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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.

Network229.0.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
229.0.0.0
Broadcast address
229.15.255.255
First usable
229.0.0.1
Last usable
229.15.255.254
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 E5000000 · Integer 3841982464 to 3843031039
Reverse DNS zones
0.229.in-addr.arpa
1.229.in-addr.arpa
2.229.in-addr.arpa
3.229.in-addr.arpa
4.229.in-addr.arpa
5.229.in-addr.arpa
6.229.in-addr.arpa
7.229.in-addr.arpa
8.229.in-addr.arpa
9.229.in-addr.arpa
10.229.in-addr.arpa
11.229.in-addr.arpa
12.229.in-addr.arpa
13.229.in-addr.arpa
14.229.in-addr.arpa
15.229.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
Address11100101.00000000.00000000.00000000229.0.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11100101.00000000.00000000.00000000229.0.0.0
Broadcast11100101.00001111.11111111.11111111229.15.255.255
Split into smaller subnets/21
/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)

229.0.0.0/12 makes 512 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1229.0.0.0/21229.0.0.1 to 229.0.7.254229.0.7.2552,046
2229.0.8.0/21229.0.8.1 to 229.0.15.254229.0.15.2552,046
3229.0.16.0/21229.0.16.1 to 229.0.23.254229.0.23.2552,046
4229.0.24.0/21229.0.24.1 to 229.0.31.254229.0.31.2552,046
5229.0.32.0/21229.0.32.1 to 229.0.39.254229.0.39.2552,046
6229.0.40.0/21229.0.40.1 to 229.0.47.254229.0.47.2552,046
7229.0.48.0/21229.0.48.1 to 229.0.55.254229.0.55.2552,046
8229.0.56.0/21229.0.56.1 to 229.0.63.254229.0.63.2552,046
9229.0.64.0/21229.0.64.1 to 229.0.71.254229.0.71.2552,046
10229.0.72.0/21229.0.72.1 to 229.0.79.254229.0.79.2552,046
11229.0.80.0/21229.0.80.1 to 229.0.87.254229.0.87.2552,046
12229.0.88.0/21229.0.88.1 to 229.0.95.254229.0.95.2552,046
13229.0.96.0/21229.0.96.1 to 229.0.103.254229.0.103.2552,046
14229.0.104.0/21229.0.104.1 to 229.0.111.254229.0.111.2552,046
15229.0.112.0/21229.0.112.1 to 229.0.119.254229.0.119.2552,046
16229.0.120.0/21229.0.120.1 to 229.0.127.254229.0.127.2552,046
17229.0.128.0/21229.0.128.1 to 229.0.135.254229.0.135.2552,046
18229.0.136.0/21229.0.136.1 to 229.0.143.254229.0.143.2552,046
19229.0.144.0/21229.0.144.1 to 229.0.151.254229.0.151.2552,046
20229.0.152.0/21229.0.152.1 to 229.0.159.254229.0.159.2552,046
21229.0.160.0/21229.0.160.1 to 229.0.167.254229.0.167.2552,046
22229.0.168.0/21229.0.168.1 to 229.0.175.254229.0.175.2552,046
23229.0.176.0/21229.0.176.1 to 229.0.183.254229.0.183.2552,046
24229.0.184.0/21229.0.184.1 to 229.0.191.254229.0.191.2552,046
25229.0.192.0/21229.0.192.1 to 229.0.199.254229.0.199.2552,046
26229.0.200.0/21229.0.200.1 to 229.0.207.254229.0.207.2552,046
27229.0.208.0/21229.0.208.1 to 229.0.215.254229.0.215.2552,046
28229.0.216.0/21229.0.216.1 to 229.0.223.254229.0.223.2552,046
