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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.

Network223.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
223.0.0.0
Broadcast address
223.255.255.255
First usable
223.0.0.1
Last usable
223.255.255.254
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 DF000000 · Integer 3741319168 to 3758096383
Reverse DNS zone
223.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11011111..00000000.00000000.00000000223.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network11011111..00000000.00000000.00000000223.0.0.0
Broadcast11011111..11111111.11111111.11111111223.255.255.255
Split into smaller subnets/18
/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)

223.0.0.0/8 makes 1,024 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1223.0.0.0/18223.0.0.1 to 223.0.63.254223.0.63.25516,382
2223.0.64.0/18223.0.64.1 to 223.0.127.254223.0.127.25516,382
3223.0.128.0/18223.0.128.1 to 223.0.191.254223.0.191.25516,382
4223.0.192.0/18223.0.192.1 to 223.0.255.254223.0.255.25516,382
5223.1.0.0/18223.1.0.1 to 223.1.63.254223.1.63.25516,382
6223.1.64.0/18223.1.64.1 to 223.1.127.254223.1.127.25516,382
7223.1.128.0/18223.1.128.1 to 223.1.191.254223.1.191.25516,382
8223.1.192.0/18223.1.192.1 to 223.1.255.254223.1.255.25516,382
9223.2.0.0/18223.2.0.1 to 223.2.63.254223.2.63.25516,382
10223.2.64.0/18223.2.64.1 to 223.2.127.254223.2.127.25516,382
11223.2.128.0/18223.2.128.1 to 223.2.191.254223.2.191.25516,382
12223.2.192.0/18223.2.192.1 to 223.2.255.254223.2.255.25516,382
13223.3.0.0/18223.3.0.1 to 223.3.63.254223.3.63.25516,382
14223.3.64.0/18223.3.64.1 to 223.3.127.254223.3.127.25516,382
15223.3.128.0/18223.3.128.1 to 223.3.191.254223.3.191.25516,382
16223.3.192.0/18223.3.192.1 to 223.3.255.254223.3.255.25516,382
17223.4.0.0/18223.4.0.1 to 223.4.63.254223.4.63.25516,382
18223.4.64.0/18223.4.64.1 to 223.4.127.254223.4.127.25516,382
19223.4.128.0/18223.4.128.1 to 223.4.191.254223.4.191.25516,382
20223.4.192.0/18223.4.192.1 to 223.4.255.254223.4.255.25516,382
21223.5.0.0/18223.5.0.1 to 223.5.63.254223.5.63.25516,382
22223.5.64.0/18223.5.64.1 to 223.5.127.254223.5.127.25516,382
23223.5.128.0/18223.5.128.1 to 223.5.191.254223.5.191.25516,382
24223.5.192.0/18223.5.192.1 to 223.5.255.254223.5.255.25516,382
25223.6.0.0/18223.6.0.1 to 223.6.63.254223.6.63.25516,382
26223.6.64.0/18223.6.64.1 to 223.6.127.254223.6.127.25516,382
27223.6.128.0/18223.6.128.1 to 223.6.191.254223.6.191.25516,382
28223.6.192.0/18223.6.192.1 to 223.6.255.254223.6.255.25516,382
29223.7.0.0/18223.7.0.1 to 223.7.63.254223.7.63.25516,382
30223.7.64.0/18223.7.64.1 to 223.7.127.254223.7.127.25516,382
31223.7.128.0/18223.7.128.1 to 223.7.191.254223.7.191.25516,382
32223.7.192.0/18223.7.192.1 to 223.7.255.254223.7.255.25516,382
33223.8.0.0/18223.8.0.1 to 223.8.63.254223.8.63.25516,382
34223.8.64.0/18223.8.64.1 to 223.8.127.254223.8.127.25516,382
35223.8.128.0/18223.8.128.1 to 223.8.191.254223.8.191.25516,382
