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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.

Network236.64.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
236.64.0.0
Broadcast address
236.95.255.255
First usable
236.64.0.1
Last usable
236.95.255.254
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 EC400000 · Integer 3963617280 to 3965714431
Reverse DNS zones
64.236.in-addr.arpa
65.236.in-addr.arpa
66.236.in-addr.arpa
67.236.in-addr.arpa
68.236.in-addr.arpa
69.236.in-addr.arpa
70.236.in-addr.arpa
71.236.in-addr.arpa
72.236.in-addr.arpa
73.236.in-addr.arpa
74.236.in-addr.arpa
75.236.in-addr.arpa
76.236.in-addr.arpa
77.236.in-addr.arpa
78.236.in-addr.arpa
79.236.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
Address11101100.01000000.00000000.00000000236.64.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network11101100.01000000.00000000.00000000236.64.0.0
Broadcast11101100.01011111.11111111.11111111236.95.255.255
Split into smaller subnets/22
/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)

236.64.0.0/11 makes 2,048 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1236.64.0.0/22236.64.0.1 to 236.64.3.254236.64.3.2551,022
2236.64.4.0/22236.64.4.1 to 236.64.7.254236.64.7.2551,022
3236.64.8.0/22236.64.8.1 to 236.64.11.254236.64.11.2551,022
4236.64.12.0/22236.64.12.1 to 236.64.15.254236.64.15.2551,022
5236.64.16.0/22236.64.16.1 to 236.64.19.254236.64.19.2551,022
6236.64.20.0/22236.64.20.1 to 236.64.23.254236.64.23.2551,022
7236.64.24.0/22236.64.24.1 to 236.64.27.254236.64.27.2551,022
8236.64.28.0/22236.64.28.1 to 236.64.31.254236.64.31.2551,022
9236.64.32.0/22236.64.32.1 to 236.64.35.254236.64.35.2551,022
10236.64.36.0/22236.64.36.1 to 236.64.39.254236.64.39.2551,022
11236.64.40.0/22236.64.40.1 to 236.64.43.254236.64.43.2551,022
12236.64.44.0/22236.64.44.1 to 236.64.47.254236.64.47.2551,022
13236.64.48.0/22236.64.48.1 to 236.64.51.254236.64.51.2551,022
14236.64.52.0/22236.64.52.1 to 236.64.55.254236.64.55.2551,022
15236.64.56.0/22236.64.56.1 to 236.64.59.254236.64.59.2551,022
16236.64.60.0/22236.64.60.1 to 236.64.63.254236.64.63.2551,022
17236.64.64.0/22236.64.64.1 to 236.64.67.254236.64.67.2551,022
18236.64.68.0/22236.64.68.1 to 236.64.71.254236.64.71.2551,022
19236.64.72.0/22236.64.72.1 to 236.64.75.254236.64.75.2551,022
20236.64.76.0/22236.64.76.1 to 236.64.79.254236.64.79.2551,022
21236.64.80.0/22236.64.80.1 to 236.64.83.254236.64.83.2551,022
22236.64.84.0/22236.64.84.1 to 236.64.87.254236.64.87.2551,022
23236.64.88.0/22236.64.88.1 to 236.64.91.254236.64.91.2551,022
24236.64.92.0/22236.64.92.1 to 236.64.95.254236.64.95.2551,022
25236.64.96.0/22236.64.96.1 to 236.64.99.254236.64.99.2551,022
26236.64.100.0/22236.64.100.1 to 236.64.103.254236.64.103.2551,022
27236.64.104.0/22236.64.104.1 to 236.64.107.254236.64.107.2551,022
28236.64.108.0/22236.64.108.1 to 236.64.111.254236.64.111.2551,022
29236.64.112.0/22236.64.112.1 to 236.64.115.254236.64.115.2551,022
30236.64.116.0/22236.64.116.1 to 236.64.119.254236.64.119.2551,022
