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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.

Network143.64.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
143.64.0.0
Broadcast address
143.95.255.255
First usable
143.64.0.1
Last usable
143.95.255.254
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
Public public
Old class
B (default /16)
As numbers
Hex 8F400000 · Integer 2403336192 to 2405433343
Reverse DNS zones
64.143.in-addr.arpa
65.143.in-addr.arpa
66.143.in-addr.arpa
67.143.in-addr.arpa
68.143.in-addr.arpa
69.143.in-addr.arpa
70.143.in-addr.arpa
71.143.in-addr.arpa
72.143.in-addr.arpa
73.143.in-addr.arpa
74.143.in-addr.arpa
75.143.in-addr.arpa
76.143.in-addr.arpa
77.143.in-addr.arpa
78.143.in-addr.arpa
79.143.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
Address10001111.01000000.00000000.00000000143.64.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network10001111.01000000.00000000.00000000143.64.0.0
Broadcast10001111.01011111.11111111.11111111143.95.255.255
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)

143.64.0.0/11 makes 1,024 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1143.64.0.0/21143.64.0.1 to 143.64.7.254143.64.7.2552,046
2143.64.8.0/21143.64.8.1 to 143.64.15.254143.64.15.2552,046
3143.64.16.0/21143.64.16.1 to 143.64.23.254143.64.23.2552,046
4143.64.24.0/21143.64.24.1 to 143.64.31.254143.64.31.2552,046
5143.64.32.0/21143.64.32.1 to 143.64.39.254143.64.39.2552,046
6143.64.40.0/21143.64.40.1 to 143.64.47.254143.64.47.2552,046
7143.64.48.0/21143.64.48.1 to 143.64.55.254143.64.55.2552,046
8143.64.56.0/21143.64.56.1 to 143.64.63.254143.64.63.2552,046
9143.64.64.0/21143.64.64.1 to 143.64.71.254143.64.71.2552,046
10143.64.72.0/21143.64.72.1 to 143.64.79.254143.64.79.2552,046
11143.64.80.0/21143.64.80.1 to 143.64.87.254143.64.87.2552,046
12143.64.88.0/21143.64.88.1 to 143.64.95.254143.64.95.2552,046
13143.64.96.0/21143.64.96.1 to 143.64.103.254143.64.103.2552,046
14143.64.104.0/21143.64.104.1 to 143.64.111.254143.64.111.2552,046
15143.64.112.0/21143.64.112.1 to 143.64.119.254143.64.119.2552,046
16143.64.120.0/21143.64.120.1 to 143.64.127.254143.64.127.2552,046
17143.64.128.0/21143.64.128.1 to 143.64.135.254143.64.135.2552,046
18143.64.136.0/21143.64.136.1 to 143.64.143.254143.64.143.2552,046
19143.64.144.0/21143.64.144.1 to 143.64.151.254143.64.151.2552,046
20143.64.152.0/21143.64.152.1 to 143.64.159.254143.64.159.2552,046
21143.64.160.0/21143.64.160.1 to 143.64.167.254143.64.167.2552,046
22143.64.168.0/21143.64.168.1 to 143.64.175.254143.64.175.2552,046
23143.64.176.0/21143.64.176.1 to 143.64.183.254143.64.183.2552,046
24143.64.184.0/21143.64.184.1 to 143.64.191.254143.64.191.2552,046
25143.64.192.0/21143.64.192.1 to 143.64.199.254143.64.199.2552,046
26143.64.200.0/21143.64.200.1 to 143.64.207.254143.64.207.2552,046
27143.64.208.0/21143.64.208.1 to 143.64.215.254143.64.215.2552,046
28143.64.216.0/21143.64.216.1 to 143.64.223.254143.64.223.2552,046
29143.64.224.0/21143.64.224.1 to 143.64.231.254143.64.231.2552,046
