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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.

Network166.22.192.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
166.22.192.0
Broadcast address
166.22.255.255
First usable
166.22.192.1
Last usable
166.22.255.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Public public
Old class
B (default /16)
As numbers
Hex A616C000 · Integer 2786508800 to 2786525183
Reverse DNS zones
192.22.166.in-addr.arpa
193.22.166.in-addr.arpa
194.22.166.in-addr.arpa
195.22.166.in-addr.arpa
196.22.166.in-addr.arpa
197.22.166.in-addr.arpa
198.22.166.in-addr.arpa
199.22.166.in-addr.arpa
200.22.166.in-addr.arpa
201.22.166.in-addr.arpa
202.22.166.in-addr.arpa
203.22.166.in-addr.arpa
204.22.166.in-addr.arpa
205.22.166.in-addr.arpa
206.22.166.in-addr.arpa
207.22.166.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10100110.00010110.11000000.00000000166.22.192.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network10100110.00010110.11000000.00000000166.22.192.0
Broadcast10100110.00010110.11111111.11111111166.22.255.255
Split into smaller subnets/27
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

166.22.192.0/18 makes 512 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1166.22.192.0/27166.22.192.1 to 166.22.192.30166.22.192.3130
2166.22.192.32/27166.22.192.33 to 166.22.192.62166.22.192.6330
3166.22.192.64/27166.22.192.65 to 166.22.192.94166.22.192.9530
4166.22.192.96/27166.22.192.97 to 166.22.192.126166.22.192.12730
5166.22.192.128/27166.22.192.129 to 166.22.192.158166.22.192.15930
6166.22.192.160/27166.22.192.161 to 166.22.192.190166.22.192.19130
7166.22.192.192/27166.22.192.193 to 166.22.192.222166.22.192.22330
8166.22.192.224/27166.22.192.225 to 166.22.192.254166.22.192.25530
9166.22.193.0/27166.22.193.1 to 166.22.193.30166.22.193.3130
10166.22.193.32/27166.22.193.33 to 166.22.193.62166.22.193.6330
11166.22.193.64/27166.22.193.65 to 166.22.193.94166.22.193.9530
12166.22.193.96/27166.22.193.97 to 166.22.193.126166.22.193.12730
13166.22.193.128/27166.22.193.129 to 166.22.193.158166.22.193.15930
14166.22.193.160/27166.22.193.161 to 166.22.193.190166.22.193.19130
15166.22.193.192/27166.22.193.193 to 166.22.193.222166.22.193.22330
16166.22.193.224/27166.22.193.225 to 166.22.193.254166.22.193.25530
17166.22.194.0/27166.22.194.1 to 166.22.194.30166.22.194.3130
18166.22.194.32/27166.22.194.33 to 166.22.194.62166.22.194.6330
19166.22.194.64/27166.22.194.65 to 166.22.194.94166.22.194.9530
20166.22.194.96/27166.22.194.97 to 166.22.194.126166.22.194.12730
21166.22.194.128/27166.22.194.129 to 166.22.194.158166.22.194.15930
22166.22.194.160/27166.22.194.161 to 166.22.194.190166.22.194.19130
23166.22.194.192/27166.22.194.193 to 166.22.194.222166.22.194.22330
24166.22.194.224/27166.22.194.225 to 166.22.194.254166.22.194.25530
25166.22.195.0/27166.22.195.1 to 166.22.195.30166.22.195.3130
26166.22.195.32/27166.22.195.33 to 166.22.195.62166.22.195.6330
27166.22.195.64/27166.22.195.65 to 166.22.195.94166.22.195.9530
28166.22.195.96/27166.22.195.97 to 166.22.195.126166.22.195.12730
