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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.

Network178.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
178.0.0.0
Broadcast address
178.255.255.255
First usable
178.0.0.1
Last usable
178.255.255.254
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 B2000000 · Integer 2986344448 to 3003121663
Reverse DNS zone
178.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10110010..00000000.00000000.00000000178.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10110010..00000000.00000000.00000000178.0.0.0
Broadcast10110010..11111111.11111111.11111111178.255.255.255
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)

178.0.0.0/8 makes 4,096 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1178.0.0.0/20178.0.0.1 to 178.0.15.254178.0.15.2554,094
2178.0.16.0/20178.0.16.1 to 178.0.31.254178.0.31.2554,094
3178.0.32.0/20178.0.32.1 to 178.0.47.254178.0.47.2554,094
4178.0.48.0/20178.0.48.1 to 178.0.63.254178.0.63.2554,094
5178.0.64.0/20178.0.64.1 to 178.0.79.254178.0.79.2554,094
6178.0.80.0/20178.0.80.1 to 178.0.95.254178.0.95.2554,094
7178.0.96.0/20178.0.96.1 to 178.0.111.254178.0.111.2554,094
8178.0.112.0/20178.0.112.1 to 178.0.127.254178.0.127.2554,094
9178.0.128.0/20178.0.128.1 to 178.0.143.254178.0.143.2554,094
10178.0.144.0/20178.0.144.1 to 178.0.159.254178.0.159.2554,094
11178.0.160.0/20178.0.160.1 to 178.0.175.254178.0.175.2554,094
12178.0.176.0/20178.0.176.1 to 178.0.191.254178.0.191.2554,094
13178.0.192.0/20178.0.192.1 to 178.0.207.254178.0.207.2554,094
14178.0.208.0/20178.0.208.1 to 178.0.223.254178.0.223.2554,094
15178.0.224.0/20178.0.224.1 to 178.0.239.254178.0.239.2554,094
16178.0.240.0/20178.0.240.1 to 178.0.255.254178.0.255.2554,094
17178.1.0.0/20178.1.0.1 to 178.1.15.254178.1.15.2554,094
18178.1.16.0/20178.1.16.1 to 178.1.31.254178.1.31.2554,094
19178.1.32.0/20178.1.32.1 to 178.1.47.254178.1.47.2554,094
20178.1.48.0/20178.1.48.1 to 178.1.63.254178.1.63.2554,094
21178.1.64.0/20178.1.64.1 to 178.1.79.254178.1.79.2554,094
22178.1.80.0/20178.1.80.1 to 178.1.95.254178.1.95.2554,094
23178.1.96.0/20178.1.96.1 to 178.1.111.254178.1.111.2554,094
24178.1.112.0/20178.1.112.1 to 178.1.127.254178.1.127.2554,094
25178.1.128.0/20178.1.128.1 to 178.1.143.254178.1.143.2554,094
26178.1.144.0/20178.1.144.1 to 178.1.159.254178.1.159.2554,094
27178.1.160.0/20178.1.160.1 to 178.1.175.254178.1.175.2554,094
28178.1.176.0/20178.1.176.1 to 178.1.191.254178.1.191.2554,094
29178.1.192.0/20178.1.192.1 to 178.1.207.254178.1.207.2554,094
30178.1.208.0/20178.1.208.1 to 178.1.223.254178.1.223.2554,094
31178.1.224.0/20178.1.224.1 to 178.1.239.254178.1.239.2554,094
32178.1.240.0/20178.1.240.1 to 178.1.255.254178.1.255.2554,094
33178.2.0.0/20178.2.0.1 to 178.2.15.254178.2.15.2554,094
34178.2.16.0/20178.2.16.1 to 178.2.31.254178.2.31.2554,094
