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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.

Network184.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
184.0.0.0
Broadcast address
187.255.255.255
First usable
184.0.0.1
Last usable
187.255.255.254
Usable hosts
67,108,862 (67,108,864 less the network and broadcast addresses)
Subnet mask
252.0.0.0
Wildcard mask
3.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/6
Type
Public public
Old class
B (default /16)
As numbers
Hex B8000000 · Integer 3087007744 to 3154116607
Reverse DNS zones
184.in-addr.arpa
185.in-addr.arpa
186.in-addr.arpa
187.in-addr.arpa
/6 is not on a 8-bit boundary, so it takes 4 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10111000.00000000.00000000.00000000184.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network10111000.00000000.00000000.00000000184.0.0.0
Broadcast10111011.11111111.11111111.11111111187.255.255.255
Split into smaller subnets/18
/7 (2)/8 (4)/9 (8)/10 (16)/11 (32)/12 (64)/13 (128)/14 (256)/15 (512)/16 (1,024)/17 (2,048)/18 (4,096)

184.0.0.0/6 makes 4,096 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1184.0.0.0/18184.0.0.1 to 184.0.63.254184.0.63.25516,382
2184.0.64.0/18184.0.64.1 to 184.0.127.254184.0.127.25516,382
3184.0.128.0/18184.0.128.1 to 184.0.191.254184.0.191.25516,382
4184.0.192.0/18184.0.192.1 to 184.0.255.254184.0.255.25516,382
5184.1.0.0/18184.1.0.1 to 184.1.63.254184.1.63.25516,382
6184.1.64.0/18184.1.64.1 to 184.1.127.254184.1.127.25516,382
7184.1.128.0/18184.1.128.1 to 184.1.191.254184.1.191.25516,382
8184.1.192.0/18184.1.192.1 to 184.1.255.254184.1.255.25516,382
9184.2.0.0/18184.2.0.1 to 184.2.63.254184.2.63.25516,382
10184.2.64.0/18184.2.64.1 to 184.2.127.254184.2.127.25516,382
11184.2.128.0/18184.2.128.1 to 184.2.191.254184.2.191.25516,382
12184.2.192.0/18184.2.192.1 to 184.2.255.254184.2.255.25516,382
13184.3.0.0/18184.3.0.1 to 184.3.63.254184.3.63.25516,382
14184.3.64.0/18184.3.64.1 to 184.3.127.254184.3.127.25516,382
15184.3.128.0/18184.3.128.1 to 184.3.191.254184.3.191.25516,382
16184.3.192.0/18184.3.192.1 to 184.3.255.254184.3.255.25516,382
17184.4.0.0/18184.4.0.1 to 184.4.63.254184.4.63.25516,382
18184.4.64.0/18184.4.64.1 to 184.4.127.254184.4.127.25516,382
19184.4.128.0/18184.4.128.1 to 184.4.191.254184.4.191.25516,382
20184.4.192.0/18184.4.192.1 to 184.4.255.254184.4.255.25516,382
21184.5.0.0/18184.5.0.1 to 184.5.63.254184.5.63.25516,382
22184.5.64.0/18184.5.64.1 to 184.5.127.254184.5.127.25516,382
23184.5.128.0/18184.5.128.1 to 184.5.191.254184.5.191.25516,382
24184.5.192.0/18184.5.192.1 to 184.5.255.254184.5.255.25516,382
25184.6.0.0/18184.6.0.1 to 184.6.63.254184.6.63.25516,382
26184.6.64.0/18184.6.64.1 to 184.6.127.254184.6.127.25516,382
27184.6.128.0/18184.6.128.1 to 184.6.191.254184.6.191.25516,382
28184.6.192.0/18184.6.192.1 to 184.6.255.254184.6.255.25516,382
29184.7.0.0/18184.7.0.1 to 184.7.63.254184.7.63.25516,382
30184.7.64.0/18184.7.64.1 to 184.7.127.254184.7.127.25516,382
