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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/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)

184.0.0.0/8 makes 4,096 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1184.0.0.0/20184.0.0.1 to 184.0.15.254184.0.15.2554,094
2184.0.16.0/20184.0.16.1 to 184.0.31.254184.0.31.2554,094
3184.0.32.0/20184.0.32.1 to 184.0.47.254184.0.47.2554,094
4184.0.48.0/20184.0.48.1 to 184.0.63.254184.0.63.2554,094
5184.0.64.0/20184.0.64.1 to 184.0.79.254184.0.79.2554,094
6184.0.80.0/20184.0.80.1 to 184.0.95.254184.0.95.2554,094
7184.0.96.0/20184.0.96.1 to 184.0.111.254184.0.111.2554,094
8184.0.112.0/20184.0.112.1 to 184.0.127.254184.0.127.2554,094
9184.0.128.0/20184.0.128.1 to 184.0.143.254184.0.143.2554,094
10184.0.144.0/20184.0.144.1 to 184.0.159.254184.0.159.2554,094
11184.0.160.0/20184.0.160.1 to 184.0.175.254184.0.175.2554,094
12184.0.176.0/20184.0.176.1 to 184.0.191.254184.0.191.2554,094
13184.0.192.0/20184.0.192.1 to 184.0.207.254184.0.207.2554,094
14184.0.208.0/20184.0.208.1 to 184.0.223.254184.0.223.2554,094
15184.0.224.0/20184.0.224.1 to 184.0.239.254184.0.239.2554,094
16184.0.240.0/20184.0.240.1 to 184.0.255.254184.0.255.2554,094
17184.1.0.0/20184.1.0.1 to 184.1.15.254184.1.15.2554,094
18184.1.16.0/20184.1.16.1 to 184.1.31.254184.1.31.2554,094
19184.1.32.0/20184.1.32.1 to 184.1.47.254184.1.47.2554,094
20184.1.48.0/20184.1.48.1 to 184.1.63.254184.1.63.2554,094
21184.1.64.0/20184.1.64.1 to 184.1.79.254184.1.79.2554,094
22184.1.80.0/20184.1.80.1 to 184.1.95.254184.1.95.2554,094
23184.1.96.0/20184.1.96.1 to 184.1.111.254184.1.111.2554,094
24184.1.112.0/20184.1.112.1 to 184.1.127.254184.1.127.2554,094
25184.1.128.0/20184.1.128.1 to 184.1.143.254184.1.143.2554,094
26184.1.144.0/20184.1.144.1 to 184.1.159.254184.1.159.2554,094
27184.1.160.0/20184.1.160.1 to 184.1.175.254184.1.175.2554,094
28184.1.176.0/20184.1.176.1 to 184.1.191.254184.1.191.2554,094
29184.1.192.0/20184.1.192.1 to 184.1.207.254184.1.207.2554,094
30184.1.208.0/20184.1.208.1 to 184.1.223.254184.1.223.2554,094
31184.1.224.0/20184.1.224.1 to 184.1.239.254184.1.239.2554,094
32184.1.240.0/20184.1.240.1 to 184.1.255.254184.1.255.2554,094
33184.2.0.0/20184.2.0.1 to 184.2.15.254184.2.15.2554,094
34184.2.16.0/20184.2.16.1 to 184.2.31.254184.2.31.2554,094
35184.2.32.0/20184.2.32.1 to 184.2.47.254184.2.47.2554,094
36184.2.48.0/20184.2.48.1 to 184.2.63.254184.2.63.2554,094
37184.2.64.0/20184.2.64.1 to 184.2.79.254184.2.79.2554,094
38184.2.80.0/20184.2.80.1 to 184.2.95.254184.2.95.2554,094
39184.2.96.0/20184.2.96.1 to 184.2.111.254184.2.111.2554,094
40184.2.112.0/20184.2.112.1 to 184.2.127.254184.2.127.2554,094
41184.2.128.0/20184.2.128.1 to 184.2.143.254184.2.143.2554,094