35178.2.32.0/20178.2.32.1 to 178.2.47.254178.2.47.2554,094
36178.2.48.0/20178.2.48.1 to 178.2.63.254178.2.63.2554,094
37178.2.64.0/20178.2.64.1 to 178.2.79.254178.2.79.2554,094
38178.2.80.0/20178.2.80.1 to 178.2.95.254178.2.95.2554,094
39178.2.96.0/20178.2.96.1 to 178.2.111.254178.2.111.2554,094
40178.2.112.0/20178.2.112.1 to 178.2.127.254178.2.127.2554,094
41178.2.128.0/20178.2.128.1 to 178.2.143.254178.2.143.2554,094
42178.2.144.0/20178.2.144.1 to 178.2.159.254178.2.159.2554,094
43178.2.160.0/20178.2.160.1 to 178.2.175.254178.2.175.2554,094
44178.2.176.0/20178.2.176.1 to 178.2.191.254178.2.191.2554,094
45178.2.192.0/20178.2.192.1 to 178.2.207.254178.2.207.2554,094
46178.2.208.0/20178.2.208.1 to 178.2.223.254178.2.223.2554,094
47178.2.224.0/20178.2.224.1 to 178.2.239.254178.2.239.2554,094
48178.2.240.0/20178.2.240.1 to 178.2.255.254178.2.255.2554,094
49178.3.0.0/20178.3.0.1 to 178.3.15.254178.3.15.2554,094
50178.3.16.0/20178.3.16.1 to 178.3.31.254178.3.31.2554,094
51178.3.32.0/20178.3.32.1 to 178.3.47.254178.3.47.2554,094
52178.3.48.0/20178.3.48.1 to 178.3.63.254178.3.63.2554,094
53178.3.64.0/20178.3.64.1 to 178.3.79.254178.3.79.2554,094
54178.3.80.0/20178.3.80.1 to 178.3.95.254178.3.95.2554,094
55178.3.96.0/20178.3.96.1 to 178.3.111.254178.3.111.2554,094
56178.3.112.0/20178.3.112.1 to 178.3.127.254178.3.127.2554,094
57178.3.128.0/20178.3.128.1 to 178.3.143.254178.3.143.2554,094
58178.3.144.0/20178.3.144.1 to 178.3.159.254178.3.159.2554,094
59178.3.160.0/20178.3.160.1 to 178.3.175.254178.3.175.2554,094
60178.3.176.0/20178.3.176.1 to 178.3.191.254178.3.191.2554,094
61178.3.192.0/20178.3.192.1 to 178.3.207.254178.3.207.2554,094
62178.3.208.0/20178.3.208.1 to 178.3.223.254178.3.223.2554,094
63178.3.224.0/20178.3.224.1 to 178.3.239.254178.3.239.2554,094
64178.3.240.0/20178.3.240.1 to 178.3.255.254178.3.255.2554,094
65178.4.0.0/20178.4.0.1 to 178.4.15.254178.4.15.2554,094
66178.4.16.0/20178.4.16.1 to 178.4.31.254178.4.31.2554,094
67178.4.32.0/20178.4.32.1 to 178.4.47.254178.4.47.2554,094
68178.4.48.0/20178.4.48.1 to 178.4.63.254178.4.63.2554,094
69178.4.64.0/20178.4.64.1 to 178.4.79.254178.4.79.2554,094
70178.4.80.0/20178.4.80.1 to 178.4.95.254178.4.95.2554,094
71178.4.96.0/20178.4.96.1 to 178.4.111.254178.4.111.2554,094
72178.4.112.0/20178.4.112.1 to 178.4.127.254178.4.127.2554,094
73178.4.128.0/20178.4.128.1 to 178.4.143.254178.4.143.2554,094
74178.4.144.0/20178.4.144.1 to 178.4.159.254178.4.159.2554,094
75178.4.160.0/20178.4.160.1 to 178.4.175.254178.4.175.2554,094
76178.4.176.0/20178.4.176.1 to 178.4.191.254178.4.191.2554,094
77178.4.192.0/20178.4.192.1 to 178.4.207.254178.4.207.2554,094
78178.4.208.0/20178.4.208.1 to 178.4.223.254178.4.223.2554,094
79178.4.224.0/20178.4.224.1 to 178.4.239.254178.4.239.2554,094
80178.4.240.0/20178.4.240.1 to 178.4.255.254178.4.255.2554,094
