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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.

Network184.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
184.0.0.0
Broadcast address
184.255.255.255
First usable
184.0.0.1
Last usable
184.255.255.254
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 B8000000 · Integer 3087007744 to 3103784959
Reverse DNS zone
184.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10111000..00000000.00000000.00000000184.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10111000..00000000.00000000.00000000184.0.0.0
Broadcast10111000..11111111.11111111.11111111184.255.255.255
Split into smaller subnets/19
/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)

184.0.0.0/8 makes 2,048 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1184.0.0.0/19184.0.0.1 to 184.0.31.254184.0.31.2558,190
2184.0.32.0/19184.0.32.1 to 184.0.63.254184.0.63.2558,190
3184.0.64.0/19184.0.64.1 to 184.0.95.254184.0.95.2558,190
4184.0.96.0/19184.0.96.1 to 184.0.127.254184.0.127.2558,190
5184.0.128.0/19184.0.128.1 to 184.0.159.254184.0.159.2558,190
6184.0.160.0/19184.0.160.1 to 184.0.191.254184.0.191.2558,190
7184.0.192.0/19184.0.192.1 to 184.0.223.254184.0.223.2558,190
8184.0.224.0/19184.0.224.1 to 184.0.255.254184.0.255.2558,190
9184.1.0.0/19184.1.0.1 to 184.1.31.254184.1.31.2558,190
10184.1.32.0/19184.1.32.1 to 184.1.63.254184.1.63.2558,190
11184.1.64.0/19184.1.64.1 to 184.1.95.254184.1.95.2558,190
12184.1.96.0/19184.1.96.1 to 184.1.127.254184.1.127.2558,190
13184.1.128.0/19184.1.128.1 to 184.1.159.254184.1.159.2558,190
14184.1.160.0/19184.1.160.1 to 184.1.191.254184.1.191.2558,190
15184.1.192.0/19184.1.192.1 to 184.1.223.254184.1.223.2558,190
16184.1.224.0/19184.1.224.1 to 184.1.255.254184.1.255.2558,190
17184.2.0.0/19184.2.0.1 to 184.2.31.254184.2.31.2558,190
18184.2.32.0/19184.2.32.1 to 184.2.63.254184.2.63.2558,190
19184.2.64.0/19184.2.64.1 to 184.2.95.254184.2.95.2558,190
20184.2.96.0/19184.2.96.1 to 184.2.127.254184.2.127.2558,190
21184.2.128.0/19184.2.128.1 to 184.2.159.254184.2.159.2558,190
22184.2.160.0/19184.2.160.1 to 184.2.191.254184.2.191.2558,190
23184.2.192.0/19184.2.192.1 to 184.2.223.254184.2.223.2558,190
24184.2.224.0/19184.2.224.1 to 184.2.255.254184.2.255.2558,190
25184.3.0.0/19184.3.0.1 to 184.3.31.254184.3.31.2558,190
26184.3.32.0/19184.3.32.1 to 184.3.63.254184.3.63.2558,190
27184.3.64.0/19184.3.64.1 to 184.3.95.254184.3.95.2558,190
28184.3.96.0/19184.3.96.1 to 184.3.127.254184.3.127.2558,190
29184.3.128.0/19184.3.128.1 to 184.3.159.254184.3.159.2558,190
30184.3.160.0/19184.3.160.1 to 184.3.191.254184.3.191.2558,190
31184.3.192.0/19184.3.192.1 to 184.3.223.254184.3.223.2558,190
32184.3.224.0/19184.3.224.1 to 184.3.255.254184.3.255.2558,190
33184.4.0.0/19184.4.0.1 to 184.4.31.254184.4.31.2558,190
34184.4.32.0/19184.4.32.1 to 184.4.63.254184.4.63.2558,190
