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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.

Network244.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
244.0.0.0
Broadcast address
244.127.255.255
First usable
244.0.0.1
Last usable
244.127.255.254
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
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F4000000 · Integer 4093640704 to 4102029311
Reverse DNS zones
0.244.in-addr.arpa
1.244.in-addr.arpa
2.244.in-addr.arpa
3.244.in-addr.arpa
4.244.in-addr.arpa
5.244.in-addr.arpa
6.244.in-addr.arpa
7.244.in-addr.arpa
8.244.in-addr.arpa
9.244.in-addr.arpa
10.244.in-addr.arpa
11.244.in-addr.arpa
12.244.in-addr.arpa
13.244.in-addr.arpa
14.244.in-addr.arpa
15.244.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
Address11110100.00000000.00000000.00000000244.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network11110100.00000000.00000000.00000000244.0.0.0
Broadcast11110100.01111111.11111111.11111111244.127.255.255
Split into smaller subnets/19
/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)

244.0.0.0/9 makes 1,024 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1244.0.0.0/19244.0.0.1 to 244.0.31.254244.0.31.2558,190
2244.0.32.0/19244.0.32.1 to 244.0.63.254244.0.63.2558,190
3244.0.64.0/19244.0.64.1 to 244.0.95.254244.0.95.2558,190
4244.0.96.0/19244.0.96.1 to 244.0.127.254244.0.127.2558,190
5244.0.128.0/19244.0.128.1 to 244.0.159.254244.0.159.2558,190
6244.0.160.0/19244.0.160.1 to 244.0.191.254244.0.191.2558,190
7244.0.192.0/19244.0.192.1 to 244.0.223.254244.0.223.2558,190
8244.0.224.0/19244.0.224.1 to 244.0.255.254244.0.255.2558,190
9244.1.0.0/19244.1.0.1 to 244.1.31.254244.1.31.2558,190
10244.1.32.0/19244.1.32.1 to 244.1.63.254244.1.63.2558,190
11244.1.64.0/19244.1.64.1 to 244.1.95.254244.1.95.2558,190
12244.1.96.0/19244.1.96.1 to 244.1.127.254244.1.127.2558,190
13244.1.128.0/19244.1.128.1 to 244.1.159.254244.1.159.2558,190
14244.1.160.0/19244.1.160.1 to 244.1.191.254244.1.191.2558,190
15244.1.192.0/19244.1.192.1 to 244.1.223.254244.1.223.2558,190
16244.1.224.0/19244.1.224.1 to 244.1.255.254244.1.255.2558,190
17244.2.0.0/19244.2.0.1 to 244.2.31.254244.2.31.2558,190
18244.2.32.0/19244.2.32.1 to 244.2.63.254244.2.63.2558,190
19244.2.64.0/19244.2.64.1 to 244.2.95.254244.2.95.2558,190
20244.2.96.0/19244.2.96.1 to 244.2.127.254244.2.127.2558,190
21244.2.128.0/19244.2.128.1 to 244.2.159.254244.2.159.2558,190
22244.2.160.0/19244.2.160.1 to 244.2.191.254244.2.191.2558,190
23244.2.192.0/19244.2.192.1 to 244.2.223.254244.2.223.2558,190
24244.2.224.0/19244.2.224.1 to 244.2.255.254244.2.255.2558,190
25244.3.0.0/19244.3.0.1 to 244.3.31.254244.3.31.2558,190
26244.3.32.0/19244.3.32.1 to 244.3.63.254244.3.63.2558,190
27244.3.64.0/19244.3.64.1 to 244.3.95.254244.3.95.2558,190
28244.3.96.0/19244.3.96.1 to 244.3.127.254244.3.127.2558,190
29244.3.128.0/19244.3.128.1 to 244.3.159.254244.3.159.2558,190