29229.0.224.0/21229.0.224.1 to 229.0.231.254229.0.231.2552,046
30229.0.232.0/21229.0.232.1 to 229.0.239.254229.0.239.2552,046
31229.0.240.0/21229.0.240.1 to 229.0.247.254229.0.247.2552,046
32229.0.248.0/21229.0.248.1 to 229.0.255.254229.0.255.2552,046
33229.1.0.0/21229.1.0.1 to 229.1.7.254229.1.7.2552,046
34229.1.8.0/21229.1.8.1 to 229.1.15.254229.1.15.2552,046
35229.1.16.0/21229.1.16.1 to 229.1.23.254229.1.23.2552,046
36229.1.24.0/21229.1.24.1 to 229.1.31.254229.1.31.2552,046
37229.1.32.0/21229.1.32.1 to 229.1.39.254229.1.39.2552,046
38229.1.40.0/21229.1.40.1 to 229.1.47.254229.1.47.2552,046
39229.1.48.0/21229.1.48.1 to 229.1.55.254229.1.55.2552,046
40229.1.56.0/21229.1.56.1 to 229.1.63.254229.1.63.2552,046
41229.1.64.0/21229.1.64.1 to 229.1.71.254229.1.71.2552,046
42229.1.72.0/21229.1.72.1 to 229.1.79.254229.1.79.2552,046
43229.1.80.0/21229.1.80.1 to 229.1.87.254229.1.87.2552,046
44229.1.88.0/21229.1.88.1 to 229.1.95.254229.1.95.2552,046
45229.1.96.0/21229.1.96.1 to 229.1.103.254229.1.103.2552,046
46229.1.104.0/21229.1.104.1 to 229.1.111.254229.1.111.2552,046
47229.1.112.0/21229.1.112.1 to 229.1.119.254229.1.119.2552,046
48229.1.120.0/21229.1.120.1 to 229.1.127.254229.1.127.2552,046
49229.1.128.0/21229.1.128.1 to 229.1.135.254229.1.135.2552,046
50229.1.136.0/21229.1.136.1 to 229.1.143.254229.1.143.2552,046
51229.1.144.0/21229.1.144.1 to 229.1.151.254229.1.151.2552,046
52229.1.152.0/21229.1.152.1 to 229.1.159.254229.1.159.2552,046
53229.1.160.0/21229.1.160.1 to 229.1.167.254229.1.167.2552,046
54229.1.168.0/21229.1.168.1 to 229.1.175.254229.1.175.2552,046
55229.1.176.0/21229.1.176.1 to 229.1.183.254229.1.183.2552,046
56229.1.184.0/21229.1.184.1 to 229.1.191.254229.1.191.2552,046
57229.1.192.0/21229.1.192.1 to 229.1.199.254229.1.199.2552,046
58229.1.200.0/21229.1.200.1 to 229.1.207.254229.1.207.2552,046
59229.1.208.0/21229.1.208.1 to 229.1.215.254229.1.215.2552,046
60229.1.216.0/21229.1.216.1 to 229.1.223.254229.1.223.2552,046
61229.1.224.0/21229.1.224.1 to 229.1.231.254229.1.231.2552,046
62229.1.232.0/21229.1.232.1 to 229.1.239.254229.1.239.2552,046
63229.1.240.0/21229.1.240.1 to 229.1.247.254229.1.247.2552,046
64229.1.248.0/21229.1.248.1 to 229.1.255.254229.1.255.2552,046
65229.2.0.0/21229.2.0.1 to 229.2.7.254229.2.7.2552,046
66229.2.8.0/21229.2.8.1 to 229.2.15.254229.2.15.2552,046
67229.2.16.0/21229.2.16.1 to 229.2.23.254229.2.23.2552,046
68229.2.24.0/21229.2.24.1 to 229.2.31.254229.2.31.2552,046
69229.2.32.0/21229.2.32.1 to 229.2.39.254229.2.39.2552,046
70229.2.40.0/21229.2.40.1 to 229.2.47.254229.2.47.2552,046
71229.2.48.0/21229.2.48.1 to 229.2.55.254229.2.55.2552,046
72229.2.56.0/21229.2.56.1 to 229.2.63.254229.2.63.2552,046
73229.2.64.0/21229.2.64.1 to 229.2.71.254229.2.71.2552,046
74229.2.72.0/21229.2.72.1 to 229.2.79.254229.2.79.2552,046
75229.2.80.0/21229.2.80.1 to 229.2.87.254229.2.87.2552,046