35184.4.64.0/19184.4.64.1 to 184.4.95.254184.4.95.2558,190
36184.4.96.0/19184.4.96.1 to 184.4.127.254184.4.127.2558,190
37184.4.128.0/19184.4.128.1 to 184.4.159.254184.4.159.2558,190
38184.4.160.0/19184.4.160.1 to 184.4.191.254184.4.191.2558,190
39184.4.192.0/19184.4.192.1 to 184.4.223.254184.4.223.2558,190
40184.4.224.0/19184.4.224.1 to 184.4.255.254184.4.255.2558,190
41184.5.0.0/19184.5.0.1 to 184.5.31.254184.5.31.2558,190
42184.5.32.0/19184.5.32.1 to 184.5.63.254184.5.63.2558,190
43184.5.64.0/19184.5.64.1 to 184.5.95.254184.5.95.2558,190
44184.5.96.0/19184.5.96.1 to 184.5.127.254184.5.127.2558,190
45184.5.128.0/19184.5.128.1 to 184.5.159.254184.5.159.2558,190
46184.5.160.0/19184.5.160.1 to 184.5.191.254184.5.191.2558,190
47184.5.192.0/19184.5.192.1 to 184.5.223.254184.5.223.2558,190
48184.5.224.0/19184.5.224.1 to 184.5.255.254184.5.255.2558,190
49184.6.0.0/19184.6.0.1 to 184.6.31.254184.6.31.2558,190
50184.6.32.0/19184.6.32.1 to 184.6.63.254184.6.63.2558,190
51184.6.64.0/19184.6.64.1 to 184.6.95.254184.6.95.2558,190
52184.6.96.0/19184.6.96.1 to 184.6.127.254184.6.127.2558,190
53184.6.128.0/19184.6.128.1 to 184.6.159.254184.6.159.2558,190
54184.6.160.0/19184.6.160.1 to 184.6.191.254184.6.191.2558,190
55184.6.192.0/19184.6.192.1 to 184.6.223.254184.6.223.2558,190
56184.6.224.0/19184.6.224.1 to 184.6.255.254184.6.255.2558,190
57184.7.0.0/19184.7.0.1 to 184.7.31.254184.7.31.2558,190
58184.7.32.0/19184.7.32.1 to 184.7.63.254184.7.63.2558,190
59184.7.64.0/19184.7.64.1 to 184.7.95.254184.7.95.2558,190
60184.7.96.0/19184.7.96.1 to 184.7.127.254184.7.127.2558,190
61184.7.128.0/19184.7.128.1 to 184.7.159.254184.7.159.2558,190
62184.7.160.0/19184.7.160.1 to 184.7.191.254184.7.191.2558,190
63184.7.192.0/19184.7.192.1 to 184.7.223.254184.7.223.2558,190
64184.7.224.0/19184.7.224.1 to 184.7.255.254184.7.255.2558,190
65184.8.0.0/19184.8.0.1 to 184.8.31.254184.8.31.2558,190
66184.8.32.0/19184.8.32.1 to 184.8.63.254184.8.63.2558,190
67184.8.64.0/19184.8.64.1 to 184.8.95.254184.8.95.2558,190
68184.8.96.0/19184.8.96.1 to 184.8.127.254184.8.127.2558,190
69184.8.128.0/19184.8.128.1 to 184.8.159.254184.8.159.2558,190
70184.8.160.0/19184.8.160.1 to 184.8.191.254184.8.191.2558,190
71184.8.192.0/19184.8.192.1 to 184.8.223.254184.8.223.2558,190
72184.8.224.0/19184.8.224.1 to 184.8.255.254184.8.255.2558,190
73184.9.0.0/19184.9.0.1 to 184.9.31.254184.9.31.2558,190
74184.9.32.0/19184.9.32.1 to 184.9.63.254184.9.63.2558,190
75184.9.64.0/19184.9.64.1 to 184.9.95.254184.9.95.2558,190
76184.9.96.0/19184.9.96.1 to 184.9.127.254184.9.127.2558,190
77184.9.128.0/19184.9.128.1 to 184.9.159.254184.9.159.2558,190
78184.9.160.0/19184.9.160.1 to 184.9.191.254184.9.191.2558,190
79184.9.192.0/19184.9.192.1 to 184.9.223.254184.9.223.2558,190
80184.9.224.0/19184.9.224.1 to 184.9.255.254184.9.255.2558,190
81184.10.0.0/19184.10.0.1 to 184.10.31.254184.10.31.2558,190
82184.10.32.0/19184.10.32.1 to 184.10.63.254184.10.63.2558,190
