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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.

Network106.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
106.0.0.0
Broadcast address
106.255.255.255
First usable
106.0.0.1
Last usable
106.255.255.254
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
A (default /8)
As numbers
Hex 6A000000 · Integer 1778384896 to 1795162111
Reverse DNS zone
106.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01101010..00000000.00000000.00000000106.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01101010..00000000.00000000.00000000106.0.0.0
Broadcast01101010..11111111.11111111.11111111106.255.255.255
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)

106.0.0.0/8 makes 2,048 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1106.0.0.0/19106.0.0.1 to 106.0.31.254106.0.31.2558,190
2106.0.32.0/19106.0.32.1 to 106.0.63.254106.0.63.2558,190
3106.0.64.0/19106.0.64.1 to 106.0.95.254106.0.95.2558,190
4106.0.96.0/19106.0.96.1 to 106.0.127.254106.0.127.2558,190
5106.0.128.0/19106.0.128.1 to 106.0.159.254106.0.159.2558,190
6106.0.160.0/19106.0.160.1 to 106.0.191.254106.0.191.2558,190
7106.0.192.0/19106.0.192.1 to 106.0.223.254106.0.223.2558,190
8106.0.224.0/19106.0.224.1 to 106.0.255.254106.0.255.2558,190
9106.1.0.0/19106.1.0.1 to 106.1.31.254106.1.31.2558,190
10106.1.32.0/19106.1.32.1 to 106.1.63.254106.1.63.2558,190
11106.1.64.0/19106.1.64.1 to 106.1.95.254106.1.95.2558,190
12106.1.96.0/19106.1.96.1 to 106.1.127.254106.1.127.2558,190
13106.1.128.0/19106.1.128.1 to 106.1.159.254106.1.159.2558,190
14106.1.160.0/19106.1.160.1 to 106.1.191.254106.1.191.2558,190
15106.1.192.0/19106.1.192.1 to 106.1.223.254106.1.223.2558,190
16106.1.224.0/19106.1.224.1 to 106.1.255.254106.1.255.2558,190
17106.2.0.0/19106.2.0.1 to 106.2.31.254106.2.31.2558,190
18106.2.32.0/19106.2.32.1 to 106.2.63.254106.2.63.2558,190
19106.2.64.0/19106.2.64.1 to 106.2.95.254106.2.95.2558,190
20106.2.96.0/19106.2.96.1 to 106.2.127.254106.2.127.2558,190
21106.2.128.0/19106.2.128.1 to 106.2.159.254106.2.159.2558,190
22106.2.160.0/19106.2.160.1 to 106.2.191.254106.2.191.2558,190
23106.2.192.0/19106.2.192.1 to 106.2.223.254106.2.223.2558,190
24106.2.224.0/19106.2.224.1 to 106.2.255.254106.2.255.2558,190
25106.3.0.0/19106.3.0.1 to 106.3.31.254106.3.31.2558,190
26106.3.32.0/19106.3.32.1 to 106.3.63.254106.3.63.2558,190
27106.3.64.0/19106.3.64.1 to 106.3.95.254106.3.95.2558,190
28106.3.96.0/19106.3.96.1 to 106.3.127.254106.3.127.2558,190
29106.3.128.0/19106.3.128.1 to 106.3.159.254106.3.159.2558,190
30106.3.160.0/19106.3.160.1 to 106.3.191.254106.3.191.2558,190
31106.3.192.0/19106.3.192.1 to 106.3.223.254106.3.223.2558,190
32106.3.224.0/19106.3.224.1 to 106.3.255.254106.3.255.2558,190
33106.4.0.0/19106.4.0.1 to 106.4.31.254106.4.31.2558,190
34106.4.32.0/19106.4.32.1 to 106.4.63.254106.4.63.2558,190