31236.64.120.0/22236.64.120.1 to 236.64.123.254236.64.123.2551,022
32236.64.124.0/22236.64.124.1 to 236.64.127.254236.64.127.2551,022
33236.64.128.0/22236.64.128.1 to 236.64.131.254236.64.131.2551,022
34236.64.132.0/22236.64.132.1 to 236.64.135.254236.64.135.2551,022
35236.64.136.0/22236.64.136.1 to 236.64.139.254236.64.139.2551,022
36236.64.140.0/22236.64.140.1 to 236.64.143.254236.64.143.2551,022
37236.64.144.0/22236.64.144.1 to 236.64.147.254236.64.147.2551,022
38236.64.148.0/22236.64.148.1 to 236.64.151.254236.64.151.2551,022
39236.64.152.0/22236.64.152.1 to 236.64.155.254236.64.155.2551,022
40236.64.156.0/22236.64.156.1 to 236.64.159.254236.64.159.2551,022
41236.64.160.0/22236.64.160.1 to 236.64.163.254236.64.163.2551,022
42236.64.164.0/22236.64.164.1 to 236.64.167.254236.64.167.2551,022
43236.64.168.0/22236.64.168.1 to 236.64.171.254236.64.171.2551,022
44236.64.172.0/22236.64.172.1 to 236.64.175.254236.64.175.2551,022
45236.64.176.0/22236.64.176.1 to 236.64.179.254236.64.179.2551,022
46236.64.180.0/22236.64.180.1 to 236.64.183.254236.64.183.2551,022
47236.64.184.0/22236.64.184.1 to 236.64.187.254236.64.187.2551,022
48236.64.188.0/22236.64.188.1 to 236.64.191.254236.64.191.2551,022
49236.64.192.0/22236.64.192.1 to 236.64.195.254236.64.195.2551,022
50236.64.196.0/22236.64.196.1 to 236.64.199.254236.64.199.2551,022
51236.64.200.0/22236.64.200.1 to 236.64.203.254236.64.203.2551,022
52236.64.204.0/22236.64.204.1 to 236.64.207.254236.64.207.2551,022
53236.64.208.0/22236.64.208.1 to 236.64.211.254236.64.211.2551,022
54236.64.212.0/22236.64.212.1 to 236.64.215.254236.64.215.2551,022
55236.64.216.0/22236.64.216.1 to 236.64.219.254236.64.219.2551,022
56236.64.220.0/22236.64.220.1 to 236.64.223.254236.64.223.2551,022
57236.64.224.0/22236.64.224.1 to 236.64.227.254236.64.227.2551,022
58236.64.228.0/22236.64.228.1 to 236.64.231.254236.64.231.2551,022
59236.64.232.0/22236.64.232.1 to 236.64.235.254236.64.235.2551,022
60236.64.236.0/22236.64.236.1 to 236.64.239.254236.64.239.2551,022
61236.64.240.0/22236.64.240.1 to 236.64.243.254236.64.243.2551,022
62236.64.244.0/22236.64.244.1 to 236.64.247.254236.64.247.2551,022
63236.64.248.0/22236.64.248.1 to 236.64.251.254236.64.251.2551,022
64236.64.252.0/22236.64.252.1 to 236.64.255.254236.64.255.2551,022
65236.65.0.0/22236.65.0.1 to 236.65.3.254236.65.3.2551,022
66236.65.4.0/22236.65.4.1 to 236.65.7.254236.65.7.2551,022
67236.65.8.0/22236.65.8.1 to 236.65.11.254236.65.11.2551,022
68236.65.12.0/22236.65.12.1 to 236.65.15.254236.65.15.2551,022
69236.65.16.0/22236.65.16.1 to 236.65.19.254236.65.19.2551,022
70236.65.20.0/22236.65.20.1 to 236.65.23.254236.65.23.2551,022
71236.65.24.0/22236.65.24.1 to 236.65.27.254236.65.27.2551,022
72236.65.28.0/22236.65.28.1 to 236.65.31.254236.65.31.2551,022
73236.65.32.0/22236.65.32.1 to 236.65.35.254236.65.35.2551,022
74236.65.36.0/22236.65.36.1 to 236.65.39.254236.65.39.2551,022
75236.65.40.0/22236.65.40.1 to 236.65.43.254236.65.43.2551,022
76236.65.44.0/22236.65.44.1 to 236.65.47.254236.65.47.2551,022