76229.2.88.0/21229.2.88.1 to 229.2.95.254229.2.95.2552,046
77229.2.96.0/21229.2.96.1 to 229.2.103.254229.2.103.2552,046
78229.2.104.0/21229.2.104.1 to 229.2.111.254229.2.111.2552,046
79229.2.112.0/21229.2.112.1 to 229.2.119.254229.2.119.2552,046
80229.2.120.0/21229.2.120.1 to 229.2.127.254229.2.127.2552,046
81229.2.128.0/21229.2.128.1 to 229.2.135.254229.2.135.2552,046
82229.2.136.0/21229.2.136.1 to 229.2.143.254229.2.143.2552,046
83229.2.144.0/21229.2.144.1 to 229.2.151.254229.2.151.2552,046
84229.2.152.0/21229.2.152.1 to 229.2.159.254229.2.159.2552,046
85229.2.160.0/21229.2.160.1 to 229.2.167.254229.2.167.2552,046
86229.2.168.0/21229.2.168.1 to 229.2.175.254229.2.175.2552,046
87229.2.176.0/21229.2.176.1 to 229.2.183.254229.2.183.2552,046
88229.2.184.0/21229.2.184.1 to 229.2.191.254229.2.191.2552,046
89229.2.192.0/21229.2.192.1 to 229.2.199.254229.2.199.2552,046
90229.2.200.0/21229.2.200.1 to 229.2.207.254229.2.207.2552,046
91229.2.208.0/21229.2.208.1 to 229.2.215.254229.2.215.2552,046
92229.2.216.0/21229.2.216.1 to 229.2.223.254229.2.223.2552,046
93229.2.224.0/21229.2.224.1 to 229.2.231.254229.2.231.2552,046
94229.2.232.0/21229.2.232.1 to 229.2.239.254229.2.239.2552,046
95229.2.240.0/21229.2.240.1 to 229.2.247.254229.2.247.2552,046
96229.2.248.0/21229.2.248.1 to 229.2.255.254229.2.255.2552,046
97229.3.0.0/21229.3.0.1 to 229.3.7.254229.3.7.2552,046
98229.3.8.0/21229.3.8.1 to 229.3.15.254229.3.15.2552,046
99229.3.16.0/21229.3.16.1 to 229.3.23.254229.3.23.2552,046
100229.3.24.0/21229.3.24.1 to 229.3.31.254229.3.31.2552,046
101229.3.32.0/21229.3.32.1 to 229.3.39.254229.3.39.2552,046
102229.3.40.0/21229.3.40.1 to 229.3.47.254229.3.47.2552,046
103229.3.48.0/21229.3.48.1 to 229.3.55.254229.3.55.2552,046
104229.3.56.0/21229.3.56.1 to 229.3.63.254229.3.63.2552,046
105229.3.64.0/21229.3.64.1 to 229.3.71.254229.3.71.2552,046
106229.3.72.0/21229.3.72.1 to 229.3.79.254229.3.79.2552,046
107229.3.80.0/21229.3.80.1 to 229.3.87.254229.3.87.2552,046
108229.3.88.0/21229.3.88.1 to 229.3.95.254229.3.95.2552,046
109229.3.96.0/21229.3.96.1 to 229.3.103.254229.3.103.2552,046
110229.3.104.0/21229.3.104.1 to 229.3.111.254229.3.111.2552,046
111229.3.112.0/21229.3.112.1 to 229.3.119.254229.3.119.2552,046
112229.3.120.0/21229.3.120.1 to 229.3.127.254229.3.127.2552,046
113229.3.128.0/21229.3.128.1 to 229.3.135.254229.3.135.2552,046
114229.3.136.0/21229.3.136.1 to 229.3.143.254229.3.143.2552,046
115229.3.144.0/21229.3.144.1 to 229.3.151.254229.3.151.2552,046
116229.3.152.0/21229.3.152.1 to 229.3.159.254229.3.159.2552,046
117229.3.160.0/21229.3.160.1 to 229.3.167.254229.3.167.2552,046
118229.3.168.0/21229.3.168.1 to 229.3.175.254229.3.175.2552,046
119229.3.176.0/21229.3.176.1 to 229.3.183.254229.3.183.2552,046
120229.3.184.0/21229.3.184.1 to 229.3.191.254229.3.191.2552,046
