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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.

Network108.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
108.0.0.0
Broadcast address
108.127.255.255
First usable
108.0.0.1
Last usable
108.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
A (default /8)
As numbers
Hex 6C000000 · Integer 1811939328 to 1820327935
Reverse DNS zones
0.108.in-addr.arpa
1.108.in-addr.arpa
2.108.in-addr.arpa
3.108.in-addr.arpa
4.108.in-addr.arpa
5.108.in-addr.arpa
6.108.in-addr.arpa
7.108.in-addr.arpa
8.108.in-addr.arpa
9.108.in-addr.arpa
10.108.in-addr.arpa
11.108.in-addr.arpa
12.108.in-addr.arpa
13.108.in-addr.arpa
14.108.in-addr.arpa
15.108.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01101100.00000000.00000000.00000000108.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01101100.00000000.00000000.00000000108.0.0.0
Broadcast01101100.01111111.11111111.11111111108.127.255.255
Split into smaller subnets/18
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

108.0.0.0/9 makes 512 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1108.0.0.0/18108.0.0.1 to 108.0.63.254108.0.63.25516,382
2108.0.64.0/18108.0.64.1 to 108.0.127.254108.0.127.25516,382
3108.0.128.0/18108.0.128.1 to 108.0.191.254108.0.191.25516,382
4108.0.192.0/18108.0.192.1 to 108.0.255.254108.0.255.25516,382
5108.1.0.0/18108.1.0.1 to 108.1.63.254108.1.63.25516,382
6108.1.64.0/18108.1.64.1 to 108.1.127.254108.1.127.25516,382
7108.1.128.0/18108.1.128.1 to 108.1.191.254108.1.191.25516,382
8108.1.192.0/18108.1.192.1 to 108.1.255.254108.1.255.25516,382
9108.2.0.0/18108.2.0.1 to 108.2.63.254108.2.63.25516,382
10108.2.64.0/18108.2.64.1 to 108.2.127.254108.2.127.25516,382
11108.2.128.0/18108.2.128.1 to 108.2.191.254108.2.191.25516,382
12108.2.192.0/18108.2.192.1 to 108.2.255.254108.2.255.25516,382
13108.3.0.0/18108.3.0.1 to 108.3.63.254108.3.63.25516,382
14108.3.64.0/18108.3.64.1 to 108.3.127.254108.3.127.25516,382
15108.3.128.0/18108.3.128.1 to 108.3.191.254108.3.191.25516,382
16108.3.192.0/18108.3.192.1 to 108.3.255.254108.3.255.25516,382
17108.4.0.0/18108.4.0.1 to 108.4.63.254108.4.63.25516,382
18108.4.64.0/18108.4.64.1 to 108.4.127.254108.4.127.25516,382
19108.4.128.0/18108.4.128.1 to 108.4.191.254108.4.191.25516,382
20108.4.192.0/18108.4.192.1 to 108.4.255.254108.4.255.25516,382
21108.5.0.0/18108.5.0.1 to 108.5.63.254108.5.63.25516,382
22108.5.64.0/18108.5.64.1 to 108.5.127.254108.5.127.25516,382
23108.5.128.0/18108.5.128.1 to 108.5.191.254108.5.191.25516,382
24108.5.192.0/18108.5.192.1 to 108.5.255.254108.5.255.25516,382
25108.6.0.0/18108.6.0.1 to 108.6.63.254108.6.63.25516,382
26108.6.64.0/18108.6.64.1 to 108.6.127.254108.6.127.25516,382
27108.6.128.0/18108.6.128.1 to 108.6.191.254108.6.191.25516,382
28108.6.192.0/18108.6.192.1 to 108.6.255.254108.6.255.25516,382
29108.7.0.0/18108.7.0.1 to 108.7.63.254108.7.63.25516,382
30108.7.64.0/18108.7.64.1 to 108.7.127.254108.7.127.25516,382
31108.7.128.0/18108.7.128.1 to 108.7.191.254108.7.191.25516,382
