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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.

Network225.160.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
225.160.0.0
Broadcast address
225.191.255.255
First usable
225.160.0.1
Last usable
225.191.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E1A00000 · Integer 3785359360 to 3787456511
Reverse DNS zones
160.225.in-addr.arpa
161.225.in-addr.arpa
162.225.in-addr.arpa
163.225.in-addr.arpa
164.225.in-addr.arpa
165.225.in-addr.arpa
166.225.in-addr.arpa
167.225.in-addr.arpa
168.225.in-addr.arpa
169.225.in-addr.arpa
170.225.in-addr.arpa
171.225.in-addr.arpa
172.225.in-addr.arpa
173.225.in-addr.arpa
174.225.in-addr.arpa
175.225.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100001.10100000.00000000.00000000225.160.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network11100001.10100000.00000000.00000000225.160.0.0
Broadcast11100001.10111111.11111111.11111111225.191.255.255
Split into smaller subnets/21
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

225.160.0.0/11 makes 1,024 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1225.160.0.0/21225.160.0.1 to 225.160.7.254225.160.7.2552,046
2225.160.8.0/21225.160.8.1 to 225.160.15.254225.160.15.2552,046
3225.160.16.0/21225.160.16.1 to 225.160.23.254225.160.23.2552,046
4225.160.24.0/21225.160.24.1 to 225.160.31.254225.160.31.2552,046
5225.160.32.0/21225.160.32.1 to 225.160.39.254225.160.39.2552,046
6225.160.40.0/21225.160.40.1 to 225.160.47.254225.160.47.2552,046
7225.160.48.0/21225.160.48.1 to 225.160.55.254225.160.55.2552,046
8225.160.56.0/21225.160.56.1 to 225.160.63.254225.160.63.2552,046
9225.160.64.0/21225.160.64.1 to 225.160.71.254225.160.71.2552,046
10225.160.72.0/21225.160.72.1 to 225.160.79.254225.160.79.2552,046
11225.160.80.0/21225.160.80.1 to 225.160.87.254225.160.87.2552,046
12225.160.88.0/21225.160.88.1 to 225.160.95.254225.160.95.2552,046
13225.160.96.0/21225.160.96.1 to 225.160.103.254225.160.103.2552,046
14225.160.104.0/21225.160.104.1 to 225.160.111.254225.160.111.2552,046
15225.160.112.0/21225.160.112.1 to 225.160.119.254225.160.119.2552,046
16225.160.120.0/21225.160.120.1 to 225.160.127.254225.160.127.2552,046
17225.160.128.0/21225.160.128.1 to 225.160.135.254225.160.135.2552,046
18225.160.136.0/21225.160.136.1 to 225.160.143.254225.160.143.2552,046
19225.160.144.0/21225.160.144.1 to 225.160.151.254225.160.151.2552,046
20225.160.152.0/21225.160.152.1 to 225.160.159.254225.160.159.2552,046
21225.160.160.0/21225.160.160.1 to 225.160.167.254225.160.167.2552,046
22225.160.168.0/21225.160.168.1 to 225.160.175.254225.160.175.2552,046
23225.160.176.0/21225.160.176.1 to 225.160.183.254225.160.183.2552,046
24225.160.184.0/21225.160.184.1 to 225.160.191.254225.160.191.2552,046
25225.160.192.0/21225.160.192.1 to 225.160.199.254225.160.199.2552,046
26225.160.200.0/21225.160.200.1 to 225.160.207.254225.160.207.2552,046
27225.160.208.0/21225.160.208.1 to 225.160.215.254225.160.215.2552,046
28225.160.216.0/21225.160.216.1 to 225.160.223.254225.160.223.2552,046
29225.160.224.0/21225.160.224.1 to 225.160.231.254225.160.231.2552,046
30225.160.232.0/21225.160.232.1 to 225.160.239.254225.160.239.2552,046