77236.65.48.0/22236.65.48.1 to 236.65.51.254236.65.51.2551,022
78236.65.52.0/22236.65.52.1 to 236.65.55.254236.65.55.2551,022
79236.65.56.0/22236.65.56.1 to 236.65.59.254236.65.59.2551,022
80236.65.60.0/22236.65.60.1 to 236.65.63.254236.65.63.2551,022
81236.65.64.0/22236.65.64.1 to 236.65.67.254236.65.67.2551,022
82236.65.68.0/22236.65.68.1 to 236.65.71.254236.65.71.2551,022
83236.65.72.0/22236.65.72.1 to 236.65.75.254236.65.75.2551,022
84236.65.76.0/22236.65.76.1 to 236.65.79.254236.65.79.2551,022
85236.65.80.0/22236.65.80.1 to 236.65.83.254236.65.83.2551,022
86236.65.84.0/22236.65.84.1 to 236.65.87.254236.65.87.2551,022
87236.65.88.0/22236.65.88.1 to 236.65.91.254236.65.91.2551,022
88236.65.92.0/22236.65.92.1 to 236.65.95.254236.65.95.2551,022
89236.65.96.0/22236.65.96.1 to 236.65.99.254236.65.99.2551,022
90236.65.100.0/22236.65.100.1 to 236.65.103.254236.65.103.2551,022
91236.65.104.0/22236.65.104.1 to 236.65.107.254236.65.107.2551,022
92236.65.108.0/22236.65.108.1 to 236.65.111.254236.65.111.2551,022
93236.65.112.0/22236.65.112.1 to 236.65.115.254236.65.115.2551,022
94236.65.116.0/22236.65.116.1 to 236.65.119.254236.65.119.2551,022
95236.65.120.0/22236.65.120.1 to 236.65.123.254236.65.123.2551,022
96236.65.124.0/22236.65.124.1 to 236.65.127.254236.65.127.2551,022
97236.65.128.0/22236.65.128.1 to 236.65.131.254236.65.131.2551,022
98236.65.132.0/22236.65.132.1 to 236.65.135.254236.65.135.2551,022
99236.65.136.0/22236.65.136.1 to 236.65.139.254236.65.139.2551,022
100236.65.140.0/22236.65.140.1 to 236.65.143.254236.65.143.2551,022
101236.65.144.0/22236.65.144.1 to 236.65.147.254236.65.147.2551,022
102236.65.148.0/22236.65.148.1 to 236.65.151.254236.65.151.2551,022
103236.65.152.0/22236.65.152.1 to 236.65.155.254236.65.155.2551,022
104236.65.156.0/22236.65.156.1 to 236.65.159.254236.65.159.2551,022
105236.65.160.0/22236.65.160.1 to 236.65.163.254236.65.163.2551,022
106236.65.164.0/22236.65.164.1 to 236.65.167.254236.65.167.2551,022
107236.65.168.0/22236.65.168.1 to 236.65.171.254236.65.171.2551,022
108236.65.172.0/22236.65.172.1 to 236.65.175.254236.65.175.2551,022
109236.65.176.0/22236.65.176.1 to 236.65.179.254236.65.179.2551,022
110236.65.180.0/22236.65.180.1 to 236.65.183.254236.65.183.2551,022
111236.65.184.0/22236.65.184.1 to 236.65.187.254236.65.187.2551,022
112236.65.188.0/22236.65.188.1 to 236.65.191.254236.65.191.2551,022
113236.65.192.0/22236.65.192.1 to 236.65.195.254236.65.195.2551,022
114236.65.196.0/22236.65.196.1 to 236.65.199.254236.65.199.2551,022
115236.65.200.0/22236.65.200.1 to 236.65.203.254236.65.203.2551,022
116236.65.204.0/22236.65.204.1 to 236.65.207.254236.65.207.2551,022
117236.65.208.0/22236.65.208.1 to 236.65.211.254236.65.211.2551,022
118236.65.212.0/22236.65.212.1 to 236.65.215.254236.65.215.2551,022
119236.65.216.0/22236.65.216.1 to 236.65.219.254236.65.219.2551,022
120236.65.220.0/22236.65.220.1 to 236.65.223.254236.65.223.2551,022
121236.65.224.0/22236.65.224.1 to 236.65.227.254236.65.227.2551,022
