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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.

Network223.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
223.0.0.0
Broadcast address
223.127.255.255
First usable
223.0.0.1
Last usable
223.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
C (default /24)
As numbers
Hex DF000000 · Integer 3741319168 to 3749707775
Reverse DNS zones
0.223.in-addr.arpa
1.223.in-addr.arpa
2.223.in-addr.arpa
3.223.in-addr.arpa
4.223.in-addr.arpa
5.223.in-addr.arpa
6.223.in-addr.arpa
7.223.in-addr.arpa
8.223.in-addr.arpa
9.223.in-addr.arpa
10.223.in-addr.arpa
11.223.in-addr.arpa
12.223.in-addr.arpa
13.223.in-addr.arpa
14.223.in-addr.arpa
15.223.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11011111.00000000.00000000.00000000223.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network11011111.00000000.00000000.00000000223.0.0.0
Broadcast11011111.01111111.11111111.11111111223.127.255.255
Split into smaller subnets/20
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

223.0.0.0/9 makes 2,048 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1223.0.0.0/20223.0.0.1 to 223.0.15.254223.0.15.2554,094
2223.0.16.0/20223.0.16.1 to 223.0.31.254223.0.31.2554,094
3223.0.32.0/20223.0.32.1 to 223.0.47.254223.0.47.2554,094
4223.0.48.0/20223.0.48.1 to 223.0.63.254223.0.63.2554,094
5223.0.64.0/20223.0.64.1 to 223.0.79.254223.0.79.2554,094
6223.0.80.0/20223.0.80.1 to 223.0.95.254223.0.95.2554,094
7223.0.96.0/20223.0.96.1 to 223.0.111.254223.0.111.2554,094
8223.0.112.0/20223.0.112.1 to 223.0.127.254223.0.127.2554,094
9223.0.128.0/20223.0.128.1 to 223.0.143.254223.0.143.2554,094
10223.0.144.0/20223.0.144.1 to 223.0.159.254223.0.159.2554,094
11223.0.160.0/20223.0.160.1 to 223.0.175.254223.0.175.2554,094
12223.0.176.0/20223.0.176.1 to 223.0.191.254223.0.191.2554,094
13223.0.192.0/20223.0.192.1 to 223.0.207.254223.0.207.2554,094
14223.0.208.0/20223.0.208.1 to 223.0.223.254223.0.223.2554,094
15223.0.224.0/20223.0.224.1 to 223.0.239.254223.0.239.2554,094
16223.0.240.0/20223.0.240.1 to 223.0.255.254223.0.255.2554,094
17223.1.0.0/20223.1.0.1 to 223.1.15.254223.1.15.2554,094
18223.1.16.0/20223.1.16.1 to 223.1.31.254223.1.31.2554,094
19223.1.32.0/20223.1.32.1 to 223.1.47.254223.1.47.2554,094
20223.1.48.0/20223.1.48.1 to 223.1.63.254223.1.63.2554,094
21223.1.64.0/20223.1.64.1 to 223.1.79.254223.1.79.2554,094
22223.1.80.0/20223.1.80.1 to 223.1.95.254223.1.95.2554,094
23223.1.96.0/20223.1.96.1 to 223.1.111.254223.1.111.2554,094
24223.1.112.0/20223.1.112.1 to 223.1.127.254223.1.127.2554,094
25223.1.128.0/20223.1.128.1 to 223.1.143.254223.1.143.2554,094
26223.1.144.0/20223.1.144.1 to 223.1.159.254223.1.159.2554,094
27223.1.160.0/20223.1.160.1 to 223.1.175.254223.1.175.2554,094
28223.1.176.0/20223.1.176.1 to 223.1.191.254223.1.191.2554,094
29223.1.192.0/20223.1.192.1 to 223.1.207.254223.1.207.2554,094
