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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.

Network177.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
177.0.0.0
Broadcast address
177.255.255.255
First usable
177.0.0.1
Last usable
177.255.255.254
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
B (default /16)
As numbers
Hex B1000000 · Integer 2969567232 to 2986344447
Reverse DNS zone
177.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10110001..00000000.00000000.00000000177.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10110001..00000000.00000000.00000000177.0.0.0
Broadcast10110001..11111111.11111111.11111111177.255.255.255
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)

177.0.0.0/8 makes 4,096 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1177.0.0.0/20177.0.0.1 to 177.0.15.254177.0.15.2554,094
2177.0.16.0/20177.0.16.1 to 177.0.31.254177.0.31.2554,094
3177.0.32.0/20177.0.32.1 to 177.0.47.254177.0.47.2554,094
4177.0.48.0/20177.0.48.1 to 177.0.63.254177.0.63.2554,094
5177.0.64.0/20177.0.64.1 to 177.0.79.254177.0.79.2554,094
6177.0.80.0/20177.0.80.1 to 177.0.95.254177.0.95.2554,094
7177.0.96.0/20177.0.96.1 to 177.0.111.254177.0.111.2554,094
8177.0.112.0/20177.0.112.1 to 177.0.127.254177.0.127.2554,094
9177.0.128.0/20177.0.128.1 to 177.0.143.254177.0.143.2554,094
10177.0.144.0/20177.0.144.1 to 177.0.159.254177.0.159.2554,094
11177.0.160.0/20177.0.160.1 to 177.0.175.254177.0.175.2554,094
12177.0.176.0/20177.0.176.1 to 177.0.191.254177.0.191.2554,094
13177.0.192.0/20177.0.192.1 to 177.0.207.254177.0.207.2554,094
14177.0.208.0/20177.0.208.1 to 177.0.223.254177.0.223.2554,094
15177.0.224.0/20177.0.224.1 to 177.0.239.254177.0.239.2554,094
16177.0.240.0/20177.0.240.1 to 177.0.255.254177.0.255.2554,094
17177.1.0.0/20177.1.0.1 to 177.1.15.254177.1.15.2554,094
18177.1.16.0/20177.1.16.1 to 177.1.31.254177.1.31.2554,094
19177.1.32.0/20177.1.32.1 to 177.1.47.254177.1.47.2554,094
20177.1.48.0/20177.1.48.1 to 177.1.63.254177.1.63.2554,094
21177.1.64.0/20177.1.64.1 to 177.1.79.254177.1.79.2554,094
22177.1.80.0/20177.1.80.1 to 177.1.95.254177.1.95.2554,094
23177.1.96.0/20177.1.96.1 to 177.1.111.254177.1.111.2554,094
24177.1.112.0/20177.1.112.1 to 177.1.127.254177.1.127.2554,094
25177.1.128.0/20177.1.128.1 to 177.1.143.254177.1.143.2554,094
26177.1.144.0/20177.1.144.1 to 177.1.159.254177.1.159.2554,094
27177.1.160.0/20177.1.160.1 to 177.1.175.254177.1.175.2554,094
28177.1.176.0/20177.1.176.1 to 177.1.191.254177.1.191.2554,094
29177.1.192.0/20177.1.192.1 to 177.1.207.254177.1.207.2554,094
30177.1.208.0/20177.1.208.1 to 177.1.223.254177.1.223.2554,094
31177.1.224.0/20177.1.224.1 to 177.1.239.254177.1.239.2554,094
32177.1.240.0/20177.1.240.1 to 177.1.255.254177.1.255.2554,094
33177.2.0.0/20177.2.0.1 to 177.2.15.254177.2.15.2554,094
34177.2.16.0/20177.2.16.1 to 177.2.31.254177.2.31.2554,094