122236.65.228.0/22236.65.228.1 to 236.65.231.254236.65.231.2551,022
123236.65.232.0/22236.65.232.1 to 236.65.235.254236.65.235.2551,022
124236.65.236.0/22236.65.236.1 to 236.65.239.254236.65.239.2551,022
125236.65.240.0/22236.65.240.1 to 236.65.243.254236.65.243.2551,022
126236.65.244.0/22236.65.244.1 to 236.65.247.254236.65.247.2551,022
127236.65.248.0/22236.65.248.1 to 236.65.251.254236.65.251.2551,022
128236.65.252.0/22236.65.252.1 to 236.65.255.254236.65.255.2551,022
129236.66.0.0/22236.66.0.1 to 236.66.3.254236.66.3.2551,022
130236.66.4.0/22236.66.4.1 to 236.66.7.254236.66.7.2551,022
131236.66.8.0/22236.66.8.1 to 236.66.11.254236.66.11.2551,022
132236.66.12.0/22236.66.12.1 to 236.66.15.254236.66.15.2551,022
133236.66.16.0/22236.66.16.1 to 236.66.19.254236.66.19.2551,022
134236.66.20.0/22236.66.20.1 to 236.66.23.254236.66.23.2551,022
135236.66.24.0/22236.66.24.1 to 236.66.27.254236.66.27.2551,022
136236.66.28.0/22236.66.28.1 to 236.66.31.254236.66.31.2551,022
137236.66.32.0/22236.66.32.1 to 236.66.35.254236.66.35.2551,022
138236.66.36.0/22236.66.36.1 to 236.66.39.254236.66.39.2551,022
139236.66.40.0/22236.66.40.1 to 236.66.43.254236.66.43.2551,022
140236.66.44.0/22236.66.44.1 to 236.66.47.254236.66.47.2551,022
141236.66.48.0/22236.66.48.1 to 236.66.51.254236.66.51.2551,022
142236.66.52.0/22236.66.52.1 to 236.66.55.254236.66.55.2551,022
143236.66.56.0/22236.66.56.1 to 236.66.59.254236.66.59.2551,022
144236.66.60.0/22236.66.60.1 to 236.66.63.254236.66.63.2551,022
145236.66.64.0/22236.66.64.1 to 236.66.67.254236.66.67.2551,022
146236.66.68.0/22236.66.68.1 to 236.66.71.254236.66.71.2551,022
147236.66.72.0/22236.66.72.1 to 236.66.75.254236.66.75.2551,022
148236.66.76.0/22236.66.76.1 to 236.66.79.254236.66.79.2551,022
149236.66.80.0/22236.66.80.1 to 236.66.83.254236.66.83.2551,022
150236.66.84.0/22236.66.84.1 to 236.66.87.254236.66.87.2551,022
151236.66.88.0/22236.66.88.1 to 236.66.91.254236.66.91.2551,022
152236.66.92.0/22236.66.92.1 to 236.66.95.254236.66.95.2551,022
153236.66.96.0/22236.66.96.1 to 236.66.99.254236.66.99.2551,022
154236.66.100.0/22236.66.100.1 to 236.66.103.254236.66.103.2551,022
155236.66.104.0/22236.66.104.1 to 236.66.107.254236.66.107.2551,022
156236.66.108.0/22236.66.108.1 to 236.66.111.254236.66.111.2551,022
157236.66.112.0/22236.66.112.1 to 236.66.115.254236.66.115.2551,022
158236.66.116.0/22236.66.116.1 to 236.66.119.254236.66.119.2551,022
159236.66.120.0/22236.66.120.1 to 236.66.123.254236.66.123.2551,022
160236.66.124.0/22236.66.124.1 to 236.66.127.254236.66.127.2551,022
161236.66.128.0/22236.66.128.1 to 236.66.131.254236.66.131.2551,022
162236.66.132.0/22236.66.132.1 to 236.66.135.254236.66.135.2551,022
163236.66.136.0/22236.66.136.1 to 236.66.139.254236.66.139.2551,022
164236.66.140.0/22236.66.140.1 to 236.66.143.254236.66.143.2551,022
165236.66.144.0/22236.66.144.1 to 236.66.147.254236.66.147.2551,022
166236.66.148.0/22236.66.148.1 to 236.66.151.254236.66.151.2551,022
167236.66.152.0/22236.66.152.1 to 236.66.155.254236.66.155.2551,022
