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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.

Network141.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
141.0.0.0
Broadcast address
141.255.255.255
First usable
141.0.0.1
Last usable
141.255.255.254
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
B (default /16)
As numbers
Hex 8D000000 · Integer 2365587456 to 2382364671
Reverse DNS zone
141.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10001101..00000000.00000000.00000000141.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10001101..00000000.00000000.00000000141.0.0.0
Broadcast10001101..11111111.11111111.11111111141.255.255.255
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)

141.0.0.0/8 makes 4,096 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1141.0.0.0/20141.0.0.1 to 141.0.15.254141.0.15.2554,094
2141.0.16.0/20141.0.16.1 to 141.0.31.254141.0.31.2554,094
3141.0.32.0/20141.0.32.1 to 141.0.47.254141.0.47.2554,094
4141.0.48.0/20141.0.48.1 to 141.0.63.254141.0.63.2554,094
5141.0.64.0/20141.0.64.1 to 141.0.79.254141.0.79.2554,094
6141.0.80.0/20141.0.80.1 to 141.0.95.254141.0.95.2554,094
7141.0.96.0/20141.0.96.1 to 141.0.111.254141.0.111.2554,094
8141.0.112.0/20141.0.112.1 to 141.0.127.254141.0.127.2554,094
9141.0.128.0/20141.0.128.1 to 141.0.143.254141.0.143.2554,094
10141.0.144.0/20141.0.144.1 to 141.0.159.254141.0.159.2554,094
11141.0.160.0/20141.0.160.1 to 141.0.175.254141.0.175.2554,094
12141.0.176.0/20141.0.176.1 to 141.0.191.254141.0.191.2554,094
13141.0.192.0/20141.0.192.1 to 141.0.207.254141.0.207.2554,094
14141.0.208.0/20141.0.208.1 to 141.0.223.254141.0.223.2554,094
15141.0.224.0/20141.0.224.1 to 141.0.239.254141.0.239.2554,094
16141.0.240.0/20141.0.240.1 to 141.0.255.254141.0.255.2554,094
17141.1.0.0/20141.1.0.1 to 141.1.15.254141.1.15.2554,094
18141.1.16.0/20141.1.16.1 to 141.1.31.254141.1.31.2554,094
19141.1.32.0/20141.1.32.1 to 141.1.47.254141.1.47.2554,094
20141.1.48.0/20141.1.48.1 to 141.1.63.254141.1.63.2554,094
21141.1.64.0/20141.1.64.1 to 141.1.79.254141.1.79.2554,094
22141.1.80.0/20141.1.80.1 to 141.1.95.254141.1.95.2554,094
23141.1.96.0/20141.1.96.1 to 141.1.111.254141.1.111.2554,094
24141.1.112.0/20141.1.112.1 to 141.1.127.254141.1.127.2554,094
25141.1.128.0/20141.1.128.1 to 141.1.143.254141.1.143.2554,094
26141.1.144.0/20141.1.144.1 to 141.1.159.254141.1.159.2554,094
27141.1.160.0/20141.1.160.1 to 141.1.175.254141.1.175.2554,094
28141.1.176.0/20141.1.176.1 to 141.1.191.254141.1.191.2554,094
29141.1.192.0/20141.1.192.1 to 141.1.207.254141.1.207.2554,094
30141.1.208.0/20141.1.208.1 to 141.1.223.254141.1.223.2554,094
31141.1.224.0/20141.1.224.1 to 141.1.239.254141.1.239.2554,094
32141.1.240.0/20141.1.240.1 to 141.1.255.254141.1.255.2554,094
33141.2.0.0/20141.2.0.1 to 141.2.15.254141.2.15.2554,094
34141.2.16.0/20141.2.16.1 to 141.2.31.254141.2.31.2554,094