30223.1.208.0/20223.1.208.1 to 223.1.223.254223.1.223.2554,094
31223.1.224.0/20223.1.224.1 to 223.1.239.254223.1.239.2554,094
32223.1.240.0/20223.1.240.1 to 223.1.255.254223.1.255.2554,094
33223.2.0.0/20223.2.0.1 to 223.2.15.254223.2.15.2554,094
34223.2.16.0/20223.2.16.1 to 223.2.31.254223.2.31.2554,094
35223.2.32.0/20223.2.32.1 to 223.2.47.254223.2.47.2554,094
36223.2.48.0/20223.2.48.1 to 223.2.63.254223.2.63.2554,094
37223.2.64.0/20223.2.64.1 to 223.2.79.254223.2.79.2554,094
38223.2.80.0/20223.2.80.1 to 223.2.95.254223.2.95.2554,094
39223.2.96.0/20223.2.96.1 to 223.2.111.254223.2.111.2554,094
40223.2.112.0/20223.2.112.1 to 223.2.127.254223.2.127.2554,094
41223.2.128.0/20223.2.128.1 to 223.2.143.254223.2.143.2554,094
42223.2.144.0/20223.2.144.1 to 223.2.159.254223.2.159.2554,094
43223.2.160.0/20223.2.160.1 to 223.2.175.254223.2.175.2554,094
44223.2.176.0/20223.2.176.1 to 223.2.191.254223.2.191.2554,094
45223.2.192.0/20223.2.192.1 to 223.2.207.254223.2.207.2554,094
46223.2.208.0/20223.2.208.1 to 223.2.223.254223.2.223.2554,094
47223.2.224.0/20223.2.224.1 to 223.2.239.254223.2.239.2554,094
48223.2.240.0/20223.2.240.1 to 223.2.255.254223.2.255.2554,094
49223.3.0.0/20223.3.0.1 to 223.3.15.254223.3.15.2554,094
50223.3.16.0/20223.3.16.1 to 223.3.31.254223.3.31.2554,094
51223.3.32.0/20223.3.32.1 to 223.3.47.254223.3.47.2554,094
52223.3.48.0/20223.3.48.1 to 223.3.63.254223.3.63.2554,094
53223.3.64.0/20223.3.64.1 to 223.3.79.254223.3.79.2554,094
54223.3.80.0/20223.3.80.1 to 223.3.95.254223.3.95.2554,094
55223.3.96.0/20223.3.96.1 to 223.3.111.254223.3.111.2554,094
56223.3.112.0/20223.3.112.1 to 223.3.127.254223.3.127.2554,094
57223.3.128.0/20223.3.128.1 to 223.3.143.254223.3.143.2554,094
58223.3.144.0/20223.3.144.1 to 223.3.159.254223.3.159.2554,094
59223.3.160.0/20223.3.160.1 to 223.3.175.254223.3.175.2554,094
60223.3.176.0/20223.3.176.1 to 223.3.191.254223.3.191.2554,094
61223.3.192.0/20223.3.192.1 to 223.3.207.254223.3.207.2554,094
62223.3.208.0/20223.3.208.1 to 223.3.223.254223.3.223.2554,094
63223.3.224.0/20223.3.224.1 to 223.3.239.254223.3.239.2554,094
64223.3.240.0/20223.3.240.1 to 223.3.255.254223.3.255.2554,094
65223.4.0.0/20223.4.0.1 to 223.4.15.254223.4.15.2554,094
66223.4.16.0/20223.4.16.1 to 223.4.31.254223.4.31.2554,094
67223.4.32.0/20223.4.32.1 to 223.4.47.254223.4.47.2554,094
68223.4.48.0/20223.4.48.1 to 223.4.63.254223.4.63.2554,094
69223.4.64.0/20223.4.64.1 to 223.4.79.254223.4.79.2554,094
70223.4.80.0/20223.4.80.1 to 223.4.95.254223.4.95.2554,094
71223.4.96.0/20223.4.96.1 to 223.4.111.254223.4.111.2554,094
72223.4.112.0/20223.4.112.1 to 223.4.127.254223.4.127.2554,094
73223.4.128.0/20223.4.128.1 to 223.4.143.254223.4.143.2554,094
74223.4.144.0/20223.4.144.1 to 223.4.159.254223.4.159.2554,094
75223.4.160.0/20223.4.160.1 to 223.4.175.254223.4.175.2554,094
76223.4.176.0/20223.4.176.1 to 223.4.191.254223.4.191.2554,094
77223.4.192.0/20223.4.192.1 to 223.4.207.254223.4.207.2554,094