32108.7.192.0/18108.7.192.1 to 108.7.255.254108.7.255.25516,382
33108.8.0.0/18108.8.0.1 to 108.8.63.254108.8.63.25516,382
34108.8.64.0/18108.8.64.1 to 108.8.127.254108.8.127.25516,382
35108.8.128.0/18108.8.128.1 to 108.8.191.254108.8.191.25516,382
36108.8.192.0/18108.8.192.1 to 108.8.255.254108.8.255.25516,382
37108.9.0.0/18108.9.0.1 to 108.9.63.254108.9.63.25516,382
38108.9.64.0/18108.9.64.1 to 108.9.127.254108.9.127.25516,382
39108.9.128.0/18108.9.128.1 to 108.9.191.254108.9.191.25516,382
40108.9.192.0/18108.9.192.1 to 108.9.255.254108.9.255.25516,382
41108.10.0.0/18108.10.0.1 to 108.10.63.254108.10.63.25516,382
42108.10.64.0/18108.10.64.1 to 108.10.127.254108.10.127.25516,382
43108.10.128.0/18108.10.128.1 to 108.10.191.254108.10.191.25516,382
44108.10.192.0/18108.10.192.1 to 108.10.255.254108.10.255.25516,382
45108.11.0.0/18108.11.0.1 to 108.11.63.254108.11.63.25516,382
46108.11.64.0/18108.11.64.1 to 108.11.127.254108.11.127.25516,382
47108.11.128.0/18108.11.128.1 to 108.11.191.254108.11.191.25516,382
48108.11.192.0/18108.11.192.1 to 108.11.255.254108.11.255.25516,382
49108.12.0.0/18108.12.0.1 to 108.12.63.254108.12.63.25516,382
50108.12.64.0/18108.12.64.1 to 108.12.127.254108.12.127.25516,382
51108.12.128.0/18108.12.128.1 to 108.12.191.254108.12.191.25516,382
52108.12.192.0/18108.12.192.1 to 108.12.255.254108.12.255.25516,382
53108.13.0.0/18108.13.0.1 to 108.13.63.254108.13.63.25516,382
54108.13.64.0/18108.13.64.1 to 108.13.127.254108.13.127.25516,382
55108.13.128.0/18108.13.128.1 to 108.13.191.254108.13.191.25516,382
56108.13.192.0/18108.13.192.1 to 108.13.255.254108.13.255.25516,382
57108.14.0.0/18108.14.0.1 to 108.14.63.254108.14.63.25516,382
58108.14.64.0/18108.14.64.1 to 108.14.127.254108.14.127.25516,382
59108.14.128.0/18108.14.128.1 to 108.14.191.254108.14.191.25516,382
60108.14.192.0/18108.14.192.1 to 108.14.255.254108.14.255.25516,382
61108.15.0.0/18108.15.0.1 to 108.15.63.254108.15.63.25516,382
62108.15.64.0/18108.15.64.1 to 108.15.127.254108.15.127.25516,382
63108.15.128.0/18108.15.128.1 to 108.15.191.254108.15.191.25516,382
64108.15.192.0/18108.15.192.1 to 108.15.255.254108.15.255.25516,382
65108.16.0.0/18108.16.0.1 to 108.16.63.254108.16.63.25516,382
66108.16.64.0/18108.16.64.1 to 108.16.127.254108.16.127.25516,382
67108.16.128.0/18108.16.128.1 to 108.16.191.254108.16.191.25516,382
68108.16.192.0/18108.16.192.1 to 108.16.255.254108.16.255.25516,382
69108.17.0.0/18108.17.0.1 to 108.17.63.254108.17.63.25516,382
70108.17.64.0/18108.17.64.1 to 108.17.127.254108.17.127.25516,382
71108.17.128.0/18108.17.128.1 to 108.17.191.254108.17.191.25516,382
72108.17.192.0/18108.17.192.1 to 108.17.255.254108.17.255.25516,382
73108.18.0.0/18108.18.0.1 to 108.18.63.254108.18.63.25516,382
74108.18.64.0/18108.18.64.1 to 108.18.127.254108.18.127.25516,382
75108.18.128.0/18108.18.128.1 to 108.18.191.254108.18.191.25516,382
76108.18.192.0/18108.18.192.1 to 108.18.255.254108.18.255.25516,382
77108.19.0.0/18108.19.0.1 to 108.19.63.254108.19.63.25516,382