30143.64.232.0/21143.64.232.1 to 143.64.239.254143.64.239.2552,046
31143.64.240.0/21143.64.240.1 to 143.64.247.254143.64.247.2552,046
32143.64.248.0/21143.64.248.1 to 143.64.255.254143.64.255.2552,046
33143.65.0.0/21143.65.0.1 to 143.65.7.254143.65.7.2552,046
34143.65.8.0/21143.65.8.1 to 143.65.15.254143.65.15.2552,046
35143.65.16.0/21143.65.16.1 to 143.65.23.254143.65.23.2552,046
36143.65.24.0/21143.65.24.1 to 143.65.31.254143.65.31.2552,046
37143.65.32.0/21143.65.32.1 to 143.65.39.254143.65.39.2552,046
38143.65.40.0/21143.65.40.1 to 143.65.47.254143.65.47.2552,046
39143.65.48.0/21143.65.48.1 to 143.65.55.254143.65.55.2552,046
40143.65.56.0/21143.65.56.1 to 143.65.63.254143.65.63.2552,046
41143.65.64.0/21143.65.64.1 to 143.65.71.254143.65.71.2552,046
42143.65.72.0/21143.65.72.1 to 143.65.79.254143.65.79.2552,046
43143.65.80.0/21143.65.80.1 to 143.65.87.254143.65.87.2552,046
44143.65.88.0/21143.65.88.1 to 143.65.95.254143.65.95.2552,046
45143.65.96.0/21143.65.96.1 to 143.65.103.254143.65.103.2552,046
46143.65.104.0/21143.65.104.1 to 143.65.111.254143.65.111.2552,046
47143.65.112.0/21143.65.112.1 to 143.65.119.254143.65.119.2552,046
48143.65.120.0/21143.65.120.1 to 143.65.127.254143.65.127.2552,046
49143.65.128.0/21143.65.128.1 to 143.65.135.254143.65.135.2552,046
50143.65.136.0/21143.65.136.1 to 143.65.143.254143.65.143.2552,046
51143.65.144.0/21143.65.144.1 to 143.65.151.254143.65.151.2552,046
52143.65.152.0/21143.65.152.1 to 143.65.159.254143.65.159.2552,046
53143.65.160.0/21143.65.160.1 to 143.65.167.254143.65.167.2552,046
54143.65.168.0/21143.65.168.1 to 143.65.175.254143.65.175.2552,046
55143.65.176.0/21143.65.176.1 to 143.65.183.254143.65.183.2552,046
56143.65.184.0/21143.65.184.1 to 143.65.191.254143.65.191.2552,046
57143.65.192.0/21143.65.192.1 to 143.65.199.254143.65.199.2552,046
58143.65.200.0/21143.65.200.1 to 143.65.207.254143.65.207.2552,046
59143.65.208.0/21143.65.208.1 to 143.65.215.254143.65.215.2552,046
60143.65.216.0/21143.65.216.1 to 143.65.223.254143.65.223.2552,046
61143.65.224.0/21143.65.224.1 to 143.65.231.254143.65.231.2552,046
62143.65.232.0/21143.65.232.1 to 143.65.239.254143.65.239.2552,046
63143.65.240.0/21143.65.240.1 to 143.65.247.254143.65.247.2552,046
64143.65.248.0/21143.65.248.1 to 143.65.255.254143.65.255.2552,046
65143.66.0.0/21143.66.0.1 to 143.66.7.254143.66.7.2552,046
66143.66.8.0/21143.66.8.1 to 143.66.15.254143.66.15.2552,046
67143.66.16.0/21143.66.16.1 to 143.66.23.254143.66.23.2552,046
68143.66.24.0/21143.66.24.1 to 143.66.31.254143.66.31.2552,046
69143.66.32.0/21143.66.32.1 to 143.66.39.254143.66.39.2552,046
70143.66.40.0/21143.66.40.1 to 143.66.47.254143.66.47.2552,046
71143.66.48.0/21143.66.48.1 to 143.66.55.254143.66.55.2552,046
72143.66.56.0/21143.66.56.1 to 143.66.63.254143.66.63.2552,046
73143.66.64.0/21143.66.64.1 to 143.66.71.254143.66.71.2552,046
74143.66.72.0/21143.66.72.1 to 143.66.79.254143.66.79.2552,046
75143.66.80.0/21143.66.80.1 to 143.66.87.254143.66.87.2552,046