121229.3.192.0/21229.3.192.1 to 229.3.199.254229.3.199.2552,046
122229.3.200.0/21229.3.200.1 to 229.3.207.254229.3.207.2552,046
123229.3.208.0/21229.3.208.1 to 229.3.215.254229.3.215.2552,046
124229.3.216.0/21229.3.216.1 to 229.3.223.254229.3.223.2552,046
125229.3.224.0/21229.3.224.1 to 229.3.231.254229.3.231.2552,046
126229.3.232.0/21229.3.232.1 to 229.3.239.254229.3.239.2552,046
127229.3.240.0/21229.3.240.1 to 229.3.247.254229.3.247.2552,046
128229.3.248.0/21229.3.248.1 to 229.3.255.254229.3.255.2552,046
129229.4.0.0/21229.4.0.1 to 229.4.7.254229.4.7.2552,046
130229.4.8.0/21229.4.8.1 to 229.4.15.254229.4.15.2552,046
131229.4.16.0/21229.4.16.1 to 229.4.23.254229.4.23.2552,046
132229.4.24.0/21229.4.24.1 to 229.4.31.254229.4.31.2552,046
133229.4.32.0/21229.4.32.1 to 229.4.39.254229.4.39.2552,046
134229.4.40.0/21229.4.40.1 to 229.4.47.254229.4.47.2552,046
135229.4.48.0/21229.4.48.1 to 229.4.55.254229.4.55.2552,046
136229.4.56.0/21229.4.56.1 to 229.4.63.254229.4.63.2552,046
137229.4.64.0/21229.4.64.1 to 229.4.71.254229.4.71.2552,046
138229.4.72.0/21229.4.72.1 to 229.4.79.254229.4.79.2552,046
139229.4.80.0/21229.4.80.1 to 229.4.87.254229.4.87.2552,046
140229.4.88.0/21229.4.88.1 to 229.4.95.254229.4.95.2552,046
141229.4.96.0/21229.4.96.1 to 229.4.103.254229.4.103.2552,046
142229.4.104.0/21229.4.104.1 to 229.4.111.254229.4.111.2552,046
143229.4.112.0/21229.4.112.1 to 229.4.119.254229.4.119.2552,046
144229.4.120.0/21229.4.120.1 to 229.4.127.254229.4.127.2552,046
145229.4.128.0/21229.4.128.1 to 229.4.135.254229.4.135.2552,046
146229.4.136.0/21229.4.136.1 to 229.4.143.254229.4.143.2552,046
147229.4.144.0/21229.4.144.1 to 229.4.151.254229.4.151.2552,046
148229.4.152.0/21229.4.152.1 to 229.4.159.254229.4.159.2552,046
149229.4.160.0/21229.4.160.1 to 229.4.167.254229.4.167.2552,046
150229.4.168.0/21229.4.168.1 to 229.4.175.254229.4.175.2552,046
151229.4.176.0/21229.4.176.1 to 229.4.183.254229.4.183.2552,046
152229.4.184.0/21229.4.184.1 to 229.4.191.254229.4.191.2552,046
153229.4.192.0/21229.4.192.1 to 229.4.199.254229.4.199.2552,046
154229.4.200.0/21229.4.200.1 to 229.4.207.254229.4.207.2552,046
155229.4.208.0/21229.4.208.1 to 229.4.215.254229.4.215.2552,046
156229.4.216.0/21229.4.216.1 to 229.4.223.254229.4.223.2552,046
157229.4.224.0/21229.4.224.1 to 229.4.231.254229.4.231.2552,046
158229.4.232.0/21229.4.232.1 to 229.4.239.254229.4.239.2552,046
159229.4.240.0/21229.4.240.1 to 229.4.247.254229.4.247.2552,046
160229.4.248.0/21229.4.248.1 to 229.4.255.254229.4.255.2552,046
161229.5.0.0/21229.5.0.1 to 229.5.7.254229.5.7.2552,046
162229.5.8.0/21229.5.8.1 to 229.5.15.254229.5.15.2552,046
163229.5.16.0/21229.5.16.1 to 229.5.23.254229.5.23.2552,046
164229.5.24.0/21229.5.24.1 to 229.5.31.254229.5.31.2552,046
165229.5.32.0/21229.5.32.1 to 229.5.39.254229.5.39.2552,046
166229.5.40.0/21229.5.40.1 to 229.5.47.254229.5.47.2552,046