31225.160.240.0/21225.160.240.1 to 225.160.247.254225.160.247.2552,046
32225.160.248.0/21225.160.248.1 to 225.160.255.254225.160.255.2552,046
33225.161.0.0/21225.161.0.1 to 225.161.7.254225.161.7.2552,046
34225.161.8.0/21225.161.8.1 to 225.161.15.254225.161.15.2552,046
35225.161.16.0/21225.161.16.1 to 225.161.23.254225.161.23.2552,046
36225.161.24.0/21225.161.24.1 to 225.161.31.254225.161.31.2552,046
37225.161.32.0/21225.161.32.1 to 225.161.39.254225.161.39.2552,046
38225.161.40.0/21225.161.40.1 to 225.161.47.254225.161.47.2552,046
39225.161.48.0/21225.161.48.1 to 225.161.55.254225.161.55.2552,046
40225.161.56.0/21225.161.56.1 to 225.161.63.254225.161.63.2552,046
41225.161.64.0/21225.161.64.1 to 225.161.71.254225.161.71.2552,046
42225.161.72.0/21225.161.72.1 to 225.161.79.254225.161.79.2552,046
43225.161.80.0/21225.161.80.1 to 225.161.87.254225.161.87.2552,046
44225.161.88.0/21225.161.88.1 to 225.161.95.254225.161.95.2552,046
45225.161.96.0/21225.161.96.1 to 225.161.103.254225.161.103.2552,046
46225.161.104.0/21225.161.104.1 to 225.161.111.254225.161.111.2552,046
47225.161.112.0/21225.161.112.1 to 225.161.119.254225.161.119.2552,046
48225.161.120.0/21225.161.120.1 to 225.161.127.254225.161.127.2552,046
49225.161.128.0/21225.161.128.1 to 225.161.135.254225.161.135.2552,046
50225.161.136.0/21225.161.136.1 to 225.161.143.254225.161.143.2552,046
51225.161.144.0/21225.161.144.1 to 225.161.151.254225.161.151.2552,046
52225.161.152.0/21225.161.152.1 to 225.161.159.254225.161.159.2552,046
53225.161.160.0/21225.161.160.1 to 225.161.167.254225.161.167.2552,046
54225.161.168.0/21225.161.168.1 to 225.161.175.254225.161.175.2552,046
55225.161.176.0/21225.161.176.1 to 225.161.183.254225.161.183.2552,046
56225.161.184.0/21225.161.184.1 to 225.161.191.254225.161.191.2552,046
57225.161.192.0/21225.161.192.1 to 225.161.199.254225.161.199.2552,046
58225.161.200.0/21225.161.200.1 to 225.161.207.254225.161.207.2552,046
59225.161.208.0/21225.161.208.1 to 225.161.215.254225.161.215.2552,046
60225.161.216.0/21225.161.216.1 to 225.161.223.254225.161.223.2552,046
61225.161.224.0/21225.161.224.1 to 225.161.231.254225.161.231.2552,046
62225.161.232.0/21225.161.232.1 to 225.161.239.254225.161.239.2552,046
63225.161.240.0/21225.161.240.1 to 225.161.247.254225.161.247.2552,046
64225.161.248.0/21225.161.248.1 to 225.161.255.254225.161.255.2552,046
65225.162.0.0/21225.162.0.1 to 225.162.7.254225.162.7.2552,046
66225.162.8.0/21225.162.8.1 to 225.162.15.254225.162.15.2552,046
67225.162.16.0/21225.162.16.1 to 225.162.23.254225.162.23.2552,046
68225.162.24.0/21225.162.24.1 to 225.162.31.254225.162.31.2552,046
69225.162.32.0/21225.162.32.1 to 225.162.39.254225.162.39.2552,046
70225.162.40.0/21225.162.40.1 to 225.162.47.254225.162.47.2552,046
71225.162.48.0/21225.162.48.1 to 225.162.55.254225.162.55.2552,046
72225.162.56.0/21225.162.56.1 to 225.162.63.254225.162.63.2552,046
73225.162.64.0/21225.162.64.1 to 225.162.71.254225.162.71.2552,046
74225.162.72.0/21225.162.72.1 to 225.162.79.254225.162.79.2552,046
75225.162.80.0/21225.162.80.1 to 225.162.87.254225.162.87.2552,046
76225.162.88.0/21225.162.88.1 to 225.162.95.254225.162.95.2552,046