78223.4.208.0/20223.4.208.1 to 223.4.223.254223.4.223.2554,094
79223.4.224.0/20223.4.224.1 to 223.4.239.254223.4.239.2554,094
80223.4.240.0/20223.4.240.1 to 223.4.255.254223.4.255.2554,094
81223.5.0.0/20223.5.0.1 to 223.5.15.254223.5.15.2554,094
82223.5.16.0/20223.5.16.1 to 223.5.31.254223.5.31.2554,094
83223.5.32.0/20223.5.32.1 to 223.5.47.254223.5.47.2554,094
84223.5.48.0/20223.5.48.1 to 223.5.63.254223.5.63.2554,094
85223.5.64.0/20223.5.64.1 to 223.5.79.254223.5.79.2554,094
86223.5.80.0/20223.5.80.1 to 223.5.95.254223.5.95.2554,094
87223.5.96.0/20223.5.96.1 to 223.5.111.254223.5.111.2554,094
88223.5.112.0/20223.5.112.1 to 223.5.127.254223.5.127.2554,094
89223.5.128.0/20223.5.128.1 to 223.5.143.254223.5.143.2554,094
90223.5.144.0/20223.5.144.1 to 223.5.159.254223.5.159.2554,094
91223.5.160.0/20223.5.160.1 to 223.5.175.254223.5.175.2554,094
92223.5.176.0/20223.5.176.1 to 223.5.191.254223.5.191.2554,094
93223.5.192.0/20223.5.192.1 to 223.5.207.254223.5.207.2554,094
94223.5.208.0/20223.5.208.1 to 223.5.223.254223.5.223.2554,094
95223.5.224.0/20223.5.224.1 to 223.5.239.254223.5.239.2554,094
96223.5.240.0/20223.5.240.1 to 223.5.255.254223.5.255.2554,094
97223.6.0.0/20223.6.0.1 to 223.6.15.254223.6.15.2554,094
98223.6.16.0/20223.6.16.1 to 223.6.31.254223.6.31.2554,094
99223.6.32.0/20223.6.32.1 to 223.6.47.254223.6.47.2554,094
100223.6.48.0/20223.6.48.1 to 223.6.63.254223.6.63.2554,094
101223.6.64.0/20223.6.64.1 to 223.6.79.254223.6.79.2554,094
102223.6.80.0/20223.6.80.1 to 223.6.95.254223.6.95.2554,094
103223.6.96.0/20223.6.96.1 to 223.6.111.254223.6.111.2554,094
104223.6.112.0/20223.6.112.1 to 223.6.127.254223.6.127.2554,094
105223.6.128.0/20223.6.128.1 to 223.6.143.254223.6.143.2554,094
106223.6.144.0/20223.6.144.1 to 223.6.159.254223.6.159.2554,094
107223.6.160.0/20223.6.160.1 to 223.6.175.254223.6.175.2554,094
108223.6.176.0/20223.6.176.1 to 223.6.191.254223.6.191.2554,094
109223.6.192.0/20223.6.192.1 to 223.6.207.254223.6.207.2554,094
110223.6.208.0/20223.6.208.1 to 223.6.223.254223.6.223.2554,094
111223.6.224.0/20223.6.224.1 to 223.6.239.254223.6.239.2554,094
112223.6.240.0/20223.6.240.1 to 223.6.255.254223.6.255.2554,094
113223.7.0.0/20223.7.0.1 to 223.7.15.254223.7.15.2554,094
114223.7.16.0/20223.7.16.1 to 223.7.31.254223.7.31.2554,094
115223.7.32.0/20223.7.32.1 to 223.7.47.254223.7.47.2554,094
116223.7.48.0/20223.7.48.1 to 223.7.63.254223.7.63.2554,094
117223.7.64.0/20223.7.64.1 to 223.7.79.254223.7.79.2554,094
118223.7.80.0/20223.7.80.1 to 223.7.95.254223.7.95.2554,094
119223.7.96.0/20223.7.96.1 to 223.7.111.254223.7.111.2554,094
120223.7.112.0/20223.7.112.1 to 223.7.127.254223.7.127.2554,094
121223.7.128.0/20223.7.128.1 to 223.7.143.254223.7.143.2554,094
122223.7.144.0/20223.7.144.1 to 223.7.159.254223.7.159.2554,094
123223.7.160.0/20223.7.160.1 to 223.7.175.254223.7.175.2554,094
124223.7.176.0/20223.7.176.1 to 223.7.191.254223.7.191.2554,094