30244.3.160.0/19244.3.160.1 to 244.3.191.254244.3.191.2558,190
31244.3.192.0/19244.3.192.1 to 244.3.223.254244.3.223.2558,190
32244.3.224.0/19244.3.224.1 to 244.3.255.254244.3.255.2558,190
33244.4.0.0/19244.4.0.1 to 244.4.31.254244.4.31.2558,190
34244.4.32.0/19244.4.32.1 to 244.4.63.254244.4.63.2558,190
35244.4.64.0/19244.4.64.1 to 244.4.95.254244.4.95.2558,190
36244.4.96.0/19244.4.96.1 to 244.4.127.254244.4.127.2558,190
37244.4.128.0/19244.4.128.1 to 244.4.159.254244.4.159.2558,190
38244.4.160.0/19244.4.160.1 to 244.4.191.254244.4.191.2558,190
39244.4.192.0/19244.4.192.1 to 244.4.223.254244.4.223.2558,190
40244.4.224.0/19244.4.224.1 to 244.4.255.254244.4.255.2558,190
41244.5.0.0/19244.5.0.1 to 244.5.31.254244.5.31.2558,190
42244.5.32.0/19244.5.32.1 to 244.5.63.254244.5.63.2558,190
43244.5.64.0/19244.5.64.1 to 244.5.95.254244.5.95.2558,190
44244.5.96.0/19244.5.96.1 to 244.5.127.254244.5.127.2558,190
45244.5.128.0/19244.5.128.1 to 244.5.159.254244.5.159.2558,190
46244.5.160.0/19244.5.160.1 to 244.5.191.254244.5.191.2558,190
47244.5.192.0/19244.5.192.1 to 244.5.223.254244.5.223.2558,190
48244.5.224.0/19244.5.224.1 to 244.5.255.254244.5.255.2558,190
49244.6.0.0/19244.6.0.1 to 244.6.31.254244.6.31.2558,190
50244.6.32.0/19244.6.32.1 to 244.6.63.254244.6.63.2558,190
51244.6.64.0/19244.6.64.1 to 244.6.95.254244.6.95.2558,190
52244.6.96.0/19244.6.96.1 to 244.6.127.254244.6.127.2558,190
53244.6.128.0/19244.6.128.1 to 244.6.159.254244.6.159.2558,190
54244.6.160.0/19244.6.160.1 to 244.6.191.254244.6.191.2558,190
55244.6.192.0/19244.6.192.1 to 244.6.223.254244.6.223.2558,190
56244.6.224.0/19244.6.224.1 to 244.6.255.254244.6.255.2558,190
57244.7.0.0/19244.7.0.1 to 244.7.31.254244.7.31.2558,190
58244.7.32.0/19244.7.32.1 to 244.7.63.254244.7.63.2558,190
59244.7.64.0/19244.7.64.1 to 244.7.95.254244.7.95.2558,190
60244.7.96.0/19244.7.96.1 to 244.7.127.254244.7.127.2558,190
61244.7.128.0/19244.7.128.1 to 244.7.159.254244.7.159.2558,190
62244.7.160.0/19244.7.160.1 to 244.7.191.254244.7.191.2558,190
63244.7.192.0/19244.7.192.1 to 244.7.223.254244.7.223.2558,190
64244.7.224.0/19244.7.224.1 to 244.7.255.254244.7.255.2558,190
65244.8.0.0/19244.8.0.1 to 244.8.31.254244.8.31.2558,190
66244.8.32.0/19244.8.32.1 to 244.8.63.254244.8.63.2558,190
67244.8.64.0/19244.8.64.1 to 244.8.95.254244.8.95.2558,190
68244.8.96.0/19244.8.96.1 to 244.8.127.254244.8.127.2558,190
69244.8.128.0/19244.8.128.1 to 244.8.159.254244.8.159.2558,190
70244.8.160.0/19244.8.160.1 to 244.8.191.254244.8.191.2558,190
71244.8.192.0/19244.8.192.1 to 244.8.223.254244.8.223.2558,190
72244.8.224.0/19244.8.224.1 to 244.8.255.254244.8.255.2558,190
73244.9.0.0/19244.9.0.1 to 244.9.31.254244.9.31.2558,190
74244.9.32.0/19244.9.32.1 to 244.9.63.254244.9.63.2558,190
75244.9.64.0/19244.9.64.1 to 244.9.95.254244.9.95.2558,190
76244.9.96.0/19244.9.96.1 to 244.9.127.254244.9.127.2558,190
77244.9.128.0/19244.9.128.1 to 244.9.159.254244.9.159.2558,190
78244.9.160.0/19244.9.160.1 to 244.9.191.254244.9.191.2558,190