29166.22.195.128/27166.22.195.129 to 166.22.195.158166.22.195.15930
30166.22.195.160/27166.22.195.161 to 166.22.195.190166.22.195.19130
31166.22.195.192/27166.22.195.193 to 166.22.195.222166.22.195.22330
32166.22.195.224/27166.22.195.225 to 166.22.195.254166.22.195.25530
33166.22.196.0/27166.22.196.1 to 166.22.196.30166.22.196.3130
34166.22.196.32/27166.22.196.33 to 166.22.196.62166.22.196.6330
35166.22.196.64/27166.22.196.65 to 166.22.196.94166.22.196.9530
36166.22.196.96/27166.22.196.97 to 166.22.196.126166.22.196.12730
37166.22.196.128/27166.22.196.129 to 166.22.196.158166.22.196.15930
38166.22.196.160/27166.22.196.161 to 166.22.196.190166.22.196.19130
39166.22.196.192/27166.22.196.193 to 166.22.196.222166.22.196.22330
40166.22.196.224/27166.22.196.225 to 166.22.196.254166.22.196.25530
41166.22.197.0/27166.22.197.1 to 166.22.197.30166.22.197.3130
42166.22.197.32/27166.22.197.33 to 166.22.197.62166.22.197.6330
43166.22.197.64/27166.22.197.65 to 166.22.197.94166.22.197.9530
44166.22.197.96/27166.22.197.97 to 166.22.197.126166.22.197.12730
45166.22.197.128/27166.22.197.129 to 166.22.197.158166.22.197.15930
46166.22.197.160/27166.22.197.161 to 166.22.197.190166.22.197.19130
47166.22.197.192/27166.22.197.193 to 166.22.197.222166.22.197.22330
48166.22.197.224/27166.22.197.225 to 166.22.197.254166.22.197.25530
49166.22.198.0/27166.22.198.1 to 166.22.198.30166.22.198.3130
50166.22.198.32/27166.22.198.33 to 166.22.198.62166.22.198.6330
51166.22.198.64/27166.22.198.65 to 166.22.198.94166.22.198.9530
52166.22.198.96/27166.22.198.97 to 166.22.198.126166.22.198.12730
53166.22.198.128/27166.22.198.129 to 166.22.198.158166.22.198.15930
54166.22.198.160/27166.22.198.161 to 166.22.198.190166.22.198.19130
55166.22.198.192/27166.22.198.193 to 166.22.198.222166.22.198.22330
56166.22.198.224/27166.22.198.225 to 166.22.198.254166.22.198.25530
57166.22.199.0/27166.22.199.1 to 166.22.199.30166.22.199.3130
58166.22.199.32/27166.22.199.33 to 166.22.199.62166.22.199.6330
59166.22.199.64/27166.22.199.65 to 166.22.199.94166.22.199.9530
60166.22.199.96/27166.22.199.97 to 166.22.199.126166.22.199.12730
61166.22.199.128/27166.22.199.129 to 166.22.199.158166.22.199.15930
62166.22.199.160/27166.22.199.161 to 166.22.199.190166.22.199.19130
63166.22.199.192/27166.22.199.193 to 166.22.199.222166.22.199.22330
64166.22.199.224/27166.22.199.225 to 166.22.199.254166.22.199.25530
65166.22.200.0/27166.22.200.1 to 166.22.200.30166.22.200.3130
66166.22.200.32/27166.22.200.33 to 166.22.200.62166.22.200.6330
67166.22.200.64/27166.22.200.65 to 166.22.200.94166.22.200.9530
68166.22.200.96/27166.22.200.97 to 166.22.200.126166.22.200.12730
69166.22.200.128/27166.22.200.129 to 166.22.200.158166.22.200.15930
70166.22.200.160/27166.22.200.161 to 166.22.200.190166.22.200.19130
71166.22.200.192/27166.22.200.193 to 166.22.200.222166.22.200.22330
72166.22.200.224/27166.22.200.225 to 166.22.200.254166.22.200.25530
73166.22.201.0/27166.22.201.1 to 166.22.201.30166.22.201.3130
74166.22.201.32/27166.22.201.33 to 166.22.201.62166.22.201.6330