125223.7.192.0/20223.7.192.1 to 223.7.207.254223.7.207.2554,094
126223.7.208.0/20223.7.208.1 to 223.7.223.254223.7.223.2554,094
127223.7.224.0/20223.7.224.1 to 223.7.239.254223.7.239.2554,094
128223.7.240.0/20223.7.240.1 to 223.7.255.254223.7.255.2554,094
129223.8.0.0/20223.8.0.1 to 223.8.15.254223.8.15.2554,094
130223.8.16.0/20223.8.16.1 to 223.8.31.254223.8.31.2554,094
131223.8.32.0/20223.8.32.1 to 223.8.47.254223.8.47.2554,094
132223.8.48.0/20223.8.48.1 to 223.8.63.254223.8.63.2554,094
133223.8.64.0/20223.8.64.1 to 223.8.79.254223.8.79.2554,094
134223.8.80.0/20223.8.80.1 to 223.8.95.254223.8.95.2554,094
135223.8.96.0/20223.8.96.1 to 223.8.111.254223.8.111.2554,094
136223.8.112.0/20223.8.112.1 to 223.8.127.254223.8.127.2554,094
137223.8.128.0/20223.8.128.1 to 223.8.143.254223.8.143.2554,094
138223.8.144.0/20223.8.144.1 to 223.8.159.254223.8.159.2554,094
139223.8.160.0/20223.8.160.1 to 223.8.175.254223.8.175.2554,094
140223.8.176.0/20223.8.176.1 to 223.8.191.254223.8.191.2554,094
141223.8.192.0/20223.8.192.1 to 223.8.207.254223.8.207.2554,094
142223.8.208.0/20223.8.208.1 to 223.8.223.254223.8.223.2554,094
143223.8.224.0/20223.8.224.1 to 223.8.239.254223.8.239.2554,094
144223.8.240.0/20223.8.240.1 to 223.8.255.254223.8.255.2554,094
145223.9.0.0/20223.9.0.1 to 223.9.15.254223.9.15.2554,094
146223.9.16.0/20223.9.16.1 to 223.9.31.254223.9.31.2554,094
147223.9.32.0/20223.9.32.1 to 223.9.47.254223.9.47.2554,094
148223.9.48.0/20223.9.48.1 to 223.9.63.254223.9.63.2554,094
149223.9.64.0/20223.9.64.1 to 223.9.79.254223.9.79.2554,094
150223.9.80.0/20223.9.80.1 to 223.9.95.254223.9.95.2554,094
151223.9.96.0/20223.9.96.1 to 223.9.111.254223.9.111.2554,094
152223.9.112.0/20223.9.112.1 to 223.9.127.254223.9.127.2554,094
153223.9.128.0/20223.9.128.1 to 223.9.143.254223.9.143.2554,094
154223.9.144.0/20223.9.144.1 to 223.9.159.254223.9.159.2554,094
155223.9.160.0/20223.9.160.1 to 223.9.175.254223.9.175.2554,094
156223.9.176.0/20223.9.176.1 to 223.9.191.254223.9.191.2554,094
157223.9.192.0/20223.9.192.1 to 223.9.207.254223.9.207.2554,094
158223.9.208.0/20223.9.208.1 to 223.9.223.254223.9.223.2554,094
159223.9.224.0/20223.9.224.1 to 223.9.239.254223.9.239.2554,094
160223.9.240.0/20223.9.240.1 to 223.9.255.254223.9.255.2554,094
161223.10.0.0/20223.10.0.1 to 223.10.15.254223.10.15.2554,094
162223.10.16.0/20223.10.16.1 to 223.10.31.254223.10.31.2554,094
163223.10.32.0/20223.10.32.1 to 223.10.47.254223.10.47.2554,094
164223.10.48.0/20223.10.48.1 to 223.10.63.254223.10.63.2554,094
165223.10.64.0/20223.10.64.1 to 223.10.79.254223.10.79.2554,094
166223.10.80.0/20223.10.80.1 to 223.10.95.254223.10.95.2554,094
167223.10.96.0/20223.10.96.1 to 223.10.111.254223.10.111.2554,094
168223.10.112.0/20223.10.112.1 to 223.10.127.254223.10.127.2554,094
169223.10.128.0/20223.10.128.1 to 223.10.143.254223.10.143.2554,094
170223.10.144.0/20223.10.144.1 to 223.10.159.254223.10.159.2554,094