35106.4.64.0/19106.4.64.1 to 106.4.95.254106.4.95.2558,190
36106.4.96.0/19106.4.96.1 to 106.4.127.254106.4.127.2558,190
37106.4.128.0/19106.4.128.1 to 106.4.159.254106.4.159.2558,190
38106.4.160.0/19106.4.160.1 to 106.4.191.254106.4.191.2558,190
39106.4.192.0/19106.4.192.1 to 106.4.223.254106.4.223.2558,190
40106.4.224.0/19106.4.224.1 to 106.4.255.254106.4.255.2558,190
41106.5.0.0/19106.5.0.1 to 106.5.31.254106.5.31.2558,190
42106.5.32.0/19106.5.32.1 to 106.5.63.254106.5.63.2558,190
43106.5.64.0/19106.5.64.1 to 106.5.95.254106.5.95.2558,190
44106.5.96.0/19106.5.96.1 to 106.5.127.254106.5.127.2558,190
45106.5.128.0/19106.5.128.1 to 106.5.159.254106.5.159.2558,190
46106.5.160.0/19106.5.160.1 to 106.5.191.254106.5.191.2558,190
47106.5.192.0/19106.5.192.1 to 106.5.223.254106.5.223.2558,190
48106.5.224.0/19106.5.224.1 to 106.5.255.254106.5.255.2558,190
49106.6.0.0/19106.6.0.1 to 106.6.31.254106.6.31.2558,190
50106.6.32.0/19106.6.32.1 to 106.6.63.254106.6.63.2558,190
51106.6.64.0/19106.6.64.1 to 106.6.95.254106.6.95.2558,190
52106.6.96.0/19106.6.96.1 to 106.6.127.254106.6.127.2558,190
53106.6.128.0/19106.6.128.1 to 106.6.159.254106.6.159.2558,190
54106.6.160.0/19106.6.160.1 to 106.6.191.254106.6.191.2558,190
55106.6.192.0/19106.6.192.1 to 106.6.223.254106.6.223.2558,190
56106.6.224.0/19106.6.224.1 to 106.6.255.254106.6.255.2558,190
57106.7.0.0/19106.7.0.1 to 106.7.31.254106.7.31.2558,190
58106.7.32.0/19106.7.32.1 to 106.7.63.254106.7.63.2558,190
59106.7.64.0/19106.7.64.1 to 106.7.95.254106.7.95.2558,190
60106.7.96.0/19106.7.96.1 to 106.7.127.254106.7.127.2558,190
61106.7.128.0/19106.7.128.1 to 106.7.159.254106.7.159.2558,190
62106.7.160.0/19106.7.160.1 to 106.7.191.254106.7.191.2558,190
63106.7.192.0/19106.7.192.1 to 106.7.223.254106.7.223.2558,190
64106.7.224.0/19106.7.224.1 to 106.7.255.254106.7.255.2558,190
65106.8.0.0/19106.8.0.1 to 106.8.31.254106.8.31.2558,190
66106.8.32.0/19106.8.32.1 to 106.8.63.254106.8.63.2558,190
67106.8.64.0/19106.8.64.1 to 106.8.95.254106.8.95.2558,190
68106.8.96.0/19106.8.96.1 to 106.8.127.254106.8.127.2558,190
69106.8.128.0/19106.8.128.1 to 106.8.159.254106.8.159.2558,190
70106.8.160.0/19106.8.160.1 to 106.8.191.254106.8.191.2558,190
71106.8.192.0/19106.8.192.1 to 106.8.223.254106.8.223.2558,190
72106.8.224.0/19106.8.224.1 to 106.8.255.254106.8.255.2558,190
73106.9.0.0/19106.9.0.1 to 106.9.31.254106.9.31.2558,190
74106.9.32.0/19106.9.32.1 to 106.9.63.254106.9.63.2558,190
75106.9.64.0/19106.9.64.1 to 106.9.95.254106.9.95.2558,190
76106.9.96.0/19106.9.96.1 to 106.9.127.254106.9.127.2558,190
77106.9.128.0/19106.9.128.1 to 106.9.159.254106.9.159.2558,190
78106.9.160.0/19106.9.160.1 to 106.9.191.254106.9.191.2558,190
79106.9.192.0/19106.9.192.1 to 106.9.223.254106.9.223.2558,190
80106.9.224.0/19106.9.224.1 to 106.9.255.254106.9.255.2558,190
81106.10.0.0/19106.10.0.1 to 106.10.31.254106.10.31.2558,190
82106.10.32.0/19106.10.32.1 to 106.10.63.254106.10.63.2558,190