35141.2.32.0/20141.2.32.1 to 141.2.47.254141.2.47.2554,094
36141.2.48.0/20141.2.48.1 to 141.2.63.254141.2.63.2554,094
37141.2.64.0/20141.2.64.1 to 141.2.79.254141.2.79.2554,094
38141.2.80.0/20141.2.80.1 to 141.2.95.254141.2.95.2554,094
39141.2.96.0/20141.2.96.1 to 141.2.111.254141.2.111.2554,094
40141.2.112.0/20141.2.112.1 to 141.2.127.254141.2.127.2554,094
41141.2.128.0/20141.2.128.1 to 141.2.143.254141.2.143.2554,094
42141.2.144.0/20141.2.144.1 to 141.2.159.254141.2.159.2554,094
43141.2.160.0/20141.2.160.1 to 141.2.175.254141.2.175.2554,094
44141.2.176.0/20141.2.176.1 to 141.2.191.254141.2.191.2554,094
45141.2.192.0/20141.2.192.1 to 141.2.207.254141.2.207.2554,094
46141.2.208.0/20141.2.208.1 to 141.2.223.254141.2.223.2554,094
47141.2.224.0/20141.2.224.1 to 141.2.239.254141.2.239.2554,094
48141.2.240.0/20141.2.240.1 to 141.2.255.254141.2.255.2554,094
49141.3.0.0/20141.3.0.1 to 141.3.15.254141.3.15.2554,094
50141.3.16.0/20141.3.16.1 to 141.3.31.254141.3.31.2554,094
51141.3.32.0/20141.3.32.1 to 141.3.47.254141.3.47.2554,094
52141.3.48.0/20141.3.48.1 to 141.3.63.254141.3.63.2554,094
53141.3.64.0/20141.3.64.1 to 141.3.79.254141.3.79.2554,094
54141.3.80.0/20141.3.80.1 to 141.3.95.254141.3.95.2554,094
55141.3.96.0/20141.3.96.1 to 141.3.111.254141.3.111.2554,094
56141.3.112.0/20141.3.112.1 to 141.3.127.254141.3.127.2554,094
57141.3.128.0/20141.3.128.1 to 141.3.143.254141.3.143.2554,094
58141.3.144.0/20141.3.144.1 to 141.3.159.254141.3.159.2554,094
59141.3.160.0/20141.3.160.1 to 141.3.175.254141.3.175.2554,094
60141.3.176.0/20141.3.176.1 to 141.3.191.254141.3.191.2554,094
61141.3.192.0/20141.3.192.1 to 141.3.207.254141.3.207.2554,094
62141.3.208.0/20141.3.208.1 to 141.3.223.254141.3.223.2554,094
63141.3.224.0/20141.3.224.1 to 141.3.239.254141.3.239.2554,094
64141.3.240.0/20141.3.240.1 to 141.3.255.254141.3.255.2554,094
65141.4.0.0/20141.4.0.1 to 141.4.15.254141.4.15.2554,094
66141.4.16.0/20141.4.16.1 to 141.4.31.254141.4.31.2554,094
67141.4.32.0/20141.4.32.1 to 141.4.47.254141.4.47.2554,094
68141.4.48.0/20141.4.48.1 to 141.4.63.254141.4.63.2554,094
69141.4.64.0/20141.4.64.1 to 141.4.79.254141.4.79.2554,094
70141.4.80.0/20141.4.80.1 to 141.4.95.254141.4.95.2554,094
71141.4.96.0/20141.4.96.1 to 141.4.111.254141.4.111.2554,094
72141.4.112.0/20141.4.112.1 to 141.4.127.254141.4.127.2554,094
73141.4.128.0/20141.4.128.1 to 141.4.143.254141.4.143.2554,094
74141.4.144.0/20141.4.144.1 to 141.4.159.254141.4.159.2554,094
75141.4.160.0/20141.4.160.1 to 141.4.175.254141.4.175.2554,094
76141.4.176.0/20141.4.176.1 to 141.4.191.254141.4.191.2554,094
77141.4.192.0/20141.4.192.1 to 141.4.207.254141.4.207.2554,094
78141.4.208.0/20141.4.208.1 to 141.4.223.254141.4.223.2554,094
79141.4.224.0/20141.4.224.1 to 141.4.239.254141.4.239.2554,094
80141.4.240.0/20141.4.240.1 to 141.4.255.254141.4.255.2554,094