36223.8.192.0/18223.8.192.1 to 223.8.255.254223.8.255.25516,382
37223.9.0.0/18223.9.0.1 to 223.9.63.254223.9.63.25516,382
38223.9.64.0/18223.9.64.1 to 223.9.127.254223.9.127.25516,382
39223.9.128.0/18223.9.128.1 to 223.9.191.254223.9.191.25516,382
40223.9.192.0/18223.9.192.1 to 223.9.255.254223.9.255.25516,382
41223.10.0.0/18223.10.0.1 to 223.10.63.254223.10.63.25516,382
42223.10.64.0/18223.10.64.1 to 223.10.127.254223.10.127.25516,382
43223.10.128.0/18223.10.128.1 to 223.10.191.254223.10.191.25516,382
44223.10.192.0/18223.10.192.1 to 223.10.255.254223.10.255.25516,382
45223.11.0.0/18223.11.0.1 to 223.11.63.254223.11.63.25516,382
46223.11.64.0/18223.11.64.1 to 223.11.127.254223.11.127.25516,382
47223.11.128.0/18223.11.128.1 to 223.11.191.254223.11.191.25516,382
48223.11.192.0/18223.11.192.1 to 223.11.255.254223.11.255.25516,382
49223.12.0.0/18223.12.0.1 to 223.12.63.254223.12.63.25516,382
50223.12.64.0/18223.12.64.1 to 223.12.127.254223.12.127.25516,382
51223.12.128.0/18223.12.128.1 to 223.12.191.254223.12.191.25516,382
52223.12.192.0/18223.12.192.1 to 223.12.255.254223.12.255.25516,382
53223.13.0.0/18223.13.0.1 to 223.13.63.254223.13.63.25516,382
54223.13.64.0/18223.13.64.1 to 223.13.127.254223.13.127.25516,382
55223.13.128.0/18223.13.128.1 to 223.13.191.254223.13.191.25516,382
56223.13.192.0/18223.13.192.1 to 223.13.255.254223.13.255.25516,382
57223.14.0.0/18223.14.0.1 to 223.14.63.254223.14.63.25516,382
58223.14.64.0/18223.14.64.1 to 223.14.127.254223.14.127.25516,382
59223.14.128.0/18223.14.128.1 to 223.14.191.254223.14.191.25516,382
60223.14.192.0/18223.14.192.1 to 223.14.255.254223.14.255.25516,382
61223.15.0.0/18223.15.0.1 to 223.15.63.254223.15.63.25516,382
62223.15.64.0/18223.15.64.1 to 223.15.127.254223.15.127.25516,382
63223.15.128.0/18223.15.128.1 to 223.15.191.254223.15.191.25516,382
64223.15.192.0/18223.15.192.1 to 223.15.255.254223.15.255.25516,382
65223.16.0.0/18223.16.0.1 to 223.16.63.254223.16.63.25516,382
66223.16.64.0/18223.16.64.1 to 223.16.127.254223.16.127.25516,382
67223.16.128.0/18223.16.128.1 to 223.16.191.254223.16.191.25516,382
68223.16.192.0/18223.16.192.1 to 223.16.255.254223.16.255.25516,382
69223.17.0.0/18223.17.0.1 to 223.17.63.254223.17.63.25516,382
70223.17.64.0/18223.17.64.1 to 223.17.127.254223.17.127.25516,382
71223.17.128.0/18223.17.128.1 to 223.17.191.254223.17.191.25516,382
72223.17.192.0/18223.17.192.1 to 223.17.255.254223.17.255.25516,382
73223.18.0.0/18223.18.0.1 to 223.18.63.254223.18.63.25516,382
74223.18.64.0/18223.18.64.1 to 223.18.127.254223.18.127.25516,382
75223.18.128.0/18223.18.128.1 to 223.18.191.254223.18.191.25516,382
76223.18.192.0/18223.18.192.1 to 223.18.255.254223.18.255.25516,382
77223.19.0.0/18223.19.0.1 to 223.19.63.254223.19.63.25516,382
78223.19.64.0/18223.19.64.1 to 223.19.127.254223.19.127.25516,382
79223.19.128.0/18223.19.128.1 to 223.19.191.254223.19.191.25516,382
80223.19.192.0/18223.19.192.1 to 223.19.255.254223.19.255.25516,382