83106.10.64.0/19106.10.64.1 to 106.10.95.254106.10.95.2558,190
84106.10.96.0/19106.10.96.1 to 106.10.127.254106.10.127.2558,190
85106.10.128.0/19106.10.128.1 to 106.10.159.254106.10.159.2558,190
86106.10.160.0/19106.10.160.1 to 106.10.191.254106.10.191.2558,190
87106.10.192.0/19106.10.192.1 to 106.10.223.254106.10.223.2558,190
88106.10.224.0/19106.10.224.1 to 106.10.255.254106.10.255.2558,190
89106.11.0.0/19106.11.0.1 to 106.11.31.254106.11.31.2558,190
90106.11.32.0/19106.11.32.1 to 106.11.63.254106.11.63.2558,190
91106.11.64.0/19106.11.64.1 to 106.11.95.254106.11.95.2558,190
92106.11.96.0/19106.11.96.1 to 106.11.127.254106.11.127.2558,190
93106.11.128.0/19106.11.128.1 to 106.11.159.254106.11.159.2558,190
94106.11.160.0/19106.11.160.1 to 106.11.191.254106.11.191.2558,190
95106.11.192.0/19106.11.192.1 to 106.11.223.254106.11.223.2558,190
96106.11.224.0/19106.11.224.1 to 106.11.255.254106.11.255.2558,190
97106.12.0.0/19106.12.0.1 to 106.12.31.254106.12.31.2558,190
98106.12.32.0/19106.12.32.1 to 106.12.63.254106.12.63.2558,190
99106.12.64.0/19106.12.64.1 to 106.12.95.254106.12.95.2558,190
100106.12.96.0/19106.12.96.1 to 106.12.127.254106.12.127.2558,190
101106.12.128.0/19106.12.128.1 to 106.12.159.254106.12.159.2558,190
102106.12.160.0/19106.12.160.1 to 106.12.191.254106.12.191.2558,190
103106.12.192.0/19106.12.192.1 to 106.12.223.254106.12.223.2558,190
104106.12.224.0/19106.12.224.1 to 106.12.255.254106.12.255.2558,190
105106.13.0.0/19106.13.0.1 to 106.13.31.254106.13.31.2558,190
106106.13.32.0/19106.13.32.1 to 106.13.63.254106.13.63.2558,190
107106.13.64.0/19106.13.64.1 to 106.13.95.254106.13.95.2558,190
108106.13.96.0/19106.13.96.1 to 106.13.127.254106.13.127.2558,190
109106.13.128.0/19106.13.128.1 to 106.13.159.254106.13.159.2558,190
110106.13.160.0/19106.13.160.1 to 106.13.191.254106.13.191.2558,190
111106.13.192.0/19106.13.192.1 to 106.13.223.254106.13.223.2558,190
112106.13.224.0/19106.13.224.1 to 106.13.255.254106.13.255.2558,190
113106.14.0.0/19106.14.0.1 to 106.14.31.254106.14.31.2558,190
114106.14.32.0/19106.14.32.1 to 106.14.63.254106.14.63.2558,190
115106.14.64.0/19106.14.64.1 to 106.14.95.254106.14.95.2558,190
116106.14.96.0/19106.14.96.1 to 106.14.127.254106.14.127.2558,190
117106.14.128.0/19106.14.128.1 to 106.14.159.254106.14.159.2558,190
118106.14.160.0/19106.14.160.1 to 106.14.191.254106.14.191.2558,190
119106.14.192.0/19106.14.192.1 to 106.14.223.254106.14.223.2558,190
120106.14.224.0/19106.14.224.1 to 106.14.255.254106.14.255.2558,190
121106.15.0.0/19106.15.0.1 to 106.15.31.254106.15.31.2558,190
122106.15.32.0/19106.15.32.1 to 106.15.63.254106.15.63.2558,190
123106.15.64.0/19106.15.64.1 to 106.15.95.254106.15.95.2558,190
124106.15.96.0/19106.15.96.1 to 106.15.127.254106.15.127.2558,190
125106.15.128.0/19106.15.128.1 to 106.15.159.254106.15.159.2558,190
126106.15.160.0/19106.15.160.1 to 106.15.191.254106.15.191.2558,190