35177.2.32.0/20177.2.32.1 to 177.2.47.254177.2.47.2554,094
36177.2.48.0/20177.2.48.1 to 177.2.63.254177.2.63.2554,094
37177.2.64.0/20177.2.64.1 to 177.2.79.254177.2.79.2554,094
38177.2.80.0/20177.2.80.1 to 177.2.95.254177.2.95.2554,094
39177.2.96.0/20177.2.96.1 to 177.2.111.254177.2.111.2554,094
40177.2.112.0/20177.2.112.1 to 177.2.127.254177.2.127.2554,094
41177.2.128.0/20177.2.128.1 to 177.2.143.254177.2.143.2554,094
42177.2.144.0/20177.2.144.1 to 177.2.159.254177.2.159.2554,094
43177.2.160.0/20177.2.160.1 to 177.2.175.254177.2.175.2554,094
44177.2.176.0/20177.2.176.1 to 177.2.191.254177.2.191.2554,094
45177.2.192.0/20177.2.192.1 to 177.2.207.254177.2.207.2554,094
46177.2.208.0/20177.2.208.1 to 177.2.223.254177.2.223.2554,094
47177.2.224.0/20177.2.224.1 to 177.2.239.254177.2.239.2554,094
48177.2.240.0/20177.2.240.1 to 177.2.255.254177.2.255.2554,094
49177.3.0.0/20177.3.0.1 to 177.3.15.254177.3.15.2554,094
50177.3.16.0/20177.3.16.1 to 177.3.31.254177.3.31.2554,094
51177.3.32.0/20177.3.32.1 to 177.3.47.254177.3.47.2554,094
52177.3.48.0/20177.3.48.1 to 177.3.63.254177.3.63.2554,094
53177.3.64.0/20177.3.64.1 to 177.3.79.254177.3.79.2554,094
54177.3.80.0/20177.3.80.1 to 177.3.95.254177.3.95.2554,094
55177.3.96.0/20177.3.96.1 to 177.3.111.254177.3.111.2554,094
56177.3.112.0/20177.3.112.1 to 177.3.127.254177.3.127.2554,094
57177.3.128.0/20177.3.128.1 to 177.3.143.254177.3.143.2554,094
58177.3.144.0/20177.3.144.1 to 177.3.159.254177.3.159.2554,094
59177.3.160.0/20177.3.160.1 to 177.3.175.254177.3.175.2554,094
60177.3.176.0/20177.3.176.1 to 177.3.191.254177.3.191.2554,094
61177.3.192.0/20177.3.192.1 to 177.3.207.254177.3.207.2554,094
62177.3.208.0/20177.3.208.1 to 177.3.223.254177.3.223.2554,094
63177.3.224.0/20177.3.224.1 to 177.3.239.254177.3.239.2554,094
64177.3.240.0/20177.3.240.1 to 177.3.255.254177.3.255.2554,094
65177.4.0.0/20177.4.0.1 to 177.4.15.254177.4.15.2554,094
66177.4.16.0/20177.4.16.1 to 177.4.31.254177.4.31.2554,094
67177.4.32.0/20177.4.32.1 to 177.4.47.254177.4.47.2554,094
68177.4.48.0/20177.4.48.1 to 177.4.63.254177.4.63.2554,094
69177.4.64.0/20177.4.64.1 to 177.4.79.254177.4.79.2554,094
70177.4.80.0/20177.4.80.1 to 177.4.95.254177.4.95.2554,094
71177.4.96.0/20177.4.96.1 to 177.4.111.254177.4.111.2554,094
72177.4.112.0/20177.4.112.1 to 177.4.127.254177.4.127.2554,094
73177.4.128.0/20177.4.128.1 to 177.4.143.254177.4.143.2554,094
74177.4.144.0/20177.4.144.1 to 177.4.159.254177.4.159.2554,094
75177.4.160.0/20177.4.160.1 to 177.4.175.254177.4.175.2554,094
76177.4.176.0/20177.4.176.1 to 177.4.191.254177.4.191.2554,094
77177.4.192.0/20177.4.192.1 to 177.4.207.254177.4.207.2554,094
78177.4.208.0/20177.4.208.1 to 177.4.223.254177.4.223.2554,094
79177.4.224.0/20177.4.224.1 to 177.4.239.254177.4.239.2554,094
80177.4.240.0/20177.4.240.1 to 177.4.255.254177.4.255.2554,094
