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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.

Network108.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
108.0.0.0
Broadcast address
108.255.255.255
First usable
108.0.0.1
Last usable
108.255.255.254
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 6C000000 · Integer 1811939328 to 1828716543
Reverse DNS zone
108.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01101100..00000000.00000000.00000000108.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01101100..00000000.00000000.00000000108.0.0.0
Broadcast01101100..11111111.11111111.11111111108.255.255.255
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)

108.0.0.0/8 makes 4,096 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1108.0.0.0/20108.0.0.1 to 108.0.15.254108.0.15.2554,094
2108.0.16.0/20108.0.16.1 to 108.0.31.254108.0.31.2554,094
3108.0.32.0/20108.0.32.1 to 108.0.47.254108.0.47.2554,094
4108.0.48.0/20108.0.48.1 to 108.0.63.254108.0.63.2554,094
5108.0.64.0/20108.0.64.1 to 108.0.79.254108.0.79.2554,094
6108.0.80.0/20108.0.80.1 to 108.0.95.254108.0.95.2554,094
7108.0.96.0/20108.0.96.1 to 108.0.111.254108.0.111.2554,094
8108.0.112.0/20108.0.112.1 to 108.0.127.254108.0.127.2554,094
9108.0.128.0/20108.0.128.1 to 108.0.143.254108.0.143.2554,094
10108.0.144.0/20108.0.144.1 to 108.0.159.254108.0.159.2554,094
11108.0.160.0/20108.0.160.1 to 108.0.175.254108.0.175.2554,094
12108.0.176.0/20108.0.176.1 to 108.0.191.254108.0.191.2554,094
13108.0.192.0/20108.0.192.1 to 108.0.207.254108.0.207.2554,094
14108.0.208.0/20108.0.208.1 to 108.0.223.254108.0.223.2554,094
15108.0.224.0/20108.0.224.1 to 108.0.239.254108.0.239.2554,094
16108.0.240.0/20108.0.240.1 to 108.0.255.254108.0.255.2554,094
17108.1.0.0/20108.1.0.1 to 108.1.15.254108.1.15.2554,094
18108.1.16.0/20108.1.16.1 to 108.1.31.254108.1.31.2554,094
19108.1.32.0/20108.1.32.1 to 108.1.47.254108.1.47.2554,094
20108.1.48.0/20108.1.48.1 to 108.1.63.254108.1.63.2554,094
21108.1.64.0/20108.1.64.1 to 108.1.79.254108.1.79.2554,094
22108.1.80.0/20108.1.80.1 to 108.1.95.254108.1.95.2554,094
23108.1.96.0/20108.1.96.1 to 108.1.111.254108.1.111.2554,094
24108.1.112.0/20108.1.112.1 to 108.1.127.254108.1.127.2554,094
25108.1.128.0/20108.1.128.1 to 108.1.143.254108.1.143.2554,094
26108.1.144.0/20108.1.144.1 to 108.1.159.254108.1.159.2554,094
27108.1.160.0/20108.1.160.1 to 108.1.175.254108.1.175.2554,094
28108.1.176.0/20108.1.176.1 to 108.1.191.254108.1.191.2554,094
29108.1.192.0/20108.1.192.1 to 108.1.207.254108.1.207.2554,094
30108.1.208.0/20108.1.208.1 to 108.1.223.254108.1.223.2554,094
31108.1.224.0/20108.1.224.1 to 108.1.239.254108.1.239.2554,094
32108.1.240.0/20108.1.240.1 to 108.1.255.254108.1.255.2554,094
33108.2.0.0/20108.2.0.1 to 108.2.15.254108.2.15.2554,094
34108.2.16.0/20108.2.16.1 to 108.2.31.254108.2.31.2554,094