81223.20.0.0/18223.20.0.1 to 223.20.63.254223.20.63.25516,382
82223.20.64.0/18223.20.64.1 to 223.20.127.254223.20.127.25516,382
83223.20.128.0/18223.20.128.1 to 223.20.191.254223.20.191.25516,382
84223.20.192.0/18223.20.192.1 to 223.20.255.254223.20.255.25516,382
85223.21.0.0/18223.21.0.1 to 223.21.63.254223.21.63.25516,382
86223.21.64.0/18223.21.64.1 to 223.21.127.254223.21.127.25516,382
87223.21.128.0/18223.21.128.1 to 223.21.191.254223.21.191.25516,382
88223.21.192.0/18223.21.192.1 to 223.21.255.254223.21.255.25516,382
89223.22.0.0/18223.22.0.1 to 223.22.63.254223.22.63.25516,382
90223.22.64.0/18223.22.64.1 to 223.22.127.254223.22.127.25516,382
91223.22.128.0/18223.22.128.1 to 223.22.191.254223.22.191.25516,382
92223.22.192.0/18223.22.192.1 to 223.22.255.254223.22.255.25516,382
93223.23.0.0/18223.23.0.1 to 223.23.63.254223.23.63.25516,382
94223.23.64.0/18223.23.64.1 to 223.23.127.254223.23.127.25516,382
95223.23.128.0/18223.23.128.1 to 223.23.191.254223.23.191.25516,382
96223.23.192.0/18223.23.192.1 to 223.23.255.254223.23.255.25516,382
97223.24.0.0/18223.24.0.1 to 223.24.63.254223.24.63.25516,382
98223.24.64.0/18223.24.64.1 to 223.24.127.254223.24.127.25516,382
99223.24.128.0/18223.24.128.1 to 223.24.191.254223.24.191.25516,382
100223.24.192.0/18223.24.192.1 to 223.24.255.254223.24.255.25516,382
101223.25.0.0/18223.25.0.1 to 223.25.63.254223.25.63.25516,382
102223.25.64.0/18223.25.64.1 to 223.25.127.254223.25.127.25516,382
103223.25.128.0/18223.25.128.1 to 223.25.191.254223.25.191.25516,382
104223.25.192.0/18223.25.192.1 to 223.25.255.254223.25.255.25516,382
105223.26.0.0/18223.26.0.1 to 223.26.63.254223.26.63.25516,382
106223.26.64.0/18223.26.64.1 to 223.26.127.254223.26.127.25516,382
107223.26.128.0/18223.26.128.1 to 223.26.191.254223.26.191.25516,382
108223.26.192.0/18223.26.192.1 to 223.26.255.254223.26.255.25516,382
109223.27.0.0/18223.27.0.1 to 223.27.63.254223.27.63.25516,382
110223.27.64.0/18223.27.64.1 to 223.27.127.254223.27.127.25516,382
111223.27.128.0/18223.27.128.1 to 223.27.191.254223.27.191.25516,382
112223.27.192.0/18223.27.192.1 to 223.27.255.254223.27.255.25516,382
113223.28.0.0/18223.28.0.1 to 223.28.63.254223.28.63.25516,382
114223.28.64.0/18223.28.64.1 to 223.28.127.254223.28.127.25516,382
115223.28.128.0/18223.28.128.1 to 223.28.191.254223.28.191.25516,382
116223.28.192.0/18223.28.192.1 to 223.28.255.254223.28.255.25516,382
117223.29.0.0/18223.29.0.1 to 223.29.63.254223.29.63.25516,382
118223.29.64.0/18223.29.64.1 to 223.29.127.254223.29.127.25516,382
119223.29.128.0/18223.29.128.1 to 223.29.191.254223.29.191.25516,382
120223.29.192.0/18223.29.192.1 to 223.29.255.254223.29.255.25516,382
121223.30.0.0/18223.30.0.1 to 223.30.63.254223.30.63.25516,382
122223.30.64.0/18223.30.64.1 to 223.30.127.254223.30.127.25516,382
123223.30.128.0/18223.30.128.1 to 223.30.191.254223.30.191.25516,382
124223.30.192.0/18223.30.192.1 to 223.30.255.254223.30.255.25516,382