42184.2.144.0/20184.2.144.1 to 184.2.159.254184.2.159.2554,094
43184.2.160.0/20184.2.160.1 to 184.2.175.254184.2.175.2554,094
44184.2.176.0/20184.2.176.1 to 184.2.191.254184.2.191.2554,094
45184.2.192.0/20184.2.192.1 to 184.2.207.254184.2.207.2554,094
46184.2.208.0/20184.2.208.1 to 184.2.223.254184.2.223.2554,094
47184.2.224.0/20184.2.224.1 to 184.2.239.254184.2.239.2554,094
48184.2.240.0/20184.2.240.1 to 184.2.255.254184.2.255.2554,094
49184.3.0.0/20184.3.0.1 to 184.3.15.254184.3.15.2554,094
50184.3.16.0/20184.3.16.1 to 184.3.31.254184.3.31.2554,094
51184.3.32.0/20184.3.32.1 to 184.3.47.254184.3.47.2554,094
52184.3.48.0/20184.3.48.1 to 184.3.63.254184.3.63.2554,094
53184.3.64.0/20184.3.64.1 to 184.3.79.254184.3.79.2554,094
54184.3.80.0/20184.3.80.1 to 184.3.95.254184.3.95.2554,094
55184.3.96.0/20184.3.96.1 to 184.3.111.254184.3.111.2554,094
56184.3.112.0/20184.3.112.1 to 184.3.127.254184.3.127.2554,094
57184.3.128.0/20184.3.128.1 to 184.3.143.254184.3.143.2554,094
58184.3.144.0/20184.3.144.1 to 184.3.159.254184.3.159.2554,094
59184.3.160.0/20184.3.160.1 to 184.3.175.254184.3.175.2554,094
60184.3.176.0/20184.3.176.1 to 184.3.191.254184.3.191.2554,094
61184.3.192.0/20184.3.192.1 to 184.3.207.254184.3.207.2554,094
62184.3.208.0/20184.3.208.1 to 184.3.223.254184.3.223.2554,094
63184.3.224.0/20184.3.224.1 to 184.3.239.254184.3.239.2554,094
64184.3.240.0/20184.3.240.1 to 184.3.255.254184.3.255.2554,094
65184.4.0.0/20184.4.0.1 to 184.4.15.254184.4.15.2554,094
66184.4.16.0/20184.4.16.1 to 184.4.31.254184.4.31.2554,094
67184.4.32.0/20184.4.32.1 to 184.4.47.254184.4.47.2554,094
68184.4.48.0/20184.4.48.1 to 184.4.63.254184.4.63.2554,094
69184.4.64.0/20184.4.64.1 to 184.4.79.254184.4.79.2554,094
70184.4.80.0/20184.4.80.1 to 184.4.95.254184.4.95.2554,094
71184.4.96.0/20184.4.96.1 to 184.4.111.254184.4.111.2554,094
72184.4.112.0/20184.4.112.1 to 184.4.127.254184.4.127.2554,094
73184.4.128.0/20184.4.128.1 to 184.4.143.254184.4.143.2554,094
74184.4.144.0/20184.4.144.1 to 184.4.159.254184.4.159.2554,094
75184.4.160.0/20184.4.160.1 to 184.4.175.254184.4.175.2554,094
76184.4.176.0/20184.4.176.1 to 184.4.191.254184.4.191.2554,094
77184.4.192.0/20184.4.192.1 to 184.4.207.254184.4.207.2554,094
78184.4.208.0/20184.4.208.1 to 184.4.223.254184.4.223.2554,094
79184.4.224.0/20184.4.224.1 to 184.4.239.254184.4.239.2554,094
80184.4.240.0/20184.4.240.1 to 184.4.255.254184.4.255.2554,094
81184.5.0.0/20184.5.0.1 to 184.5.15.254184.5.15.2554,094
82184.5.16.0/20184.5.16.1 to 184.5.31.254184.5.31.2554,094
83184.5.32.0/20184.5.32.1 to 184.5.47.254184.5.47.2554,094
84184.5.48.0/20184.5.48.1 to 184.5.63.254184.5.63.2554,094
85184.5.64.0/20184.5.64.1 to 184.5.79.254184.5.79.2554,094
86184.5.80.0/20184.5.80.1 to 184.5.95.254184.5.95.2554,094