35108.2.32.0/20108.2.32.1 to 108.2.47.254108.2.47.2554,094
36108.2.48.0/20108.2.48.1 to 108.2.63.254108.2.63.2554,094
37108.2.64.0/20108.2.64.1 to 108.2.79.254108.2.79.2554,094
38108.2.80.0/20108.2.80.1 to 108.2.95.254108.2.95.2554,094
39108.2.96.0/20108.2.96.1 to 108.2.111.254108.2.111.2554,094
40108.2.112.0/20108.2.112.1 to 108.2.127.254108.2.127.2554,094
41108.2.128.0/20108.2.128.1 to 108.2.143.254108.2.143.2554,094
42108.2.144.0/20108.2.144.1 to 108.2.159.254108.2.159.2554,094
43108.2.160.0/20108.2.160.1 to 108.2.175.254108.2.175.2554,094
44108.2.176.0/20108.2.176.1 to 108.2.191.254108.2.191.2554,094
45108.2.192.0/20108.2.192.1 to 108.2.207.254108.2.207.2554,094
46108.2.208.0/20108.2.208.1 to 108.2.223.254108.2.223.2554,094
47108.2.224.0/20108.2.224.1 to 108.2.239.254108.2.239.2554,094
48108.2.240.0/20108.2.240.1 to 108.2.255.254108.2.255.2554,094
49108.3.0.0/20108.3.0.1 to 108.3.15.254108.3.15.2554,094
50108.3.16.0/20108.3.16.1 to 108.3.31.254108.3.31.2554,094
51108.3.32.0/20108.3.32.1 to 108.3.47.254108.3.47.2554,094
52108.3.48.0/20108.3.48.1 to 108.3.63.254108.3.63.2554,094
53108.3.64.0/20108.3.64.1 to 108.3.79.254108.3.79.2554,094
54108.3.80.0/20108.3.80.1 to 108.3.95.254108.3.95.2554,094
55108.3.96.0/20108.3.96.1 to 108.3.111.254108.3.111.2554,094
56108.3.112.0/20108.3.112.1 to 108.3.127.254108.3.127.2554,094
57108.3.128.0/20108.3.128.1 to 108.3.143.254108.3.143.2554,094
58108.3.144.0/20108.3.144.1 to 108.3.159.254108.3.159.2554,094
59108.3.160.0/20108.3.160.1 to 108.3.175.254108.3.175.2554,094
60108.3.176.0/20108.3.176.1 to 108.3.191.254108.3.191.2554,094
61108.3.192.0/20108.3.192.1 to 108.3.207.254108.3.207.2554,094
62108.3.208.0/20108.3.208.1 to 108.3.223.254108.3.223.2554,094
63108.3.224.0/20108.3.224.1 to 108.3.239.254108.3.239.2554,094
64108.3.240.0/20108.3.240.1 to 108.3.255.254108.3.255.2554,094
65108.4.0.0/20108.4.0.1 to 108.4.15.254108.4.15.2554,094
66108.4.16.0/20108.4.16.1 to 108.4.31.254108.4.31.2554,094
67108.4.32.0/20108.4.32.1 to 108.4.47.254108.4.47.2554,094
68108.4.48.0/20108.4.48.1 to 108.4.63.254108.4.63.2554,094
69108.4.64.0/20108.4.64.1 to 108.4.79.254108.4.79.2554,094
70108.4.80.0/20108.4.80.1 to 108.4.95.254108.4.95.2554,094
71108.4.96.0/20108.4.96.1 to 108.4.111.254108.4.111.2554,094
72108.4.112.0/20108.4.112.1 to 108.4.127.254108.4.127.2554,094
73108.4.128.0/20108.4.128.1 to 108.4.143.254108.4.143.2554,094
74108.4.144.0/20108.4.144.1 to 108.4.159.254108.4.159.2554,094
75108.4.160.0/20108.4.160.1 to 108.4.175.254108.4.175.2554,094
76108.4.176.0/20108.4.176.1 to 108.4.191.254108.4.191.2554,094
77108.4.192.0/20108.4.192.1 to 108.4.207.254108.4.207.2554,094
78108.4.208.0/20108.4.208.1 to 108.4.223.254108.4.223.2554,094
79108.4.224.0/20108.4.224.1 to 108.4.239.254108.4.239.2554,094
80108.4.240.0/20108.4.240.1 to 108.4.255.254108.4.255.2554,094