83184.10.64.0/19184.10.64.1 to 184.10.95.254184.10.95.2558,190
84184.10.96.0/19184.10.96.1 to 184.10.127.254184.10.127.2558,190
85184.10.128.0/19184.10.128.1 to 184.10.159.254184.10.159.2558,190
86184.10.160.0/19184.10.160.1 to 184.10.191.254184.10.191.2558,190
87184.10.192.0/19184.10.192.1 to 184.10.223.254184.10.223.2558,190
88184.10.224.0/19184.10.224.1 to 184.10.255.254184.10.255.2558,190
89184.11.0.0/19184.11.0.1 to 184.11.31.254184.11.31.2558,190
90184.11.32.0/19184.11.32.1 to 184.11.63.254184.11.63.2558,190
91184.11.64.0/19184.11.64.1 to 184.11.95.254184.11.95.2558,190
92184.11.96.0/19184.11.96.1 to 184.11.127.254184.11.127.2558,190
93184.11.128.0/19184.11.128.1 to 184.11.159.254184.11.159.2558,190
94184.11.160.0/19184.11.160.1 to 184.11.191.254184.11.191.2558,190
95184.11.192.0/19184.11.192.1 to 184.11.223.254184.11.223.2558,190
96184.11.224.0/19184.11.224.1 to 184.11.255.254184.11.255.2558,190
97184.12.0.0/19184.12.0.1 to 184.12.31.254184.12.31.2558,190
98184.12.32.0/19184.12.32.1 to 184.12.63.254184.12.63.2558,190
99184.12.64.0/19184.12.64.1 to 184.12.95.254184.12.95.2558,190
100184.12.96.0/19184.12.96.1 to 184.12.127.254184.12.127.2558,190
101184.12.128.0/19184.12.128.1 to 184.12.159.254184.12.159.2558,190
102184.12.160.0/19184.12.160.1 to 184.12.191.254184.12.191.2558,190
103184.12.192.0/19184.12.192.1 to 184.12.223.254184.12.223.2558,190
104184.12.224.0/19184.12.224.1 to 184.12.255.254184.12.255.2558,190
105184.13.0.0/19184.13.0.1 to 184.13.31.254184.13.31.2558,190
106184.13.32.0/19184.13.32.1 to 184.13.63.254184.13.63.2558,190
107184.13.64.0/19184.13.64.1 to 184.13.95.254184.13.95.2558,190
108184.13.96.0/19184.13.96.1 to 184.13.127.254184.13.127.2558,190
109184.13.128.0/19184.13.128.1 to 184.13.159.254184.13.159.2558,190
110184.13.160.0/19184.13.160.1 to 184.13.191.254184.13.191.2558,190
111184.13.192.0/19184.13.192.1 to 184.13.223.254184.13.223.2558,190
112184.13.224.0/19184.13.224.1 to 184.13.255.254184.13.255.2558,190
113184.14.0.0/19184.14.0.1 to 184.14.31.254184.14.31.2558,190
114184.14.32.0/19184.14.32.1 to 184.14.63.254184.14.63.2558,190
115184.14.64.0/19184.14.64.1 to 184.14.95.254184.14.95.2558,190
116184.14.96.0/19184.14.96.1 to 184.14.127.254184.14.127.2558,190
117184.14.128.0/19184.14.128.1 to 184.14.159.254184.14.159.2558,190
118184.14.160.0/19184.14.160.1 to 184.14.191.254184.14.191.2558,190
119184.14.192.0/19184.14.192.1 to 184.14.223.254184.14.223.2558,190
120184.14.224.0/19184.14.224.1 to 184.14.255.254184.14.255.2558,190
121184.15.0.0/19184.15.0.1 to 184.15.31.254184.15.31.2558,190
122184.15.32.0/19184.15.32.1 to 184.15.63.254184.15.63.2558,190
123184.15.64.0/19184.15.64.1 to 184.15.95.254184.15.95.2558,190
124184.15.96.0/19184.15.96.1 to 184.15.127.254184.15.127.2558,190
125184.15.128.0/19184.15.128.1 to 184.15.159.254184.15.159.2558,190
126184.15.160.0/19184.15.160.1 to 184.15.191.254184.15.191.2558,190