31184.7.128.0/18184.7.128.1 to 184.7.191.254184.7.191.25516,382
32184.7.192.0/18184.7.192.1 to 184.7.255.254184.7.255.25516,382
33184.8.0.0/18184.8.0.1 to 184.8.63.254184.8.63.25516,382
34184.8.64.0/18184.8.64.1 to 184.8.127.254184.8.127.25516,382
35184.8.128.0/18184.8.128.1 to 184.8.191.254184.8.191.25516,382
36184.8.192.0/18184.8.192.1 to 184.8.255.254184.8.255.25516,382
37184.9.0.0/18184.9.0.1 to 184.9.63.254184.9.63.25516,382
38184.9.64.0/18184.9.64.1 to 184.9.127.254184.9.127.25516,382
39184.9.128.0/18184.9.128.1 to 184.9.191.254184.9.191.25516,382
40184.9.192.0/18184.9.192.1 to 184.9.255.254184.9.255.25516,382
41184.10.0.0/18184.10.0.1 to 184.10.63.254184.10.63.25516,382
42184.10.64.0/18184.10.64.1 to 184.10.127.254184.10.127.25516,382
43184.10.128.0/18184.10.128.1 to 184.10.191.254184.10.191.25516,382
44184.10.192.0/18184.10.192.1 to 184.10.255.254184.10.255.25516,382
45184.11.0.0/18184.11.0.1 to 184.11.63.254184.11.63.25516,382
46184.11.64.0/18184.11.64.1 to 184.11.127.254184.11.127.25516,382
47184.11.128.0/18184.11.128.1 to 184.11.191.254184.11.191.25516,382
48184.11.192.0/18184.11.192.1 to 184.11.255.254184.11.255.25516,382
49184.12.0.0/18184.12.0.1 to 184.12.63.254184.12.63.25516,382
50184.12.64.0/18184.12.64.1 to 184.12.127.254184.12.127.25516,382
51184.12.128.0/18184.12.128.1 to 184.12.191.254184.12.191.25516,382
52184.12.192.0/18184.12.192.1 to 184.12.255.254184.12.255.25516,382
53184.13.0.0/18184.13.0.1 to 184.13.63.254184.13.63.25516,382
54184.13.64.0/18184.13.64.1 to 184.13.127.254184.13.127.25516,382
55184.13.128.0/18184.13.128.1 to 184.13.191.254184.13.191.25516,382
56184.13.192.0/18184.13.192.1 to 184.13.255.254184.13.255.25516,382
57184.14.0.0/18184.14.0.1 to 184.14.63.254184.14.63.25516,382
58184.14.64.0/18184.14.64.1 to 184.14.127.254184.14.127.25516,382
59184.14.128.0/18184.14.128.1 to 184.14.191.254184.14.191.25516,382
60184.14.192.0/18184.14.192.1 to 184.14.255.254184.14.255.25516,382
61184.15.0.0/18184.15.0.1 to 184.15.63.254184.15.63.25516,382
62184.15.64.0/18184.15.64.1 to 184.15.127.254184.15.127.25516,382
63184.15.128.0/18184.15.128.1 to 184.15.191.254184.15.191.25516,382
64184.15.192.0/18184.15.192.1 to 184.15.255.254184.15.255.25516,382
65184.16.0.0/18184.16.0.1 to 184.16.63.254184.16.63.25516,382
66184.16.64.0/18184.16.64.1 to 184.16.127.254184.16.127.25516,382
67184.16.128.0/18184.16.128.1 to 184.16.191.254184.16.191.25516,382
68184.16.192.0/18184.16.192.1 to 184.16.255.254184.16.255.25516,382
69184.17.0.0/18184.17.0.1 to 184.17.63.254184.17.63.25516,382
70184.17.64.0/18184.17.64.1 to 184.17.127.254184.17.127.25516,382
71184.17.128.0/18184.17.128.1 to 184.17.191.254184.17.191.25516,382
72184.17.192.0/18184.17.192.1 to 184.17.255.254184.17.255.25516,382
73184.18.0.0/18184.18.0.1 to 184.18.63.254184.18.63.25516,382
74184.18.64.0/18184.18.64.1 to 184.18.127.254184.18.127.25516,382
75184.18.128.0/18184.18.128.1 to 184.18.191.254184.18.191.25516,382
76184.18.192.0/18184.18.192.1 to 184.18.255.254184.18.255.25516,382
77184.19.0.0/18184.19.0.1 to 184.19.63.254184.19.63.25516,382