167229.5.48.0/21229.5.48.1 to 229.5.55.254229.5.55.2552,046
168229.5.56.0/21229.5.56.1 to 229.5.63.254229.5.63.2552,046
169229.5.64.0/21229.5.64.1 to 229.5.71.254229.5.71.2552,046
170229.5.72.0/21229.5.72.1 to 229.5.79.254229.5.79.2552,046
171229.5.80.0/21229.5.80.1 to 229.5.87.254229.5.87.2552,046
172229.5.88.0/21229.5.88.1 to 229.5.95.254229.5.95.2552,046
173229.5.96.0/21229.5.96.1 to 229.5.103.254229.5.103.2552,046
174229.5.104.0/21229.5.104.1 to 229.5.111.254229.5.111.2552,046
175229.5.112.0/21229.5.112.1 to 229.5.119.254229.5.119.2552,046
176229.5.120.0/21229.5.120.1 to 229.5.127.254229.5.127.2552,046
177229.5.128.0/21229.5.128.1 to 229.5.135.254229.5.135.2552,046
178229.5.136.0/21229.5.136.1 to 229.5.143.254229.5.143.2552,046
179229.5.144.0/21229.5.144.1 to 229.5.151.254229.5.151.2552,046
180229.5.152.0/21229.5.152.1 to 229.5.159.254229.5.159.2552,046
181229.5.160.0/21229.5.160.1 to 229.5.167.254229.5.167.2552,046
182229.5.168.0/21229.5.168.1 to 229.5.175.254229.5.175.2552,046
183229.5.176.0/21229.5.176.1 to 229.5.183.254229.5.183.2552,046
184229.5.184.0/21229.5.184.1 to 229.5.191.254229.5.191.2552,046
185229.5.192.0/21229.5.192.1 to 229.5.199.254229.5.199.2552,046
186229.5.200.0/21229.5.200.1 to 229.5.207.254229.5.207.2552,046
187229.5.208.0/21229.5.208.1 to 229.5.215.254229.5.215.2552,046
188229.5.216.0/21229.5.216.1 to 229.5.223.254229.5.223.2552,046
189229.5.224.0/21229.5.224.1 to 229.5.231.254229.5.231.2552,046
190229.5.232.0/21229.5.232.1 to 229.5.239.254229.5.239.2552,046
191229.5.240.0/21229.5.240.1 to 229.5.247.254229.5.247.2552,046
192229.5.248.0/21229.5.248.1 to 229.5.255.254229.5.255.2552,046
193229.6.0.0/21229.6.0.1 to 229.6.7.254229.6.7.2552,046
194229.6.8.0/21229.6.8.1 to 229.6.15.254229.6.15.2552,046
195229.6.16.0/21229.6.16.1 to 229.6.23.254229.6.23.2552,046
196229.6.24.0/21229.6.24.1 to 229.6.31.254229.6.31.2552,046
197229.6.32.0/21229.6.32.1 to 229.6.39.254229.6.39.2552,046
198229.6.40.0/21229.6.40.1 to 229.6.47.254229.6.47.2552,046
199229.6.48.0/21229.6.48.1 to 229.6.55.254229.6.55.2552,046
200229.6.56.0/21229.6.56.1 to 229.6.63.254229.6.63.2552,046
201229.6.64.0/21229.6.64.1 to 229.6.71.254229.6.71.2552,046
202229.6.72.0/21229.6.72.1 to 229.6.79.254229.6.79.2552,046
203229.6.80.0/21229.6.80.1 to 229.6.87.254229.6.87.2552,046
204229.6.88.0/21229.6.88.1 to 229.6.95.254229.6.95.2552,046
205229.6.96.0/21229.6.96.1 to 229.6.103.254229.6.103.2552,046
206229.6.104.0/21229.6.104.1 to 229.6.111.254229.6.111.2552,046
207229.6.112.0/21229.6.112.1 to 229.6.119.254229.6.119.2552,046
208229.6.120.0/21229.6.120.1 to 229.6.127.254229.6.127.2552,046
209229.6.128.0/21229.6.128.1 to 229.6.135.254229.6.135.2552,046
210229.6.136.0/21229.6.136.1 to 229.6.143.254229.6.143.2552,046
211229.6.144.0/21229.6.144.1 to 229.6.151.254229.6.151.2552,046