77225.162.96.0/21225.162.96.1 to 225.162.103.254225.162.103.2552,046
78225.162.104.0/21225.162.104.1 to 225.162.111.254225.162.111.2552,046
79225.162.112.0/21225.162.112.1 to 225.162.119.254225.162.119.2552,046
80225.162.120.0/21225.162.120.1 to 225.162.127.254225.162.127.2552,046
81225.162.128.0/21225.162.128.1 to 225.162.135.254225.162.135.2552,046
82225.162.136.0/21225.162.136.1 to 225.162.143.254225.162.143.2552,046
83225.162.144.0/21225.162.144.1 to 225.162.151.254225.162.151.2552,046
84225.162.152.0/21225.162.152.1 to 225.162.159.254225.162.159.2552,046
85225.162.160.0/21225.162.160.1 to 225.162.167.254225.162.167.2552,046
86225.162.168.0/21225.162.168.1 to 225.162.175.254225.162.175.2552,046
87225.162.176.0/21225.162.176.1 to 225.162.183.254225.162.183.2552,046
88225.162.184.0/21225.162.184.1 to 225.162.191.254225.162.191.2552,046
89225.162.192.0/21225.162.192.1 to 225.162.199.254225.162.199.2552,046
90225.162.200.0/21225.162.200.1 to 225.162.207.254225.162.207.2552,046
91225.162.208.0/21225.162.208.1 to 225.162.215.254225.162.215.2552,046
92225.162.216.0/21225.162.216.1 to 225.162.223.254225.162.223.2552,046
93225.162.224.0/21225.162.224.1 to 225.162.231.254225.162.231.2552,046
94225.162.232.0/21225.162.232.1 to 225.162.239.254225.162.239.2552,046
95225.162.240.0/21225.162.240.1 to 225.162.247.254225.162.247.2552,046
96225.162.248.0/21225.162.248.1 to 225.162.255.254225.162.255.2552,046
97225.163.0.0/21225.163.0.1 to 225.163.7.254225.163.7.2552,046
98225.163.8.0/21225.163.8.1 to 225.163.15.254225.163.15.2552,046
99225.163.16.0/21225.163.16.1 to 225.163.23.254225.163.23.2552,046
100225.163.24.0/21225.163.24.1 to 225.163.31.254225.163.31.2552,046
101225.163.32.0/21225.163.32.1 to 225.163.39.254225.163.39.2552,046
102225.163.40.0/21225.163.40.1 to 225.163.47.254225.163.47.2552,046
103225.163.48.0/21225.163.48.1 to 225.163.55.254225.163.55.2552,046
104225.163.56.0/21225.163.56.1 to 225.163.63.254225.163.63.2552,046
105225.163.64.0/21225.163.64.1 to 225.163.71.254225.163.71.2552,046
106225.163.72.0/21225.163.72.1 to 225.163.79.254225.163.79.2552,046
107225.163.80.0/21225.163.80.1 to 225.163.87.254225.163.87.2552,046
108225.163.88.0/21225.163.88.1 to 225.163.95.254225.163.95.2552,046
109225.163.96.0/21225.163.96.1 to 225.163.103.254225.163.103.2552,046
110225.163.104.0/21225.163.104.1 to 225.163.111.254225.163.111.2552,046
111225.163.112.0/21225.163.112.1 to 225.163.119.254225.163.119.2552,046
112225.163.120.0/21225.163.120.1 to 225.163.127.254225.163.127.2552,046
113225.163.128.0/21225.163.128.1 to 225.163.135.254225.163.135.2552,046
114225.163.136.0/21225.163.136.1 to 225.163.143.254225.163.143.2552,046
115225.163.144.0/21225.163.144.1 to 225.163.151.254225.163.151.2552,046
116225.163.152.0/21225.163.152.1 to 225.163.159.254225.163.159.2552,046
117225.163.160.0/21225.163.160.1 to 225.163.167.254225.163.167.2552,046
118225.163.168.0/21225.163.168.1 to 225.163.175.254225.163.175.2552,046
119225.163.176.0/21225.163.176.1 to 225.163.183.254225.163.183.2552,046
120225.163.184.0/21225.163.184.1 to 225.163.191.254225.163.191.2552,046
121225.163.192.0/21225.163.192.1 to 225.163.199.254225.163.199.2552,046