81177.5.0.0/20177.5.0.1 to 177.5.15.254177.5.15.2554,094
82177.5.16.0/20177.5.16.1 to 177.5.31.254177.5.31.2554,094
83177.5.32.0/20177.5.32.1 to 177.5.47.254177.5.47.2554,094
84177.5.48.0/20177.5.48.1 to 177.5.63.254177.5.63.2554,094
85177.5.64.0/20177.5.64.1 to 177.5.79.254177.5.79.2554,094
86177.5.80.0/20177.5.80.1 to 177.5.95.254177.5.95.2554,094
87177.5.96.0/20177.5.96.1 to 177.5.111.254177.5.111.2554,094
88177.5.112.0/20177.5.112.1 to 177.5.127.254177.5.127.2554,094
89177.5.128.0/20177.5.128.1 to 177.5.143.254177.5.143.2554,094
90177.5.144.0/20177.5.144.1 to 177.5.159.254177.5.159.2554,094
91177.5.160.0/20177.5.160.1 to 177.5.175.254177.5.175.2554,094
92177.5.176.0/20177.5.176.1 to 177.5.191.254177.5.191.2554,094
93177.5.192.0/20177.5.192.1 to 177.5.207.254177.5.207.2554,094
94177.5.208.0/20177.5.208.1 to 177.5.223.254177.5.223.2554,094
95177.5.224.0/20177.5.224.1 to 177.5.239.254177.5.239.2554,094
96177.5.240.0/20177.5.240.1 to 177.5.255.254177.5.255.2554,094
97177.6.0.0/20177.6.0.1 to 177.6.15.254177.6.15.2554,094
98177.6.16.0/20177.6.16.1 to 177.6.31.254177.6.31.2554,094
99177.6.32.0/20177.6.32.1 to 177.6.47.254177.6.47.2554,094
100177.6.48.0/20177.6.48.1 to 177.6.63.254177.6.63.2554,094
101177.6.64.0/20177.6.64.1 to 177.6.79.254177.6.79.2554,094
102177.6.80.0/20177.6.80.1 to 177.6.95.254177.6.95.2554,094
103177.6.96.0/20177.6.96.1 to 177.6.111.254177.6.111.2554,094
104177.6.112.0/20177.6.112.1 to 177.6.127.254177.6.127.2554,094
105177.6.128.0/20177.6.128.1 to 177.6.143.254177.6.143.2554,094
106177.6.144.0/20177.6.144.1 to 177.6.159.254177.6.159.2554,094
107177.6.160.0/20177.6.160.1 to 177.6.175.254177.6.175.2554,094
108177.6.176.0/20177.6.176.1 to 177.6.191.254177.6.191.2554,094
109177.6.192.0/20177.6.192.1 to 177.6.207.254177.6.207.2554,094
110177.6.208.0/20177.6.208.1 to 177.6.223.254177.6.223.2554,094
111177.6.224.0/20177.6.224.1 to 177.6.239.254177.6.239.2554,094
112177.6.240.0/20177.6.240.1 to 177.6.255.254177.6.255.2554,094
113177.7.0.0/20177.7.0.1 to 177.7.15.254177.7.15.2554,094
114177.7.16.0/20177.7.16.1 to 177.7.31.254177.7.31.2554,094
115177.7.32.0/20177.7.32.1 to 177.7.47.254177.7.47.2554,094
116177.7.48.0/20177.7.48.1 to 177.7.63.254177.7.63.2554,094
117177.7.64.0/20177.7.64.1 to 177.7.79.254177.7.79.2554,094
118177.7.80.0/20177.7.80.1 to 177.7.95.254177.7.95.2554,094
119177.7.96.0/20177.7.96.1 to 177.7.111.254177.7.111.2554,094
120177.7.112.0/20177.7.112.1 to 177.7.127.254177.7.127.2554,094
121177.7.128.0/20177.7.128.1 to 177.7.143.254177.7.143.2554,094
122177.7.144.0/20177.7.144.1 to 177.7.159.254177.7.159.2554,094
123177.7.160.0/20177.7.160.1 to 177.7.175.254177.7.175.2554,094
124177.7.176.0/20177.7.176.1 to 177.7.191.254177.7.191.2554,094
125177.7.192.0/20177.7.192.1 to 177.7.207.254177.7.207.2554,094
126177.7.208.0/20177.7.208.1 to 177.7.223.254177.7.223.2554,094