171223.10.160.0/20223.10.160.1 to 223.10.175.254223.10.175.2554,094
172223.10.176.0/20223.10.176.1 to 223.10.191.254223.10.191.2554,094
173223.10.192.0/20223.10.192.1 to 223.10.207.254223.10.207.2554,094
174223.10.208.0/20223.10.208.1 to 223.10.223.254223.10.223.2554,094
175223.10.224.0/20223.10.224.1 to 223.10.239.254223.10.239.2554,094
176223.10.240.0/20223.10.240.1 to 223.10.255.254223.10.255.2554,094
177223.11.0.0/20223.11.0.1 to 223.11.15.254223.11.15.2554,094
178223.11.16.0/20223.11.16.1 to 223.11.31.254223.11.31.2554,094
179223.11.32.0/20223.11.32.1 to 223.11.47.254223.11.47.2554,094
180223.11.48.0/20223.11.48.1 to 223.11.63.254223.11.63.2554,094
181223.11.64.0/20223.11.64.1 to 223.11.79.254223.11.79.2554,094
182223.11.80.0/20223.11.80.1 to 223.11.95.254223.11.95.2554,094
183223.11.96.0/20223.11.96.1 to 223.11.111.254223.11.111.2554,094
184223.11.112.0/20223.11.112.1 to 223.11.127.254223.11.127.2554,094
185223.11.128.0/20223.11.128.1 to 223.11.143.254223.11.143.2554,094
186223.11.144.0/20223.11.144.1 to 223.11.159.254223.11.159.2554,094
187223.11.160.0/20223.11.160.1 to 223.11.175.254223.11.175.2554,094
188223.11.176.0/20223.11.176.1 to 223.11.191.254223.11.191.2554,094
189223.11.192.0/20223.11.192.1 to 223.11.207.254223.11.207.2554,094
190223.11.208.0/20223.11.208.1 to 223.11.223.254223.11.223.2554,094
191223.11.224.0/20223.11.224.1 to 223.11.239.254223.11.239.2554,094
192223.11.240.0/20223.11.240.1 to 223.11.255.254223.11.255.2554,094
193223.12.0.0/20223.12.0.1 to 223.12.15.254223.12.15.2554,094
194223.12.16.0/20223.12.16.1 to 223.12.31.254223.12.31.2554,094
195223.12.32.0/20223.12.32.1 to 223.12.47.254223.12.47.2554,094
196223.12.48.0/20223.12.48.1 to 223.12.63.254223.12.63.2554,094
197223.12.64.0/20223.12.64.1 to 223.12.79.254223.12.79.2554,094
198223.12.80.0/20223.12.80.1 to 223.12.95.254223.12.95.2554,094
199223.12.96.0/20223.12.96.1 to 223.12.111.254223.12.111.2554,094
200223.12.112.0/20223.12.112.1 to 223.12.127.254223.12.127.2554,094
201223.12.128.0/20223.12.128.1 to 223.12.143.254223.12.143.2554,094
202223.12.144.0/20223.12.144.1 to 223.12.159.254223.12.159.2554,094
203223.12.160.0/20223.12.160.1 to 223.12.175.254223.12.175.2554,094
204223.12.176.0/20223.12.176.1 to 223.12.191.254223.12.191.2554,094
205223.12.192.0/20223.12.192.1 to 223.12.207.254223.12.207.2554,094
206223.12.208.0/20223.12.208.1 to 223.12.223.254223.12.223.2554,094
207223.12.224.0/20223.12.224.1 to 223.12.239.254223.12.239.2554,094
208223.12.240.0/20223.12.240.1 to 223.12.255.254223.12.255.2554,094
209223.13.0.0/20223.13.0.1 to 223.13.15.254223.13.15.2554,094
210223.13.16.0/20223.13.16.1 to 223.13.31.254223.13.31.2554,094
211223.13.32.0/20223.13.32.1 to 223.13.47.254223.13.47.2554,094
212223.13.48.0/20223.13.48.1 to 223.13.63.254223.13.63.2554,094
213223.13.64.0/20223.13.64.1 to 223.13.79.254223.13.79.2554,094