78184.19.64.0/18184.19.64.1 to 184.19.127.254184.19.127.25516,382
79184.19.128.0/18184.19.128.1 to 184.19.191.254184.19.191.25516,382
80184.19.192.0/18184.19.192.1 to 184.19.255.254184.19.255.25516,382
81184.20.0.0/18184.20.0.1 to 184.20.63.254184.20.63.25516,382
82184.20.64.0/18184.20.64.1 to 184.20.127.254184.20.127.25516,382
83184.20.128.0/18184.20.128.1 to 184.20.191.254184.20.191.25516,382
84184.20.192.0/18184.20.192.1 to 184.20.255.254184.20.255.25516,382
85184.21.0.0/18184.21.0.1 to 184.21.63.254184.21.63.25516,382
86184.21.64.0/18184.21.64.1 to 184.21.127.254184.21.127.25516,382
87184.21.128.0/18184.21.128.1 to 184.21.191.254184.21.191.25516,382
88184.21.192.0/18184.21.192.1 to 184.21.255.254184.21.255.25516,382
89184.22.0.0/18184.22.0.1 to 184.22.63.254184.22.63.25516,382
90184.22.64.0/18184.22.64.1 to 184.22.127.254184.22.127.25516,382
91184.22.128.0/18184.22.128.1 to 184.22.191.254184.22.191.25516,382
92184.22.192.0/18184.22.192.1 to 184.22.255.254184.22.255.25516,382
93184.23.0.0/18184.23.0.1 to 184.23.63.254184.23.63.25516,382
94184.23.64.0/18184.23.64.1 to 184.23.127.254184.23.127.25516,382
95184.23.128.0/18184.23.128.1 to 184.23.191.254184.23.191.25516,382
96184.23.192.0/18184.23.192.1 to 184.23.255.254184.23.255.25516,382
97184.24.0.0/18184.24.0.1 to 184.24.63.254184.24.63.25516,382
98184.24.64.0/18184.24.64.1 to 184.24.127.254184.24.127.25516,382
99184.24.128.0/18184.24.128.1 to 184.24.191.254184.24.191.25516,382
100184.24.192.0/18184.24.192.1 to 184.24.255.254184.24.255.25516,382
101184.25.0.0/18184.25.0.1 to 184.25.63.254184.25.63.25516,382
102184.25.64.0/18184.25.64.1 to 184.25.127.254184.25.127.25516,382
103184.25.128.0/18184.25.128.1 to 184.25.191.254184.25.191.25516,382
104184.25.192.0/18184.25.192.1 to 184.25.255.254184.25.255.25516,382
105184.26.0.0/18184.26.0.1 to 184.26.63.254184.26.63.25516,382
106184.26.64.0/18184.26.64.1 to 184.26.127.254184.26.127.25516,382
107184.26.128.0/18184.26.128.1 to 184.26.191.254184.26.191.25516,382
108184.26.192.0/18184.26.192.1 to 184.26.255.254184.26.255.25516,382
109184.27.0.0/18184.27.0.1 to 184.27.63.254184.27.63.25516,382
110184.27.64.0/18184.27.64.1 to 184.27.127.254184.27.127.25516,382
111184.27.128.0/18184.27.128.1 to 184.27.191.254184.27.191.25516,382
112184.27.192.0/18184.27.192.1 to 184.27.255.254184.27.255.25516,382
113184.28.0.0/18184.28.0.1 to 184.28.63.254184.28.63.25516,382
114184.28.64.0/18184.28.64.1 to 184.28.127.254184.28.127.25516,382
115184.28.128.0/18184.28.128.1 to 184.28.191.254184.28.191.25516,382
116184.28.192.0/18184.28.192.1 to 184.28.255.254184.28.255.25516,382
117184.29.0.0/18184.29.0.1 to 184.29.63.254184.29.63.25516,382
118184.29.64.0/18184.29.64.1 to 184.29.127.254184.29.127.25516,382
119184.29.128.0/18184.29.128.1 to 184.29.191.254184.29.191.25516,382
120184.29.192.0/18184.29.192.1 to 184.29.255.254184.29.255.25516,382
121184.30.0.0/18184.30.0.1 to 184.30.63.254184.30.63.25516,382
122184.30.64.0/18184.30.64.1 to 184.30.127.254184.30.127.25516,382