75166.22.201.64/27166.22.201.65 to 166.22.201.94166.22.201.9530
76166.22.201.96/27166.22.201.97 to 166.22.201.126166.22.201.12730
77166.22.201.128/27166.22.201.129 to 166.22.201.158166.22.201.15930
78166.22.201.160/27166.22.201.161 to 166.22.201.190166.22.201.19130
79166.22.201.192/27166.22.201.193 to 166.22.201.222166.22.201.22330
80166.22.201.224/27166.22.201.225 to 166.22.201.254166.22.201.25530
81166.22.202.0/27166.22.202.1 to 166.22.202.30166.22.202.3130
82166.22.202.32/27166.22.202.33 to 166.22.202.62166.22.202.6330
83166.22.202.64/27166.22.202.65 to 166.22.202.94166.22.202.9530
84166.22.202.96/27166.22.202.97 to 166.22.202.126166.22.202.12730
85166.22.202.128/27166.22.202.129 to 166.22.202.158166.22.202.15930
86166.22.202.160/27166.22.202.161 to 166.22.202.190166.22.202.19130
87166.22.202.192/27166.22.202.193 to 166.22.202.222166.22.202.22330
88166.22.202.224/27166.22.202.225 to 166.22.202.254166.22.202.25530
89166.22.203.0/27166.22.203.1 to 166.22.203.30166.22.203.3130
90166.22.203.32/27166.22.203.33 to 166.22.203.62166.22.203.6330
91166.22.203.64/27166.22.203.65 to 166.22.203.94166.22.203.9530
92166.22.203.96/27166.22.203.97 to 166.22.203.126166.22.203.12730
93166.22.203.128/27166.22.203.129 to 166.22.203.158166.22.203.15930
94166.22.203.160/27166.22.203.161 to 166.22.203.190166.22.203.19130
95166.22.203.192/27166.22.203.193 to 166.22.203.222166.22.203.22330
96166.22.203.224/27166.22.203.225 to 166.22.203.254166.22.203.25530
97166.22.204.0/27166.22.204.1 to 166.22.204.30166.22.204.3130
98166.22.204.32/27166.22.204.33 to 166.22.204.62166.22.204.6330
99166.22.204.64/27166.22.204.65 to 166.22.204.94166.22.204.9530
100166.22.204.96/27166.22.204.97 to 166.22.204.126166.22.204.12730
101166.22.204.128/27166.22.204.129 to 166.22.204.158166.22.204.15930
102166.22.204.160/27166.22.204.161 to 166.22.204.190166.22.204.19130
103166.22.204.192/27166.22.204.193 to 166.22.204.222166.22.204.22330
104166.22.204.224/27166.22.204.225 to 166.22.204.254166.22.204.25530
105166.22.205.0/27166.22.205.1 to 166.22.205.30166.22.205.3130
106166.22.205.32/27166.22.205.33 to 166.22.205.62166.22.205.6330
107166.22.205.64/27166.22.205.65 to 166.22.205.94166.22.205.9530
108166.22.205.96/27166.22.205.97 to 166.22.205.126166.22.205.12730
109166.22.205.128/27166.22.205.129 to 166.22.205.158166.22.205.15930
110166.22.205.160/27166.22.205.161 to 166.22.205.190166.22.205.19130
111166.22.205.192/27166.22.205.193 to 166.22.205.222166.22.205.22330
112166.22.205.224/27166.22.205.225 to 166.22.205.254166.22.205.25530
113166.22.206.0/27166.22.206.1 to 166.22.206.30166.22.206.3130
114166.22.206.32/27166.22.206.33 to 166.22.206.62166.22.206.6330
115166.22.206.64/27166.22.206.65 to 166.22.206.94166.22.206.9530
116166.22.206.96/27166.22.206.97 to 166.22.206.126166.22.206.12730
117166.22.206.128/27166.22.206.129 to 166.22.206.158166.22.206.15930
118166.22.206.160/27166.22.206.161 to 166.22.206.190166.22.206.19130
119166.22.206.192/27166.22.206.193 to 166.22.206.222166.22.206.22330
120166.22.206.224/27166.22.206.225 to 166.22.206.254166.22.206.25530