81141.5.0.0/20141.5.0.1 to 141.5.15.254141.5.15.2554,094
82141.5.16.0/20141.5.16.1 to 141.5.31.254141.5.31.2554,094
83141.5.32.0/20141.5.32.1 to 141.5.47.254141.5.47.2554,094
84141.5.48.0/20141.5.48.1 to 141.5.63.254141.5.63.2554,094
85141.5.64.0/20141.5.64.1 to 141.5.79.254141.5.79.2554,094
86141.5.80.0/20141.5.80.1 to 141.5.95.254141.5.95.2554,094
87141.5.96.0/20141.5.96.1 to 141.5.111.254141.5.111.2554,094
88141.5.112.0/20141.5.112.1 to 141.5.127.254141.5.127.2554,094
89141.5.128.0/20141.5.128.1 to 141.5.143.254141.5.143.2554,094
90141.5.144.0/20141.5.144.1 to 141.5.159.254141.5.159.2554,094
91141.5.160.0/20141.5.160.1 to 141.5.175.254141.5.175.2554,094
92141.5.176.0/20141.5.176.1 to 141.5.191.254141.5.191.2554,094
93141.5.192.0/20141.5.192.1 to 141.5.207.254141.5.207.2554,094
94141.5.208.0/20141.5.208.1 to 141.5.223.254141.5.223.2554,094
95141.5.224.0/20141.5.224.1 to 141.5.239.254141.5.239.2554,094
96141.5.240.0/20141.5.240.1 to 141.5.255.254141.5.255.2554,094
97141.6.0.0/20141.6.0.1 to 141.6.15.254141.6.15.2554,094
98141.6.16.0/20141.6.16.1 to 141.6.31.254141.6.31.2554,094
99141.6.32.0/20141.6.32.1 to 141.6.47.254141.6.47.2554,094
100141.6.48.0/20141.6.48.1 to 141.6.63.254141.6.63.2554,094
101141.6.64.0/20141.6.64.1 to 141.6.79.254141.6.79.2554,094
102141.6.80.0/20141.6.80.1 to 141.6.95.254141.6.95.2554,094
103141.6.96.0/20141.6.96.1 to 141.6.111.254141.6.111.2554,094
104141.6.112.0/20141.6.112.1 to 141.6.127.254141.6.127.2554,094
105141.6.128.0/20141.6.128.1 to 141.6.143.254141.6.143.2554,094
106141.6.144.0/20141.6.144.1 to 141.6.159.254141.6.159.2554,094
107141.6.160.0/20141.6.160.1 to 141.6.175.254141.6.175.2554,094
108141.6.176.0/20141.6.176.1 to 141.6.191.254141.6.191.2554,094
109141.6.192.0/20141.6.192.1 to 141.6.207.254141.6.207.2554,094
110141.6.208.0/20141.6.208.1 to 141.6.223.254141.6.223.2554,094
111141.6.224.0/20141.6.224.1 to 141.6.239.254141.6.239.2554,094
112141.6.240.0/20141.6.240.1 to 141.6.255.254141.6.255.2554,094
113141.7.0.0/20141.7.0.1 to 141.7.15.254141.7.15.2554,094
114141.7.16.0/20141.7.16.1 to 141.7.31.254141.7.31.2554,094
115141.7.32.0/20141.7.32.1 to 141.7.47.254141.7.47.2554,094
116141.7.48.0/20141.7.48.1 to 141.7.63.254141.7.63.2554,094
117141.7.64.0/20141.7.64.1 to 141.7.79.254141.7.79.2554,094
118141.7.80.0/20141.7.80.1 to 141.7.95.254141.7.95.2554,094
119141.7.96.0/20141.7.96.1 to 141.7.111.254141.7.111.2554,094
120141.7.112.0/20141.7.112.1 to 141.7.127.254141.7.127.2554,094
121141.7.128.0/20141.7.128.1 to 141.7.143.254141.7.143.2554,094
122141.7.144.0/20141.7.144.1 to 141.7.159.254141.7.159.2554,094
123141.7.160.0/20141.7.160.1 to 141.7.175.254141.7.175.2554,094
124141.7.176.0/20141.7.176.1 to 141.7.191.254141.7.191.2554,094
125141.7.192.0/20141.7.192.1 to 141.7.207.254141.7.207.2554,094
126141.7.208.0/20141.7.208.1 to 141.7.223.254141.7.223.2554,094