123184.30.128.0/18184.30.128.1 to 184.30.191.254184.30.191.25516,382
124184.30.192.0/18184.30.192.1 to 184.30.255.254184.30.255.25516,382
125184.31.0.0/18184.31.0.1 to 184.31.63.254184.31.63.25516,382
126184.31.64.0/18184.31.64.1 to 184.31.127.254184.31.127.25516,382
127184.31.128.0/18184.31.128.1 to 184.31.191.254184.31.191.25516,382
128184.31.192.0/18184.31.192.1 to 184.31.255.254184.31.255.25516,382
129184.32.0.0/18184.32.0.1 to 184.32.63.254184.32.63.25516,382
130184.32.64.0/18184.32.64.1 to 184.32.127.254184.32.127.25516,382
131184.32.128.0/18184.32.128.1 to 184.32.191.254184.32.191.25516,382
132184.32.192.0/18184.32.192.1 to 184.32.255.254184.32.255.25516,382
133184.33.0.0/18184.33.0.1 to 184.33.63.254184.33.63.25516,382
134184.33.64.0/18184.33.64.1 to 184.33.127.254184.33.127.25516,382
135184.33.128.0/18184.33.128.1 to 184.33.191.254184.33.191.25516,382
136184.33.192.0/18184.33.192.1 to 184.33.255.254184.33.255.25516,382
137184.34.0.0/18184.34.0.1 to 184.34.63.254184.34.63.25516,382
138184.34.64.0/18184.34.64.1 to 184.34.127.254184.34.127.25516,382
139184.34.128.0/18184.34.128.1 to 184.34.191.254184.34.191.25516,382
140184.34.192.0/18184.34.192.1 to 184.34.255.254184.34.255.25516,382
141184.35.0.0/18184.35.0.1 to 184.35.63.254184.35.63.25516,382
142184.35.64.0/18184.35.64.1 to 184.35.127.254184.35.127.25516,382
143184.35.128.0/18184.35.128.1 to 184.35.191.254184.35.191.25516,382
144184.35.192.0/18184.35.192.1 to 184.35.255.254184.35.255.25516,382
145184.36.0.0/18184.36.0.1 to 184.36.63.254184.36.63.25516,382
146184.36.64.0/18184.36.64.1 to 184.36.127.254184.36.127.25516,382
147184.36.128.0/18184.36.128.1 to 184.36.191.254184.36.191.25516,382
148184.36.192.0/18184.36.192.1 to 184.36.255.254184.36.255.25516,382
149184.37.0.0/18184.37.0.1 to 184.37.63.254184.37.63.25516,382
150184.37.64.0/18184.37.64.1 to 184.37.127.254184.37.127.25516,382
151184.37.128.0/18184.37.128.1 to 184.37.191.254184.37.191.25516,382
152184.37.192.0/18184.37.192.1 to 184.37.255.254184.37.255.25516,382
153184.38.0.0/18184.38.0.1 to 184.38.63.254184.38.63.25516,382
154184.38.64.0/18184.38.64.1 to 184.38.127.254184.38.127.25516,382
155184.38.128.0/18184.38.128.1 to 184.38.191.254184.38.191.25516,382
156184.38.192.0/18184.38.192.1 to 184.38.255.254184.38.255.25516,382
157184.39.0.0/18184.39.0.1 to 184.39.63.254184.39.63.25516,382
158184.39.64.0/18184.39.64.1 to 184.39.127.254184.39.127.25516,382
159184.39.128.0/18184.39.128.1 to 184.39.191.254184.39.191.25516,382
160184.39.192.0/18184.39.192.1 to 184.39.255.254184.39.255.25516,382
161184.40.0.0/18184.40.0.1 to 184.40.63.254184.40.63.25516,382
162184.40.64.0/18184.40.64.1 to 184.40.127.254184.40.127.25516,382
163184.40.128.0/18184.40.128.1 to 184.40.191.254184.40.191.25516,382
164184.40.192.0/18184.40.192.1 to 184.40.255.254184.40.255.25516,382
165184.41.0.0/18184.41.0.1 to 184.41.63.254184.41.63.25516,382
166184.41.64.0/18184.41.64.1 to 184.41.127.254184.41.127.25516,382
167184.41.128.0/18184.41.128.1 to 184.41.191.254184.41.191.25516,382