127184.15.192.0/19184.15.192.1 to 184.15.223.254184.15.223.2558,190
128184.15.224.0/19184.15.224.1 to 184.15.255.254184.15.255.2558,190
129184.16.0.0/19184.16.0.1 to 184.16.31.254184.16.31.2558,190
130184.16.32.0/19184.16.32.1 to 184.16.63.254184.16.63.2558,190
131184.16.64.0/19184.16.64.1 to 184.16.95.254184.16.95.2558,190
132184.16.96.0/19184.16.96.1 to 184.16.127.254184.16.127.2558,190
133184.16.128.0/19184.16.128.1 to 184.16.159.254184.16.159.2558,190
134184.16.160.0/19184.16.160.1 to 184.16.191.254184.16.191.2558,190
135184.16.192.0/19184.16.192.1 to 184.16.223.254184.16.223.2558,190
136184.16.224.0/19184.16.224.1 to 184.16.255.254184.16.255.2558,190
137184.17.0.0/19184.17.0.1 to 184.17.31.254184.17.31.2558,190
138184.17.32.0/19184.17.32.1 to 184.17.63.254184.17.63.2558,190
139184.17.64.0/19184.17.64.1 to 184.17.95.254184.17.95.2558,190
140184.17.96.0/19184.17.96.1 to 184.17.127.254184.17.127.2558,190
141184.17.128.0/19184.17.128.1 to 184.17.159.254184.17.159.2558,190
142184.17.160.0/19184.17.160.1 to 184.17.191.254184.17.191.2558,190
143184.17.192.0/19184.17.192.1 to 184.17.223.254184.17.223.2558,190
144184.17.224.0/19184.17.224.1 to 184.17.255.254184.17.255.2558,190
145184.18.0.0/19184.18.0.1 to 184.18.31.254184.18.31.2558,190
146184.18.32.0/19184.18.32.1 to 184.18.63.254184.18.63.2558,190
147184.18.64.0/19184.18.64.1 to 184.18.95.254184.18.95.2558,190
148184.18.96.0/19184.18.96.1 to 184.18.127.254184.18.127.2558,190
149184.18.128.0/19184.18.128.1 to 184.18.159.254184.18.159.2558,190
150184.18.160.0/19184.18.160.1 to 184.18.191.254184.18.191.2558,190
151184.18.192.0/19184.18.192.1 to 184.18.223.254184.18.223.2558,190
152184.18.224.0/19184.18.224.1 to 184.18.255.254184.18.255.2558,190
153184.19.0.0/19184.19.0.1 to 184.19.31.254184.19.31.2558,190
154184.19.32.0/19184.19.32.1 to 184.19.63.254184.19.63.2558,190
155184.19.64.0/19184.19.64.1 to 184.19.95.254184.19.95.2558,190
156184.19.96.0/19184.19.96.1 to 184.19.127.254184.19.127.2558,190
157184.19.128.0/19184.19.128.1 to 184.19.159.254184.19.159.2558,190
158184.19.160.0/19184.19.160.1 to 184.19.191.254184.19.191.2558,190
159184.19.192.0/19184.19.192.1 to 184.19.223.254184.19.223.2558,190
160184.19.224.0/19184.19.224.1 to 184.19.255.254184.19.255.2558,190
161184.20.0.0/19184.20.0.1 to 184.20.31.254184.20.31.2558,190
162184.20.32.0/19184.20.32.1 to 184.20.63.254184.20.63.2558,190
163184.20.64.0/19184.20.64.1 to 184.20.95.254184.20.95.2558,190
164184.20.96.0/19184.20.96.1 to 184.20.127.254184.20.127.2558,190
165184.20.128.0/19184.20.128.1 to 184.20.159.254184.20.159.2558,190
166184.20.160.0/19184.20.160.1 to 184.20.191.254184.20.191.2558,190
167184.20.192.0/19184.20.192.1 to 184.20.223.254184.20.223.2558,190
168184.20.224.0/19184.20.224.1 to 184.20.255.254184.20.255.2558,190
169184.21.0.0/19184.21.0.1 to 184.21.31.254184.21.31.2558,190