125223.31.0.0/18223.31.0.1 to 223.31.63.254223.31.63.25516,382
126223.31.64.0/18223.31.64.1 to 223.31.127.254223.31.127.25516,382
127223.31.128.0/18223.31.128.1 to 223.31.191.254223.31.191.25516,382
128223.31.192.0/18223.31.192.1 to 223.31.255.254223.31.255.25516,382
129223.32.0.0/18223.32.0.1 to 223.32.63.254223.32.63.25516,382
130223.32.64.0/18223.32.64.1 to 223.32.127.254223.32.127.25516,382
131223.32.128.0/18223.32.128.1 to 223.32.191.254223.32.191.25516,382
132223.32.192.0/18223.32.192.1 to 223.32.255.254223.32.255.25516,382
133223.33.0.0/18223.33.0.1 to 223.33.63.254223.33.63.25516,382
134223.33.64.0/18223.33.64.1 to 223.33.127.254223.33.127.25516,382
135223.33.128.0/18223.33.128.1 to 223.33.191.254223.33.191.25516,382
136223.33.192.0/18223.33.192.1 to 223.33.255.254223.33.255.25516,382
137223.34.0.0/18223.34.0.1 to 223.34.63.254223.34.63.25516,382
138223.34.64.0/18223.34.64.1 to 223.34.127.254223.34.127.25516,382
139223.34.128.0/18223.34.128.1 to 223.34.191.254223.34.191.25516,382
140223.34.192.0/18223.34.192.1 to 223.34.255.254223.34.255.25516,382
141223.35.0.0/18223.35.0.1 to 223.35.63.254223.35.63.25516,382
142223.35.64.0/18223.35.64.1 to 223.35.127.254223.35.127.25516,382
143223.35.128.0/18223.35.128.1 to 223.35.191.254223.35.191.25516,382
144223.35.192.0/18223.35.192.1 to 223.35.255.254223.35.255.25516,382
145223.36.0.0/18223.36.0.1 to 223.36.63.254223.36.63.25516,382
146223.36.64.0/18223.36.64.1 to 223.36.127.254223.36.127.25516,382
147223.36.128.0/18223.36.128.1 to 223.36.191.254223.36.191.25516,382
148223.36.192.0/18223.36.192.1 to 223.36.255.254223.36.255.25516,382
149223.37.0.0/18223.37.0.1 to 223.37.63.254223.37.63.25516,382
150223.37.64.0/18223.37.64.1 to 223.37.127.254223.37.127.25516,382
151223.37.128.0/18223.37.128.1 to 223.37.191.254223.37.191.25516,382
152223.37.192.0/18223.37.192.1 to 223.37.255.254223.37.255.25516,382
153223.38.0.0/18223.38.0.1 to 223.38.63.254223.38.63.25516,382
154223.38.64.0/18223.38.64.1 to 223.38.127.254223.38.127.25516,382
155223.38.128.0/18223.38.128.1 to 223.38.191.254223.38.191.25516,382
156223.38.192.0/18223.38.192.1 to 223.38.255.254223.38.255.25516,382
157223.39.0.0/18223.39.0.1 to 223.39.63.254223.39.63.25516,382
158223.39.64.0/18223.39.64.1 to 223.39.127.254223.39.127.25516,382
159223.39.128.0/18223.39.128.1 to 223.39.191.254223.39.191.25516,382
160223.39.192.0/18223.39.192.1 to 223.39.255.254223.39.255.25516,382
161223.40.0.0/18223.40.0.1 to 223.40.63.254223.40.63.25516,382
162223.40.64.0/18223.40.64.1 to 223.40.127.254223.40.127.25516,382
163223.40.128.0/18223.40.128.1 to 223.40.191.254223.40.191.25516,382
164223.40.192.0/18223.40.192.1 to 223.40.255.254223.40.255.25516,382
165223.41.0.0/18223.41.0.1 to 223.41.63.254223.41.63.25516,382
166223.41.64.0/18223.41.64.1 to 223.41.127.254223.41.127.25516,382
167223.41.128.0/18223.41.128.1 to 223.41.191.254223.41.191.25516,382
168223.41.192.0/18223.41.192.1 to 223.41.255.254223.41.255.25516,382
169223.42.0.0/18223.42.0.1 to 223.42.63.254223.42.63.25516,382