122225.163.200.0/21225.163.200.1 to 225.163.207.254225.163.207.2552,046
123225.163.208.0/21225.163.208.1 to 225.163.215.254225.163.215.2552,046
124225.163.216.0/21225.163.216.1 to 225.163.223.254225.163.223.2552,046
125225.163.224.0/21225.163.224.1 to 225.163.231.254225.163.231.2552,046
126225.163.232.0/21225.163.232.1 to 225.163.239.254225.163.239.2552,046
127225.163.240.0/21225.163.240.1 to 225.163.247.254225.163.247.2552,046
128225.163.248.0/21225.163.248.1 to 225.163.255.254225.163.255.2552,046
129225.164.0.0/21225.164.0.1 to 225.164.7.254225.164.7.2552,046
130225.164.8.0/21225.164.8.1 to 225.164.15.254225.164.15.2552,046
131225.164.16.0/21225.164.16.1 to 225.164.23.254225.164.23.2552,046
132225.164.24.0/21225.164.24.1 to 225.164.31.254225.164.31.2552,046
133225.164.32.0/21225.164.32.1 to 225.164.39.254225.164.39.2552,046
134225.164.40.0/21225.164.40.1 to 225.164.47.254225.164.47.2552,046
135225.164.48.0/21225.164.48.1 to 225.164.55.254225.164.55.2552,046
136225.164.56.0/21225.164.56.1 to 225.164.63.254225.164.63.2552,046
137225.164.64.0/21225.164.64.1 to 225.164.71.254225.164.71.2552,046
138225.164.72.0/21225.164.72.1 to 225.164.79.254225.164.79.2552,046
139225.164.80.0/21225.164.80.1 to 225.164.87.254225.164.87.2552,046
140225.164.88.0/21225.164.88.1 to 225.164.95.254225.164.95.2552,046
141225.164.96.0/21225.164.96.1 to 225.164.103.254225.164.103.2552,046
142225.164.104.0/21225.164.104.1 to 225.164.111.254225.164.111.2552,046
143225.164.112.0/21225.164.112.1 to 225.164.119.254225.164.119.2552,046
144225.164.120.0/21225.164.120.1 to 225.164.127.254225.164.127.2552,046
145225.164.128.0/21225.164.128.1 to 225.164.135.254225.164.135.2552,046
146225.164.136.0/21225.164.136.1 to 225.164.143.254225.164.143.2552,046
147225.164.144.0/21225.164.144.1 to 225.164.151.254225.164.151.2552,046
148225.164.152.0/21225.164.152.1 to 225.164.159.254225.164.159.2552,046
149225.164.160.0/21225.164.160.1 to 225.164.167.254225.164.167.2552,046
150225.164.168.0/21225.164.168.1 to 225.164.175.254225.164.175.2552,046
151225.164.176.0/21225.164.176.1 to 225.164.183.254225.164.183.2552,046
152225.164.184.0/21225.164.184.1 to 225.164.191.254225.164.191.2552,046
153225.164.192.0/21225.164.192.1 to 225.164.199.254225.164.199.2552,046
154225.164.200.0/21225.164.200.1 to 225.164.207.254225.164.207.2552,046
155225.164.208.0/21225.164.208.1 to 225.164.215.254225.164.215.2552,046
156225.164.216.0/21225.164.216.1 to 225.164.223.254225.164.223.2552,046
157225.164.224.0/21225.164.224.1 to 225.164.231.254225.164.231.2552,046
158225.164.232.0/21225.164.232.1 to 225.164.239.254225.164.239.2552,046
159225.164.240.0/21225.164.240.1 to 225.164.247.254225.164.247.2552,046
160225.164.248.0/21225.164.248.1 to 225.164.255.254225.164.255.2552,046
161225.165.0.0/21225.165.0.1 to 225.165.7.254225.165.7.2552,046
162225.165.8.0/21225.165.8.1 to 225.165.15.254225.165.15.2552,046
163225.165.16.0/21225.165.16.1 to 225.165.23.254225.165.23.2552,046
164225.165.24.0/21225.165.24.1 to 225.165.31.254225.165.31.2552,046
165225.165.32.0/21225.165.32.1 to 225.165.39.254225.165.39.2552,046
166225.165.40.0/21225.165.40.1 to 225.165.47.254225.165.47.2552,046
167225.165.48.0/21225.165.48.1 to 225.165.55.254225.165.55.2552,046