81178.5.0.0/20178.5.0.1 to 178.5.15.254178.5.15.2554,094
82178.5.16.0/20178.5.16.1 to 178.5.31.254178.5.31.2554,094
83178.5.32.0/20178.5.32.1 to 178.5.47.254178.5.47.2554,094
84178.5.48.0/20178.5.48.1 to 178.5.63.254178.5.63.2554,094
85178.5.64.0/20178.5.64.1 to 178.5.79.254178.5.79.2554,094
86178.5.80.0/20178.5.80.1 to 178.5.95.254178.5.95.2554,094
87178.5.96.0/20178.5.96.1 to 178.5.111.254178.5.111.2554,094
88178.5.112.0/20178.5.112.1 to 178.5.127.254178.5.127.2554,094
89178.5.128.0/20178.5.128.1 to 178.5.143.254178.5.143.2554,094
90178.5.144.0/20178.5.144.1 to 178.5.159.254178.5.159.2554,094
91178.5.160.0/20178.5.160.1 to 178.5.175.254178.5.175.2554,094
92178.5.176.0/20178.5.176.1 to 178.5.191.254178.5.191.2554,094
93178.5.192.0/20178.5.192.1 to 178.5.207.254178.5.207.2554,094
94178.5.208.0/20178.5.208.1 to 178.5.223.254178.5.223.2554,094
95178.5.224.0/20178.5.224.1 to 178.5.239.254178.5.239.2554,094
96178.5.240.0/20178.5.240.1 to 178.5.255.254178.5.255.2554,094
97178.6.0.0/20178.6.0.1 to 178.6.15.254178.6.15.2554,094
98178.6.16.0/20178.6.16.1 to 178.6.31.254178.6.31.2554,094
99178.6.32.0/20178.6.32.1 to 178.6.47.254178.6.47.2554,094
100178.6.48.0/20178.6.48.1 to 178.6.63.254178.6.63.2554,094
101178.6.64.0/20178.6.64.1 to 178.6.79.254178.6.79.2554,094
102178.6.80.0/20178.6.80.1 to 178.6.95.254178.6.95.2554,094
103178.6.96.0/20178.6.96.1 to 178.6.111.254178.6.111.2554,094
104178.6.112.0/20178.6.112.1 to 178.6.127.254178.6.127.2554,094
105178.6.128.0/20178.6.128.1 to 178.6.143.254178.6.143.2554,094
106178.6.144.0/20178.6.144.1 to 178.6.159.254178.6.159.2554,094
107178.6.160.0/20178.6.160.1 to 178.6.175.254178.6.175.2554,094
108178.6.176.0/20178.6.176.1 to 178.6.191.254178.6.191.2554,094
109178.6.192.0/20178.6.192.1 to 178.6.207.254178.6.207.2554,094
110178.6.208.0/20178.6.208.1 to 178.6.223.254178.6.223.2554,094
111178.6.224.0/20178.6.224.1 to 178.6.239.254178.6.239.2554,094
112178.6.240.0/20178.6.240.1 to 178.6.255.254178.6.255.2554,094
113178.7.0.0/20178.7.0.1 to 178.7.15.254178.7.15.2554,094
114178.7.16.0/20178.7.16.1 to 178.7.31.254178.7.31.2554,094
115178.7.32.0/20178.7.32.1 to 178.7.47.254178.7.47.2554,094
116178.7.48.0/20178.7.48.1 to 178.7.63.254178.7.63.2554,094
117178.7.64.0/20178.7.64.1 to 178.7.79.254178.7.79.2554,094
118178.7.80.0/20178.7.80.1 to 178.7.95.254178.7.95.2554,094
119178.7.96.0/20178.7.96.1 to 178.7.111.254178.7.111.2554,094
120178.7.112.0/20178.7.112.1 to 178.7.127.254178.7.127.2554,094
121178.7.128.0/20178.7.128.1 to 178.7.143.254178.7.143.2554,094
122178.7.144.0/20178.7.144.1 to 178.7.159.254178.7.159.2554,094
123178.7.160.0/20178.7.160.1 to 178.7.175.254178.7.175.2554,094
124178.7.176.0/20178.7.176.1 to 178.7.191.254178.7.191.2554,094
125178.7.192.0/20178.7.192.1 to 178.7.207.254178.7.207.2554,094
126178.7.208.0/20178.7.208.1 to 178.7.223.254178.7.223.2554,094
