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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.

Network233.32.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
233.32.0.0
Broadcast address
233.47.255.255
First usable
233.32.0.1
Last usable
233.47.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E9200000 · Integer 3911188480 to 3912237055
Reverse DNS zones
32.233.in-addr.arpa
33.233.in-addr.arpa
34.233.in-addr.arpa
35.233.in-addr.arpa
36.233.in-addr.arpa
37.233.in-addr.arpa
38.233.in-addr.arpa
39.233.in-addr.arpa
40.233.in-addr.arpa
41.233.in-addr.arpa
42.233.in-addr.arpa
43.233.in-addr.arpa
44.233.in-addr.arpa
45.233.in-addr.arpa
46.233.in-addr.arpa
47.233.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11101001.00100000.00000000.00000000233.32.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11101001.00100000.00000000.00000000233.32.0.0
Broadcast11101001.00101111.11111111.11111111233.47.255.255
Split into smaller subnets/22
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

233.32.0.0/12 makes 1,024 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1233.32.0.0/22233.32.0.1 to 233.32.3.254233.32.3.2551,022
2233.32.4.0/22233.32.4.1 to 233.32.7.254233.32.7.2551,022
3233.32.8.0/22233.32.8.1 to 233.32.11.254233.32.11.2551,022
4233.32.12.0/22233.32.12.1 to 233.32.15.254233.32.15.2551,022
5233.32.16.0/22233.32.16.1 to 233.32.19.254233.32.19.2551,022
6233.32.20.0/22233.32.20.1 to 233.32.23.254233.32.23.2551,022
7233.32.24.0/22233.32.24.1 to 233.32.27.254233.32.27.2551,022
8233.32.28.0/22233.32.28.1 to 233.32.31.254233.32.31.2551,022
9233.32.32.0/22233.32.32.1 to 233.32.35.254233.32.35.2551,022
10233.32.36.0/22233.32.36.1 to 233.32.39.254233.32.39.2551,022
11233.32.40.0/22233.32.40.1 to 233.32.43.254233.32.43.2551,022
12233.32.44.0/22233.32.44.1 to 233.32.47.254233.32.47.2551,022
13233.32.48.0/22233.32.48.1 to 233.32.51.254233.32.51.2551,022
14233.32.52.0/22233.32.52.1 to 233.32.55.254233.32.55.2551,022
15233.32.56.0/22233.32.56.1 to 233.32.59.254233.32.59.2551,022
16233.32.60.0/22233.32.60.1 to 233.32.63.254233.32.63.2551,022
17233.32.64.0/22233.32.64.1 to 233.32.67.254233.32.67.2551,022
18233.32.68.0/22233.32.68.1 to 233.32.71.254233.32.71.2551,022
19233.32.72.0/22233.32.72.1 to 233.32.75.254233.32.75.2551,022
20233.32.76.0/22233.32.76.1 to 233.32.79.254233.32.79.2551,022
21233.32.80.0/22233.32.80.1 to 233.32.83.254233.32.83.2551,022
22233.32.84.0/22233.32.84.1 to 233.32.87.254233.32.87.2551,022
23233.32.88.0/22233.32.88.1 to 233.32.91.254233.32.91.2551,022
24233.32.92.0/22233.32.92.1 to 233.32.95.254233.32.95.2551,022
25233.32.96.0/22233.32.96.1 to 233.32.99.254233.32.99.2551,022
26233.32.100.0/22233.32.100.1 to 233.32.103.254233.32.103.2551,022
27233.32.104.0/22233.32.104.1 to 233.32.107.254233.32.107.2551,022
28233.32.108.0/22233.32.108.1 to 233.32.111.254233.32.111.2551,022
29233.32.112.0/22233.32.112.1 to 233.32.115.254233.32.115.2551,022
30233.32.116.0/22233.32.116.1 to 233.32.119.254233.32.119.2551,022