79244.9.192.0/19244.9.192.1 to 244.9.223.254244.9.223.2558,190
80244.9.224.0/19244.9.224.1 to 244.9.255.254244.9.255.2558,190
81244.10.0.0/19244.10.0.1 to 244.10.31.254244.10.31.2558,190
82244.10.32.0/19244.10.32.1 to 244.10.63.254244.10.63.2558,190
83244.10.64.0/19244.10.64.1 to 244.10.95.254244.10.95.2558,190
84244.10.96.0/19244.10.96.1 to 244.10.127.254244.10.127.2558,190
85244.10.128.0/19244.10.128.1 to 244.10.159.254244.10.159.2558,190
86244.10.160.0/19244.10.160.1 to 244.10.191.254244.10.191.2558,190
87244.10.192.0/19244.10.192.1 to 244.10.223.254244.10.223.2558,190
88244.10.224.0/19244.10.224.1 to 244.10.255.254244.10.255.2558,190
89244.11.0.0/19244.11.0.1 to 244.11.31.254244.11.31.2558,190
90244.11.32.0/19244.11.32.1 to 244.11.63.254244.11.63.2558,190
91244.11.64.0/19244.11.64.1 to 244.11.95.254244.11.95.2558,190
92244.11.96.0/19244.11.96.1 to 244.11.127.254244.11.127.2558,190
93244.11.128.0/19244.11.128.1 to 244.11.159.254244.11.159.2558,190
94244.11.160.0/19244.11.160.1 to 244.11.191.254244.11.191.2558,190
95244.11.192.0/19244.11.192.1 to 244.11.223.254244.11.223.2558,190
96244.11.224.0/19244.11.224.1 to 244.11.255.254244.11.255.2558,190
97244.12.0.0/19244.12.0.1 to 244.12.31.254244.12.31.2558,190
98244.12.32.0/19244.12.32.1 to 244.12.63.254244.12.63.2558,190
99244.12.64.0/19244.12.64.1 to 244.12.95.254244.12.95.2558,190
100244.12.96.0/19244.12.96.1 to 244.12.127.254244.12.127.2558,190
101244.12.128.0/19244.12.128.1 to 244.12.159.254244.12.159.2558,190
102244.12.160.0/19244.12.160.1 to 244.12.191.254244.12.191.2558,190
103244.12.192.0/19244.12.192.1 to 244.12.223.254244.12.223.2558,190
104244.12.224.0/19244.12.224.1 to 244.12.255.254244.12.255.2558,190
105244.13.0.0/19244.13.0.1 to 244.13.31.254244.13.31.2558,190
106244.13.32.0/19244.13.32.1 to 244.13.63.254244.13.63.2558,190
107244.13.64.0/19244.13.64.1 to 244.13.95.254244.13.95.2558,190
108244.13.96.0/19244.13.96.1 to 244.13.127.254244.13.127.2558,190
109244.13.128.0/19244.13.128.1 to 244.13.159.254244.13.159.2558,190
110244.13.160.0/19244.13.160.1 to 244.13.191.254244.13.191.2558,190
111244.13.192.0/19244.13.192.1 to 244.13.223.254244.13.223.2558,190
112244.13.224.0/19244.13.224.1 to 244.13.255.254244.13.255.2558,190
113244.14.0.0/19244.14.0.1 to 244.14.31.254244.14.31.2558,190
114244.14.32.0/19244.14.32.1 to 244.14.63.254244.14.63.2558,190
115244.14.64.0/19244.14.64.1 to 244.14.95.254244.14.95.2558,190
116244.14.96.0/19244.14.96.1 to 244.14.127.254244.14.127.2558,190
117244.14.128.0/19244.14.128.1 to 244.14.159.254244.14.159.2558,190
118244.14.160.0/19244.14.160.1 to 244.14.191.254244.14.191.2558,190
119244.14.192.0/19244.14.192.1 to 244.14.223.254244.14.223.2558,190
120244.14.224.0/19244.14.224.1 to 244.14.255.254244.14.255.2558,190
121244.15.0.0/19244.15.0.1 to 244.15.31.254244.15.31.2558,190
122244.15.32.0/19244.15.32.1 to 244.15.63.254244.15.63.2558,190
123244.15.64.0/19244.15.64.1 to 244.15.95.254244.15.95.2558,190