127178.7.224.0/20178.7.224.1 to 178.7.239.254178.7.239.2554,094
128178.7.240.0/20178.7.240.1 to 178.7.255.254178.7.255.2554,094
129178.8.0.0/20178.8.0.1 to 178.8.15.254178.8.15.2554,094
130178.8.16.0/20178.8.16.1 to 178.8.31.254178.8.31.2554,094
131178.8.32.0/20178.8.32.1 to 178.8.47.254178.8.47.2554,094
132178.8.48.0/20178.8.48.1 to 178.8.63.254178.8.63.2554,094
133178.8.64.0/20178.8.64.1 to 178.8.79.254178.8.79.2554,094
134178.8.80.0/20178.8.80.1 to 178.8.95.254178.8.95.2554,094
135178.8.96.0/20178.8.96.1 to 178.8.111.254178.8.111.2554,094
136178.8.112.0/20178.8.112.1 to 178.8.127.254178.8.127.2554,094
137178.8.128.0/20178.8.128.1 to 178.8.143.254178.8.143.2554,094
138178.8.144.0/20178.8.144.1 to 178.8.159.254178.8.159.2554,094
139178.8.160.0/20178.8.160.1 to 178.8.175.254178.8.175.2554,094
140178.8.176.0/20178.8.176.1 to 178.8.191.254178.8.191.2554,094
141178.8.192.0/20178.8.192.1 to 178.8.207.254178.8.207.2554,094
142178.8.208.0/20178.8.208.1 to 178.8.223.254178.8.223.2554,094
143178.8.224.0/20178.8.224.1 to 178.8.239.254178.8.239.2554,094
144178.8.240.0/20178.8.240.1 to 178.8.255.254178.8.255.2554,094
145178.9.0.0/20178.9.0.1 to 178.9.15.254178.9.15.2554,094
146178.9.16.0/20178.9.16.1 to 178.9.31.254178.9.31.2554,094
147178.9.32.0/20178.9.32.1 to 178.9.47.254178.9.47.2554,094
148178.9.48.0/20178.9.48.1 to 178.9.63.254178.9.63.2554,094
149178.9.64.0/20178.9.64.1 to 178.9.79.254178.9.79.2554,094
150178.9.80.0/20178.9.80.1 to 178.9.95.254178.9.95.2554,094
151178.9.96.0/20178.9.96.1 to 178.9.111.254178.9.111.2554,094
152178.9.112.0/20178.9.112.1 to 178.9.127.254178.9.127.2554,094
153178.9.128.0/20178.9.128.1 to 178.9.143.254178.9.143.2554,094
154178.9.144.0/20178.9.144.1 to 178.9.159.254178.9.159.2554,094
155178.9.160.0/20178.9.160.1 to 178.9.175.254178.9.175.2554,094
156178.9.176.0/20178.9.176.1 to 178.9.191.254178.9.191.2554,094
157178.9.192.0/20178.9.192.1 to 178.9.207.254178.9.207.2554,094
158178.9.208.0/20178.9.208.1 to 178.9.223.254178.9.223.2554,094
159178.9.224.0/20178.9.224.1 to 178.9.239.254178.9.239.2554,094
160178.9.240.0/20178.9.240.1 to 178.9.255.254178.9.255.2554,094
161178.10.0.0/20178.10.0.1 to 178.10.15.254178.10.15.2554,094
162178.10.16.0/20178.10.16.1 to 178.10.31.254178.10.31.2554,094
163178.10.32.0/20178.10.32.1 to 178.10.47.254178.10.47.2554,094
164178.10.48.0/20178.10.48.1 to 178.10.63.254178.10.63.2554,094
165178.10.64.0/20178.10.64.1 to 178.10.79.254178.10.79.2554,094
166178.10.80.0/20178.10.80.1 to 178.10.95.254178.10.95.2554,094
167178.10.96.0/20178.10.96.1 to 178.10.111.254178.10.111.2554,094
168178.10.112.0/20178.10.112.1 to 178.10.127.254178.10.127.2554,094
169178.10.128.0/20178.10.128.1 to 178.10.143.254178.10.143.2554,094
170178.10.144.0/20178.10.144.1 to 178.10.159.254178.10.159.2554,094
171178.10.160.0/20178.10.160.1 to 178.10.175.254178.10.175.2554,094