31233.32.120.0/22233.32.120.1 to 233.32.123.254233.32.123.2551,022
32233.32.124.0/22233.32.124.1 to 233.32.127.254233.32.127.2551,022
33233.32.128.0/22233.32.128.1 to 233.32.131.254233.32.131.2551,022
34233.32.132.0/22233.32.132.1 to 233.32.135.254233.32.135.2551,022
35233.32.136.0/22233.32.136.1 to 233.32.139.254233.32.139.2551,022
36233.32.140.0/22233.32.140.1 to 233.32.143.254233.32.143.2551,022
37233.32.144.0/22233.32.144.1 to 233.32.147.254233.32.147.2551,022
38233.32.148.0/22233.32.148.1 to 233.32.151.254233.32.151.2551,022
39233.32.152.0/22233.32.152.1 to 233.32.155.254233.32.155.2551,022
40233.32.156.0/22233.32.156.1 to 233.32.159.254233.32.159.2551,022
41233.32.160.0/22233.32.160.1 to 233.32.163.254233.32.163.2551,022
42233.32.164.0/22233.32.164.1 to 233.32.167.254233.32.167.2551,022
43233.32.168.0/22233.32.168.1 to 233.32.171.254233.32.171.2551,022
44233.32.172.0/22233.32.172.1 to 233.32.175.254233.32.175.2551,022
45233.32.176.0/22233.32.176.1 to 233.32.179.254233.32.179.2551,022
46233.32.180.0/22233.32.180.1 to 233.32.183.254233.32.183.2551,022
47233.32.184.0/22233.32.184.1 to 233.32.187.254233.32.187.2551,022
48233.32.188.0/22233.32.188.1 to 233.32.191.254233.32.191.2551,022
49233.32.192.0/22233.32.192.1 to 233.32.195.254233.32.195.2551,022
50233.32.196.0/22233.32.196.1 to 233.32.199.254233.32.199.2551,022
51233.32.200.0/22233.32.200.1 to 233.32.203.254233.32.203.2551,022
52233.32.204.0/22233.32.204.1 to 233.32.207.254233.32.207.2551,022
53233.32.208.0/22233.32.208.1 to 233.32.211.254233.32.211.2551,022
54233.32.212.0/22233.32.212.1 to 233.32.215.254233.32.215.2551,022
55233.32.216.0/22233.32.216.1 to 233.32.219.254233.32.219.2551,022
56233.32.220.0/22233.32.220.1 to 233.32.223.254233.32.223.2551,022
57233.32.224.0/22233.32.224.1 to 233.32.227.254233.32.227.2551,022
58233.32.228.0/22233.32.228.1 to 233.32.231.254233.32.231.2551,022
59233.32.232.0/22233.32.232.1 to 233.32.235.254233.32.235.2551,022
60233.32.236.0/22233.32.236.1 to 233.32.239.254233.32.239.2551,022
61233.32.240.0/22233.32.240.1 to 233.32.243.254233.32.243.2551,022
62233.32.244.0/22233.32.244.1 to 233.32.247.254233.32.247.2551,022
63233.32.248.0/22233.32.248.1 to 233.32.251.254233.32.251.2551,022
64233.32.252.0/22233.32.252.1 to 233.32.255.254233.32.255.2551,022
65233.33.0.0/22233.33.0.1 to 233.33.3.254233.33.3.2551,022
66233.33.4.0/22233.33.4.1 to 233.33.7.254233.33.7.2551,022
67233.33.8.0/22233.33.8.1 to 233.33.11.254233.33.11.2551,022
68233.33.12.0/22233.33.12.1 to 233.33.15.254233.33.15.2551,022
69233.33.16.0/22233.33.16.1 to 233.33.19.254233.33.19.2551,022
70233.33.20.0/22233.33.20.1 to 233.33.23.254233.33.23.2551,022
71233.33.24.0/22233.33.24.1 to 233.33.27.254233.33.27.2551,022
72233.33.28.0/22233.33.28.1 to 233.33.31.254233.33.31.2551,022
73233.33.32.0/22233.33.32.1 to 233.33.35.254233.33.35.2551,022
74233.33.36.0/22233.33.36.1 to 233.33.39.254233.33.39.2551,022
75233.33.40.0/22233.33.40.1 to 233.33.43.254233.33.43.2551,022
76233.33.44.0/22233.33.44.1 to 233.33.47.254233.33.47.2551,022