168225.165.56.0/21225.165.56.1 to 225.165.63.254225.165.63.2552,046
169225.165.64.0/21225.165.64.1 to 225.165.71.254225.165.71.2552,046
170225.165.72.0/21225.165.72.1 to 225.165.79.254225.165.79.2552,046
171225.165.80.0/21225.165.80.1 to 225.165.87.254225.165.87.2552,046
172225.165.88.0/21225.165.88.1 to 225.165.95.254225.165.95.2552,046
173225.165.96.0/21225.165.96.1 to 225.165.103.254225.165.103.2552,046
174225.165.104.0/21225.165.104.1 to 225.165.111.254225.165.111.2552,046
175225.165.112.0/21225.165.112.1 to 225.165.119.254225.165.119.2552,046
176225.165.120.0/21225.165.120.1 to 225.165.127.254225.165.127.2552,046
177225.165.128.0/21225.165.128.1 to 225.165.135.254225.165.135.2552,046
178225.165.136.0/21225.165.136.1 to 225.165.143.254225.165.143.2552,046
179225.165.144.0/21225.165.144.1 to 225.165.151.254225.165.151.2552,046
180225.165.152.0/21225.165.152.1 to 225.165.159.254225.165.159.2552,046
181225.165.160.0/21225.165.160.1 to 225.165.167.254225.165.167.2552,046
182225.165.168.0/21225.165.168.1 to 225.165.175.254225.165.175.2552,046
183225.165.176.0/21225.165.176.1 to 225.165.183.254225.165.183.2552,046
184225.165.184.0/21225.165.184.1 to 225.165.191.254225.165.191.2552,046
185225.165.192.0/21225.165.192.1 to 225.165.199.254225.165.199.2552,046
186225.165.200.0/21225.165.200.1 to 225.165.207.254225.165.207.2552,046
187225.165.208.0/21225.165.208.1 to 225.165.215.254225.165.215.2552,046
188225.165.216.0/21225.165.216.1 to 225.165.223.254225.165.223.2552,046
189225.165.224.0/21225.165.224.1 to 225.165.231.254225.165.231.2552,046
190225.165.232.0/21225.165.232.1 to 225.165.239.254225.165.239.2552,046
191225.165.240.0/21225.165.240.1 to 225.165.247.254225.165.247.2552,046
192225.165.248.0/21225.165.248.1 to 225.165.255.254225.165.255.2552,046
193225.166.0.0/21225.166.0.1 to 225.166.7.254225.166.7.2552,046
194225.166.8.0/21225.166.8.1 to 225.166.15.254225.166.15.2552,046
195225.166.16.0/21225.166.16.1 to 225.166.23.254225.166.23.2552,046
196225.166.24.0/21225.166.24.1 to 225.166.31.254225.166.31.2552,046
197225.166.32.0/21225.166.32.1 to 225.166.39.254225.166.39.2552,046
198225.166.40.0/21225.166.40.1 to 225.166.47.254225.166.47.2552,046
199225.166.48.0/21225.166.48.1 to 225.166.55.254225.166.55.2552,046
200225.166.56.0/21225.166.56.1 to 225.166.63.254225.166.63.2552,046
201225.166.64.0/21225.166.64.1 to 225.166.71.254225.166.71.2552,046
202225.166.72.0/21225.166.72.1 to 225.166.79.254225.166.79.2552,046
203225.166.80.0/21225.166.80.1 to 225.166.87.254225.166.87.2552,046
204225.166.88.0/21225.166.88.1 to 225.166.95.254225.166.95.2552,046
205225.166.96.0/21225.166.96.1 to 225.166.103.254225.166.103.2552,046
206225.166.104.0/21225.166.104.1 to 225.166.111.254225.166.111.2552,046
207225.166.112.0/21225.166.112.1 to 225.166.119.254225.166.119.2552,046
208225.166.120.0/21225.166.120.1 to 225.166.127.254225.166.127.2552,046
209225.166.128.0/21225.166.128.1 to 225.166.135.254225.166.135.2552,046
210225.166.136.0/21225.166.136.1 to 225.166.143.254225.166.143.2552,046
211225.166.144.0/21225.166.144.1 to 225.166.151.254225.166.151.2552,046
212225.166.152.0/21225.166.152.1 to 225.166.159.254225.166.159.2552,046