172178.10.176.0/20178.10.176.1 to 178.10.191.254178.10.191.2554,094
173178.10.192.0/20178.10.192.1 to 178.10.207.254178.10.207.2554,094
174178.10.208.0/20178.10.208.1 to 178.10.223.254178.10.223.2554,094
175178.10.224.0/20178.10.224.1 to 178.10.239.254178.10.239.2554,094
176178.10.240.0/20178.10.240.1 to 178.10.255.254178.10.255.2554,094
177178.11.0.0/20178.11.0.1 to 178.11.15.254178.11.15.2554,094
178178.11.16.0/20178.11.16.1 to 178.11.31.254178.11.31.2554,094
179178.11.32.0/20178.11.32.1 to 178.11.47.254178.11.47.2554,094
180178.11.48.0/20178.11.48.1 to 178.11.63.254178.11.63.2554,094
181178.11.64.0/20178.11.64.1 to 178.11.79.254178.11.79.2554,094
182178.11.80.0/20178.11.80.1 to 178.11.95.254178.11.95.2554,094
183178.11.96.0/20178.11.96.1 to 178.11.111.254178.11.111.2554,094
184178.11.112.0/20178.11.112.1 to 178.11.127.254178.11.127.2554,094
185178.11.128.0/20178.11.128.1 to 178.11.143.254178.11.143.2554,094
186178.11.144.0/20178.11.144.1 to 178.11.159.254178.11.159.2554,094
187178.11.160.0/20178.11.160.1 to 178.11.175.254178.11.175.2554,094
188178.11.176.0/20178.11.176.1 to 178.11.191.254178.11.191.2554,094
189178.11.192.0/20178.11.192.1 to 178.11.207.254178.11.207.2554,094
190178.11.208.0/20178.11.208.1 to 178.11.223.254178.11.223.2554,094
191178.11.224.0/20178.11.224.1 to 178.11.239.254178.11.239.2554,094
192178.11.240.0/20178.11.240.1 to 178.11.255.254178.11.255.2554,094
193178.12.0.0/20178.12.0.1 to 178.12.15.254178.12.15.2554,094
194178.12.16.0/20178.12.16.1 to 178.12.31.254178.12.31.2554,094
195178.12.32.0/20178.12.32.1 to 178.12.47.254178.12.47.2554,094
196178.12.48.0/20178.12.48.1 to 178.12.63.254178.12.63.2554,094
197178.12.64.0/20178.12.64.1 to 178.12.79.254178.12.79.2554,094
198178.12.80.0/20178.12.80.1 to 178.12.95.254178.12.95.2554,094
199178.12.96.0/20178.12.96.1 to 178.12.111.254178.12.111.2554,094
200178.12.112.0/20178.12.112.1 to 178.12.127.254178.12.127.2554,094
201178.12.128.0/20178.12.128.1 to 178.12.143.254178.12.143.2554,094
202178.12.144.0/20178.12.144.1 to 178.12.159.254178.12.159.2554,094
203178.12.160.0/20178.12.160.1 to 178.12.175.254178.12.175.2554,094
204178.12.176.0/20178.12.176.1 to 178.12.191.254178.12.191.2554,094
205178.12.192.0/20178.12.192.1 to 178.12.207.254178.12.207.2554,094
206178.12.208.0/20178.12.208.1 to 178.12.223.254178.12.223.2554,094
207178.12.224.0/20178.12.224.1 to 178.12.239.254178.12.239.2554,094
208178.12.240.0/20178.12.240.1 to 178.12.255.254178.12.255.2554,094
209178.13.0.0/20178.13.0.1 to 178.13.15.254178.13.15.2554,094
210178.13.16.0/20178.13.16.1 to 178.13.31.254178.13.31.2554,094
211178.13.32.0/20178.13.32.1 to 178.13.47.254178.13.47.2554,094
212178.13.48.0/20178.13.48.1 to 178.13.63.254178.13.63.2554,094
213178.13.64.0/20178.13.64.1 to 178.13.79.254178.13.79.2554,094
214178.13.80.0/20178.13.80.1 to 178.13.95.254178.13.95.2554,094