77233.33.48.0/22233.33.48.1 to 233.33.51.254233.33.51.2551,022
78233.33.52.0/22233.33.52.1 to 233.33.55.254233.33.55.2551,022
79233.33.56.0/22233.33.56.1 to 233.33.59.254233.33.59.2551,022
80233.33.60.0/22233.33.60.1 to 233.33.63.254233.33.63.2551,022
81233.33.64.0/22233.33.64.1 to 233.33.67.254233.33.67.2551,022
82233.33.68.0/22233.33.68.1 to 233.33.71.254233.33.71.2551,022
83233.33.72.0/22233.33.72.1 to 233.33.75.254233.33.75.2551,022
84233.33.76.0/22233.33.76.1 to 233.33.79.254233.33.79.2551,022
85233.33.80.0/22233.33.80.1 to 233.33.83.254233.33.83.2551,022
86233.33.84.0/22233.33.84.1 to 233.33.87.254233.33.87.2551,022
87233.33.88.0/22233.33.88.1 to 233.33.91.254233.33.91.2551,022
88233.33.92.0/22233.33.92.1 to 233.33.95.254233.33.95.2551,022
89233.33.96.0/22233.33.96.1 to 233.33.99.254233.33.99.2551,022
90233.33.100.0/22233.33.100.1 to 233.33.103.254233.33.103.2551,022
91233.33.104.0/22233.33.104.1 to 233.33.107.254233.33.107.2551,022
92233.33.108.0/22233.33.108.1 to 233.33.111.254233.33.111.2551,022
93233.33.112.0/22233.33.112.1 to 233.33.115.254233.33.115.2551,022
94233.33.116.0/22233.33.116.1 to 233.33.119.254233.33.119.2551,022
95233.33.120.0/22233.33.120.1 to 233.33.123.254233.33.123.2551,022
96233.33.124.0/22233.33.124.1 to 233.33.127.254233.33.127.2551,022
97233.33.128.0/22233.33.128.1 to 233.33.131.254233.33.131.2551,022
98233.33.132.0/22233.33.132.1 to 233.33.135.254233.33.135.2551,022
99233.33.136.0/22233.33.136.1 to 233.33.139.254233.33.139.2551,022
100233.33.140.0/22233.33.140.1 to 233.33.143.254233.33.143.2551,022
101233.33.144.0/22233.33.144.1 to 233.33.147.254233.33.147.2551,022
102233.33.148.0/22233.33.148.1 to 233.33.151.254233.33.151.2551,022
103233.33.152.0/22233.33.152.1 to 233.33.155.254233.33.155.2551,022
104233.33.156.0/22233.33.156.1 to 233.33.159.254233.33.159.2551,022
105233.33.160.0/22233.33.160.1 to 233.33.163.254233.33.163.2551,022
106233.33.164.0/22233.33.164.1 to 233.33.167.254233.33.167.2551,022
107233.33.168.0/22233.33.168.1 to 233.33.171.254233.33.171.2551,022
108233.33.172.0/22233.33.172.1 to 233.33.175.254233.33.175.2551,022
109233.33.176.0/22233.33.176.1 to 233.33.179.254233.33.179.2551,022
110233.33.180.0/22233.33.180.1 to 233.33.183.254233.33.183.2551,022
111233.33.184.0/22233.33.184.1 to 233.33.187.254233.33.187.2551,022
112233.33.188.0/22233.33.188.1 to 233.33.191.254233.33.191.2551,022
113233.33.192.0/22233.33.192.1 to 233.33.195.254233.33.195.2551,022
114233.33.196.0/22233.33.196.1 to 233.33.199.254233.33.199.2551,022
115233.33.200.0/22233.33.200.1 to 233.33.203.254233.33.203.2551,022
116233.33.204.0/22233.33.204.1 to 233.33.207.254233.33.207.2551,022
117233.33.208.0/22233.33.208.1 to 233.33.211.254233.33.211.2551,022
118233.33.212.0/22233.33.212.1 to 233.33.215.254233.33.215.2551,022
119233.33.216.0/22233.33.216.1 to 233.33.219.254233.33.219.2551,022
120233.33.220.0/22233.33.220.1 to 233.33.223.254233.33.223.2551,022
121233.33.224.0/22233.33.224.1 to 233.33.227.254233.33.227.2551,022