121166.22.207.0/27166.22.207.1 to 166.22.207.30166.22.207.3130
122166.22.207.32/27166.22.207.33 to 166.22.207.62166.22.207.6330
123166.22.207.64/27166.22.207.65 to 166.22.207.94166.22.207.9530
124166.22.207.96/27166.22.207.97 to 166.22.207.126166.22.207.12730
125166.22.207.128/27166.22.207.129 to 166.22.207.158166.22.207.15930
126166.22.207.160/27166.22.207.161 to 166.22.207.190166.22.207.19130
127166.22.207.192/27166.22.207.193 to 166.22.207.222166.22.207.22330
128166.22.207.224/27166.22.207.225 to 166.22.207.254166.22.207.25530
129166.22.208.0/27166.22.208.1 to 166.22.208.30166.22.208.3130
130166.22.208.32/27166.22.208.33 to 166.22.208.62166.22.208.6330
131166.22.208.64/27166.22.208.65 to 166.22.208.94166.22.208.9530
132166.22.208.96/27166.22.208.97 to 166.22.208.126166.22.208.12730
133166.22.208.128/27166.22.208.129 to 166.22.208.158166.22.208.15930
134166.22.208.160/27166.22.208.161 to 166.22.208.190166.22.208.19130
135166.22.208.192/27166.22.208.193 to 166.22.208.222166.22.208.22330
136166.22.208.224/27166.22.208.225 to 166.22.208.254166.22.208.25530
137166.22.209.0/27166.22.209.1 to 166.22.209.30166.22.209.3130
138166.22.209.32/27166.22.209.33 to 166.22.209.62166.22.209.6330
139166.22.209.64/27166.22.209.65 to 166.22.209.94166.22.209.9530
140166.22.209.96/27166.22.209.97 to 166.22.209.126166.22.209.12730
141166.22.209.128/27166.22.209.129 to 166.22.209.158166.22.209.15930
142166.22.209.160/27166.22.209.161 to 166.22.209.190166.22.209.19130
143166.22.209.192/27166.22.209.193 to 166.22.209.222166.22.209.22330
144166.22.209.224/27166.22.209.225 to 166.22.209.254166.22.209.25530
145166.22.210.0/27166.22.210.1 to 166.22.210.30166.22.210.3130
146166.22.210.32/27166.22.210.33 to 166.22.210.62166.22.210.6330
147166.22.210.64/27166.22.210.65 to 166.22.210.94166.22.210.9530
148166.22.210.96/27166.22.210.97 to 166.22.210.126166.22.210.12730
149166.22.210.128/27166.22.210.129 to 166.22.210.158166.22.210.15930
150166.22.210.160/27166.22.210.161 to 166.22.210.190166.22.210.19130
151166.22.210.192/27166.22.210.193 to 166.22.210.222166.22.210.22330
152166.22.210.224/27166.22.210.225 to 166.22.210.254166.22.210.25530
153166.22.211.0/27166.22.211.1 to 166.22.211.30166.22.211.3130
154166.22.211.32/27166.22.211.33 to 166.22.211.62166.22.211.6330
155166.22.211.64/27166.22.211.65 to 166.22.211.94166.22.211.9530
156166.22.211.96/27166.22.211.97 to 166.22.211.126166.22.211.12730
157166.22.211.128/27166.22.211.129 to 166.22.211.158166.22.211.15930
158166.22.211.160/27166.22.211.161 to 166.22.211.190166.22.211.19130
159166.22.211.192/27166.22.211.193 to 166.22.211.222166.22.211.22330
160166.22.211.224/27166.22.211.225 to 166.22.211.254166.22.211.25530
161166.22.212.0/27166.22.212.1 to 166.22.212.30166.22.212.3130
162166.22.212.32/27166.22.212.33 to 166.22.212.62166.22.212.6330
163166.22.212.64/27166.22.212.65 to 166.22.212.94166.22.212.9530
164166.22.212.96/27166.22.212.97 to 166.22.212.126166.22.212.12730
165166.22.212.128/27166.22.212.129 to 166.22.212.158166.22.212.15930
166166.22.212.160/27166.22.212.161 to 166.22.212.190166.22.212.19130