76143.66.88.0/21143.66.88.1 to 143.66.95.254143.66.95.2552,046
77143.66.96.0/21143.66.96.1 to 143.66.103.254143.66.103.2552,046
78143.66.104.0/21143.66.104.1 to 143.66.111.254143.66.111.2552,046
79143.66.112.0/21143.66.112.1 to 143.66.119.254143.66.119.2552,046
80143.66.120.0/21143.66.120.1 to 143.66.127.254143.66.127.2552,046
81143.66.128.0/21143.66.128.1 to 143.66.135.254143.66.135.2552,046
82143.66.136.0/21143.66.136.1 to 143.66.143.254143.66.143.2552,046
83143.66.144.0/21143.66.144.1 to 143.66.151.254143.66.151.2552,046
84143.66.152.0/21143.66.152.1 to 143.66.159.254143.66.159.2552,046
85143.66.160.0/21143.66.160.1 to 143.66.167.254143.66.167.2552,046
86143.66.168.0/21143.66.168.1 to 143.66.175.254143.66.175.2552,046
87143.66.176.0/21143.66.176.1 to 143.66.183.254143.66.183.2552,046
88143.66.184.0/21143.66.184.1 to 143.66.191.254143.66.191.2552,046
89143.66.192.0/21143.66.192.1 to 143.66.199.254143.66.199.2552,046
90143.66.200.0/21143.66.200.1 to 143.66.207.254143.66.207.2552,046
91143.66.208.0/21143.66.208.1 to 143.66.215.254143.66.215.2552,046
92143.66.216.0/21143.66.216.1 to 143.66.223.254143.66.223.2552,046
93143.66.224.0/21143.66.224.1 to 143.66.231.254143.66.231.2552,046
94143.66.232.0/21143.66.232.1 to 143.66.239.254143.66.239.2552,046
95143.66.240.0/21143.66.240.1 to 143.66.247.254143.66.247.2552,046
96143.66.248.0/21143.66.248.1 to 143.66.255.254143.66.255.2552,046
97143.67.0.0/21143.67.0.1 to 143.67.7.254143.67.7.2552,046
98143.67.8.0/21143.67.8.1 to 143.67.15.254143.67.15.2552,046
99143.67.16.0/21143.67.16.1 to 143.67.23.254143.67.23.2552,046
100143.67.24.0/21143.67.24.1 to 143.67.31.254143.67.31.2552,046
101143.67.32.0/21143.67.32.1 to 143.67.39.254143.67.39.2552,046
102143.67.40.0/21143.67.40.1 to 143.67.47.254143.67.47.2552,046
103143.67.48.0/21143.67.48.1 to 143.67.55.254143.67.55.2552,046
104143.67.56.0/21143.67.56.1 to 143.67.63.254143.67.63.2552,046
105143.67.64.0/21143.67.64.1 to 143.67.71.254143.67.71.2552,046
106143.67.72.0/21143.67.72.1 to 143.67.79.254143.67.79.2552,046
107143.67.80.0/21143.67.80.1 to 143.67.87.254143.67.87.2552,046
108143.67.88.0/21143.67.88.1 to 143.67.95.254143.67.95.2552,046
109143.67.96.0/21143.67.96.1 to 143.67.103.254143.67.103.2552,046
110143.67.104.0/21143.67.104.1 to 143.67.111.254143.67.111.2552,046
111143.67.112.0/21143.67.112.1 to 143.67.119.254143.67.119.2552,046
112143.67.120.0/21143.67.120.1 to 143.67.127.254143.67.127.2552,046
113143.67.128.0/21143.67.128.1 to 143.67.135.254143.67.135.2552,046
114143.67.136.0/21143.67.136.1 to 143.67.143.254143.67.143.2552,046
115143.67.144.0/21143.67.144.1 to 143.67.151.254143.67.151.2552,046
116143.67.152.0/21143.67.152.1 to 143.67.159.254143.67.159.2552,046
117143.67.160.0/21143.67.160.1 to 143.67.167.254143.67.167.2552,046
118143.67.168.0/21143.67.168.1 to 143.67.175.254143.67.175.2552,046
119143.67.176.0/21143.67.176.1 to 143.67.183.254143.67.183.2552,046
120143.67.184.0/21143.67.184.1 to 143.67.191.254143.67.191.2552,046
121143.67.192.0/21143.67.192.1 to 143.67.199.254143.67.199.2552,046