122233.33.228.0/22233.33.228.1 to 233.33.231.254233.33.231.2551,022
123233.33.232.0/22233.33.232.1 to 233.33.235.254233.33.235.2551,022
124233.33.236.0/22233.33.236.1 to 233.33.239.254233.33.239.2551,022
125233.33.240.0/22233.33.240.1 to 233.33.243.254233.33.243.2551,022
126233.33.244.0/22233.33.244.1 to 233.33.247.254233.33.247.2551,022
127233.33.248.0/22233.33.248.1 to 233.33.251.254233.33.251.2551,022
128233.33.252.0/22233.33.252.1 to 233.33.255.254233.33.255.2551,022
129233.34.0.0/22233.34.0.1 to 233.34.3.254233.34.3.2551,022
130233.34.4.0/22233.34.4.1 to 233.34.7.254233.34.7.2551,022
131233.34.8.0/22233.34.8.1 to 233.34.11.254233.34.11.2551,022
132233.34.12.0/22233.34.12.1 to 233.34.15.254233.34.15.2551,022
133233.34.16.0/22233.34.16.1 to 233.34.19.254233.34.19.2551,022
134233.34.20.0/22233.34.20.1 to 233.34.23.254233.34.23.2551,022
135233.34.24.0/22233.34.24.1 to 233.34.27.254233.34.27.2551,022
136233.34.28.0/22233.34.28.1 to 233.34.31.254233.34.31.2551,022
137233.34.32.0/22233.34.32.1 to 233.34.35.254233.34.35.2551,022
138233.34.36.0/22233.34.36.1 to 233.34.39.254233.34.39.2551,022
139233.34.40.0/22233.34.40.1 to 233.34.43.254233.34.43.2551,022
140233.34.44.0/22233.34.44.1 to 233.34.47.254233.34.47.2551,022
141233.34.48.0/22233.34.48.1 to 233.34.51.254233.34.51.2551,022
142233.34.52.0/22233.34.52.1 to 233.34.55.254233.34.55.2551,022
143233.34.56.0/22233.34.56.1 to 233.34.59.254233.34.59.2551,022
144233.34.60.0/22233.34.60.1 to 233.34.63.254233.34.63.2551,022
145233.34.64.0/22233.34.64.1 to 233.34.67.254233.34.67.2551,022
146233.34.68.0/22233.34.68.1 to 233.34.71.254233.34.71.2551,022
147233.34.72.0/22233.34.72.1 to 233.34.75.254233.34.75.2551,022
148233.34.76.0/22233.34.76.1 to 233.34.79.254233.34.79.2551,022
149233.34.80.0/22233.34.80.1 to 233.34.83.254233.34.83.2551,022
150233.34.84.0/22233.34.84.1 to 233.34.87.254233.34.87.2551,022
151233.34.88.0/22233.34.88.1 to 233.34.91.254233.34.91.2551,022
152233.34.92.0/22233.34.92.1 to 233.34.95.254233.34.95.2551,022
153233.34.96.0/22233.34.96.1 to 233.34.99.254233.34.99.2551,022
154233.34.100.0/22233.34.100.1 to 233.34.103.254233.34.103.2551,022
155233.34.104.0/22233.34.104.1 to 233.34.107.254233.34.107.2551,022
156233.34.108.0/22233.34.108.1 to 233.34.111.254233.34.111.2551,022
157233.34.112.0/22233.34.112.1 to 233.34.115.254233.34.115.2551,022
158233.34.116.0/22233.34.116.1 to 233.34.119.254233.34.119.2551,022
159233.34.120.0/22233.34.120.1 to 233.34.123.254233.34.123.2551,022
160233.34.124.0/22233.34.124.1 to 233.34.127.254233.34.127.2551,022
161233.34.128.0/22233.34.128.1 to 233.34.131.254233.34.131.2551,022
162233.34.132.0/22233.34.132.1 to 233.34.135.254233.34.135.2551,022
163233.34.136.0/22233.34.136.1 to 233.34.139.254233.34.139.2551,022
164233.34.140.0/22233.34.140.1 to 233.34.143.254233.34.143.2551,022
165233.34.144.0/22233.34.144.1 to 233.34.147.254233.34.147.2551,022
166233.34.148.0/22233.34.148.1 to 233.34.151.254233.34.151.2551,022
167233.34.152.0/22233.34.152.1 to 233.34.155.254233.34.155.2551,022