167166.22.212.192/27166.22.212.193 to 166.22.212.222166.22.212.22330
168166.22.212.224/27166.22.212.225 to 166.22.212.254166.22.212.25530
169166.22.213.0/27166.22.213.1 to 166.22.213.30166.22.213.3130
170166.22.213.32/27166.22.213.33 to 166.22.213.62166.22.213.6330
171166.22.213.64/27166.22.213.65 to 166.22.213.94166.22.213.9530
172166.22.213.96/27166.22.213.97 to 166.22.213.126166.22.213.12730
173166.22.213.128/27166.22.213.129 to 166.22.213.158166.22.213.15930
174166.22.213.160/27166.22.213.161 to 166.22.213.190166.22.213.19130
175166.22.213.192/27166.22.213.193 to 166.22.213.222166.22.213.22330
176166.22.213.224/27166.22.213.225 to 166.22.213.254166.22.213.25530
177166.22.214.0/27166.22.214.1 to 166.22.214.30166.22.214.3130
178166.22.214.32/27166.22.214.33 to 166.22.214.62166.22.214.6330
179166.22.214.64/27166.22.214.65 to 166.22.214.94166.22.214.9530
180166.22.214.96/27166.22.214.97 to 166.22.214.126166.22.214.12730
181166.22.214.128/27166.22.214.129 to 166.22.214.158166.22.214.15930
182166.22.214.160/27166.22.214.161 to 166.22.214.190166.22.214.19130
183166.22.214.192/27166.22.214.193 to 166.22.214.222166.22.214.22330
184166.22.214.224/27166.22.214.225 to 166.22.214.254166.22.214.25530
185166.22.215.0/27166.22.215.1 to 166.22.215.30166.22.215.3130
186166.22.215.32/27166.22.215.33 to 166.22.215.62166.22.215.6330
187166.22.215.64/27166.22.215.65 to 166.22.215.94166.22.215.9530
188166.22.215.96/27166.22.215.97 to 166.22.215.126166.22.215.12730
189166.22.215.128/27166.22.215.129 to 166.22.215.158166.22.215.15930
190166.22.215.160/27166.22.215.161 to 166.22.215.190166.22.215.19130
191166.22.215.192/27166.22.215.193 to 166.22.215.222166.22.215.22330
192166.22.215.224/27166.22.215.225 to 166.22.215.254166.22.215.25530
193166.22.216.0/27166.22.216.1 to 166.22.216.30166.22.216.3130
194166.22.216.32/27166.22.216.33 to 166.22.216.62166.22.216.6330
195166.22.216.64/27166.22.216.65 to 166.22.216.94166.22.216.9530
196166.22.216.96/27166.22.216.97 to 166.22.216.126166.22.216.12730
197166.22.216.128/27166.22.216.129 to 166.22.216.158166.22.216.15930
198166.22.216.160/27166.22.216.161 to 166.22.216.190166.22.216.19130
199166.22.216.192/27166.22.216.193 to 166.22.216.222166.22.216.22330
200166.22.216.224/27166.22.216.225 to 166.22.216.254166.22.216.25530
201166.22.217.0/27166.22.217.1 to 166.22.217.30166.22.217.3130
202166.22.217.32/27166.22.217.33 to 166.22.217.62166.22.217.6330
203166.22.217.64/27166.22.217.65 to 166.22.217.94166.22.217.9530
204166.22.217.96/27166.22.217.97 to 166.22.217.126166.22.217.12730
205166.22.217.128/27166.22.217.129 to 166.22.217.158166.22.217.15930
206166.22.217.160/27166.22.217.161 to 166.22.217.190166.22.217.19130
207166.22.217.192/27166.22.217.193 to 166.22.217.222166.22.217.22330
208166.22.217.224/27166.22.217.225 to 166.22.217.254166.22.217.25530
209166.22.218.0/27166.22.218.1 to 166.22.218.30166.22.218.3130
210166.22.218.32/27166.22.218.33 to 166.22.218.62166.22.218.6330
211166.22.218.64/27166.22.218.65 to 166.22.218.94166.22.218.9530