127177.7.224.0/20177.7.224.1 to 177.7.239.254177.7.239.2554,094
128177.7.240.0/20177.7.240.1 to 177.7.255.254177.7.255.2554,094
129177.8.0.0/20177.8.0.1 to 177.8.15.254177.8.15.2554,094
130177.8.16.0/20177.8.16.1 to 177.8.31.254177.8.31.2554,094
131177.8.32.0/20177.8.32.1 to 177.8.47.254177.8.47.2554,094
132177.8.48.0/20177.8.48.1 to 177.8.63.254177.8.63.2554,094
133177.8.64.0/20177.8.64.1 to 177.8.79.254177.8.79.2554,094
134177.8.80.0/20177.8.80.1 to 177.8.95.254177.8.95.2554,094
135177.8.96.0/20177.8.96.1 to 177.8.111.254177.8.111.2554,094
136177.8.112.0/20177.8.112.1 to 177.8.127.254177.8.127.2554,094
137177.8.128.0/20177.8.128.1 to 177.8.143.254177.8.143.2554,094
138177.8.144.0/20177.8.144.1 to 177.8.159.254177.8.159.2554,094
139177.8.160.0/20177.8.160.1 to 177.8.175.254177.8.175.2554,094
140177.8.176.0/20177.8.176.1 to 177.8.191.254177.8.191.2554,094
141177.8.192.0/20177.8.192.1 to 177.8.207.254177.8.207.2554,094
142177.8.208.0/20177.8.208.1 to 177.8.223.254177.8.223.2554,094
143177.8.224.0/20177.8.224.1 to 177.8.239.254177.8.239.2554,094
144177.8.240.0/20177.8.240.1 to 177.8.255.254177.8.255.2554,094
145177.9.0.0/20177.9.0.1 to 177.9.15.254177.9.15.2554,094
146177.9.16.0/20177.9.16.1 to 177.9.31.254177.9.31.2554,094
147177.9.32.0/20177.9.32.1 to 177.9.47.254177.9.47.2554,094
148177.9.48.0/20177.9.48.1 to 177.9.63.254177.9.63.2554,094
149177.9.64.0/20177.9.64.1 to 177.9.79.254177.9.79.2554,094
150177.9.80.0/20177.9.80.1 to 177.9.95.254177.9.95.2554,094
151177.9.96.0/20177.9.96.1 to 177.9.111.254177.9.111.2554,094
152177.9.112.0/20177.9.112.1 to 177.9.127.254177.9.127.2554,094
153177.9.128.0/20177.9.128.1 to 177.9.143.254177.9.143.2554,094
154177.9.144.0/20177.9.144.1 to 177.9.159.254177.9.159.2554,094
155177.9.160.0/20177.9.160.1 to 177.9.175.254177.9.175.2554,094
156177.9.176.0/20177.9.176.1 to 177.9.191.254177.9.191.2554,094
157177.9.192.0/20177.9.192.1 to 177.9.207.254177.9.207.2554,094
158177.9.208.0/20177.9.208.1 to 177.9.223.254177.9.223.2554,094
159177.9.224.0/20177.9.224.1 to 177.9.239.254177.9.239.2554,094
160177.9.240.0/20177.9.240.1 to 177.9.255.254177.9.255.2554,094
161177.10.0.0/20177.10.0.1 to 177.10.15.254177.10.15.2554,094
162177.10.16.0/20177.10.16.1 to 177.10.31.254177.10.31.2554,094
163177.10.32.0/20177.10.32.1 to 177.10.47.254177.10.47.2554,094
164177.10.48.0/20177.10.48.1 to 177.10.63.254177.10.63.2554,094
165177.10.64.0/20177.10.64.1 to 177.10.79.254177.10.79.2554,094
166177.10.80.0/20177.10.80.1 to 177.10.95.254177.10.95.2554,094
167177.10.96.0/20177.10.96.1 to 177.10.111.254177.10.111.2554,094
168177.10.112.0/20177.10.112.1 to 177.10.127.254177.10.127.2554,094
169177.10.128.0/20177.10.128.1 to 177.10.143.254177.10.143.2554,094
170177.10.144.0/20177.10.144.1 to 177.10.159.254177.10.159.2554,094
171177.10.160.0/20177.10.160.1 to 177.10.175.254177.10.175.2554,094