124244.15.96.0/19244.15.96.1 to 244.15.127.254244.15.127.2558,190
125244.15.128.0/19244.15.128.1 to 244.15.159.254244.15.159.2558,190
126244.15.160.0/19244.15.160.1 to 244.15.191.254244.15.191.2558,190
127244.15.192.0/19244.15.192.1 to 244.15.223.254244.15.223.2558,190
128244.15.224.0/19244.15.224.1 to 244.15.255.254244.15.255.2558,190
129244.16.0.0/19244.16.0.1 to 244.16.31.254244.16.31.2558,190
130244.16.32.0/19244.16.32.1 to 244.16.63.254244.16.63.2558,190
131244.16.64.0/19244.16.64.1 to 244.16.95.254244.16.95.2558,190
132244.16.96.0/19244.16.96.1 to 244.16.127.254244.16.127.2558,190
133244.16.128.0/19244.16.128.1 to 244.16.159.254244.16.159.2558,190
134244.16.160.0/19244.16.160.1 to 244.16.191.254244.16.191.2558,190
135244.16.192.0/19244.16.192.1 to 244.16.223.254244.16.223.2558,190
136244.16.224.0/19244.16.224.1 to 244.16.255.254244.16.255.2558,190
137244.17.0.0/19244.17.0.1 to 244.17.31.254244.17.31.2558,190
138244.17.32.0/19244.17.32.1 to 244.17.63.254244.17.63.2558,190
139244.17.64.0/19244.17.64.1 to 244.17.95.254244.17.95.2558,190
140244.17.96.0/19244.17.96.1 to 244.17.127.254244.17.127.2558,190
141244.17.128.0/19244.17.128.1 to 244.17.159.254244.17.159.2558,190
142244.17.160.0/19244.17.160.1 to 244.17.191.254244.17.191.2558,190
143244.17.192.0/19244.17.192.1 to 244.17.223.254244.17.223.2558,190
144244.17.224.0/19244.17.224.1 to 244.17.255.254244.17.255.2558,190
145244.18.0.0/19244.18.0.1 to 244.18.31.254244.18.31.2558,190
146244.18.32.0/19244.18.32.1 to 244.18.63.254244.18.63.2558,190
147244.18.64.0/19244.18.64.1 to 244.18.95.254244.18.95.2558,190
148244.18.96.0/19244.18.96.1 to 244.18.127.254244.18.127.2558,190
149244.18.128.0/19244.18.128.1 to 244.18.159.254244.18.159.2558,190
150244.18.160.0/19244.18.160.1 to 244.18.191.254244.18.191.2558,190
151244.18.192.0/19244.18.192.1 to 244.18.223.254244.18.223.2558,190
152244.18.224.0/19244.18.224.1 to 244.18.255.254244.18.255.2558,190
153244.19.0.0/19244.19.0.1 to 244.19.31.254244.19.31.2558,190
154244.19.32.0/19244.19.32.1 to 244.19.63.254244.19.63.2558,190
155244.19.64.0/19244.19.64.1 to 244.19.95.254244.19.95.2558,190
156244.19.96.0/19244.19.96.1 to 244.19.127.254244.19.127.2558,190
157244.19.128.0/19244.19.128.1 to 244.19.159.254244.19.159.2558,190
158244.19.160.0/19244.19.160.1 to 244.19.191.254244.19.191.2558,190
159244.19.192.0/19244.19.192.1 to 244.19.223.254244.19.223.2558,190
160244.19.224.0/19244.19.224.1 to 244.19.255.254244.19.255.2558,190
161244.20.0.0/19244.20.0.1 to 244.20.31.254244.20.31.2558,190
162244.20.32.0/19244.20.32.1 to 244.20.63.254244.20.63.2558,190
163244.20.64.0/19244.20.64.1 to 244.20.95.254244.20.95.2558,190
164244.20.96.0/19244.20.96.1 to 244.20.127.254244.20.127.2558,190
165244.20.128.0/19244.20.128.1 to 244.20.159.254244.20.159.2558,190
166244.20.160.0/19244.20.160.1 to 244.20.191.254244.20.191.2558,190
167244.20.192.0/19244.20.192.1 to 244.20.223.254244.20.223.2558,190
168244.20.224.0/19244.20.224.1 to 244.20.255.254244.20.255.2558,190