87184.5.96.0/20184.5.96.1 to 184.5.111.254184.5.111.2554,094
88184.5.112.0/20184.5.112.1 to 184.5.127.254184.5.127.2554,094
89184.5.128.0/20184.5.128.1 to 184.5.143.254184.5.143.2554,094
90184.5.144.0/20184.5.144.1 to 184.5.159.254184.5.159.2554,094
91184.5.160.0/20184.5.160.1 to 184.5.175.254184.5.175.2554,094
92184.5.176.0/20184.5.176.1 to 184.5.191.254184.5.191.2554,094
93184.5.192.0/20184.5.192.1 to 184.5.207.254184.5.207.2554,094
94184.5.208.0/20184.5.208.1 to 184.5.223.254184.5.223.2554,094
95184.5.224.0/20184.5.224.1 to 184.5.239.254184.5.239.2554,094
96184.5.240.0/20184.5.240.1 to 184.5.255.254184.5.255.2554,094
97184.6.0.0/20184.6.0.1 to 184.6.15.254184.6.15.2554,094
98184.6.16.0/20184.6.16.1 to 184.6.31.254184.6.31.2554,094
99184.6.32.0/20184.6.32.1 to 184.6.47.254184.6.47.2554,094
100184.6.48.0/20184.6.48.1 to 184.6.63.254184.6.63.2554,094
101184.6.64.0/20184.6.64.1 to 184.6.79.254184.6.79.2554,094
102184.6.80.0/20184.6.80.1 to 184.6.95.254184.6.95.2554,094
103184.6.96.0/20184.6.96.1 to 184.6.111.254184.6.111.2554,094
104184.6.112.0/20184.6.112.1 to 184.6.127.254184.6.127.2554,094
105184.6.128.0/20184.6.128.1 to 184.6.143.254184.6.143.2554,094
106184.6.144.0/20184.6.144.1 to 184.6.159.254184.6.159.2554,094
107184.6.160.0/20184.6.160.1 to 184.6.175.254184.6.175.2554,094
108184.6.176.0/20184.6.176.1 to 184.6.191.254184.6.191.2554,094
109184.6.192.0/20184.6.192.1 to 184.6.207.254184.6.207.2554,094
110184.6.208.0/20184.6.208.1 to 184.6.223.254184.6.223.2554,094
111184.6.224.0/20184.6.224.1 to 184.6.239.254184.6.239.2554,094
112184.6.240.0/20184.6.240.1 to 184.6.255.254184.6.255.2554,094
113184.7.0.0/20184.7.0.1 to 184.7.15.254184.7.15.2554,094
114184.7.16.0/20184.7.16.1 to 184.7.31.254184.7.31.2554,094
115184.7.32.0/20184.7.32.1 to 184.7.47.254184.7.47.2554,094
116184.7.48.0/20184.7.48.1 to 184.7.63.254184.7.63.2554,094
117184.7.64.0/20184.7.64.1 to 184.7.79.254184.7.79.2554,094
118184.7.80.0/20184.7.80.1 to 184.7.95.254184.7.95.2554,094
119184.7.96.0/20184.7.96.1 to 184.7.111.254184.7.111.2554,094
120184.7.112.0/20184.7.112.1 to 184.7.127.254184.7.127.2554,094
121184.7.128.0/20184.7.128.1 to 184.7.143.254184.7.143.2554,094
122184.7.144.0/20184.7.144.1 to 184.7.159.254184.7.159.2554,094
123184.7.160.0/20184.7.160.1 to 184.7.175.254184.7.175.2554,094
124184.7.176.0/20184.7.176.1 to 184.7.191.254184.7.191.2554,094
125184.7.192.0/20184.7.192.1 to 184.7.207.254184.7.207.2554,094
126184.7.208.0/20184.7.208.1 to 184.7.223.254184.7.223.2554,094
127184.7.224.0/20184.7.224.1 to 184.7.239.254184.7.239.2554,094
128184.7.240.0/20184.7.240.1 to 184.7.255.254184.7.255.2554,094
129184.8.0.0/20184.8.0.1 to 184.8.15.254184.8.15.2554,094
130184.8.16.0/20184.8.16.1 to 184.8.31.254184.8.31.2554,094
131184.8.32.0/20184.8.32.1 to 184.8.47.254184.8.47.2554,094