127106.15.192.0/19106.15.192.1 to 106.15.223.254106.15.223.2558,190
128106.15.224.0/19106.15.224.1 to 106.15.255.254106.15.255.2558,190
129106.16.0.0/19106.16.0.1 to 106.16.31.254106.16.31.2558,190
130106.16.32.0/19106.16.32.1 to 106.16.63.254106.16.63.2558,190
131106.16.64.0/19106.16.64.1 to 106.16.95.254106.16.95.2558,190
132106.16.96.0/19106.16.96.1 to 106.16.127.254106.16.127.2558,190
133106.16.128.0/19106.16.128.1 to 106.16.159.254106.16.159.2558,190
134106.16.160.0/19106.16.160.1 to 106.16.191.254106.16.191.2558,190
135106.16.192.0/19106.16.192.1 to 106.16.223.254106.16.223.2558,190
136106.16.224.0/19106.16.224.1 to 106.16.255.254106.16.255.2558,190
137106.17.0.0/19106.17.0.1 to 106.17.31.254106.17.31.2558,190
138106.17.32.0/19106.17.32.1 to 106.17.63.254106.17.63.2558,190
139106.17.64.0/19106.17.64.1 to 106.17.95.254106.17.95.2558,190
140106.17.96.0/19106.17.96.1 to 106.17.127.254106.17.127.2558,190
141106.17.128.0/19106.17.128.1 to 106.17.159.254106.17.159.2558,190
142106.17.160.0/19106.17.160.1 to 106.17.191.254106.17.191.2558,190
143106.17.192.0/19106.17.192.1 to 106.17.223.254106.17.223.2558,190
144106.17.224.0/19106.17.224.1 to 106.17.255.254106.17.255.2558,190
145106.18.0.0/19106.18.0.1 to 106.18.31.254106.18.31.2558,190
146106.18.32.0/19106.18.32.1 to 106.18.63.254106.18.63.2558,190
147106.18.64.0/19106.18.64.1 to 106.18.95.254106.18.95.2558,190
148106.18.96.0/19106.18.96.1 to 106.18.127.254106.18.127.2558,190
149106.18.128.0/19106.18.128.1 to 106.18.159.254106.18.159.2558,190
150106.18.160.0/19106.18.160.1 to 106.18.191.254106.18.191.2558,190
151106.18.192.0/19106.18.192.1 to 106.18.223.254106.18.223.2558,190
152106.18.224.0/19106.18.224.1 to 106.18.255.254106.18.255.2558,190
153106.19.0.0/19106.19.0.1 to 106.19.31.254106.19.31.2558,190
154106.19.32.0/19106.19.32.1 to 106.19.63.254106.19.63.2558,190
155106.19.64.0/19106.19.64.1 to 106.19.95.254106.19.95.2558,190
156106.19.96.0/19106.19.96.1 to 106.19.127.254106.19.127.2558,190
157106.19.128.0/19106.19.128.1 to 106.19.159.254106.19.159.2558,190
158106.19.160.0/19106.19.160.1 to 106.19.191.254106.19.191.2558,190
159106.19.192.0/19106.19.192.1 to 106.19.223.254106.19.223.2558,190
160106.19.224.0/19106.19.224.1 to 106.19.255.254106.19.255.2558,190
161106.20.0.0/19106.20.0.1 to 106.20.31.254106.20.31.2558,190
162106.20.32.0/19106.20.32.1 to 106.20.63.254106.20.63.2558,190
163106.20.64.0/19106.20.64.1 to 106.20.95.254106.20.95.2558,190
164106.20.96.0/19106.20.96.1 to 106.20.127.254106.20.127.2558,190
165106.20.128.0/19106.20.128.1 to 106.20.159.254106.20.159.2558,190
166106.20.160.0/19106.20.160.1 to 106.20.191.254106.20.191.2558,190
167106.20.192.0/19106.20.192.1 to 106.20.223.254106.20.223.2558,190
168106.20.224.0/19106.20.224.1 to 106.20.255.254106.20.255.2558,190
169106.21.0.0/19106.21.0.1 to 106.21.31.254106.21.31.2558,190