127141.7.224.0/20141.7.224.1 to 141.7.239.254141.7.239.2554,094
128141.7.240.0/20141.7.240.1 to 141.7.255.254141.7.255.2554,094
129141.8.0.0/20141.8.0.1 to 141.8.15.254141.8.15.2554,094
130141.8.16.0/20141.8.16.1 to 141.8.31.254141.8.31.2554,094
131141.8.32.0/20141.8.32.1 to 141.8.47.254141.8.47.2554,094
132141.8.48.0/20141.8.48.1 to 141.8.63.254141.8.63.2554,094
133141.8.64.0/20141.8.64.1 to 141.8.79.254141.8.79.2554,094
134141.8.80.0/20141.8.80.1 to 141.8.95.254141.8.95.2554,094
135141.8.96.0/20141.8.96.1 to 141.8.111.254141.8.111.2554,094
136141.8.112.0/20141.8.112.1 to 141.8.127.254141.8.127.2554,094
137141.8.128.0/20141.8.128.1 to 141.8.143.254141.8.143.2554,094
138141.8.144.0/20141.8.144.1 to 141.8.159.254141.8.159.2554,094
139141.8.160.0/20141.8.160.1 to 141.8.175.254141.8.175.2554,094
140141.8.176.0/20141.8.176.1 to 141.8.191.254141.8.191.2554,094
141141.8.192.0/20141.8.192.1 to 141.8.207.254141.8.207.2554,094
142141.8.208.0/20141.8.208.1 to 141.8.223.254141.8.223.2554,094
143141.8.224.0/20141.8.224.1 to 141.8.239.254141.8.239.2554,094
144141.8.240.0/20141.8.240.1 to 141.8.255.254141.8.255.2554,094
145141.9.0.0/20141.9.0.1 to 141.9.15.254141.9.15.2554,094
146141.9.16.0/20141.9.16.1 to 141.9.31.254141.9.31.2554,094
147141.9.32.0/20141.9.32.1 to 141.9.47.254141.9.47.2554,094
148141.9.48.0/20141.9.48.1 to 141.9.63.254141.9.63.2554,094
149141.9.64.0/20141.9.64.1 to 141.9.79.254141.9.79.2554,094
150141.9.80.0/20141.9.80.1 to 141.9.95.254141.9.95.2554,094
151141.9.96.0/20141.9.96.1 to 141.9.111.254141.9.111.2554,094
152141.9.112.0/20141.9.112.1 to 141.9.127.254141.9.127.2554,094
153141.9.128.0/20141.9.128.1 to 141.9.143.254141.9.143.2554,094
154141.9.144.0/20141.9.144.1 to 141.9.159.254141.9.159.2554,094
155141.9.160.0/20141.9.160.1 to 141.9.175.254141.9.175.2554,094
156141.9.176.0/20141.9.176.1 to 141.9.191.254141.9.191.2554,094
157141.9.192.0/20141.9.192.1 to 141.9.207.254141.9.207.2554,094
158141.9.208.0/20141.9.208.1 to 141.9.223.254141.9.223.2554,094
159141.9.224.0/20141.9.224.1 to 141.9.239.254141.9.239.2554,094
160141.9.240.0/20141.9.240.1 to 141.9.255.254141.9.255.2554,094
161141.10.0.0/20141.10.0.1 to 141.10.15.254141.10.15.2554,094
162141.10.16.0/20141.10.16.1 to 141.10.31.254141.10.31.2554,094
163141.10.32.0/20141.10.32.1 to 141.10.47.254141.10.47.2554,094
164141.10.48.0/20141.10.48.1 to 141.10.63.254141.10.63.2554,094
165141.10.64.0/20141.10.64.1 to 141.10.79.254141.10.79.2554,094
166141.10.80.0/20141.10.80.1 to 141.10.95.254141.10.95.2554,094
167141.10.96.0/20141.10.96.1 to 141.10.111.254141.10.111.2554,094
168141.10.112.0/20141.10.112.1 to 141.10.127.254141.10.127.2554,094
169141.10.128.0/20141.10.128.1 to 141.10.143.254141.10.143.2554,094
170141.10.144.0/20141.10.144.1 to 141.10.159.254141.10.159.2554,094
171141.10.160.0/20141.10.160.1 to 141.10.175.254141.10.175.2554,094