132184.8.48.0/20184.8.48.1 to 184.8.63.254184.8.63.2554,094
133184.8.64.0/20184.8.64.1 to 184.8.79.254184.8.79.2554,094
134184.8.80.0/20184.8.80.1 to 184.8.95.254184.8.95.2554,094
135184.8.96.0/20184.8.96.1 to 184.8.111.254184.8.111.2554,094
136184.8.112.0/20184.8.112.1 to 184.8.127.254184.8.127.2554,094
137184.8.128.0/20184.8.128.1 to 184.8.143.254184.8.143.2554,094
138184.8.144.0/20184.8.144.1 to 184.8.159.254184.8.159.2554,094
139184.8.160.0/20184.8.160.1 to 184.8.175.254184.8.175.2554,094
140184.8.176.0/20184.8.176.1 to 184.8.191.254184.8.191.2554,094
141184.8.192.0/20184.8.192.1 to 184.8.207.254184.8.207.2554,094
142184.8.208.0/20184.8.208.1 to 184.8.223.254184.8.223.2554,094
143184.8.224.0/20184.8.224.1 to 184.8.239.254184.8.239.2554,094
144184.8.240.0/20184.8.240.1 to 184.8.255.254184.8.255.2554,094
145184.9.0.0/20184.9.0.1 to 184.9.15.254184.9.15.2554,094
146184.9.16.0/20184.9.16.1 to 184.9.31.254184.9.31.2554,094
147184.9.32.0/20184.9.32.1 to 184.9.47.254184.9.47.2554,094
148184.9.48.0/20184.9.48.1 to 184.9.63.254184.9.63.2554,094
149184.9.64.0/20184.9.64.1 to 184.9.79.254184.9.79.2554,094
150184.9.80.0/20184.9.80.1 to 184.9.95.254184.9.95.2554,094
151184.9.96.0/20184.9.96.1 to 184.9.111.254184.9.111.2554,094
152184.9.112.0/20184.9.112.1 to 184.9.127.254184.9.127.2554,094
153184.9.128.0/20184.9.128.1 to 184.9.143.254184.9.143.2554,094
154184.9.144.0/20184.9.144.1 to 184.9.159.254184.9.159.2554,094
155184.9.160.0/20184.9.160.1 to 184.9.175.254184.9.175.2554,094
156184.9.176.0/20184.9.176.1 to 184.9.191.254184.9.191.2554,094
157184.9.192.0/20184.9.192.1 to 184.9.207.254184.9.207.2554,094
158184.9.208.0/20184.9.208.1 to 184.9.223.254184.9.223.2554,094
159184.9.224.0/20184.9.224.1 to 184.9.239.254184.9.239.2554,094
160184.9.240.0/20184.9.240.1 to 184.9.255.254184.9.255.2554,094
161184.10.0.0/20184.10.0.1 to 184.10.15.254184.10.15.2554,094
162184.10.16.0/20184.10.16.1 to 184.10.31.254184.10.31.2554,094
163184.10.32.0/20184.10.32.1 to 184.10.47.254184.10.47.2554,094
164184.10.48.0/20184.10.48.1 to 184.10.63.254184.10.63.2554,094
165184.10.64.0/20184.10.64.1 to 184.10.79.254184.10.79.2554,094
166184.10.80.0/20184.10.80.1 to 184.10.95.254184.10.95.2554,094
167184.10.96.0/20184.10.96.1 to 184.10.111.254184.10.111.2554,094
168184.10.112.0/20184.10.112.1 to 184.10.127.254184.10.127.2554,094
169184.10.128.0/20184.10.128.1 to 184.10.143.254184.10.143.2554,094
170184.10.144.0/20184.10.144.1 to 184.10.159.254184.10.159.2554,094
171184.10.160.0/20184.10.160.1 to 184.10.175.254184.10.175.2554,094
172184.10.176.0/20184.10.176.1 to 184.10.191.254184.10.191.2554,094
173184.10.192.0/20184.10.192.1 to 184.10.207.254184.10.207.2554,094
174184.10.208.0/20184.10.208.1 to 184.10.223.254184.10.223.2554,094