214223.13.80.0/20223.13.80.1 to 223.13.95.254223.13.95.2554,094
215223.13.96.0/20223.13.96.1 to 223.13.111.254223.13.111.2554,094
216223.13.112.0/20223.13.112.1 to 223.13.127.254223.13.127.2554,094
217223.13.128.0/20223.13.128.1 to 223.13.143.254223.13.143.2554,094
218223.13.144.0/20223.13.144.1 to 223.13.159.254223.13.159.2554,094
219223.13.160.0/20223.13.160.1 to 223.13.175.254223.13.175.2554,094
220223.13.176.0/20223.13.176.1 to 223.13.191.254223.13.191.2554,094
221223.13.192.0/20223.13.192.1 to 223.13.207.254223.13.207.2554,094
222223.13.208.0/20223.13.208.1 to 223.13.223.254223.13.223.2554,094
223223.13.224.0/20223.13.224.1 to 223.13.239.254223.13.239.2554,094
224223.13.240.0/20223.13.240.1 to 223.13.255.254223.13.255.2554,094
225223.14.0.0/20223.14.0.1 to 223.14.15.254223.14.15.2554,094
226223.14.16.0/20223.14.16.1 to 223.14.31.254223.14.31.2554,094
227223.14.32.0/20223.14.32.1 to 223.14.47.254223.14.47.2554,094
228223.14.48.0/20223.14.48.1 to 223.14.63.254223.14.63.2554,094
229223.14.64.0/20223.14.64.1 to 223.14.79.254223.14.79.2554,094
230223.14.80.0/20223.14.80.1 to 223.14.95.254223.14.95.2554,094
231223.14.96.0/20223.14.96.1 to 223.14.111.254223.14.111.2554,094
232223.14.112.0/20223.14.112.1 to 223.14.127.254223.14.127.2554,094
233223.14.128.0/20223.14.128.1 to 223.14.143.254223.14.143.2554,094
234223.14.144.0/20223.14.144.1 to 223.14.159.254223.14.159.2554,094
235223.14.160.0/20223.14.160.1 to 223.14.175.254223.14.175.2554,094
236223.14.176.0/20223.14.176.1 to 223.14.191.254223.14.191.2554,094
237223.14.192.0/20223.14.192.1 to 223.14.207.254223.14.207.2554,094
238223.14.208.0/20223.14.208.1 to 223.14.223.254223.14.223.2554,094
239223.14.224.0/20223.14.224.1 to 223.14.239.254223.14.239.2554,094
240223.14.240.0/20223.14.240.1 to 223.14.255.254223.14.255.2554,094
241223.15.0.0/20223.15.0.1 to 223.15.15.254223.15.15.2554,094
242223.15.16.0/20223.15.16.1 to 223.15.31.254223.15.31.2554,094
243223.15.32.0/20223.15.32.1 to 223.15.47.254223.15.47.2554,094
244223.15.48.0/20223.15.48.1 to 223.15.63.254223.15.63.2554,094
245223.15.64.0/20223.15.64.1 to 223.15.79.254223.15.79.2554,094
246223.15.80.0/20223.15.80.1 to 223.15.95.254223.15.95.2554,094
247223.15.96.0/20223.15.96.1 to 223.15.111.254223.15.111.2554,094
248223.15.112.0/20223.15.112.1 to 223.15.127.254223.15.127.2554,094
249223.15.128.0/20223.15.128.1 to 223.15.143.254223.15.143.2554,094
250223.15.144.0/20223.15.144.1 to 223.15.159.254223.15.159.2554,094
251223.15.160.0/20223.15.160.1 to 223.15.175.254223.15.175.2554,094
252223.15.176.0/20223.15.176.1 to 223.15.191.254223.15.191.2554,094
253223.15.192.0/20223.15.192.1 to 223.15.207.254223.15.207.2554,094
254223.15.208.0/20223.15.208.1 to 223.15.223.254223.15.223.2554,094
255223.15.224.0/20223.15.224.1 to 223.15.239.254223.15.239.2554,094
256223.15.240.0/20223.15.240.1 to 223.15.255.254223.15.255.2554,094

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.