78108.19.64.0/18108.19.64.1 to 108.19.127.254108.19.127.25516,382
79108.19.128.0/18108.19.128.1 to 108.19.191.254108.19.191.25516,382
80108.19.192.0/18108.19.192.1 to 108.19.255.254108.19.255.25516,382
81108.20.0.0/18108.20.0.1 to 108.20.63.254108.20.63.25516,382
82108.20.64.0/18108.20.64.1 to 108.20.127.254108.20.127.25516,382
83108.20.128.0/18108.20.128.1 to 108.20.191.254108.20.191.25516,382
84108.20.192.0/18108.20.192.1 to 108.20.255.254108.20.255.25516,382
85108.21.0.0/18108.21.0.1 to 108.21.63.254108.21.63.25516,382
86108.21.64.0/18108.21.64.1 to 108.21.127.254108.21.127.25516,382
87108.21.128.0/18108.21.128.1 to 108.21.191.254108.21.191.25516,382
88108.21.192.0/18108.21.192.1 to 108.21.255.254108.21.255.25516,382
89108.22.0.0/18108.22.0.1 to 108.22.63.254108.22.63.25516,382
90108.22.64.0/18108.22.64.1 to 108.22.127.254108.22.127.25516,382
91108.22.128.0/18108.22.128.1 to 108.22.191.254108.22.191.25516,382
92108.22.192.0/18108.22.192.1 to 108.22.255.254108.22.255.25516,382
93108.23.0.0/18108.23.0.1 to 108.23.63.254108.23.63.25516,382
94108.23.64.0/18108.23.64.1 to 108.23.127.254108.23.127.25516,382
95108.23.128.0/18108.23.128.1 to 108.23.191.254108.23.191.25516,382
96108.23.192.0/18108.23.192.1 to 108.23.255.254108.23.255.25516,382
97108.24.0.0/18108.24.0.1 to 108.24.63.254108.24.63.25516,382
98108.24.64.0/18108.24.64.1 to 108.24.127.254108.24.127.25516,382
99108.24.128.0/18108.24.128.1 to 108.24.191.254108.24.191.25516,382
100108.24.192.0/18108.24.192.1 to 108.24.255.254108.24.255.25516,382
101108.25.0.0/18108.25.0.1 to 108.25.63.254108.25.63.25516,382
102108.25.64.0/18108.25.64.1 to 108.25.127.254108.25.127.25516,382
103108.25.128.0/18108.25.128.1 to 108.25.191.254108.25.191.25516,382
104108.25.192.0/18108.25.192.1 to 108.25.255.254108.25.255.25516,382
105108.26.0.0/18108.26.0.1 to 108.26.63.254108.26.63.25516,382
106108.26.64.0/18108.26.64.1 to 108.26.127.254108.26.127.25516,382
107108.26.128.0/18108.26.128.1 to 108.26.191.254108.26.191.25516,382
108108.26.192.0/18108.26.192.1 to 108.26.255.254108.26.255.25516,382
109108.27.0.0/18108.27.0.1 to 108.27.63.254108.27.63.25516,382
110108.27.64.0/18108.27.64.1 to 108.27.127.254108.27.127.25516,382
111108.27.128.0/18108.27.128.1 to 108.27.191.254108.27.191.25516,382
112108.27.192.0/18108.27.192.1 to 108.27.255.254108.27.255.25516,382
113108.28.0.0/18108.28.0.1 to 108.28.63.254108.28.63.25516,382
114108.28.64.0/18108.28.64.1 to 108.28.127.254108.28.127.25516,382
115108.28.128.0/18108.28.128.1 to 108.28.191.254108.28.191.25516,382
116108.28.192.0/18108.28.192.1 to 108.28.255.254108.28.255.25516,382
117108.29.0.0/18108.29.0.1 to 108.29.63.254108.29.63.25516,382
118108.29.64.0/18108.29.64.1 to 108.29.127.254108.29.127.25516,382
119108.29.128.0/18108.29.128.1 to 108.29.191.254108.29.191.25516,382
120108.29.192.0/18108.29.192.1 to 108.29.255.254108.29.255.25516,382
121108.30.0.0/18108.30.0.1 to 108.30.63.254108.30.63.25516,382
122108.30.64.0/18108.30.64.1 to 108.30.127.254108.30.127.25516,382