175184.10.224.0/20184.10.224.1 to 184.10.239.254184.10.239.2554,094
176184.10.240.0/20184.10.240.1 to 184.10.255.254184.10.255.2554,094
177184.11.0.0/20184.11.0.1 to 184.11.15.254184.11.15.2554,094
178184.11.16.0/20184.11.16.1 to 184.11.31.254184.11.31.2554,094
179184.11.32.0/20184.11.32.1 to 184.11.47.254184.11.47.2554,094
180184.11.48.0/20184.11.48.1 to 184.11.63.254184.11.63.2554,094
181184.11.64.0/20184.11.64.1 to 184.11.79.254184.11.79.2554,094
182184.11.80.0/20184.11.80.1 to 184.11.95.254184.11.95.2554,094
183184.11.96.0/20184.11.96.1 to 184.11.111.254184.11.111.2554,094
184184.11.112.0/20184.11.112.1 to 184.11.127.254184.11.127.2554,094
185184.11.128.0/20184.11.128.1 to 184.11.143.254184.11.143.2554,094
186184.11.144.0/20184.11.144.1 to 184.11.159.254184.11.159.2554,094
187184.11.160.0/20184.11.160.1 to 184.11.175.254184.11.175.2554,094
188184.11.176.0/20184.11.176.1 to 184.11.191.254184.11.191.2554,094
189184.11.192.0/20184.11.192.1 to 184.11.207.254184.11.207.2554,094
190184.11.208.0/20184.11.208.1 to 184.11.223.254184.11.223.2554,094
191184.11.224.0/20184.11.224.1 to 184.11.239.254184.11.239.2554,094
192184.11.240.0/20184.11.240.1 to 184.11.255.254184.11.255.2554,094
193184.12.0.0/20184.12.0.1 to 184.12.15.254184.12.15.2554,094
194184.12.16.0/20184.12.16.1 to 184.12.31.254184.12.31.2554,094
195184.12.32.0/20184.12.32.1 to 184.12.47.254184.12.47.2554,094
196184.12.48.0/20184.12.48.1 to 184.12.63.254184.12.63.2554,094
197184.12.64.0/20184.12.64.1 to 184.12.79.254184.12.79.2554,094
198184.12.80.0/20184.12.80.1 to 184.12.95.254184.12.95.2554,094
199184.12.96.0/20184.12.96.1 to 184.12.111.254184.12.111.2554,094
200184.12.112.0/20184.12.112.1 to 184.12.127.254184.12.127.2554,094
201184.12.128.0/20184.12.128.1 to 184.12.143.254184.12.143.2554,094
202184.12.144.0/20184.12.144.1 to 184.12.159.254184.12.159.2554,094
203184.12.160.0/20184.12.160.1 to 184.12.175.254184.12.175.2554,094
204184.12.176.0/20184.12.176.1 to 184.12.191.254184.12.191.2554,094
205184.12.192.0/20184.12.192.1 to 184.12.207.254184.12.207.2554,094
206184.12.208.0/20184.12.208.1 to 184.12.223.254184.12.223.2554,094
207184.12.224.0/20184.12.224.1 to 184.12.239.254184.12.239.2554,094
208184.12.240.0/20184.12.240.1 to 184.12.255.254184.12.255.2554,094
209184.13.0.0/20184.13.0.1 to 184.13.15.254184.13.15.2554,094
210184.13.16.0/20184.13.16.1 to 184.13.31.254184.13.31.2554,094
211184.13.32.0/20184.13.32.1 to 184.13.47.254184.13.47.2554,094
212184.13.48.0/20184.13.48.1 to 184.13.63.254184.13.63.2554,094
213184.13.64.0/20184.13.64.1 to 184.13.79.254184.13.79.2554,094
214184.13.80.0/20184.13.80.1 to 184.13.95.254184.13.95.2554,094
215184.13.96.0/20184.13.96.1 to 184.13.111.254184.13.111.2554,094
216184.13.112.0/20184.13.112.1 to 184.13.127.254184.13.127.2554,094