168233.34.156.0/22233.34.156.1 to 233.34.159.254233.34.159.2551,022
169233.34.160.0/22233.34.160.1 to 233.34.163.254233.34.163.2551,022
170233.34.164.0/22233.34.164.1 to 233.34.167.254233.34.167.2551,022
171233.34.168.0/22233.34.168.1 to 233.34.171.254233.34.171.2551,022
172233.34.172.0/22233.34.172.1 to 233.34.175.254233.34.175.2551,022
173233.34.176.0/22233.34.176.1 to 233.34.179.254233.34.179.2551,022
174233.34.180.0/22233.34.180.1 to 233.34.183.254233.34.183.2551,022
175233.34.184.0/22233.34.184.1 to 233.34.187.254233.34.187.2551,022
176233.34.188.0/22233.34.188.1 to 233.34.191.254233.34.191.2551,022
177233.34.192.0/22233.34.192.1 to 233.34.195.254233.34.195.2551,022
178233.34.196.0/22233.34.196.1 to 233.34.199.254233.34.199.2551,022
179233.34.200.0/22233.34.200.1 to 233.34.203.254233.34.203.2551,022
180233.34.204.0/22233.34.204.1 to 233.34.207.254233.34.207.2551,022
181233.34.208.0/22233.34.208.1 to 233.34.211.254233.34.211.2551,022
182233.34.212.0/22233.34.212.1 to 233.34.215.254233.34.215.2551,022
183233.34.216.0/22233.34.216.1 to 233.34.219.254233.34.219.2551,022
184233.34.220.0/22233.34.220.1 to 233.34.223.254233.34.223.2551,022
185233.34.224.0/22233.34.224.1 to 233.34.227.254233.34.227.2551,022
186233.34.228.0/22233.34.228.1 to 233.34.231.254233.34.231.2551,022
187233.34.232.0/22233.34.232.1 to 233.34.235.254233.34.235.2551,022
188233.34.236.0/22233.34.236.1 to 233.34.239.254233.34.239.2551,022
189233.34.240.0/22233.34.240.1 to 233.34.243.254233.34.243.2551,022
190233.34.244.0/22233.34.244.1 to 233.34.247.254233.34.247.2551,022
191233.34.248.0/22233.34.248.1 to 233.34.251.254233.34.251.2551,022
192233.34.252.0/22233.34.252.1 to 233.34.255.254233.34.255.2551,022
193233.35.0.0/22233.35.0.1 to 233.35.3.254233.35.3.2551,022
194233.35.4.0/22233.35.4.1 to 233.35.7.254233.35.7.2551,022
195233.35.8.0/22233.35.8.1 to 233.35.11.254233.35.11.2551,022
196233.35.12.0/22233.35.12.1 to 233.35.15.254233.35.15.2551,022
197233.35.16.0/22233.35.16.1 to 233.35.19.254233.35.19.2551,022
198233.35.20.0/22233.35.20.1 to 233.35.23.254233.35.23.2551,022
199233.35.24.0/22233.35.24.1 to 233.35.27.254233.35.27.2551,022
200233.35.28.0/22233.35.28.1 to 233.35.31.254233.35.31.2551,022
201233.35.32.0/22233.35.32.1 to 233.35.35.254233.35.35.2551,022
202233.35.36.0/22233.35.36.1 to 233.35.39.254233.35.39.2551,022
203233.35.40.0/22233.35.40.1 to 233.35.43.254233.35.43.2551,022
204233.35.44.0/22233.35.44.1 to 233.35.47.254233.35.47.2551,022
205233.35.48.0/22233.35.48.1 to 233.35.51.254233.35.51.2551,022
206233.35.52.0/22233.35.52.1 to 233.35.55.254233.35.55.2551,022
207233.35.56.0/22233.35.56.1 to 233.35.59.254233.35.59.2551,022
208233.35.60.0/22233.35.60.1 to 233.35.63.254233.35.63.2551,022
209233.35.64.0/22233.35.64.1 to 233.35.67.254233.35.67.2551,022
210233.35.68.0/22233.35.68.1 to 233.35.71.254233.35.71.2551,022
211233.35.72.0/22233.35.72.1 to 233.35.75.254233.35.75.2551,022
212233.35.76.0/22233.35.76.1 to 233.35.79.254233.35.79.2551,022