169244.21.0.0/19244.21.0.1 to 244.21.31.254244.21.31.2558,190
170244.21.32.0/19244.21.32.1 to 244.21.63.254244.21.63.2558,190
171244.21.64.0/19244.21.64.1 to 244.21.95.254244.21.95.2558,190
172244.21.96.0/19244.21.96.1 to 244.21.127.254244.21.127.2558,190
173244.21.128.0/19244.21.128.1 to 244.21.159.254244.21.159.2558,190
174244.21.160.0/19244.21.160.1 to 244.21.191.254244.21.191.2558,190
175244.21.192.0/19244.21.192.1 to 244.21.223.254244.21.223.2558,190
176244.21.224.0/19244.21.224.1 to 244.21.255.254244.21.255.2558,190
177244.22.0.0/19244.22.0.1 to 244.22.31.254244.22.31.2558,190
178244.22.32.0/19244.22.32.1 to 244.22.63.254244.22.63.2558,190
179244.22.64.0/19244.22.64.1 to 244.22.95.254244.22.95.2558,190
180244.22.96.0/19244.22.96.1 to 244.22.127.254244.22.127.2558,190
181244.22.128.0/19244.22.128.1 to 244.22.159.254244.22.159.2558,190
182244.22.160.0/19244.22.160.1 to 244.22.191.254244.22.191.2558,190
183244.22.192.0/19244.22.192.1 to 244.22.223.254244.22.223.2558,190
184244.22.224.0/19244.22.224.1 to 244.22.255.254244.22.255.2558,190
185244.23.0.0/19244.23.0.1 to 244.23.31.254244.23.31.2558,190
186244.23.32.0/19244.23.32.1 to 244.23.63.254244.23.63.2558,190
187244.23.64.0/19244.23.64.1 to 244.23.95.254244.23.95.2558,190
188244.23.96.0/19244.23.96.1 to 244.23.127.254244.23.127.2558,190
189244.23.128.0/19244.23.128.1 to 244.23.159.254244.23.159.2558,190
190244.23.160.0/19244.23.160.1 to 244.23.191.254244.23.191.2558,190
191244.23.192.0/19244.23.192.1 to 244.23.223.254244.23.223.2558,190
192244.23.224.0/19244.23.224.1 to 244.23.255.254244.23.255.2558,190
193244.24.0.0/19244.24.0.1 to 244.24.31.254244.24.31.2558,190
194244.24.32.0/19244.24.32.1 to 244.24.63.254244.24.63.2558,190
195244.24.64.0/19244.24.64.1 to 244.24.95.254244.24.95.2558,190
196244.24.96.0/19244.24.96.1 to 244.24.127.254244.24.127.2558,190
197244.24.128.0/19244.24.128.1 to 244.24.159.254244.24.159.2558,190
198244.24.160.0/19244.24.160.1 to 244.24.191.254244.24.191.2558,190
199244.24.192.0/19244.24.192.1 to 244.24.223.254244.24.223.2558,190
200244.24.224.0/19244.24.224.1 to 244.24.255.254244.24.255.2558,190
201244.25.0.0/19244.25.0.1 to 244.25.31.254244.25.31.2558,190
202244.25.32.0/19244.25.32.1 to 244.25.63.254244.25.63.2558,190
203244.25.64.0/19244.25.64.1 to 244.25.95.254244.25.95.2558,190
204244.25.96.0/19244.25.96.1 to 244.25.127.254244.25.127.2558,190
205244.25.128.0/19244.25.128.1 to 244.25.159.254244.25.159.2558,190
206244.25.160.0/19244.25.160.1 to 244.25.191.254244.25.191.2558,190
207244.25.192.0/19244.25.192.1 to 244.25.223.254244.25.223.2558,190
208244.25.224.0/19244.25.224.1 to 244.25.255.254244.25.255.2558,190
209244.26.0.0/19244.26.0.1 to 244.26.31.254244.26.31.2558,190
210244.26.32.0/19244.26.32.1 to 244.26.63.254244.26.63.2558,190
211244.26.64.0/19244.26.64.1 to 244.26.95.254244.26.95.2558,190
212244.26.96.0/19244.26.96.1 to 244.26.127.254244.26.127.2558,190