168236.66.156.0/22236.66.156.1 to 236.66.159.254236.66.159.2551,022
169236.66.160.0/22236.66.160.1 to 236.66.163.254236.66.163.2551,022
170236.66.164.0/22236.66.164.1 to 236.66.167.254236.66.167.2551,022
171236.66.168.0/22236.66.168.1 to 236.66.171.254236.66.171.2551,022
172236.66.172.0/22236.66.172.1 to 236.66.175.254236.66.175.2551,022
173236.66.176.0/22236.66.176.1 to 236.66.179.254236.66.179.2551,022
174236.66.180.0/22236.66.180.1 to 236.66.183.254236.66.183.2551,022
175236.66.184.0/22236.66.184.1 to 236.66.187.254236.66.187.2551,022
176236.66.188.0/22236.66.188.1 to 236.66.191.254236.66.191.2551,022
177236.66.192.0/22236.66.192.1 to 236.66.195.254236.66.195.2551,022
178236.66.196.0/22236.66.196.1 to 236.66.199.254236.66.199.2551,022
179236.66.200.0/22236.66.200.1 to 236.66.203.254236.66.203.2551,022
180236.66.204.0/22236.66.204.1 to 236.66.207.254236.66.207.2551,022
181236.66.208.0/22236.66.208.1 to 236.66.211.254236.66.211.2551,022
182236.66.212.0/22236.66.212.1 to 236.66.215.254236.66.215.2551,022
183236.66.216.0/22236.66.216.1 to 236.66.219.254236.66.219.2551,022
184236.66.220.0/22236.66.220.1 to 236.66.223.254236.66.223.2551,022
185236.66.224.0/22236.66.224.1 to 236.66.227.254236.66.227.2551,022
186236.66.228.0/22236.66.228.1 to 236.66.231.254236.66.231.2551,022
187236.66.232.0/22236.66.232.1 to 236.66.235.254236.66.235.2551,022
188236.66.236.0/22236.66.236.1 to 236.66.239.254236.66.239.2551,022
189236.66.240.0/22236.66.240.1 to 236.66.243.254236.66.243.2551,022
190236.66.244.0/22236.66.244.1 to 236.66.247.254236.66.247.2551,022
191236.66.248.0/22236.66.248.1 to 236.66.251.254236.66.251.2551,022
192236.66.252.0/22236.66.252.1 to 236.66.255.254236.66.255.2551,022
193236.67.0.0/22236.67.0.1 to 236.67.3.254236.67.3.2551,022
194236.67.4.0/22236.67.4.1 to 236.67.7.254236.67.7.2551,022
195236.67.8.0/22236.67.8.1 to 236.67.11.254236.67.11.2551,022
196236.67.12.0/22236.67.12.1 to 236.67.15.254236.67.15.2551,022
197236.67.16.0/22236.67.16.1 to 236.67.19.254236.67.19.2551,022
198236.67.20.0/22236.67.20.1 to 236.67.23.254236.67.23.2551,022
199236.67.24.0/22236.67.24.1 to 236.67.27.254236.67.27.2551,022
200236.67.28.0/22236.67.28.1 to 236.67.31.254236.67.31.2551,022
201236.67.32.0/22236.67.32.1 to 236.67.35.254236.67.35.2551,022
202236.67.36.0/22236.67.36.1 to 236.67.39.254236.67.39.2551,022
203236.67.40.0/22236.67.40.1 to 236.67.43.254236.67.43.2551,022
204236.67.44.0/22236.67.44.1 to 236.67.47.254236.67.47.2551,022
205236.67.48.0/22236.67.48.1 to 236.67.51.254236.67.51.2551,022
206236.67.52.0/22236.67.52.1 to 236.67.55.254236.67.55.2551,022
207236.67.56.0/22236.67.56.1 to 236.67.59.254236.67.59.2551,022
208236.67.60.0/22236.67.60.1 to 236.67.63.254236.67.63.2551,022
209236.67.64.0/22236.67.64.1 to 236.67.67.254236.67.67.2551,022
210236.67.68.0/22236.67.68.1 to 236.67.71.254236.67.71.2551,022
211236.67.72.0/22236.67.72.1 to 236.67.75.254236.67.75.2551,022
212236.67.76.0/22236.67.76.1 to 236.67.79.254236.67.79.2551,022