213233.35.80.0/22233.35.80.1 to 233.35.83.254233.35.83.2551,022
214233.35.84.0/22233.35.84.1 to 233.35.87.254233.35.87.2551,022
215233.35.88.0/22233.35.88.1 to 233.35.91.254233.35.91.2551,022
216233.35.92.0/22233.35.92.1 to 233.35.95.254233.35.95.2551,022
217233.35.96.0/22233.35.96.1 to 233.35.99.254233.35.99.2551,022
218233.35.100.0/22233.35.100.1 to 233.35.103.254233.35.103.2551,022
219233.35.104.0/22233.35.104.1 to 233.35.107.254233.35.107.2551,022
220233.35.108.0/22233.35.108.1 to 233.35.111.254233.35.111.2551,022
221233.35.112.0/22233.35.112.1 to 233.35.115.254233.35.115.2551,022
222233.35.116.0/22233.35.116.1 to 233.35.119.254233.35.119.2551,022
223233.35.120.0/22233.35.120.1 to 233.35.123.254233.35.123.2551,022
224233.35.124.0/22233.35.124.1 to 233.35.127.254233.35.127.2551,022
225233.35.128.0/22233.35.128.1 to 233.35.131.254233.35.131.2551,022
226233.35.132.0/22233.35.132.1 to 233.35.135.254233.35.135.2551,022
227233.35.136.0/22233.35.136.1 to 233.35.139.254233.35.139.2551,022
228233.35.140.0/22233.35.140.1 to 233.35.143.254233.35.143.2551,022
229233.35.144.0/22233.35.144.1 to 233.35.147.254233.35.147.2551,022
230233.35.148.0/22233.35.148.1 to 233.35.151.254233.35.151.2551,022
231233.35.152.0/22233.35.152.1 to 233.35.155.254233.35.155.2551,022
232233.35.156.0/22233.35.156.1 to 233.35.159.254233.35.159.2551,022
233233.35.160.0/22233.35.160.1 to 233.35.163.254233.35.163.2551,022
234233.35.164.0/22233.35.164.1 to 233.35.167.254233.35.167.2551,022
235233.35.168.0/22233.35.168.1 to 233.35.171.254233.35.171.2551,022
236233.35.172.0/22233.35.172.1 to 233.35.175.254233.35.175.2551,022
237233.35.176.0/22233.35.176.1 to 233.35.179.254233.35.179.2551,022
238233.35.180.0/22233.35.180.1 to 233.35.183.254233.35.183.2551,022
239233.35.184.0/22233.35.184.1 to 233.35.187.254233.35.187.2551,022
240233.35.188.0/22233.35.188.1 to 233.35.191.254233.35.191.2551,022
241233.35.192.0/22233.35.192.1 to 233.35.195.254233.35.195.2551,022
242233.35.196.0/22233.35.196.1 to 233.35.199.254233.35.199.2551,022
243233.35.200.0/22233.35.200.1 to 233.35.203.254233.35.203.2551,022
244233.35.204.0/22233.35.204.1 to 233.35.207.254233.35.207.2551,022
245233.35.208.0/22233.35.208.1 to 233.35.211.254233.35.211.2551,022
246233.35.212.0/22233.35.212.1 to 233.35.215.254233.35.215.2551,022
247233.35.216.0/22233.35.216.1 to 233.35.219.254233.35.219.2551,022
248233.35.220.0/22233.35.220.1 to 233.35.223.254233.35.223.2551,022
249233.35.224.0/22233.35.224.1 to 233.35.227.254233.35.227.2551,022
250233.35.228.0/22233.35.228.1 to 233.35.231.254233.35.231.2551,022
251233.35.232.0/22233.35.232.1 to 233.35.235.254233.35.235.2551,022
252233.35.236.0/22233.35.236.1 to 233.35.239.254233.35.239.2551,022
253233.35.240.0/22233.35.240.1 to 233.35.243.254233.35.243.2551,022
254233.35.244.0/22233.35.244.1 to 233.35.247.254233.35.247.2551,022
255233.35.248.0/22233.35.248.1 to 233.35.251.254233.35.251.2551,022
256233.35.252.0/22233.35.252.1 to 233.35.255.254233.35.255.2551,022

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.