81108.5.0.0/20108.5.0.1 to 108.5.15.254108.5.15.2554,094
82108.5.16.0/20108.5.16.1 to 108.5.31.254108.5.31.2554,094
83108.5.32.0/20108.5.32.1 to 108.5.47.254108.5.47.2554,094
84108.5.48.0/20108.5.48.1 to 108.5.63.254108.5.63.2554,094
85108.5.64.0/20108.5.64.1 to 108.5.79.254108.5.79.2554,094
86108.5.80.0/20108.5.80.1 to 108.5.95.254108.5.95.2554,094
87108.5.96.0/20108.5.96.1 to 108.5.111.254108.5.111.2554,094
88108.5.112.0/20108.5.112.1 to 108.5.127.254108.5.127.2554,094
89108.5.128.0/20108.5.128.1 to 108.5.143.254108.5.143.2554,094
90108.5.144.0/20108.5.144.1 to 108.5.159.254108.5.159.2554,094
91108.5.160.0/20108.5.160.1 to 108.5.175.254108.5.175.2554,094
92108.5.176.0/20108.5.176.1 to 108.5.191.254108.5.191.2554,094
93108.5.192.0/20108.5.192.1 to 108.5.207.254108.5.207.2554,094
94108.5.208.0/20108.5.208.1 to 108.5.223.254108.5.223.2554,094
95108.5.224.0/20108.5.224.1 to 108.5.239.254108.5.239.2554,094
96108.5.240.0/20108.5.240.1 to 108.5.255.254108.5.255.2554,094
97108.6.0.0/20108.6.0.1 to 108.6.15.254108.6.15.2554,094
98108.6.16.0/20108.6.16.1 to 108.6.31.254108.6.31.2554,094
99108.6.32.0/20108.6.32.1 to 108.6.47.254108.6.47.2554,094
100108.6.48.0/20108.6.48.1 to 108.6.63.254108.6.63.2554,094
101108.6.64.0/20108.6.64.1 to 108.6.79.254108.6.79.2554,094
102108.6.80.0/20108.6.80.1 to 108.6.95.254108.6.95.2554,094
103108.6.96.0/20108.6.96.1 to 108.6.111.254108.6.111.2554,094
104108.6.112.0/20108.6.112.1 to 108.6.127.254108.6.127.2554,094
105108.6.128.0/20108.6.128.1 to 108.6.143.254108.6.143.2554,094
106108.6.144.0/20108.6.144.1 to 108.6.159.254108.6.159.2554,094
107108.6.160.0/20108.6.160.1 to 108.6.175.254108.6.175.2554,094
108108.6.176.0/20108.6.176.1 to 108.6.191.254108.6.191.2554,094
109108.6.192.0/20108.6.192.1 to 108.6.207.254108.6.207.2554,094
110108.6.208.0/20108.6.208.1 to 108.6.223.254108.6.223.2554,094
111108.6.224.0/20108.6.224.1 to 108.6.239.254108.6.239.2554,094
112108.6.240.0/20108.6.240.1 to 108.6.255.254108.6.255.2554,094
113108.7.0.0/20108.7.0.1 to 108.7.15.254108.7.15.2554,094
114108.7.16.0/20108.7.16.1 to 108.7.31.254108.7.31.2554,094
115108.7.32.0/20108.7.32.1 to 108.7.47.254108.7.47.2554,094
116108.7.48.0/20108.7.48.1 to 108.7.63.254108.7.63.2554,094
117108.7.64.0/20108.7.64.1 to 108.7.79.254108.7.79.2554,094
118108.7.80.0/20108.7.80.1 to 108.7.95.254108.7.95.2554,094
119108.7.96.0/20108.7.96.1 to 108.7.111.254108.7.111.2554,094
120108.7.112.0/20108.7.112.1 to 108.7.127.254108.7.127.2554,094
121108.7.128.0/20108.7.128.1 to 108.7.143.254108.7.143.2554,094
122108.7.144.0/20108.7.144.1 to 108.7.159.254108.7.159.2554,094
123108.7.160.0/20108.7.160.1 to 108.7.175.254108.7.175.2554,094
124108.7.176.0/20108.7.176.1 to 108.7.191.254108.7.191.2554,094
125108.7.192.0/20108.7.192.1 to 108.7.207.254108.7.207.2554,094
126108.7.208.0/20108.7.208.1 to 108.7.223.254108.7.223.2554,094