123108.30.128.0/18108.30.128.1 to 108.30.191.254108.30.191.25516,382
124108.30.192.0/18108.30.192.1 to 108.30.255.254108.30.255.25516,382
125108.31.0.0/18108.31.0.1 to 108.31.63.254108.31.63.25516,382
126108.31.64.0/18108.31.64.1 to 108.31.127.254108.31.127.25516,382
127108.31.128.0/18108.31.128.1 to 108.31.191.254108.31.191.25516,382
128108.31.192.0/18108.31.192.1 to 108.31.255.254108.31.255.25516,382
129108.32.0.0/18108.32.0.1 to 108.32.63.254108.32.63.25516,382
130108.32.64.0/18108.32.64.1 to 108.32.127.254108.32.127.25516,382
131108.32.128.0/18108.32.128.1 to 108.32.191.254108.32.191.25516,382
132108.32.192.0/18108.32.192.1 to 108.32.255.254108.32.255.25516,382
133108.33.0.0/18108.33.0.1 to 108.33.63.254108.33.63.25516,382
134108.33.64.0/18108.33.64.1 to 108.33.127.254108.33.127.25516,382
135108.33.128.0/18108.33.128.1 to 108.33.191.254108.33.191.25516,382
136108.33.192.0/18108.33.192.1 to 108.33.255.254108.33.255.25516,382
137108.34.0.0/18108.34.0.1 to 108.34.63.254108.34.63.25516,382
138108.34.64.0/18108.34.64.1 to 108.34.127.254108.34.127.25516,382
139108.34.128.0/18108.34.128.1 to 108.34.191.254108.34.191.25516,382
140108.34.192.0/18108.34.192.1 to 108.34.255.254108.34.255.25516,382
141108.35.0.0/18108.35.0.1 to 108.35.63.254108.35.63.25516,382
142108.35.64.0/18108.35.64.1 to 108.35.127.254108.35.127.25516,382
143108.35.128.0/18108.35.128.1 to 108.35.191.254108.35.191.25516,382
144108.35.192.0/18108.35.192.1 to 108.35.255.254108.35.255.25516,382
145108.36.0.0/18108.36.0.1 to 108.36.63.254108.36.63.25516,382
146108.36.64.0/18108.36.64.1 to 108.36.127.254108.36.127.25516,382
147108.36.128.0/18108.36.128.1 to 108.36.191.254108.36.191.25516,382
148108.36.192.0/18108.36.192.1 to 108.36.255.254108.36.255.25516,382
149108.37.0.0/18108.37.0.1 to 108.37.63.254108.37.63.25516,382
150108.37.64.0/18108.37.64.1 to 108.37.127.254108.37.127.25516,382
151108.37.128.0/18108.37.128.1 to 108.37.191.254108.37.191.25516,382
152108.37.192.0/18108.37.192.1 to 108.37.255.254108.37.255.25516,382
153108.38.0.0/18108.38.0.1 to 108.38.63.254108.38.63.25516,382
154108.38.64.0/18108.38.64.1 to 108.38.127.254108.38.127.25516,382
155108.38.128.0/18108.38.128.1 to 108.38.191.254108.38.191.25516,382
156108.38.192.0/18108.38.192.1 to 108.38.255.254108.38.255.25516,382
157108.39.0.0/18108.39.0.1 to 108.39.63.254108.39.63.25516,382
158108.39.64.0/18108.39.64.1 to 108.39.127.254108.39.127.25516,382
159108.39.128.0/18108.39.128.1 to 108.39.191.254108.39.191.25516,382
160108.39.192.0/18108.39.192.1 to 108.39.255.254108.39.255.25516,382
161108.40.0.0/18108.40.0.1 to 108.40.63.254108.40.63.25516,382
162108.40.64.0/18108.40.64.1 to 108.40.127.254108.40.127.25516,382
163108.40.128.0/18108.40.128.1 to 108.40.191.254108.40.191.25516,382
164108.40.192.0/18108.40.192.1 to 108.40.255.254108.40.255.25516,382
165108.41.0.0/18108.41.0.1 to 108.41.63.254108.41.63.25516,382
166108.41.64.0/18108.41.64.1 to 108.41.127.254108.41.127.25516,382
167108.41.128.0/18108.41.128.1 to 108.41.191.254108.41.191.25516,382