122143.67.200.0/21143.67.200.1 to 143.67.207.254143.67.207.2552,046
123143.67.208.0/21143.67.208.1 to 143.67.215.254143.67.215.2552,046
124143.67.216.0/21143.67.216.1 to 143.67.223.254143.67.223.2552,046
125143.67.224.0/21143.67.224.1 to 143.67.231.254143.67.231.2552,046
126143.67.232.0/21143.67.232.1 to 143.67.239.254143.67.239.2552,046
127143.67.240.0/21143.67.240.1 to 143.67.247.254143.67.247.2552,046
128143.67.248.0/21143.67.248.1 to 143.67.255.254143.67.255.2552,046
129143.68.0.0/21143.68.0.1 to 143.68.7.254143.68.7.2552,046
130143.68.8.0/21143.68.8.1 to 143.68.15.254143.68.15.2552,046
131143.68.16.0/21143.68.16.1 to 143.68.23.254143.68.23.2552,046
132143.68.24.0/21143.68.24.1 to 143.68.31.254143.68.31.2552,046
133143.68.32.0/21143.68.32.1 to 143.68.39.254143.68.39.2552,046
134143.68.40.0/21143.68.40.1 to 143.68.47.254143.68.47.2552,046
135143.68.48.0/21143.68.48.1 to 143.68.55.254143.68.55.2552,046
136143.68.56.0/21143.68.56.1 to 143.68.63.254143.68.63.2552,046
137143.68.64.0/21143.68.64.1 to 143.68.71.254143.68.71.2552,046
138143.68.72.0/21143.68.72.1 to 143.68.79.254143.68.79.2552,046
139143.68.80.0/21143.68.80.1 to 143.68.87.254143.68.87.2552,046
140143.68.88.0/21143.68.88.1 to 143.68.95.254143.68.95.2552,046
141143.68.96.0/21143.68.96.1 to 143.68.103.254143.68.103.2552,046
142143.68.104.0/21143.68.104.1 to 143.68.111.254143.68.111.2552,046
143143.68.112.0/21143.68.112.1 to 143.68.119.254143.68.119.2552,046
144143.68.120.0/21143.68.120.1 to 143.68.127.254143.68.127.2552,046
145143.68.128.0/21143.68.128.1 to 143.68.135.254143.68.135.2552,046
146143.68.136.0/21143.68.136.1 to 143.68.143.254143.68.143.2552,046
147143.68.144.0/21143.68.144.1 to 143.68.151.254143.68.151.2552,046
148143.68.152.0/21143.68.152.1 to 143.68.159.254143.68.159.2552,046
149143.68.160.0/21143.68.160.1 to 143.68.167.254143.68.167.2552,046
150143.68.168.0/21143.68.168.1 to 143.68.175.254143.68.175.2552,046
151143.68.176.0/21143.68.176.1 to 143.68.183.254143.68.183.2552,046
152143.68.184.0/21143.68.184.1 to 143.68.191.254143.68.191.2552,046
153143.68.192.0/21143.68.192.1 to 143.68.199.254143.68.199.2552,046
154143.68.200.0/21143.68.200.1 to 143.68.207.254143.68.207.2552,046
155143.68.208.0/21143.68.208.1 to 143.68.215.254143.68.215.2552,046
156143.68.216.0/21143.68.216.1 to 143.68.223.254143.68.223.2552,046
157143.68.224.0/21143.68.224.1 to 143.68.231.254143.68.231.2552,046
158143.68.232.0/21143.68.232.1 to 143.68.239.254143.68.239.2552,046
159143.68.240.0/21143.68.240.1 to 143.68.247.254143.68.247.2552,046
160143.68.248.0/21143.68.248.1 to 143.68.255.254143.68.255.2552,046
161143.69.0.0/21143.69.0.1 to 143.69.7.254143.69.7.2552,046
162143.69.8.0/21143.69.8.1 to 143.69.15.254143.69.15.2552,046
163143.69.16.0/21143.69.16.1 to 143.69.23.254143.69.23.2552,046
164143.69.24.0/21143.69.24.1 to 143.69.31.254143.69.31.2552,046
165143.69.32.0/21143.69.32.1 to 143.69.39.254143.69.39.2552,046
166143.69.40.0/21143.69.40.1 to 143.69.47.254143.69.47.2552,046