213225.166.160.0/21225.166.160.1 to 225.166.167.254225.166.167.2552,046
214225.166.168.0/21225.166.168.1 to 225.166.175.254225.166.175.2552,046
215225.166.176.0/21225.166.176.1 to 225.166.183.254225.166.183.2552,046
216225.166.184.0/21225.166.184.1 to 225.166.191.254225.166.191.2552,046
217225.166.192.0/21225.166.192.1 to 225.166.199.254225.166.199.2552,046
218225.166.200.0/21225.166.200.1 to 225.166.207.254225.166.207.2552,046
219225.166.208.0/21225.166.208.1 to 225.166.215.254225.166.215.2552,046
220225.166.216.0/21225.166.216.1 to 225.166.223.254225.166.223.2552,046
221225.166.224.0/21225.166.224.1 to 225.166.231.254225.166.231.2552,046
222225.166.232.0/21225.166.232.1 to 225.166.239.254225.166.239.2552,046
223225.166.240.0/21225.166.240.1 to 225.166.247.254225.166.247.2552,046
224225.166.248.0/21225.166.248.1 to 225.166.255.254225.166.255.2552,046
225225.167.0.0/21225.167.0.1 to 225.167.7.254225.167.7.2552,046
226225.167.8.0/21225.167.8.1 to 225.167.15.254225.167.15.2552,046
227225.167.16.0/21225.167.16.1 to 225.167.23.254225.167.23.2552,046
228225.167.24.0/21225.167.24.1 to 225.167.31.254225.167.31.2552,046
229225.167.32.0/21225.167.32.1 to 225.167.39.254225.167.39.2552,046
230225.167.40.0/21225.167.40.1 to 225.167.47.254225.167.47.2552,046
231225.167.48.0/21225.167.48.1 to 225.167.55.254225.167.55.2552,046
232225.167.56.0/21225.167.56.1 to 225.167.63.254225.167.63.2552,046
233225.167.64.0/21225.167.64.1 to 225.167.71.254225.167.71.2552,046
234225.167.72.0/21225.167.72.1 to 225.167.79.254225.167.79.2552,046
235225.167.80.0/21225.167.80.1 to 225.167.87.254225.167.87.2552,046
236225.167.88.0/21225.167.88.1 to 225.167.95.254225.167.95.2552,046
237225.167.96.0/21225.167.96.1 to 225.167.103.254225.167.103.2552,046
238225.167.104.0/21225.167.104.1 to 225.167.111.254225.167.111.2552,046
239225.167.112.0/21225.167.112.1 to 225.167.119.254225.167.119.2552,046
240225.167.120.0/21225.167.120.1 to 225.167.127.254225.167.127.2552,046
241225.167.128.0/21225.167.128.1 to 225.167.135.254225.167.135.2552,046
242225.167.136.0/21225.167.136.1 to 225.167.143.254225.167.143.2552,046
243225.167.144.0/21225.167.144.1 to 225.167.151.254225.167.151.2552,046
244225.167.152.0/21225.167.152.1 to 225.167.159.254225.167.159.2552,046
245225.167.160.0/21225.167.160.1 to 225.167.167.254225.167.167.2552,046
246225.167.168.0/21225.167.168.1 to 225.167.175.254225.167.175.2552,046
247225.167.176.0/21225.167.176.1 to 225.167.183.254225.167.183.2552,046
248225.167.184.0/21225.167.184.1 to 225.167.191.254225.167.191.2552,046
249225.167.192.0/21225.167.192.1 to 225.167.199.254225.167.199.2552,046
250225.167.200.0/21225.167.200.1 to 225.167.207.254225.167.207.2552,046
251225.167.208.0/21225.167.208.1 to 225.167.215.254225.167.215.2552,046
252225.167.216.0/21225.167.216.1 to 225.167.223.254225.167.223.2552,046
253225.167.224.0/21225.167.224.1 to 225.167.231.254225.167.231.2552,046
254225.167.232.0/21225.167.232.1 to 225.167.239.254225.167.239.2552,046
255225.167.240.0/21225.167.240.1 to 225.167.247.254225.167.247.2552,046
256225.167.248.0/21225.167.248.1 to 225.167.255.254225.167.255.2552,046

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.