170184.21.32.0/19184.21.32.1 to 184.21.63.254184.21.63.2558,190
171184.21.64.0/19184.21.64.1 to 184.21.95.254184.21.95.2558,190
172184.21.96.0/19184.21.96.1 to 184.21.127.254184.21.127.2558,190
173184.21.128.0/19184.21.128.1 to 184.21.159.254184.21.159.2558,190
174184.21.160.0/19184.21.160.1 to 184.21.191.254184.21.191.2558,190
175184.21.192.0/19184.21.192.1 to 184.21.223.254184.21.223.2558,190
176184.21.224.0/19184.21.224.1 to 184.21.255.254184.21.255.2558,190
177184.22.0.0/19184.22.0.1 to 184.22.31.254184.22.31.2558,190
178184.22.32.0/19184.22.32.1 to 184.22.63.254184.22.63.2558,190
179184.22.64.0/19184.22.64.1 to 184.22.95.254184.22.95.2558,190
180184.22.96.0/19184.22.96.1 to 184.22.127.254184.22.127.2558,190
181184.22.128.0/19184.22.128.1 to 184.22.159.254184.22.159.2558,190
182184.22.160.0/19184.22.160.1 to 184.22.191.254184.22.191.2558,190
183184.22.192.0/19184.22.192.1 to 184.22.223.254184.22.223.2558,190
184184.22.224.0/19184.22.224.1 to 184.22.255.254184.22.255.2558,190
185184.23.0.0/19184.23.0.1 to 184.23.31.254184.23.31.2558,190
186184.23.32.0/19184.23.32.1 to 184.23.63.254184.23.63.2558,190
187184.23.64.0/19184.23.64.1 to 184.23.95.254184.23.95.2558,190
188184.23.96.0/19184.23.96.1 to 184.23.127.254184.23.127.2558,190
189184.23.128.0/19184.23.128.1 to 184.23.159.254184.23.159.2558,190
190184.23.160.0/19184.23.160.1 to 184.23.191.254184.23.191.2558,190
191184.23.192.0/19184.23.192.1 to 184.23.223.254184.23.223.2558,190
192184.23.224.0/19184.23.224.1 to 184.23.255.254184.23.255.2558,190
193184.24.0.0/19184.24.0.1 to 184.24.31.254184.24.31.2558,190
194184.24.32.0/19184.24.32.1 to 184.24.63.254184.24.63.2558,190
195184.24.64.0/19184.24.64.1 to 184.24.95.254184.24.95.2558,190
196184.24.96.0/19184.24.96.1 to 184.24.127.254184.24.127.2558,190
197184.24.128.0/19184.24.128.1 to 184.24.159.254184.24.159.2558,190
198184.24.160.0/19184.24.160.1 to 184.24.191.254184.24.191.2558,190
199184.24.192.0/19184.24.192.1 to 184.24.223.254184.24.223.2558,190
200184.24.224.0/19184.24.224.1 to 184.24.255.254184.24.255.2558,190
201184.25.0.0/19184.25.0.1 to 184.25.31.254184.25.31.2558,190
202184.25.32.0/19184.25.32.1 to 184.25.63.254184.25.63.2558,190
203184.25.64.0/19184.25.64.1 to 184.25.95.254184.25.95.2558,190
204184.25.96.0/19184.25.96.1 to 184.25.127.254184.25.127.2558,190
205184.25.128.0/19184.25.128.1 to 184.25.159.254184.25.159.2558,190
206184.25.160.0/19184.25.160.1 to 184.25.191.254184.25.191.2558,190
207184.25.192.0/19184.25.192.1 to 184.25.223.254184.25.223.2558,190
208184.25.224.0/19184.25.224.1 to 184.25.255.254184.25.255.2558,190
209184.26.0.0/19184.26.0.1 to 184.26.31.254184.26.31.2558,190
210184.26.32.0/19184.26.32.1 to 184.26.63.254184.26.63.2558,190
211184.26.64.0/19184.26.64.1 to 184.26.95.254184.26.95.2558,190
212184.26.96.0/19184.26.96.1 to 184.26.127.254184.26.127.2558,190
213184.26.128.0/19184.26.128.1 to 184.26.159.254184.26.159.2558,190