212166.22.218.96/27166.22.218.97 to 166.22.218.126166.22.218.12730
213166.22.218.128/27166.22.218.129 to 166.22.218.158166.22.218.15930
214166.22.218.160/27166.22.218.161 to 166.22.218.190166.22.218.19130
215166.22.218.192/27166.22.218.193 to 166.22.218.222166.22.218.22330
216166.22.218.224/27166.22.218.225 to 166.22.218.254166.22.218.25530
217166.22.219.0/27166.22.219.1 to 166.22.219.30166.22.219.3130
218166.22.219.32/27166.22.219.33 to 166.22.219.62166.22.219.6330
219166.22.219.64/27166.22.219.65 to 166.22.219.94166.22.219.9530
220166.22.219.96/27166.22.219.97 to 166.22.219.126166.22.219.12730
221166.22.219.128/27166.22.219.129 to 166.22.219.158166.22.219.15930
222166.22.219.160/27166.22.219.161 to 166.22.219.190166.22.219.19130
223166.22.219.192/27166.22.219.193 to 166.22.219.222166.22.219.22330
224166.22.219.224/27166.22.219.225 to 166.22.219.254166.22.219.25530
225166.22.220.0/27166.22.220.1 to 166.22.220.30166.22.220.3130
226166.22.220.32/27166.22.220.33 to 166.22.220.62166.22.220.6330
227166.22.220.64/27166.22.220.65 to 166.22.220.94166.22.220.9530
228166.22.220.96/27166.22.220.97 to 166.22.220.126166.22.220.12730
229166.22.220.128/27166.22.220.129 to 166.22.220.158166.22.220.15930
230166.22.220.160/27166.22.220.161 to 166.22.220.190166.22.220.19130
231166.22.220.192/27166.22.220.193 to 166.22.220.222166.22.220.22330
232166.22.220.224/27166.22.220.225 to 166.22.220.254166.22.220.25530
233166.22.221.0/27166.22.221.1 to 166.22.221.30166.22.221.3130
234166.22.221.32/27166.22.221.33 to 166.22.221.62166.22.221.6330
235166.22.221.64/27166.22.221.65 to 166.22.221.94166.22.221.9530
236166.22.221.96/27166.22.221.97 to 166.22.221.126166.22.221.12730
237166.22.221.128/27166.22.221.129 to 166.22.221.158166.22.221.15930
238166.22.221.160/27166.22.221.161 to 166.22.221.190166.22.221.19130
239166.22.221.192/27166.22.221.193 to 166.22.221.222166.22.221.22330
240166.22.221.224/27166.22.221.225 to 166.22.221.254166.22.221.25530
241166.22.222.0/27166.22.222.1 to 166.22.222.30166.22.222.3130
242166.22.222.32/27166.22.222.33 to 166.22.222.62166.22.222.6330
243166.22.222.64/27166.22.222.65 to 166.22.222.94166.22.222.9530
244166.22.222.96/27166.22.222.97 to 166.22.222.126166.22.222.12730
245166.22.222.128/27166.22.222.129 to 166.22.222.158166.22.222.15930
246166.22.222.160/27166.22.222.161 to 166.22.222.190166.22.222.19130
247166.22.222.192/27166.22.222.193 to 166.22.222.222166.22.222.22330
248166.22.222.224/27166.22.222.225 to 166.22.222.254166.22.222.25530
249166.22.223.0/27166.22.223.1 to 166.22.223.30166.22.223.3130
250166.22.223.32/27166.22.223.33 to 166.22.223.62166.22.223.6330
251166.22.223.64/27166.22.223.65 to 166.22.223.94166.22.223.9530
252166.22.223.96/27166.22.223.97 to 166.22.223.126166.22.223.12730
253166.22.223.128/27166.22.223.129 to 166.22.223.158166.22.223.15930
254166.22.223.160/27166.22.223.161 to 166.22.223.190166.22.223.19130
255166.22.223.192/27166.22.223.193 to 166.22.223.222166.22.223.22330
256166.22.223.224/27166.22.223.225 to 166.22.223.254166.22.223.25530

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.