167143.69.48.0/21143.69.48.1 to 143.69.55.254143.69.55.2552,046
168143.69.56.0/21143.69.56.1 to 143.69.63.254143.69.63.2552,046
169143.69.64.0/21143.69.64.1 to 143.69.71.254143.69.71.2552,046
170143.69.72.0/21143.69.72.1 to 143.69.79.254143.69.79.2552,046
171143.69.80.0/21143.69.80.1 to 143.69.87.254143.69.87.2552,046
172143.69.88.0/21143.69.88.1 to 143.69.95.254143.69.95.2552,046
173143.69.96.0/21143.69.96.1 to 143.69.103.254143.69.103.2552,046
174143.69.104.0/21143.69.104.1 to 143.69.111.254143.69.111.2552,046
175143.69.112.0/21143.69.112.1 to 143.69.119.254143.69.119.2552,046
176143.69.120.0/21143.69.120.1 to 143.69.127.254143.69.127.2552,046
177143.69.128.0/21143.69.128.1 to 143.69.135.254143.69.135.2552,046
178143.69.136.0/21143.69.136.1 to 143.69.143.254143.69.143.2552,046
179143.69.144.0/21143.69.144.1 to 143.69.151.254143.69.151.2552,046
180143.69.152.0/21143.69.152.1 to 143.69.159.254143.69.159.2552,046
181143.69.160.0/21143.69.160.1 to 143.69.167.254143.69.167.2552,046
182143.69.168.0/21143.69.168.1 to 143.69.175.254143.69.175.2552,046
183143.69.176.0/21143.69.176.1 to 143.69.183.254143.69.183.2552,046
184143.69.184.0/21143.69.184.1 to 143.69.191.254143.69.191.2552,046
185143.69.192.0/21143.69.192.1 to 143.69.199.254143.69.199.2552,046
186143.69.200.0/21143.69.200.1 to 143.69.207.254143.69.207.2552,046
187143.69.208.0/21143.69.208.1 to 143.69.215.254143.69.215.2552,046
188143.69.216.0/21143.69.216.1 to 143.69.223.254143.69.223.2552,046
189143.69.224.0/21143.69.224.1 to 143.69.231.254143.69.231.2552,046
190143.69.232.0/21143.69.232.1 to 143.69.239.254143.69.239.2552,046
191143.69.240.0/21143.69.240.1 to 143.69.247.254143.69.247.2552,046
192143.69.248.0/21143.69.248.1 to 143.69.255.254143.69.255.2552,046
193143.70.0.0/21143.70.0.1 to 143.70.7.254143.70.7.2552,046
194143.70.8.0/21143.70.8.1 to 143.70.15.254143.70.15.2552,046
195143.70.16.0/21143.70.16.1 to 143.70.23.254143.70.23.2552,046
196143.70.24.0/21143.70.24.1 to 143.70.31.254143.70.31.2552,046
197143.70.32.0/21143.70.32.1 to 143.70.39.254143.70.39.2552,046
198143.70.40.0/21143.70.40.1 to 143.70.47.254143.70.47.2552,046
199143.70.48.0/21143.70.48.1 to 143.70.55.254143.70.55.2552,046
200143.70.56.0/21143.70.56.1 to 143.70.63.254143.70.63.2552,046
201143.70.64.0/21143.70.64.1 to 143.70.71.254143.70.71.2552,046
202143.70.72.0/21143.70.72.1 to 143.70.79.254143.70.79.2552,046
203143.70.80.0/21143.70.80.1 to 143.70.87.254143.70.87.2552,046
204143.70.88.0/21143.70.88.1 to 143.70.95.254143.70.95.2552,046
205143.70.96.0/21143.70.96.1 to 143.70.103.254143.70.103.2552,046
206143.70.104.0/21143.70.104.1 to 143.70.111.254143.70.111.2552,046
207143.70.112.0/21143.70.112.1 to 143.70.119.254143.70.119.2552,046
208143.70.120.0/21143.70.120.1 to 143.70.127.254143.70.127.2552,046
209143.70.128.0/21143.70.128.1 to 143.70.135.254143.70.135.2552,046
210143.70.136.0/21143.70.136.1 to 143.70.143.254143.70.143.2552,046
211143.70.144.0/21143.70.144.1 to 143.70.151.254143.70.151.2552,046
212143.70.152.0/21143.70.152.1 to 143.70.159.254143.70.159.2552,046