127108.7.224.0/20108.7.224.1 to 108.7.239.254108.7.239.2554,094
128108.7.240.0/20108.7.240.1 to 108.7.255.254108.7.255.2554,094
129108.8.0.0/20108.8.0.1 to 108.8.15.254108.8.15.2554,094
130108.8.16.0/20108.8.16.1 to 108.8.31.254108.8.31.2554,094
131108.8.32.0/20108.8.32.1 to 108.8.47.254108.8.47.2554,094
132108.8.48.0/20108.8.48.1 to 108.8.63.254108.8.63.2554,094
133108.8.64.0/20108.8.64.1 to 108.8.79.254108.8.79.2554,094
134108.8.80.0/20108.8.80.1 to 108.8.95.254108.8.95.2554,094
135108.8.96.0/20108.8.96.1 to 108.8.111.254108.8.111.2554,094
136108.8.112.0/20108.8.112.1 to 108.8.127.254108.8.127.2554,094
137108.8.128.0/20108.8.128.1 to 108.8.143.254108.8.143.2554,094
138108.8.144.0/20108.8.144.1 to 108.8.159.254108.8.159.2554,094
139108.8.160.0/20108.8.160.1 to 108.8.175.254108.8.175.2554,094
140108.8.176.0/20108.8.176.1 to 108.8.191.254108.8.191.2554,094
141108.8.192.0/20108.8.192.1 to 108.8.207.254108.8.207.2554,094
142108.8.208.0/20108.8.208.1 to 108.8.223.254108.8.223.2554,094
143108.8.224.0/20108.8.224.1 to 108.8.239.254108.8.239.2554,094
144108.8.240.0/20108.8.240.1 to 108.8.255.254108.8.255.2554,094
145108.9.0.0/20108.9.0.1 to 108.9.15.254108.9.15.2554,094
146108.9.16.0/20108.9.16.1 to 108.9.31.254108.9.31.2554,094
147108.9.32.0/20108.9.32.1 to 108.9.47.254108.9.47.2554,094
148108.9.48.0/20108.9.48.1 to 108.9.63.254108.9.63.2554,094
149108.9.64.0/20108.9.64.1 to 108.9.79.254108.9.79.2554,094
150108.9.80.0/20108.9.80.1 to 108.9.95.254108.9.95.2554,094
151108.9.96.0/20108.9.96.1 to 108.9.111.254108.9.111.2554,094
152108.9.112.0/20108.9.112.1 to 108.9.127.254108.9.127.2554,094
153108.9.128.0/20108.9.128.1 to 108.9.143.254108.9.143.2554,094
154108.9.144.0/20108.9.144.1 to 108.9.159.254108.9.159.2554,094
155108.9.160.0/20108.9.160.1 to 108.9.175.254108.9.175.2554,094
156108.9.176.0/20108.9.176.1 to 108.9.191.254108.9.191.2554,094
157108.9.192.0/20108.9.192.1 to 108.9.207.254108.9.207.2554,094
158108.9.208.0/20108.9.208.1 to 108.9.223.254108.9.223.2554,094
159108.9.224.0/20108.9.224.1 to 108.9.239.254108.9.239.2554,094
160108.9.240.0/20108.9.240.1 to 108.9.255.254108.9.255.2554,094
161108.10.0.0/20108.10.0.1 to 108.10.15.254108.10.15.2554,094
162108.10.16.0/20108.10.16.1 to 108.10.31.254108.10.31.2554,094
163108.10.32.0/20108.10.32.1 to 108.10.47.254108.10.47.2554,094
164108.10.48.0/20108.10.48.1 to 108.10.63.254108.10.63.2554,094
165108.10.64.0/20108.10.64.1 to 108.10.79.254108.10.79.2554,094
166108.10.80.0/20108.10.80.1 to 108.10.95.254108.10.95.2554,094
167108.10.96.0/20108.10.96.1 to 108.10.111.254108.10.111.2554,094
168108.10.112.0/20108.10.112.1 to 108.10.127.254108.10.127.2554,094
169108.10.128.0/20108.10.128.1 to 108.10.143.254108.10.143.2554,094
170108.10.144.0/20108.10.144.1 to 108.10.159.254108.10.159.2554,094
171108.10.160.0/20108.10.160.1 to 108.10.175.254108.10.175.2554,094