172177.10.176.0/20177.10.176.1 to 177.10.191.254177.10.191.2554,094
173177.10.192.0/20177.10.192.1 to 177.10.207.254177.10.207.2554,094
174177.10.208.0/20177.10.208.1 to 177.10.223.254177.10.223.2554,094
175177.10.224.0/20177.10.224.1 to 177.10.239.254177.10.239.2554,094
176177.10.240.0/20177.10.240.1 to 177.10.255.254177.10.255.2554,094
177177.11.0.0/20177.11.0.1 to 177.11.15.254177.11.15.2554,094
178177.11.16.0/20177.11.16.1 to 177.11.31.254177.11.31.2554,094
179177.11.32.0/20177.11.32.1 to 177.11.47.254177.11.47.2554,094
180177.11.48.0/20177.11.48.1 to 177.11.63.254177.11.63.2554,094
181177.11.64.0/20177.11.64.1 to 177.11.79.254177.11.79.2554,094
182177.11.80.0/20177.11.80.1 to 177.11.95.254177.11.95.2554,094
183177.11.96.0/20177.11.96.1 to 177.11.111.254177.11.111.2554,094
184177.11.112.0/20177.11.112.1 to 177.11.127.254177.11.127.2554,094
185177.11.128.0/20177.11.128.1 to 177.11.143.254177.11.143.2554,094
186177.11.144.0/20177.11.144.1 to 177.11.159.254177.11.159.2554,094
187177.11.160.0/20177.11.160.1 to 177.11.175.254177.11.175.2554,094
188177.11.176.0/20177.11.176.1 to 177.11.191.254177.11.191.2554,094
189177.11.192.0/20177.11.192.1 to 177.11.207.254177.11.207.2554,094
190177.11.208.0/20177.11.208.1 to 177.11.223.254177.11.223.2554,094
191177.11.224.0/20177.11.224.1 to 177.11.239.254177.11.239.2554,094
192177.11.240.0/20177.11.240.1 to 177.11.255.254177.11.255.2554,094
193177.12.0.0/20177.12.0.1 to 177.12.15.254177.12.15.2554,094
194177.12.16.0/20177.12.16.1 to 177.12.31.254177.12.31.2554,094
195177.12.32.0/20177.12.32.1 to 177.12.47.254177.12.47.2554,094
196177.12.48.0/20177.12.48.1 to 177.12.63.254177.12.63.2554,094
197177.12.64.0/20177.12.64.1 to 177.12.79.254177.12.79.2554,094
198177.12.80.0/20177.12.80.1 to 177.12.95.254177.12.95.2554,094
199177.12.96.0/20177.12.96.1 to 177.12.111.254177.12.111.2554,094
200177.12.112.0/20177.12.112.1 to 177.12.127.254177.12.127.2554,094
201177.12.128.0/20177.12.128.1 to 177.12.143.254177.12.143.2554,094
202177.12.144.0/20177.12.144.1 to 177.12.159.254177.12.159.2554,094
203177.12.160.0/20177.12.160.1 to 177.12.175.254177.12.175.2554,094
204177.12.176.0/20177.12.176.1 to 177.12.191.254177.12.191.2554,094
205177.12.192.0/20177.12.192.1 to 177.12.207.254177.12.207.2554,094
206177.12.208.0/20177.12.208.1 to 177.12.223.254177.12.223.2554,094
207177.12.224.0/20177.12.224.1 to 177.12.239.254177.12.239.2554,094
208177.12.240.0/20177.12.240.1 to 177.12.255.254177.12.255.2554,094
209177.13.0.0/20177.13.0.1 to 177.13.15.254177.13.15.2554,094
210177.13.16.0/20177.13.16.1 to 177.13.31.254177.13.31.2554,094
211177.13.32.0/20177.13.32.1 to 177.13.47.254177.13.47.2554,094
212177.13.48.0/20177.13.48.1 to 177.13.63.254177.13.63.2554,094
213177.13.64.0/20177.13.64.1 to 177.13.79.254177.13.79.2554,094
214177.13.80.0/20177.13.80.1 to 177.13.95.254177.13.95.2554,094