170223.42.64.0/18223.42.64.1 to 223.42.127.254223.42.127.25516,382
171223.42.128.0/18223.42.128.1 to 223.42.191.254223.42.191.25516,382
172223.42.192.0/18223.42.192.1 to 223.42.255.254223.42.255.25516,382
173223.43.0.0/18223.43.0.1 to 223.43.63.254223.43.63.25516,382
174223.43.64.0/18223.43.64.1 to 223.43.127.254223.43.127.25516,382
175223.43.128.0/18223.43.128.1 to 223.43.191.254223.43.191.25516,382
176223.43.192.0/18223.43.192.1 to 223.43.255.254223.43.255.25516,382
177223.44.0.0/18223.44.0.1 to 223.44.63.254223.44.63.25516,382
178223.44.64.0/18223.44.64.1 to 223.44.127.254223.44.127.25516,382
179223.44.128.0/18223.44.128.1 to 223.44.191.254223.44.191.25516,382
180223.44.192.0/18223.44.192.1 to 223.44.255.254223.44.255.25516,382
181223.45.0.0/18223.45.0.1 to 223.45.63.254223.45.63.25516,382
182223.45.64.0/18223.45.64.1 to 223.45.127.254223.45.127.25516,382
183223.45.128.0/18223.45.128.1 to 223.45.191.254223.45.191.25516,382
184223.45.192.0/18223.45.192.1 to 223.45.255.254223.45.255.25516,382
185223.46.0.0/18223.46.0.1 to 223.46.63.254223.46.63.25516,382
186223.46.64.0/18223.46.64.1 to 223.46.127.254223.46.127.25516,382
187223.46.128.0/18223.46.128.1 to 223.46.191.254223.46.191.25516,382
188223.46.192.0/18223.46.192.1 to 223.46.255.254223.46.255.25516,382
189223.47.0.0/18223.47.0.1 to 223.47.63.254223.47.63.25516,382
190223.47.64.0/18223.47.64.1 to 223.47.127.254223.47.127.25516,382
191223.47.128.0/18223.47.128.1 to 223.47.191.254223.47.191.25516,382
192223.47.192.0/18223.47.192.1 to 223.47.255.254223.47.255.25516,382
193223.48.0.0/18223.48.0.1 to 223.48.63.254223.48.63.25516,382
194223.48.64.0/18223.48.64.1 to 223.48.127.254223.48.127.25516,382
195223.48.128.0/18223.48.128.1 to 223.48.191.254223.48.191.25516,382
196223.48.192.0/18223.48.192.1 to 223.48.255.254223.48.255.25516,382
197223.49.0.0/18223.49.0.1 to 223.49.63.254223.49.63.25516,382
198223.49.64.0/18223.49.64.1 to 223.49.127.254223.49.127.25516,382
199223.49.128.0/18223.49.128.1 to 223.49.191.254223.49.191.25516,382
200223.49.192.0/18223.49.192.1 to 223.49.255.254223.49.255.25516,382
201223.50.0.0/18223.50.0.1 to 223.50.63.254223.50.63.25516,382
202223.50.64.0/18223.50.64.1 to 223.50.127.254223.50.127.25516,382
203223.50.128.0/18223.50.128.1 to 223.50.191.254223.50.191.25516,382
204223.50.192.0/18223.50.192.1 to 223.50.255.254223.50.255.25516,382
205223.51.0.0/18223.51.0.1 to 223.51.63.254223.51.63.25516,382
206223.51.64.0/18223.51.64.1 to 223.51.127.254223.51.127.25516,382
207223.51.128.0/18223.51.128.1 to 223.51.191.254223.51.191.25516,382
208223.51.192.0/18223.51.192.1 to 223.51.255.254223.51.255.25516,382
209223.52.0.0/18223.52.0.1 to 223.52.63.254223.52.63.25516,382
210223.52.64.0/18223.52.64.1 to 223.52.127.254223.52.127.25516,382
211223.52.128.0/18223.52.128.1 to 223.52.191.254223.52.191.25516,382
212223.52.192.0/18223.52.192.1 to 223.52.255.254223.52.255.25516,382
213223.53.0.0/18223.53.0.1 to 223.53.63.254223.53.63.25516,382