213244.26.128.0/19244.26.128.1 to 244.26.159.254244.26.159.2558,190
214244.26.160.0/19244.26.160.1 to 244.26.191.254244.26.191.2558,190
215244.26.192.0/19244.26.192.1 to 244.26.223.254244.26.223.2558,190
216244.26.224.0/19244.26.224.1 to 244.26.255.254244.26.255.2558,190
217244.27.0.0/19244.27.0.1 to 244.27.31.254244.27.31.2558,190
218244.27.32.0/19244.27.32.1 to 244.27.63.254244.27.63.2558,190
219244.27.64.0/19244.27.64.1 to 244.27.95.254244.27.95.2558,190
220244.27.96.0/19244.27.96.1 to 244.27.127.254244.27.127.2558,190
221244.27.128.0/19244.27.128.1 to 244.27.159.254244.27.159.2558,190
222244.27.160.0/19244.27.160.1 to 244.27.191.254244.27.191.2558,190
223244.27.192.0/19244.27.192.1 to 244.27.223.254244.27.223.2558,190
224244.27.224.0/19244.27.224.1 to 244.27.255.254244.27.255.2558,190
225244.28.0.0/19244.28.0.1 to 244.28.31.254244.28.31.2558,190
226244.28.32.0/19244.28.32.1 to 244.28.63.254244.28.63.2558,190
227244.28.64.0/19244.28.64.1 to 244.28.95.254244.28.95.2558,190
228244.28.96.0/19244.28.96.1 to 244.28.127.254244.28.127.2558,190
229244.28.128.0/19244.28.128.1 to 244.28.159.254244.28.159.2558,190
230244.28.160.0/19244.28.160.1 to 244.28.191.254244.28.191.2558,190
231244.28.192.0/19244.28.192.1 to 244.28.223.254244.28.223.2558,190
232244.28.224.0/19244.28.224.1 to 244.28.255.254244.28.255.2558,190
233244.29.0.0/19244.29.0.1 to 244.29.31.254244.29.31.2558,190
234244.29.32.0/19244.29.32.1 to 244.29.63.254244.29.63.2558,190
235244.29.64.0/19244.29.64.1 to 244.29.95.254244.29.95.2558,190
236244.29.96.0/19244.29.96.1 to 244.29.127.254244.29.127.2558,190
237244.29.128.0/19244.29.128.1 to 244.29.159.254244.29.159.2558,190
238244.29.160.0/19244.29.160.1 to 244.29.191.254244.29.191.2558,190
239244.29.192.0/19244.29.192.1 to 244.29.223.254244.29.223.2558,190
240244.29.224.0/19244.29.224.1 to 244.29.255.254244.29.255.2558,190
241244.30.0.0/19244.30.0.1 to 244.30.31.254244.30.31.2558,190
242244.30.32.0/19244.30.32.1 to 244.30.63.254244.30.63.2558,190
243244.30.64.0/19244.30.64.1 to 244.30.95.254244.30.95.2558,190
244244.30.96.0/19244.30.96.1 to 244.30.127.254244.30.127.2558,190
245244.30.128.0/19244.30.128.1 to 244.30.159.254244.30.159.2558,190
246244.30.160.0/19244.30.160.1 to 244.30.191.254244.30.191.2558,190
247244.30.192.0/19244.30.192.1 to 244.30.223.254244.30.223.2558,190
248244.30.224.0/19244.30.224.1 to 244.30.255.254244.30.255.2558,190
249244.31.0.0/19244.31.0.1 to 244.31.31.254244.31.31.2558,190
250244.31.32.0/19244.31.32.1 to 244.31.63.254244.31.63.2558,190
251244.31.64.0/19244.31.64.1 to 244.31.95.254244.31.95.2558,190
252244.31.96.0/19244.31.96.1 to 244.31.127.254244.31.127.2558,190
253244.31.128.0/19244.31.128.1 to 244.31.159.254244.31.159.2558,190
254244.31.160.0/19244.31.160.1 to 244.31.191.254244.31.191.2558,190
255244.31.192.0/19244.31.192.1 to 244.31.223.254244.31.223.2558,190
256244.31.224.0/19244.31.224.1 to 244.31.255.254244.31.255.2558,190

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.