168184.41.192.0/18184.41.192.1 to 184.41.255.254184.41.255.25516,382
169184.42.0.0/18184.42.0.1 to 184.42.63.254184.42.63.25516,382
170184.42.64.0/18184.42.64.1 to 184.42.127.254184.42.127.25516,382
171184.42.128.0/18184.42.128.1 to 184.42.191.254184.42.191.25516,382
172184.42.192.0/18184.42.192.1 to 184.42.255.254184.42.255.25516,382
173184.43.0.0/18184.43.0.1 to 184.43.63.254184.43.63.25516,382
174184.43.64.0/18184.43.64.1 to 184.43.127.254184.43.127.25516,382
175184.43.128.0/18184.43.128.1 to 184.43.191.254184.43.191.25516,382
176184.43.192.0/18184.43.192.1 to 184.43.255.254184.43.255.25516,382
177184.44.0.0/18184.44.0.1 to 184.44.63.254184.44.63.25516,382
178184.44.64.0/18184.44.64.1 to 184.44.127.254184.44.127.25516,382
179184.44.128.0/18184.44.128.1 to 184.44.191.254184.44.191.25516,382
180184.44.192.0/18184.44.192.1 to 184.44.255.254184.44.255.25516,382
181184.45.0.0/18184.45.0.1 to 184.45.63.254184.45.63.25516,382
182184.45.64.0/18184.45.64.1 to 184.45.127.254184.45.127.25516,382
183184.45.128.0/18184.45.128.1 to 184.45.191.254184.45.191.25516,382
184184.45.192.0/18184.45.192.1 to 184.45.255.254184.45.255.25516,382
185184.46.0.0/18184.46.0.1 to 184.46.63.254184.46.63.25516,382
186184.46.64.0/18184.46.64.1 to 184.46.127.254184.46.127.25516,382
187184.46.128.0/18184.46.128.1 to 184.46.191.254184.46.191.25516,382
188184.46.192.0/18184.46.192.1 to 184.46.255.254184.46.255.25516,382
189184.47.0.0/18184.47.0.1 to 184.47.63.254184.47.63.25516,382
190184.47.64.0/18184.47.64.1 to 184.47.127.254184.47.127.25516,382
191184.47.128.0/18184.47.128.1 to 184.47.191.254184.47.191.25516,382
192184.47.192.0/18184.47.192.1 to 184.47.255.254184.47.255.25516,382
193184.48.0.0/18184.48.0.1 to 184.48.63.254184.48.63.25516,382
194184.48.64.0/18184.48.64.1 to 184.48.127.254184.48.127.25516,382
195184.48.128.0/18184.48.128.1 to 184.48.191.254184.48.191.25516,382
196184.48.192.0/18184.48.192.1 to 184.48.255.254184.48.255.25516,382
197184.49.0.0/18184.49.0.1 to 184.49.63.254184.49.63.25516,382
198184.49.64.0/18184.49.64.1 to 184.49.127.254184.49.127.25516,382
199184.49.128.0/18184.49.128.1 to 184.49.191.254184.49.191.25516,382
200184.49.192.0/18184.49.192.1 to 184.49.255.254184.49.255.25516,382
201184.50.0.0/18184.50.0.1 to 184.50.63.254184.50.63.25516,382
202184.50.64.0/18184.50.64.1 to 184.50.127.254184.50.127.25516,382
203184.50.128.0/18184.50.128.1 to 184.50.191.254184.50.191.25516,382
204184.50.192.0/18184.50.192.1 to 184.50.255.254184.50.255.25516,382
205184.51.0.0/18184.51.0.1 to 184.51.63.254184.51.63.25516,382
206184.51.64.0/18184.51.64.1 to 184.51.127.254184.51.127.25516,382
207184.51.128.0/18184.51.128.1 to 184.51.191.254184.51.191.25516,382
208184.51.192.0/18184.51.192.1 to 184.51.255.254184.51.255.25516,382
209184.52.0.0/18184.52.0.1 to 184.52.63.254184.52.63.25516,382
210184.52.64.0/18184.52.64.1 to 184.52.127.254184.52.127.25516,382
211184.52.128.0/18184.52.128.1 to 184.52.191.254184.52.191.25516,382
212184.52.192.0/18184.52.192.1 to 184.52.255.254184.52.255.25516,382
