202.62.127.25516,382
251202.62.128.0/18202.62.128.1 to 202.62.191.254202.62.191.25516,382
252202.62.192.0/18202.62.192.1 to 202.62.255.254202.62.255.25516,382
253202.63.0.0/18202.63.0.1 to 202.63.63.254202.63.63.25516,382
254202.63.64.0/18202.63.64.1 to 202.63.127.254202.63.127.25516,382
255202.63.128.0/18202.63.128.1 to 202.63.191.254202.63.191.25516,382
256202.63.192.0/18202.63.192.1 to 202.63.255.254202.63.255.25516,382

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.