215177.13.96.0/20177.13.96.1 to 177.13.111.254177.13.111.2554,094
216177.13.112.0/20177.13.112.1 to 177.13.127.254177.13.127.2554,094
217177.13.128.0/20177.13.128.1 to 177.13.143.254177.13.143.2554,094
218177.13.144.0/20177.13.144.1 to 177.13.159.254177.13.159.2554,094
219177.13.160.0/20177.13.160.1 to 177.13.175.254177.13.175.2554,094
220177.13.176.0/20177.13.176.1 to 177.13.191.254177.13.191.2554,094
221177.13.192.0/20177.13.192.1 to 177.13.207.254177.13.207.2554,094
222177.13.208.0/20177.13.208.1 to 177.13.223.254177.13.223.2554,094
223177.13.224.0/20177.13.224.1 to 177.13.239.254177.13.239.2554,094
224177.13.240.0/20177.13.240.1 to 177.13.255.254177.13.255.2554,094
225177.14.0.0/20177.14.0.1 to 177.14.15.254177.14.15.2554,094
226177.14.16.0/20177.14.16.1 to 177.14.31.254177.14.31.2554,094
227177.14.32.0/20177.14.32.1 to 177.14.47.254177.14.47.2554,094
228177.14.48.0/20177.14.48.1 to 177.14.63.254177.14.63.2554,094
229177.14.64.0/20177.14.64.1 to 177.14.79.254177.14.79.2554,094
230177.14.80.0/20177.14.80.1 to 177.14.95.254177.14.95.2554,094
231177.14.96.0/20177.14.96.1 to 177.14.111.254177.14.111.2554,094
232177.14.112.0/20177.14.112.1 to 177.14.127.254177.14.127.2554,094
233177.14.128.0/20177.14.128.1 to 177.14.143.254177.14.143.2554,094
234177.14.144.0/20177.14.144.1 to 177.14.159.254177.14.159.2554,094
235177.14.160.0/20177.14.160.1 to 177.14.175.254177.14.175.2554,094
236177.14.176.0/20177.14.176.1 to 177.14.191.254177.14.191.2554,094
237177.14.192.0/20177.14.192.1 to 177.14.207.254177.14.207.2554,094
238177.14.208.0/20177.14.208.1 to 177.14.223.254177.14.223.2554,094
239177.14.224.0/20177.14.224.1 to 177.14.239.254177.14.239.2554,094
240177.14.240.0/20177.14.240.1 to 177.14.255.254177.14.255.2554,094
241177.15.0.0/20177.15.0.1 to 177.15.15.254177.15.15.2554,094
242177.15.16.0/20177.15.16.1 to 177.15.31.254177.15.31.2554,094
243177.15.32.0/20177.15.32.1 to 177.15.47.254177.15.47.2554,094
244177.15.48.0/20177.15.48.1 to 177.15.63.254177.15.63.2554,094
245177.15.64.0/20177.15.64.1 to 177.15.79.254177.15.79.2554,094
246177.15.80.0/20177.15.80.1 to 177.15.95.254177.15.95.2554,094
247177.15.96.0/20177.15.96.1 to 177.15.111.254177.15.111.2554,094
248177.15.112.0/20177.15.112.1 to 177.15.127.254177.15.127.2554,094
249177.15.128.0/20177.15.128.1 to 177.15.143.254177.15.143.2554,094
250177.15.144.0/20177.15.144.1 to 177.15.159.254177.15.159.2554,094
251177.15.160.0/20177.15.160.1 to 177.15.175.254177.15.175.2554,094
252177.15.176.0/20177.15.176.1 to 177.15.191.254177.15.191.2554,094
253177.15.192.0/20177.15.192.1 to 177.15.207.254177.15.207.2554,094
254177.15.208.0/20177.15.208.1 to 177.15.223.254177.15.223.2554,094
255177.15.224.0/20177.15.224.1 to 177.15.239.254177.15.239.2554,094
256177.15.240.0/20177.15.240.1 to 177.15.255.254177.15.255.2554,094

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.