172141.10.176.0/20141.10.176.1 to 141.10.191.254141.10.191.2554,094
173141.10.192.0/20141.10.192.1 to 141.10.207.254141.10.207.2554,094
174141.10.208.0/20141.10.208.1 to 141.10.223.254141.10.223.2554,094
175141.10.224.0/20141.10.224.1 to 141.10.239.254141.10.239.2554,094
176141.10.240.0/20141.10.240.1 to 141.10.255.254141.10.255.2554,094
177141.11.0.0/20141.11.0.1 to 141.11.15.254141.11.15.2554,094
178141.11.16.0/20141.11.16.1 to 141.11.31.254141.11.31.2554,094
179141.11.32.0/20141.11.32.1 to 141.11.47.254141.11.47.2554,094
180141.11.48.0/20141.11.48.1 to 141.11.63.254141.11.63.2554,094
181141.11.64.0/20141.11.64.1 to 141.11.79.254141.11.79.2554,094
182141.11.80.0/20141.11.80.1 to 141.11.95.254141.11.95.2554,094
183141.11.96.0/20141.11.96.1 to 141.11.111.254141.11.111.2554,094
184141.11.112.0/20141.11.112.1 to 141.11.127.254141.11.127.2554,094
185141.11.128.0/20141.11.128.1 to 141.11.143.254141.11.143.2554,094
186141.11.144.0/20141.11.144.1 to 141.11.159.254141.11.159.2554,094
187141.11.160.0/20141.11.160.1 to 141.11.175.254141.11.175.2554,094
188141.11.176.0/20141.11.176.1 to 141.11.191.254141.11.191.2554,094
189141.11.192.0/20141.11.192.1 to 141.11.207.254141.11.207.2554,094
190141.11.208.0/20141.11.208.1 to 141.11.223.254141.11.223.2554,094
191141.11.224.0/20141.11.224.1 to 141.11.239.254141.11.239.2554,094
192141.11.240.0/20141.11.240.1 to 141.11.255.254141.11.255.2554,094
193141.12.0.0/20141.12.0.1 to 141.12.15.254141.12.15.2554,094
194141.12.16.0/20141.12.16.1 to 141.12.31.254141.12.31.2554,094
195141.12.32.0/20141.12.32.1 to 141.12.47.254141.12.47.2554,094
196141.12.48.0/20141.12.48.1 to 141.12.63.254141.12.63.2554,094
197141.12.64.0/20141.12.64.1 to 141.12.79.254141.12.79.2554,094
198141.12.80.0/20141.12.80.1 to 141.12.95.254141.12.95.2554,094
199141.12.96.0/20141.12.96.1 to 141.12.111.254141.12.111.2554,094
200141.12.112.0/20141.12.112.1 to 141.12.127.254141.12.127.2554,094
201141.12.128.0/20141.12.128.1 to 141.12.143.254141.12.143.2554,094
202141.12.144.0/20141.12.144.1 to 141.12.159.254141.12.159.2554,094
203141.12.160.0/20141.12.160.1 to 141.12.175.254141.12.175.2554,094
204141.12.176.0/20141.12.176.1 to 141.12.191.254141.12.191.2554,094
205141.12.192.0/20141.12.192.1 to 141.12.207.254141.12.207.2554,094
206141.12.208.0/20141.12.208.1 to 141.12.223.254141.12.223.2554,094
207141.12.224.0/20141.12.224.1 to 141.12.239.254141.12.239.2554,094
208141.12.240.0/20141.12.240.1 to 141.12.255.254141.12.255.2554,094
209141.13.0.0/20141.13.0.1 to 141.13.15.254141.13.15.2554,094
210141.13.16.0/20141.13.16.1 to 141.13.31.254141.13.31.2554,094
211141.13.32.0/20141.13.32.1 to 141.13.47.254141.13.47.2554,094
212141.13.48.0/20141.13.48.1 to 141.13.63.254141.13.63.2554,094
213141.13.64.0/20141.13.64.1 to 141.13.79.254141.13.79.2554,094
214141.13.80.0/20141.13.80.1 to 141.13.95.254141.13.95.2554,094