213236.67.80.0/22236.67.80.1 to 236.67.83.254236.67.83.2551,022
214236.67.84.0/22236.67.84.1 to 236.67.87.254236.67.87.2551,022
215236.67.88.0/22236.67.88.1 to 236.67.91.254236.67.91.2551,022
216236.67.92.0/22236.67.92.1 to 236.67.95.254236.67.95.2551,022
217236.67.96.0/22236.67.96.1 to 236.67.99.254236.67.99.2551,022
218236.67.100.0/22236.67.100.1 to 236.67.103.254236.67.103.2551,022
219236.67.104.0/22236.67.104.1 to 236.67.107.254236.67.107.2551,022
220236.67.108.0/22236.67.108.1 to 236.67.111.254236.67.111.2551,022
221236.67.112.0/22236.67.112.1 to 236.67.115.254236.67.115.2551,022
222236.67.116.0/22236.67.116.1 to 236.67.119.254236.67.119.2551,022
223236.67.120.0/22236.67.120.1 to 236.67.123.254236.67.123.2551,022
224236.67.124.0/22236.67.124.1 to 236.67.127.254236.67.127.2551,022
225236.67.128.0/22236.67.128.1 to 236.67.131.254236.67.131.2551,022
226236.67.132.0/22236.67.132.1 to 236.67.135.254236.67.135.2551,022
227236.67.136.0/22236.67.136.1 to 236.67.139.254236.67.139.2551,022
228236.67.140.0/22236.67.140.1 to 236.67.143.254236.67.143.2551,022
229236.67.144.0/22236.67.144.1 to 236.67.147.254236.67.147.2551,022
230236.67.148.0/22236.67.148.1 to 236.67.151.254236.67.151.2551,022
231236.67.152.0/22236.67.152.1 to 236.67.155.254236.67.155.2551,022
232236.67.156.0/22236.67.156.1 to 236.67.159.254236.67.159.2551,022
233236.67.160.0/22236.67.160.1 to 236.67.163.254236.67.163.2551,022
234236.67.164.0/22236.67.164.1 to 236.67.167.254236.67.167.2551,022
235236.67.168.0/22236.67.168.1 to 236.67.171.254236.67.171.2551,022
236236.67.172.0/22236.67.172.1 to 236.67.175.254236.67.175.2551,022
237236.67.176.0/22236.67.176.1 to 236.67.179.254236.67.179.2551,022
238236.67.180.0/22236.67.180.1 to 236.67.183.254236.67.183.2551,022
239236.67.184.0/22236.67.184.1 to 236.67.187.254236.67.187.2551,022
240236.67.188.0/22236.67.188.1 to 236.67.191.254236.67.191.2551,022
241236.67.192.0/22236.67.192.1 to 236.67.195.254236.67.195.2551,022
242236.67.196.0/22236.67.196.1 to 236.67.199.254236.67.199.2551,022
243236.67.200.0/22236.67.200.1 to 236.67.203.254236.67.203.2551,022
244236.67.204.0/22236.67.204.1 to 236.67.207.254236.67.207.2551,022
245236.67.208.0/22236.67.208.1 to 236.67.211.254236.67.211.2551,022
246236.67.212.0/22236.67.212.1 to 236.67.215.254236.67.215.2551,022
247236.67.216.0/22236.67.216.1 to 236.67.219.254236.67.219.2551,022
248236.67.220.0/22236.67.220.1 to 236.67.223.254236.67.223.2551,022
249236.67.224.0/22236.67.224.1 to 236.67.227.254236.67.227.2551,022
250236.67.228.0/22236.67.228.1 to 236.67.231.254236.67.231.2551,022
251236.67.232.0/22236.67.232.1 to 236.67.235.254236.67.235.2551,022
252236.67.236.0/22236.67.236.1 to 236.67.239.254236.67.239.2551,022
253236.67.240.0/22236.67.240.1 to 236.67.243.254236.67.243.2551,022
254236.67.244.0/22236.67.244.1 to 236.67.247.254236.67.247.2551,022
255236.67.248.0/22236.67.248.1 to 236.67.251.254236.67.251.2551,022
256236.67.252.0/22236.67.252.1 to 236.67.255.254236.67.255.2551,022

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.