215178.13.96.0/20178.13.96.1 to 178.13.111.254178.13.111.2554,094
216178.13.112.0/20178.13.112.1 to 178.13.127.254178.13.127.2554,094
217178.13.128.0/20178.13.128.1 to 178.13.143.254178.13.143.2554,094
218178.13.144.0/20178.13.144.1 to 178.13.159.254178.13.159.2554,094
219178.13.160.0/20178.13.160.1 to 178.13.175.254178.13.175.2554,094
220178.13.176.0/20178.13.176.1 to 178.13.191.254178.13.191.2554,094
221178.13.192.0/20178.13.192.1 to 178.13.207.254178.13.207.2554,094
222178.13.208.0/20178.13.208.1 to 178.13.223.254178.13.223.2554,094
223178.13.224.0/20178.13.224.1 to 178.13.239.254178.13.239.2554,094
224178.13.240.0/20178.13.240.1 to 178.13.255.254178.13.255.2554,094
225178.14.0.0/20178.14.0.1 to 178.14.15.254178.14.15.2554,094
226178.14.16.0/20178.14.16.1 to 178.14.31.254178.14.31.2554,094
227178.14.32.0/20178.14.32.1 to 178.14.47.254178.14.47.2554,094
228178.14.48.0/20178.14.48.1 to 178.14.63.254178.14.63.2554,094
229178.14.64.0/20178.14.64.1 to 178.14.79.254178.14.79.2554,094
230178.14.80.0/20178.14.80.1 to 178.14.95.254178.14.95.2554,094
231178.14.96.0/20178.14.96.1 to 178.14.111.254178.14.111.2554,094
232178.14.112.0/20178.14.112.1 to 178.14.127.254178.14.127.2554,094
233178.14.128.0/20178.14.128.1 to 178.14.143.254178.14.143.2554,094
234178.14.144.0/20178.14.144.1 to 178.14.159.254178.14.159.2554,094
235178.14.160.0/20178.14.160.1 to 178.14.175.254178.14.175.2554,094
236178.14.176.0/20178.14.176.1 to 178.14.191.254178.14.191.2554,094
237178.14.192.0/20178.14.192.1 to 178.14.207.254178.14.207.2554,094
238178.14.208.0/20178.14.208.1 to 178.14.223.254178.14.223.2554,094
239178.14.224.0/20178.14.224.1 to 178.14.239.254178.14.239.2554,094
240178.14.240.0/20178.14.240.1 to 178.14.255.254178.14.255.2554,094
241178.15.0.0/20178.15.0.1 to 178.15.15.254178.15.15.2554,094
242178.15.16.0/20178.15.16.1 to 178.15.31.254178.15.31.2554,094
243178.15.32.0/20178.15.32.1 to 178.15.47.254178.15.47.2554,094
244178.15.48.0/20178.15.48.1 to 178.15.63.254178.15.63.2554,094
245178.15.64.0/20178.15.64.1 to 178.15.79.254178.15.79.2554,094
246178.15.80.0/20178.15.80.1 to 178.15.95.254178.15.95.2554,094
247178.15.96.0/20178.15.96.1 to 178.15.111.254178.15.111.2554,094
248178.15.112.0/20178.15.112.1 to 178.15.127.254178.15.127.2554,094
249178.15.128.0/20178.15.128.1 to 178.15.143.254178.15.143.2554,094
250178.15.144.0/20178.15.144.1 to 178.15.159.254178.15.159.2554,094
251178.15.160.0/20178.15.160.1 to 178.15.175.254178.15.175.2554,094
252178.15.176.0/20178.15.176.1 to 178.15.191.254178.15.191.2554,094
253178.15.192.0/20178.15.192.1 to 178.15.207.254178.15.207.2554,094
254178.15.208.0/20178.15.208.1 to 178.15.223.254178.15.223.2554,094
255178.15.224.0/20178.15.224.1 to 178.15.239.254178.15.239.2554,094
256178.15.240.0/20178.15.240.1 to 178.15.255.254178.15.255.2554,094

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.