215141.13.96.0/20141.13.96.1 to 141.13.111.254141.13.111.2554,094
216141.13.112.0/20141.13.112.1 to 141.13.127.254141.13.127.2554,094
217141.13.128.0/20141.13.128.1 to 141.13.143.254141.13.143.2554,094
218141.13.144.0/20141.13.144.1 to 141.13.159.254141.13.159.2554,094
219141.13.160.0/20141.13.160.1 to 141.13.175.254141.13.175.2554,094
220141.13.176.0/20141.13.176.1 to 141.13.191.254141.13.191.2554,094
221141.13.192.0/20141.13.192.1 to 141.13.207.254141.13.207.2554,094
222141.13.208.0/20141.13.208.1 to 141.13.223.254141.13.223.2554,094
223141.13.224.0/20141.13.224.1 to 141.13.239.254141.13.239.2554,094
224141.13.240.0/20141.13.240.1 to 141.13.255.254141.13.255.2554,094
225141.14.0.0/20141.14.0.1 to 141.14.15.254141.14.15.2554,094
226141.14.16.0/20141.14.16.1 to 141.14.31.254141.14.31.2554,094
227141.14.32.0/20141.14.32.1 to 141.14.47.254141.14.47.2554,094
228141.14.48.0/20141.14.48.1 to 141.14.63.254141.14.63.2554,094
229141.14.64.0/20141.14.64.1 to 141.14.79.254141.14.79.2554,094
230141.14.80.0/20141.14.80.1 to 141.14.95.254141.14.95.2554,094
231141.14.96.0/20141.14.96.1 to 141.14.111.254141.14.111.2554,094
232141.14.112.0/20141.14.112.1 to 141.14.127.254141.14.127.2554,094
233141.14.128.0/20141.14.128.1 to 141.14.143.254141.14.143.2554,094
234141.14.144.0/20141.14.144.1 to 141.14.159.254141.14.159.2554,094
235141.14.160.0/20141.14.160.1 to 141.14.175.254141.14.175.2554,094
236141.14.176.0/20141.14.176.1 to 141.14.191.254141.14.191.2554,094
237141.14.192.0/20141.14.192.1 to 141.14.207.254141.14.207.2554,094
238141.14.208.0/20141.14.208.1 to 141.14.223.254141.14.223.2554,094
239141.14.224.0/20141.14.224.1 to 141.14.239.254141.14.239.2554,094
240141.14.240.0/20141.14.240.1 to 141.14.255.254141.14.255.2554,094
241141.15.0.0/20141.15.0.1 to 141.15.15.254141.15.15.2554,094
242141.15.16.0/20141.15.16.1 to 141.15.31.254141.15.31.2554,094
243141.15.32.0/20141.15.32.1 to 141.15.47.254141.15.47.2554,094
244141.15.48.0/20141.15.48.1 to 141.15.63.254141.15.63.2554,094
245141.15.64.0/20141.15.64.1 to 141.15.79.254141.15.79.2554,094
246141.15.80.0/20141.15.80.1 to 141.15.95.254141.15.95.2554,094
247141.15.96.0/20141.15.96.1 to 141.15.111.254141.15.111.2554,094
248141.15.112.0/20141.15.112.1 to 141.15.127.254141.15.127.2554,094
249141.15.128.0/20141.15.128.1 to 141.15.143.254141.15.143.2554,094
250141.15.144.0/20141.15.144.1 to 141.15.159.254141.15.159.2554,094
251141.15.160.0/20141.15.160.1 to 141.15.175.254141.15.175.2554,094
252141.15.176.0/20141.15.176.1 to 141.15.191.254141.15.191.2554,094
253141.15.192.0/20141.15.192.1 to 141.15.207.254141.15.207.2554,094
254141.15.208.0/20141.15.208.1 to 141.15.223.254141.15.223.2554,094
255141.15.224.0/20141.15.224.1 to 141.15.239.254141.15.239.2554,094
256141.15.240.0/20141.15.240.1 to 141.15.255.254141.15.255.2554,094

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.