217184.13.128.0/20184.13.128.1 to 184.13.143.254184.13.143.2554,094
218184.13.144.0/20184.13.144.1 to 184.13.159.254184.13.159.2554,094
219184.13.160.0/20184.13.160.1 to 184.13.175.254184.13.175.2554,094
220184.13.176.0/20184.13.176.1 to 184.13.191.254184.13.191.2554,094
221184.13.192.0/20184.13.192.1 to 184.13.207.254184.13.207.2554,094
222184.13.208.0/20184.13.208.1 to 184.13.223.254184.13.223.2554,094
223184.13.224.0/20184.13.224.1 to 184.13.239.254184.13.239.2554,094
224184.13.240.0/20184.13.240.1 to 184.13.255.254184.13.255.2554,094
225184.14.0.0/20184.14.0.1 to 184.14.15.254184.14.15.2554,094
226184.14.16.0/20184.14.16.1 to 184.14.31.254184.14.31.2554,094
227184.14.32.0/20184.14.32.1 to 184.14.47.254184.14.47.2554,094
228184.14.48.0/20184.14.48.1 to 184.14.63.254184.14.63.2554,094
229184.14.64.0/20184.14.64.1 to 184.14.79.254184.14.79.2554,094
230184.14.80.0/20184.14.80.1 to 184.14.95.254184.14.95.2554,094
231184.14.96.0/20184.14.96.1 to 184.14.111.254184.14.111.2554,094
232184.14.112.0/20184.14.112.1 to 184.14.127.254184.14.127.2554,094
233184.14.128.0/20184.14.128.1 to 184.14.143.254184.14.143.2554,094
234184.14.144.0/20184.14.144.1 to 184.14.159.254184.14.159.2554,094
235184.14.160.0/20184.14.160.1 to 184.14.175.254184.14.175.2554,094
236184.14.176.0/20184.14.176.1 to 184.14.191.254184.14.191.2554,094
237184.14.192.0/20184.14.192.1 to 184.14.207.254184.14.207.2554,094
238184.14.208.0/20184.14.208.1 to 184.14.223.254184.14.223.2554,094
239184.14.224.0/20184.14.224.1 to 184.14.239.254184.14.239.2554,094
240184.14.240.0/20184.14.240.1 to 184.14.255.254184.14.255.2554,094
241184.15.0.0/20184.15.0.1 to 184.15.15.254184.15.15.2554,094
242184.15.16.0/20184.15.16.1 to 184.15.31.254184.15.31.2554,094
243184.15.32.0/20184.15.32.1 to 184.15.47.254184.15.47.2554,094
244184.15.48.0/20184.15.48.1 to 184.15.63.254184.15.63.2554,094
245184.15.64.0/20184.15.64.1 to 184.15.79.254184.15.79.2554,094
246184.15.80.0/20184.15.80.1 to 184.15.95.254184.15.95.2554,094
247184.15.96.0/20184.15.96.1 to 184.15.111.254184.15.111.2554,094
248184.15.112.0/20184.15.112.1 to 184.15.127.254184.15.127.2554,094
249184.15.128.0/20184.15.128.1 to 184.15.143.254184.15.143.2554,094
250184.15.144.0/20184.15.144.1 to 184.15.159.254184.15.159.2554,094
251184.15.160.0/20184.15.160.1 to 184.15.175.254184.15.175.2554,094
252184.15.176.0/20184.15.176.1 to 184.15.191.254184.15.191.2554,094
253184.15.192.0/20184.15.192.1 to 184.15.207.254184.15.207.2554,094
254184.15.208.0/20184.15.208.1 to 184.15.223.254184.15.223.2554,094
255184.15.224.0/20184.15.224.1 to 184.15.239.254184.15.239.2554,094
256184.15.240.0/20184.15.240.1 to 184.15.255.254184.15.255.2554,094

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.