168108.41.192.0/18108.41.192.1 to 108.41.255.254108.41.255.25516,382
169108.42.0.0/18108.42.0.1 to 108.42.63.254108.42.63.25516,382
170108.42.64.0/18108.42.64.1 to 108.42.127.254108.42.127.25516,382
171108.42.128.0/18108.42.128.1 to 108.42.191.254108.42.191.25516,382
172108.42.192.0/18108.42.192.1 to 108.42.255.254108.42.255.25516,382
173108.43.0.0/18108.43.0.1 to 108.43.63.254108.43.63.25516,382
174108.43.64.0/18108.43.64.1 to 108.43.127.254108.43.127.25516,382
175108.43.128.0/18108.43.128.1 to 108.43.191.254108.43.191.25516,382
176108.43.192.0/18108.43.192.1 to 108.43.255.254108.43.255.25516,382
177108.44.0.0/18108.44.0.1 to 108.44.63.254108.44.63.25516,382
178108.44.64.0/18108.44.64.1 to 108.44.127.254108.44.127.25516,382
179108.44.128.0/18108.44.128.1 to 108.44.191.254108.44.191.25516,382
180108.44.192.0/18108.44.192.1 to 108.44.255.254108.44.255.25516,382
181108.45.0.0/18108.45.0.1 to 108.45.63.254108.45.63.25516,382
182108.45.64.0/18108.45.64.1 to 108.45.127.254108.45.127.25516,382
183108.45.128.0/18108.45.128.1 to 108.45.191.254108.45.191.25516,382
184108.45.192.0/18108.45.192.1 to 108.45.255.254108.45.255.25516,382
185108.46.0.0/18108.46.0.1 to 108.46.63.254108.46.63.25516,382
186108.46.64.0/18108.46.64.1 to 108.46.127.254108.46.127.25516,382
187108.46.128.0/18108.46.128.1 to 108.46.191.254108.46.191.25516,382
188108.46.192.0/18108.46.192.1 to 108.46.255.254108.46.255.25516,382
189108.47.0.0/18108.47.0.1 to 108.47.63.254108.47.63.25516,382
190108.47.64.0/18108.47.64.1 to 108.47.127.254108.47.127.25516,382
191108.47.128.0/18108.47.128.1 to 108.47.191.254108.47.191.25516,382
192108.47.192.0/18108.47.192.1 to 108.47.255.254108.47.255.25516,382
193108.48.0.0/18108.48.0.1 to 108.48.63.254108.48.63.25516,382
194108.48.64.0/18108.48.64.1 to 108.48.127.254108.48.127.25516,382
195108.48.128.0/18108.48.128.1 to 108.48.191.254108.48.191.25516,382
196108.48.192.0/18108.48.192.1 to 108.48.255.254108.48.255.25516,382
197108.49.0.0/18108.49.0.1 to 108.49.63.254108.49.63.25516,382
198108.49.64.0/18108.49.64.1 to 108.49.127.254108.49.127.25516,382
199108.49.128.0/18108.49.128.1 to 108.49.191.254108.49.191.25516,382
200108.49.192.0/18108.49.192.1 to 108.49.255.254108.49.255.25516,382
201108.50.0.0/18108.50.0.1 to 108.50.63.254108.50.63.25516,382
202108.50.64.0/18108.50.64.1 to 108.50.127.254108.50.127.25516,382
203108.50.128.0/18108.50.128.1 to 108.50.191.254108.50.191.25516,382
204108.50.192.0/18108.50.192.1 to 108.50.255.254108.50.255.25516,382
205108.51.0.0/18108.51.0.1 to 108.51.63.254108.51.63.25516,382
206108.51.64.0/18108.51.64.1 to 108.51.127.254108.51.127.25516,382
207108.51.128.0/18108.51.128.1 to 108.51.191.254108.51.191.25516,382
208108.51.192.0/18108.51.192.1 to 108.51.255.254108.51.255.25516,382
209108.52.0.0/18108.52.0.1 to 108.52.63.254108.52.63.25516,382
210108.52.64.0/18108.52.64.1 to 108.52.127.254108.52.127.25516,382
211108.52.128.0/18108.52.128.1 to 108.52.191.254108.52.191.25516,382
212108.52.192.0/18108.52.192.1 to 108.52.255.254108.52.255.25516,382