213143.70.160.0/21143.70.160.1 to 143.70.167.254143.70.167.2552,046
214143.70.168.0/21143.70.168.1 to 143.70.175.254143.70.175.2552,046
215143.70.176.0/21143.70.176.1 to 143.70.183.254143.70.183.2552,046
216143.70.184.0/21143.70.184.1 to 143.70.191.254143.70.191.2552,046
217143.70.192.0/21143.70.192.1 to 143.70.199.254143.70.199.2552,046
218143.70.200.0/21143.70.200.1 to 143.70.207.254143.70.207.2552,046
219143.70.208.0/21143.70.208.1 to 143.70.215.254143.70.215.2552,046
220143.70.216.0/21143.70.216.1 to 143.70.223.254143.70.223.2552,046
221143.70.224.0/21143.70.224.1 to 143.70.231.254143.70.231.2552,046
222143.70.232.0/21143.70.232.1 to 143.70.239.254143.70.239.2552,046
223143.70.240.0/21143.70.240.1 to 143.70.247.254143.70.247.2552,046
224143.70.248.0/21143.70.248.1 to 143.70.255.254143.70.255.2552,046
225143.71.0.0/21143.71.0.1 to 143.71.7.254143.71.7.2552,046
226143.71.8.0/21143.71.8.1 to 143.71.15.254143.71.15.2552,046
227143.71.16.0/21143.71.16.1 to 143.71.23.254143.71.23.2552,046
228143.71.24.0/21143.71.24.1 to 143.71.31.254143.71.31.2552,046
229143.71.32.0/21143.71.32.1 to 143.71.39.254143.71.39.2552,046
230143.71.40.0/21143.71.40.1 to 143.71.47.254143.71.47.2552,046
231143.71.48.0/21143.71.48.1 to 143.71.55.254143.71.55.2552,046
232143.71.56.0/21143.71.56.1 to 143.71.63.254143.71.63.2552,046
233143.71.64.0/21143.71.64.1 to 143.71.71.254143.71.71.2552,046
234143.71.72.0/21143.71.72.1 to 143.71.79.254143.71.79.2552,046
235143.71.80.0/21143.71.80.1 to 143.71.87.254143.71.87.2552,046
236143.71.88.0/21143.71.88.1 to 143.71.95.254143.71.95.2552,046
237143.71.96.0/21143.71.96.1 to 143.71.103.254143.71.103.2552,046
238143.71.104.0/21143.71.104.1 to 143.71.111.254143.71.111.2552,046
239143.71.112.0/21143.71.112.1 to 143.71.119.254143.71.119.2552,046
240143.71.120.0/21143.71.120.1 to 143.71.127.254143.71.127.2552,046
241143.71.128.0/21143.71.128.1 to 143.71.135.254143.71.135.2552,046
242143.71.136.0/21143.71.136.1 to 143.71.143.254143.71.143.2552,046
243143.71.144.0/21143.71.144.1 to 143.71.151.254143.71.151.2552,046
244143.71.152.0/21143.71.152.1 to 143.71.159.254143.71.159.2552,046
245143.71.160.0/21143.71.160.1 to 143.71.167.254143.71.167.2552,046
246143.71.168.0/21143.71.168.1 to 143.71.175.254143.71.175.2552,046
247143.71.176.0/21143.71.176.1 to 143.71.183.254143.71.183.2552,046
248143.71.184.0/21143.71.184.1 to 143.71.191.254143.71.191.2552,046
249143.71.192.0/21143.71.192.1 to 143.71.199.254143.71.199.2552,046
250143.71.200.0/21143.71.200.1 to 143.71.207.254143.71.207.2552,046
251143.71.208.0/21143.71.208.1 to 143.71.215.254143.71.215.2552,046
252143.71.216.0/21143.71.216.1 to 143.71.223.254143.71.223.2552,046
253143.71.224.0/21143.71.224.1 to 143.71.231.254143.71.231.2552,046
254143.71.232.0/21143.71.232.1 to 143.71.239.254143.71.239.2552,046
255143.71.240.0/21143.71.240.1 to 143.71.247.254143.71.247.2552,046
256143.71.248.0/21143.71.248.1 to 143.71.255.254143.71.255.2552,046

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.