214223.53.64.0/18223.53.64.1 to 223.53.127.254223.53.127.25516,382
215223.53.128.0/18223.53.128.1 to 223.53.191.254223.53.191.25516,382
216223.53.192.0/18223.53.192.1 to 223.53.255.254223.53.255.25516,382
217223.54.0.0/18223.54.0.1 to 223.54.63.254223.54.63.25516,382
218223.54.64.0/18223.54.64.1 to 223.54.127.254223.54.127.25516,382
219223.54.128.0/18223.54.128.1 to 223.54.191.254223.54.191.25516,382
220223.54.192.0/18223.54.192.1 to 223.54.255.254223.54.255.25516,382
221223.55.0.0/18223.55.0.1 to 223.55.63.254223.55.63.25516,382
222223.55.64.0/18223.55.64.1 to 223.55.127.254223.55.127.25516,382
223223.55.128.0/18223.55.128.1 to 223.55.191.254223.55.191.25516,382
224223.55.192.0/18223.55.192.1 to 223.55.255.254223.55.255.25516,382
225223.56.0.0/18223.56.0.1 to 223.56.63.254223.56.63.25516,382
226223.56.64.0/18223.56.64.1 to 223.56.127.254223.56.127.25516,382
227223.56.128.0/18223.56.128.1 to 223.56.191.254223.56.191.25516,382
228223.56.192.0/18223.56.192.1 to 223.56.255.254223.56.255.25516,382
229223.57.0.0/18223.57.0.1 to 223.57.63.254223.57.63.25516,382
230223.57.64.0/18223.57.64.1 to 223.57.127.254223.57.127.25516,382
231223.57.128.0/18223.57.128.1 to 223.57.191.254223.57.191.25516,382
232223.57.192.0/18223.57.192.1 to 223.57.255.254223.57.255.25516,382
233223.58.0.0/18223.58.0.1 to 223.58.63.254223.58.63.25516,382
234223.58.64.0/18223.58.64.1 to 223.58.127.254223.58.127.25516,382
235223.58.128.0/18223.58.128.1 to 223.58.191.254223.58.191.25516,382
236223.58.192.0/18223.58.192.1 to 223.58.255.254223.58.255.25516,382
237223.59.0.0/18223.59.0.1 to 223.59.63.254223.59.63.25516,382
238223.59.64.0/18223.59.64.1 to 223.59.127.254223.59.127.25516,382
239223.59.128.0/18223.59.128.1 to 223.59.191.254223.59.191.25516,382
240223.59.192.0/18223.59.192.1 to 223.59.255.254223.59.255.25516,382
241223.60.0.0/18223.60.0.1 to 223.60.63.254223.60.63.25516,382
242223.60.64.0/18223.60.64.1 to 223.60.127.254223.60.127.25516,382
243223.60.128.0/18223.60.128.1 to 223.60.191.254223.60.191.25516,382
244223.60.192.0/18223.60.192.1 to 223.60.255.254223.60.255.25516,382
245223.61.0.0/18223.61.0.1 to 223.61.63.254223.61.63.25516,382
246223.61.64.0/18223.61.64.1 to 223.61.127.254223.61.127.25516,382
247223.61.128.0/18223.61.128.1 to 223.61.191.254223.61.191.25516,382
248223.61.192.0/18223.61.192.1 to 223.61.255.254223.61.255.25516,382
249223.62.0.0/18223.62.0.1 to 223.62.63.254223.62.63.25516,382
250223.62.64.0/18223.62.64.1 to 223.62.127.254223.62.127.25516,382
251223.62.128.0/18223.62.128.1 to 223.62.191.254223.62.191.25516,382
252223.62.192.0/18223.62.192.1 to 223.62.255.254223.62.255.25516,382
253223.63.0.0/18223.63.0.1 to 223.63.63.254223.63.63.25516,382
254223.63.64.0/18223.63.64.1 to 223.63.127.254223.63.127.25516,382
255223.63.128.0/18223.63.128.1 to 223.63.191.254223.63.191.25516,382
256223.63.192.0/18223.63.192.1 to 223.63.255.254223.63.255.25516,382

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.