172108.10.176.0/20108.10.176.1 to 108.10.191.254108.10.191.2554,094
173108.10.192.0/20108.10.192.1 to 108.10.207.254108.10.207.2554,094
174108.10.208.0/20108.10.208.1 to 108.10.223.254108.10.223.2554,094
175108.10.224.0/20108.10.224.1 to 108.10.239.254108.10.239.2554,094
176108.10.240.0/20108.10.240.1 to 108.10.255.254108.10.255.2554,094
177108.11.0.0/20108.11.0.1 to 108.11.15.254108.11.15.2554,094
178108.11.16.0/20108.11.16.1 to 108.11.31.254108.11.31.2554,094
179108.11.32.0/20108.11.32.1 to 108.11.47.254108.11.47.2554,094
180108.11.48.0/20108.11.48.1 to 108.11.63.254108.11.63.2554,094
181108.11.64.0/20108.11.64.1 to 108.11.79.254108.11.79.2554,094
182108.11.80.0/20108.11.80.1 to 108.11.95.254108.11.95.2554,094
183108.11.96.0/20108.11.96.1 to 108.11.111.254108.11.111.2554,094
184108.11.112.0/20108.11.112.1 to 108.11.127.254108.11.127.2554,094
185108.11.128.0/20108.11.128.1 to 108.11.143.254108.11.143.2554,094
186108.11.144.0/20108.11.144.1 to 108.11.159.254108.11.159.2554,094
187108.11.160.0/20108.11.160.1 to 108.11.175.254108.11.175.2554,094
188108.11.176.0/20108.11.176.1 to 108.11.191.254108.11.191.2554,094
189108.11.192.0/20108.11.192.1 to 108.11.207.254108.11.207.2554,094
190108.11.208.0/20108.11.208.1 to 108.11.223.254108.11.223.2554,094
191108.11.224.0/20108.11.224.1 to 108.11.239.254108.11.239.2554,094
192108.11.240.0/20108.11.240.1 to 108.11.255.254108.11.255.2554,094
193108.12.0.0/20108.12.0.1 to 108.12.15.254108.12.15.2554,094
194108.12.16.0/20108.12.16.1 to 108.12.31.254108.12.31.2554,094
195108.12.32.0/20108.12.32.1 to 108.12.47.254108.12.47.2554,094
196108.12.48.0/20108.12.48.1 to 108.12.63.254108.12.63.2554,094
197108.12.64.0/20108.12.64.1 to 108.12.79.254108.12.79.2554,094
198108.12.80.0/20108.12.80.1 to 108.12.95.254108.12.95.2554,094
199108.12.96.0/20108.12.96.1 to 108.12.111.254108.12.111.2554,094
200108.12.112.0/20108.12.112.1 to 108.12.127.254108.12.127.2554,094
201108.12.128.0/20108.12.128.1 to 108.12.143.254108.12.143.2554,094
202108.12.144.0/20108.12.144.1 to 108.12.159.254108.12.159.2554,094
203108.12.160.0/20108.12.160.1 to 108.12.175.254108.12.175.2554,094
204108.12.176.0/20108.12.176.1 to 108.12.191.254108.12.191.2554,094
205108.12.192.0/20108.12.192.1 to 108.12.207.254108.12.207.2554,094
206108.12.208.0/20108.12.208.1 to 108.12.223.254108.12.223.2554,094
207108.12.224.0/20108.12.224.1 to 108.12.239.254108.12.239.2554,094
208108.12.240.0/20108.12.240.1 to 108.12.255.254108.12.255.2554,094
209108.13.0.0/20108.13.0.1 to 108.13.15.254108.13.15.2554,094
210108.13.16.0/20108.13.16.1 to 108.13.31.254108.13.31.2554,094
211108.13.32.0/20108.13.32.1 to 108.13.47.254108.13.47.2554,094
212108.13.48.0/20108.13.48.1 to 108.13.63.254108.13.63.2554,094
213108.13.64.0/20108.13.64.1 to 108.13.79.254108.13.79.2554,094
214108.13.80.0/20108.13.80.1 to 108.13.95.254108.13.95.2554,094