170106.21.32.0/19106.21.32.1 to 106.21.63.254106.21.63.2558,190
171106.21.64.0/19106.21.64.1 to 106.21.95.254106.21.95.2558,190
172106.21.96.0/19106.21.96.1 to 106.21.127.254106.21.127.2558,190
173106.21.128.0/19106.21.128.1 to 106.21.159.254106.21.159.2558,190
174106.21.160.0/19106.21.160.1 to 106.21.191.254106.21.191.2558,190
175106.21.192.0/19106.21.192.1 to 106.21.223.254106.21.223.2558,190
176106.21.224.0/19106.21.224.1 to 106.21.255.254106.21.255.2558,190
177106.22.0.0/19106.22.0.1 to 106.22.31.254106.22.31.2558,190
178106.22.32.0/19106.22.32.1 to 106.22.63.254106.22.63.2558,190
179106.22.64.0/19106.22.64.1 to 106.22.95.254106.22.95.2558,190
180106.22.96.0/19106.22.96.1 to 106.22.127.254106.22.127.2558,190
181106.22.128.0/19106.22.128.1 to 106.22.159.254106.22.159.2558,190
182106.22.160.0/19106.22.160.1 to 106.22.191.254106.22.191.2558,190
183106.22.192.0/19106.22.192.1 to 106.22.223.254106.22.223.2558,190
184106.22.224.0/19106.22.224.1 to 106.22.255.254106.22.255.2558,190
185106.23.0.0/19106.23.0.1 to 106.23.31.254106.23.31.2558,190
186106.23.32.0/19106.23.32.1 to 106.23.63.254106.23.63.2558,190
187106.23.64.0/19106.23.64.1 to 106.23.95.254106.23.95.2558,190
188106.23.96.0/19106.23.96.1 to 106.23.127.254106.23.127.2558,190
189106.23.128.0/19106.23.128.1 to 106.23.159.254106.23.159.2558,190
190106.23.160.0/19106.23.160.1 to 106.23.191.254106.23.191.2558,190
191106.23.192.0/19106.23.192.1 to 106.23.223.254106.23.223.2558,190
192106.23.224.0/19106.23.224.1 to 106.23.255.254106.23.255.2558,190
193106.24.0.0/19106.24.0.1 to 106.24.31.254106.24.31.2558,190
194106.24.32.0/19106.24.32.1 to 106.24.63.254106.24.63.2558,190
195106.24.64.0/19106.24.64.1 to 106.24.95.254106.24.95.2558,190
196106.24.96.0/19106.24.96.1 to 106.24.127.254106.24.127.2558,190
197106.24.128.0/19106.24.128.1 to 106.24.159.254106.24.159.2558,190
198106.24.160.0/19106.24.160.1 to 106.24.191.254106.24.191.2558,190
199106.24.192.0/19106.24.192.1 to 106.24.223.254106.24.223.2558,190
200106.24.224.0/19106.24.224.1 to 106.24.255.254106.24.255.2558,190
201106.25.0.0/19106.25.0.1 to 106.25.31.254106.25.31.2558,190
202106.25.32.0/19106.25.32.1 to 106.25.63.254106.25.63.2558,190
203106.25.64.0/19106.25.64.1 to 106.25.95.254106.25.95.2558,190
204106.25.96.0/19106.25.96.1 to 106.25.127.254106.25.127.2558,190
205106.25.128.0/19106.25.128.1 to 106.25.159.254106.25.159.2558,190
206106.25.160.0/19106.25.160.1 to 106.25.191.254106.25.191.2558,190
207106.25.192.0/19106.25.192.1 to 106.25.223.254106.25.223.2558,190
208106.25.224.0/19106.25.224.1 to 106.25.255.254106.25.255.2558,190
209106.26.0.0/19106.26.0.1 to 106.26.31.254106.26.31.2558,190
210106.26.32.0/19106.26.32.1 to 106.26.63.254106.26.63.2558,190
211106.26.64.0/19106.26.64.1 to 106.26.95.254106.26.95.2558,190
212106.26.96.0/19106.26.96.1 to 106.26.127.254106.26.127.2558,190
213106.26.128.0/19106.26.128.1 to 106.26.159.254106.26.159.2558,190