213108.53.0.0/18108.53.0.1 to 108.53.63.254108.53.63.25516,382
214108.53.64.0/18108.53.64.1 to 108.53.127.254108.53.127.25516,382
215108.53.128.0/18108.53.128.1 to 108.53.191.254108.53.191.25516,382
216108.53.192.0/18108.53.192.1 to 108.53.255.254108.53.255.25516,382
217108.54.0.0/18108.54.0.1 to 108.54.63.254108.54.63.25516,382
218108.54.64.0/18108.54.64.1 to 108.54.127.254108.54.127.25516,382
219108.54.128.0/18108.54.128.1 to 108.54.191.254108.54.191.25516,382
220108.54.192.0/18108.54.192.1 to 108.54.255.254108.54.255.25516,382
221108.55.0.0/18108.55.0.1 to 108.55.63.254108.55.63.25516,382
222108.55.64.0/18108.55.64.1 to 108.55.127.254108.55.127.25516,382
223108.55.128.0/18108.55.128.1 to 108.55.191.254108.55.191.25516,382
224108.55.192.0/18108.55.192.1 to 108.55.255.254108.55.255.25516,382
225108.56.0.0/18108.56.0.1 to 108.56.63.254108.56.63.25516,382
226108.56.64.0/18108.56.64.1 to 108.56.127.254108.56.127.25516,382
227108.56.128.0/18108.56.128.1 to 108.56.191.254108.56.191.25516,382
228108.56.192.0/18108.56.192.1 to 108.56.255.254108.56.255.25516,382
229108.57.0.0/18108.57.0.1 to 108.57.63.254108.57.63.25516,382
230108.57.64.0/18108.57.64.1 to 108.57.127.254108.57.127.25516,382
231108.57.128.0/18108.57.128.1 to 108.57.191.254108.57.191.25516,382
232108.57.192.0/18108.57.192.1 to 108.57.255.254108.57.255.25516,382
233108.58.0.0/18108.58.0.1 to 108.58.63.254108.58.63.25516,382
234108.58.64.0/18108.58.64.1 to 108.58.127.254108.58.127.25516,382
235108.58.128.0/18108.58.128.1 to 108.58.191.254108.58.191.25516,382
236108.58.192.0/18108.58.192.1 to 108.58.255.254108.58.255.25516,382
237108.59.0.0/18108.59.0.1 to 108.59.63.254108.59.63.25516,382
238108.59.64.0/18108.59.64.1 to 108.59.127.254108.59.127.25516,382
239108.59.128.0/18108.59.128.1 to 108.59.191.254108.59.191.25516,382
240108.59.192.0/18108.59.192.1 to 108.59.255.254108.59.255.25516,382
241108.60.0.0/18108.60.0.1 to 108.60.63.254108.60.63.25516,382
242108.60.64.0/18108.60.64.1 to 108.60.127.254108.60.127.25516,382
243108.60.128.0/18108.60.128.1 to 108.60.191.254108.60.191.25516,382
244108.60.192.0/18108.60.192.1 to 108.60.255.254108.60.255.25516,382
245108.61.0.0/18108.61.0.1 to 108.61.63.254108.61.63.25516,382
246108.61.64.0/18108.61.64.1 to 108.61.127.254108.61.127.25516,382
247108.61.128.0/18108.61.128.1 to 108.61.191.254108.61.191.25516,382
248108.61.192.0/18108.61.192.1 to 108.61.255.254108.61.255.25516,382
249108.62.0.0/18108.62.0.1 to 108.62.63.254108.62.63.25516,382
250108.62.64.0/18108.62.64.1 to 108.62.127.254108.62.127.25516,382
251108.62.128.0/18108.62.128.1 to 108.62.191.254108.62.191.25516,382
252108.62.192.0/18108.62.192.1 to 108.62.255.254108.62.255.25516,382
253108.63.0.0/18108.63.0.1 to 108.63.63.254108.63.63.25516,382
254108.63.64.0/18108.63.64.1 to 108.63.127.254108.63.127.25516,382
255108.63.128.0/18108.63.128.1 to 108.63.191.254108.63.191.25516,382
256108.63.192.0/18108.63.192.1 to 108.63.255.254108.63.255.25516,382

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.