215108.13.96.0/20108.13.96.1 to 108.13.111.254108.13.111.2554,094
216108.13.112.0/20108.13.112.1 to 108.13.127.254108.13.127.2554,094
217108.13.128.0/20108.13.128.1 to 108.13.143.254108.13.143.2554,094
218108.13.144.0/20108.13.144.1 to 108.13.159.254108.13.159.2554,094
219108.13.160.0/20108.13.160.1 to 108.13.175.254108.13.175.2554,094
220108.13.176.0/20108.13.176.1 to 108.13.191.254108.13.191.2554,094
221108.13.192.0/20108.13.192.1 to 108.13.207.254108.13.207.2554,094
222108.13.208.0/20108.13.208.1 to 108.13.223.254108.13.223.2554,094
223108.13.224.0/20108.13.224.1 to 108.13.239.254108.13.239.2554,094
224108.13.240.0/20108.13.240.1 to 108.13.255.254108.13.255.2554,094
225108.14.0.0/20108.14.0.1 to 108.14.15.254108.14.15.2554,094
226108.14.16.0/20108.14.16.1 to 108.14.31.254108.14.31.2554,094
227108.14.32.0/20108.14.32.1 to 108.14.47.254108.14.47.2554,094
228108.14.48.0/20108.14.48.1 to 108.14.63.254108.14.63.2554,094
229108.14.64.0/20108.14.64.1 to 108.14.79.254108.14.79.2554,094
230108.14.80.0/20108.14.80.1 to 108.14.95.254108.14.95.2554,094
231108.14.96.0/20108.14.96.1 to 108.14.111.254108.14.111.2554,094
232108.14.112.0/20108.14.112.1 to 108.14.127.254108.14.127.2554,094
233108.14.128.0/20108.14.128.1 to 108.14.143.254108.14.143.2554,094
234108.14.144.0/20108.14.144.1 to 108.14.159.254108.14.159.2554,094
235108.14.160.0/20108.14.160.1 to 108.14.175.254108.14.175.2554,094
236108.14.176.0/20108.14.176.1 to 108.14.191.254108.14.191.2554,094
237108.14.192.0/20108.14.192.1 to 108.14.207.254108.14.207.2554,094
238108.14.208.0/20108.14.208.1 to 108.14.223.254108.14.223.2554,094
239108.14.224.0/20108.14.224.1 to 108.14.239.254108.14.239.2554,094
240108.14.240.0/20108.14.240.1 to 108.14.255.254108.14.255.2554,094
241108.15.0.0/20108.15.0.1 to 108.15.15.254108.15.15.2554,094
242108.15.16.0/20108.15.16.1 to 108.15.31.254108.15.31.2554,094
243108.15.32.0/20108.15.32.1 to 108.15.47.254108.15.47.2554,094
244108.15.48.0/20108.15.48.1 to 108.15.63.254108.15.63.2554,094
245108.15.64.0/20108.15.64.1 to 108.15.79.254108.15.79.2554,094
246108.15.80.0/20108.15.80.1 to 108.15.95.254108.15.95.2554,094
247108.15.96.0/20108.15.96.1 to 108.15.111.254108.15.111.2554,094
248108.15.112.0/20108.15.112.1 to 108.15.127.254108.15.127.2554,094
249108.15.128.0/20108.15.128.1 to 108.15.143.254108.15.143.2554,094
250108.15.144.0/20108.15.144.1 to 108.15.159.254108.15.159.2554,094
251108.15.160.0/20108.15.160.1 to 108.15.175.254108.15.175.2554,094
252108.15.176.0/20108.15.176.1 to 108.15.191.254108.15.191.2554,094
253108.15.192.0/20108.15.192.1 to 108.15.207.254108.15.207.2554,094
254108.15.208.0/20108.15.208.1 to 108.15.223.254108.15.223.2554,094
255108.15.224.0/20108.15.224.1 to 108.15.239.254108.15.239.2554,094
256108.15.240.0/20108.15.240.1 to 108.15.255.254108.15.255.2554,094

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.