213184.53.0.0/18184.53.0.1 to 184.53.63.254184.53.63.25516,382
214184.53.64.0/18184.53.64.1 to 184.53.127.254184.53.127.25516,382
215184.53.128.0/18184.53.128.1 to 184.53.191.254184.53.191.25516,382
216184.53.192.0/18184.53.192.1 to 184.53.255.254184.53.255.25516,382
217184.54.0.0/18184.54.0.1 to 184.54.63.254184.54.63.25516,382
218184.54.64.0/18184.54.64.1 to 184.54.127.254184.54.127.25516,382
219184.54.128.0/18184.54.128.1 to 184.54.191.254184.54.191.25516,382
220184.54.192.0/18184.54.192.1 to 184.54.255.254184.54.255.25516,382
221184.55.0.0/18184.55.0.1 to 184.55.63.254184.55.63.25516,382
222184.55.64.0/18184.55.64.1 to 184.55.127.254184.55.127.25516,382
223184.55.128.0/18184.55.128.1 to 184.55.191.254184.55.191.25516,382
224184.55.192.0/18184.55.192.1 to 184.55.255.254184.55.255.25516,382
225184.56.0.0/18184.56.0.1 to 184.56.63.254184.56.63.25516,382
226184.56.64.0/18184.56.64.1 to 184.56.127.254184.56.127.25516,382
227184.56.128.0/18184.56.128.1 to 184.56.191.254184.56.191.25516,382
228184.56.192.0/18184.56.192.1 to 184.56.255.254184.56.255.25516,382
229184.57.0.0/18184.57.0.1 to 184.57.63.254184.57.63.25516,382
230184.57.64.0/18184.57.64.1 to 184.57.127.254184.57.127.25516,382
231184.57.128.0/18184.57.128.1 to 184.57.191.254184.57.191.25516,382
232184.57.192.0/18184.57.192.1 to 184.57.255.254184.57.255.25516,382
233184.58.0.0/18184.58.0.1 to 184.58.63.254184.58.63.25516,382
234184.58.64.0/18184.58.64.1 to 184.58.127.254184.58.127.25516,382
235184.58.128.0/18184.58.128.1 to 184.58.191.254184.58.191.25516,382
236184.58.192.0/18184.58.192.1 to 184.58.255.254184.58.255.25516,382
237184.59.0.0/18184.59.0.1 to 184.59.63.254184.59.63.25516,382
238184.59.64.0/18184.59.64.1 to 184.59.127.254184.59.127.25516,382
239184.59.128.0/18184.59.128.1 to 184.59.191.254184.59.191.25516,382
240184.59.192.0/18184.59.192.1 to 184.59.255.254184.59.255.25516,382
241184.60.0.0/18184.60.0.1 to 184.60.63.254184.60.63.25516,382
242184.60.64.0/18184.60.64.1 to 184.60.127.254184.60.127.25516,382
243184.60.128.0/18184.60.128.1 to 184.60.191.254184.60.191.25516,382
244184.60.192.0/18184.60.192.1 to 184.60.255.254184.60.255.25516,382
245184.61.0.0/18184.61.0.1 to 184.61.63.254184.61.63.25516,382
246184.61.64.0/18184.61.64.1 to 184.61.127.254184.61.127.25516,382
247184.61.128.0/18184.61.128.1 to 184.61.191.254184.61.191.25516,382
248184.61.192.0/18184.61.192.1 to 184.61.255.254184.61.255.25516,382
249184.62.0.0/18184.62.0.1 to 184.62.63.254184.62.63.25516,382
250184.62.64.0/18184.62.64.1 to 184.62.127.254184.62.127.25516,382
251184.62.128.0/18184.62.128.1 to 184.62.191.254184.62.191.25516,382
252184.62.192.0/18184.62.192.1 to 184.62.255.254184.62.255.25516,382
253184.63.0.0/18184.63.0.1 to 184.63.63.254184.63.63.25516,382
254184.63.64.0/18184.63.64.1 to 184.63.127.254184.63.127.25516,382
255184.63.128.0/18184.63.128.1 to 184.63.191.254184.63.191.25516,382
256184.63.192.0/18184.63.192.1 to 184.63.255.254184.63.255.25516,382

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.