214184.26.160.0/19184.26.160.1 to 184.26.191.254184.26.191.2558,190
215184.26.192.0/19184.26.192.1 to 184.26.223.254184.26.223.2558,190
216184.26.224.0/19184.26.224.1 to 184.26.255.254184.26.255.2558,190
217184.27.0.0/19184.27.0.1 to 184.27.31.254184.27.31.2558,190
218184.27.32.0/19184.27.32.1 to 184.27.63.254184.27.63.2558,190
219184.27.64.0/19184.27.64.1 to 184.27.95.254184.27.95.2558,190
220184.27.96.0/19184.27.96.1 to 184.27.127.254184.27.127.2558,190
221184.27.128.0/19184.27.128.1 to 184.27.159.254184.27.159.2558,190
222184.27.160.0/19184.27.160.1 to 184.27.191.254184.27.191.2558,190
223184.27.192.0/19184.27.192.1 to 184.27.223.254184.27.223.2558,190
224184.27.224.0/19184.27.224.1 to 184.27.255.254184.27.255.2558,190
225184.28.0.0/19184.28.0.1 to 184.28.31.254184.28.31.2558,190
226184.28.32.0/19184.28.32.1 to 184.28.63.254184.28.63.2558,190
227184.28.64.0/19184.28.64.1 to 184.28.95.254184.28.95.2558,190
228184.28.96.0/19184.28.96.1 to 184.28.127.254184.28.127.2558,190
229184.28.128.0/19184.28.128.1 to 184.28.159.254184.28.159.2558,190
230184.28.160.0/19184.28.160.1 to 184.28.191.254184.28.191.2558,190
231184.28.192.0/19184.28.192.1 to 184.28.223.254184.28.223.2558,190
232184.28.224.0/19184.28.224.1 to 184.28.255.254184.28.255.2558,190
233184.29.0.0/19184.29.0.1 to 184.29.31.254184.29.31.2558,190
234184.29.32.0/19184.29.32.1 to 184.29.63.254184.29.63.2558,190
235184.29.64.0/19184.29.64.1 to 184.29.95.254184.29.95.2558,190
236184.29.96.0/19184.29.96.1 to 184.29.127.254184.29.127.2558,190
237184.29.128.0/19184.29.128.1 to 184.29.159.254184.29.159.2558,190
238184.29.160.0/19184.29.160.1 to 184.29.191.254184.29.191.2558,190
239184.29.192.0/19184.29.192.1 to 184.29.223.254184.29.223.2558,190
240184.29.224.0/19184.29.224.1 to 184.29.255.254184.29.255.2558,190
241184.30.0.0/19184.30.0.1 to 184.30.31.254184.30.31.2558,190
242184.30.32.0/19184.30.32.1 to 184.30.63.254184.30.63.2558,190
243184.30.64.0/19184.30.64.1 to 184.30.95.254184.30.95.2558,190
244184.30.96.0/19184.30.96.1 to 184.30.127.254184.30.127.2558,190
245184.30.128.0/19184.30.128.1 to 184.30.159.254184.30.159.2558,190
246184.30.160.0/19184.30.160.1 to 184.30.191.254184.30.191.2558,190
247184.30.192.0/19184.30.192.1 to 184.30.223.254184.30.223.2558,190
248184.30.224.0/19184.30.224.1 to 184.30.255.254184.30.255.2558,190
249184.31.0.0/19184.31.0.1 to 184.31.31.254184.31.31.2558,190
250184.31.32.0/19184.31.32.1 to 184.31.63.254184.31.63.2558,190
251184.31.64.0/19184.31.64.1 to 184.31.95.254184.31.95.2558,190
252184.31.96.0/19184.31.96.1 to 184.31.127.254184.31.127.2558,190
253184.31.128.0/19184.31.128.1 to 184.31.159.254184.31.159.2558,190
254184.31.160.0/19184.31.160.1 to 184.31.191.254184.31.191.2558,190
255184.31.192.0/19184.31.192.1 to 184.31.223.254184.31.223.2558,190
256184.31.224.0/19184.31.224.1 to 184.31.255.254184.31.255.2558,190

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.