214106.26.160.0/19106.26.160.1 to 106.26.191.254106.26.191.2558,190
215106.26.192.0/19106.26.192.1 to 106.26.223.254106.26.223.2558,190
216106.26.224.0/19106.26.224.1 to 106.26.255.254106.26.255.2558,190
217106.27.0.0/19106.27.0.1 to 106.27.31.254106.27.31.2558,190
218106.27.32.0/19106.27.32.1 to 106.27.63.254106.27.63.2558,190
219106.27.64.0/19106.27.64.1 to 106.27.95.254106.27.95.2558,190
220106.27.96.0/19106.27.96.1 to 106.27.127.254106.27.127.2558,190
221106.27.128.0/19106.27.128.1 to 106.27.159.254106.27.159.2558,190
222106.27.160.0/19106.27.160.1 to 106.27.191.254106.27.191.2558,190
223106.27.192.0/19106.27.192.1 to 106.27.223.254106.27.223.2558,190
224106.27.224.0/19106.27.224.1 to 106.27.255.254106.27.255.2558,190
225106.28.0.0/19106.28.0.1 to 106.28.31.254106.28.31.2558,190
226106.28.32.0/19106.28.32.1 to 106.28.63.254106.28.63.2558,190
227106.28.64.0/19106.28.64.1 to 106.28.95.254106.28.95.2558,190
228106.28.96.0/19106.28.96.1 to 106.28.127.254106.28.127.2558,190
229106.28.128.0/19106.28.128.1 to 106.28.159.254106.28.159.2558,190
230106.28.160.0/19106.28.160.1 to 106.28.191.254106.28.191.2558,190
231106.28.192.0/19106.28.192.1 to 106.28.223.254106.28.223.2558,190
232106.28.224.0/19106.28.224.1 to 106.28.255.254106.28.255.2558,190
233106.29.0.0/19106.29.0.1 to 106.29.31.254106.29.31.2558,190
234106.29.32.0/19106.29.32.1 to 106.29.63.254106.29.63.2558,190
235106.29.64.0/19106.29.64.1 to 106.29.95.254106.29.95.2558,190
236106.29.96.0/19106.29.96.1 to 106.29.127.254106.29.127.2558,190
237106.29.128.0/19106.29.128.1 to 106.29.159.254106.29.159.2558,190
238106.29.160.0/19106.29.160.1 to 106.29.191.254106.29.191.2558,190
239106.29.192.0/19106.29.192.1 to 106.29.223.254106.29.223.2558,190
240106.29.224.0/19106.29.224.1 to 106.29.255.254106.29.255.2558,190
241106.30.0.0/19106.30.0.1 to 106.30.31.254106.30.31.2558,190
242106.30.32.0/19106.30.32.1 to 106.30.63.254106.30.63.2558,190
243106.30.64.0/19106.30.64.1 to 106.30.95.254106.30.95.2558,190
244106.30.96.0/19106.30.96.1 to 106.30.127.254106.30.127.2558,190
245106.30.128.0/19106.30.128.1 to 106.30.159.254106.30.159.2558,190
246106.30.160.0/19106.30.160.1 to 106.30.191.254106.30.191.2558,190
247106.30.192.0/19106.30.192.1 to 106.30.223.254106.30.223.2558,190
248106.30.224.0/19106.30.224.1 to 106.30.255.254106.30.255.2558,190
249106.31.0.0/19106.31.0.1 to 106.31.31.254106.31.31.2558,190
250106.31.32.0/19106.31.32.1 to 106.31.63.254106.31.63.2558,190
251106.31.64.0/19106.31.64.1 to 106.31.95.254106.31.95.2558,190
252106.31.96.0/19106.31.96.1 to 106.31.127.254106.31.127.2558,190
253106.31.128.0/19106.31.128.1 to 106.31.159.254106.31.159.2558,190
254106.31.160.0/19106.31.160.1 to 106.31.191.254106.31.191.2558,190
255106.31.192.0/19106.31.192.1 to 106.31.223.254106.31.223.2558,190
256106.31.224.0/19106.31.224.1 to 106.31.255.254106.31.255.2558,190

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.