212229.6.152.0/21229.6.152.1 to 229.6.159.254229.6.159.2552,046
213229.6.160.0/21229.6.160.1 to 229.6.167.254229.6.167.2552,046
214229.6.168.0/21229.6.168.1 to 229.6.175.254229.6.175.2552,046
215229.6.176.0/21229.6.176.1 to 229.6.183.254229.6.183.2552,046
216229.6.184.0/21229.6.184.1 to 229.6.191.254229.6.191.2552,046
217229.6.192.0/21229.6.192.1 to 229.6.199.254229.6.199.2552,046
218229.6.200.0/21229.6.200.1 to 229.6.207.254229.6.207.2552,046
219229.6.208.0/21229.6.208.1 to 229.6.215.254229.6.215.2552,046
220229.6.216.0/21229.6.216.1 to 229.6.223.254229.6.223.2552,046
221229.6.224.0/21229.6.224.1 to 229.6.231.254229.6.231.2552,046
222229.6.232.0/21229.6.232.1 to 229.6.239.254229.6.239.2552,046
223229.6.240.0/21229.6.240.1 to 229.6.247.254229.6.247.2552,046
224229.6.248.0/21229.6.248.1 to 229.6.255.254229.6.255.2552,046
225229.7.0.0/21229.7.0.1 to 229.7.7.254229.7.7.2552,046
226229.7.8.0/21229.7.8.1 to 229.7.15.254229.7.15.2552,046
227229.7.16.0/21229.7.16.1 to 229.7.23.254229.7.23.2552,046
228229.7.24.0/21229.7.24.1 to 229.7.31.254229.7.31.2552,046
229229.7.32.0/21229.7.32.1 to 229.7.39.254229.7.39.2552,046
230229.7.40.0/21229.7.40.1 to 229.7.47.254229.7.47.2552,046
231229.7.48.0/21229.7.48.1 to 229.7.55.254229.7.55.2552,046
232229.7.56.0/21229.7.56.1 to 229.7.63.254229.7.63.2552,046
233229.7.64.0/21229.7.64.1 to 229.7.71.254229.7.71.2552,046
234229.7.72.0/21229.7.72.1 to 229.7.79.254229.7.79.2552,046
235229.7.80.0/21229.7.80.1 to 229.7.87.254229.7.87.2552,046
236229.7.88.0/21229.7.88.1 to 229.7.95.254229.7.95.2552,046
237229.7.96.0/21229.7.96.1 to 229.7.103.254229.7.103.2552,046
238229.7.104.0/21229.7.104.1 to 229.7.111.254229.7.111.2552,046
239229.7.112.0/21229.7.112.1 to 229.7.119.254229.7.119.2552,046
240229.7.120.0/21229.7.120.1 to 229.7.127.254229.7.127.2552,046
241229.7.128.0/21229.7.128.1 to 229.7.135.254229.7.135.2552,046
242229.7.136.0/21229.7.136.1 to 229.7.143.254229.7.143.2552,046
243229.7.144.0/21229.7.144.1 to 229.7.151.254229.7.151.2552,046
244229.7.152.0/21229.7.152.1 to 229.7.159.254229.7.159.2552,046
245229.7.160.0/21229.7.160.1 to 229.7.167.254229.7.167.2552,046
246229.7.168.0/21229.7.168.1 to 229.7.175.254229.7.175.2552,046
247229.7.176.0/21229.7.176.1 to 229.7.183.254229.7.183.2552,046
248229.7.184.0/21229.7.184.1 to 229.7.191.254229.7.191.2552,046
249229.7.192.0/21229.7.192.1 to 229.7.199.254229.7.199.2552,046
250229.7.200.0/21229.7.200.1 to 229.7.207.254229.7.207.2552,046
251229.7.208.0/21229.7.208.1 to 229.7.215.254229.7.215.2552,046
252229.7.216.0/21229.7.216.1 to 229.7.223.254229.7.223.2552,046
253229.7.224.0/21229.7.224.1 to 229.7.231.254229.7.231.2552,046
254229.7.232.0/21229.7.232.1 to 229.7.239.254229.7.239.2552,046
255229.7.240.0/21229.7.240.1 to 229.7.247.254229.7.247.2552,046
256229.7.248.0/21229.7.248.1 to 229.7.255.254229.7.255.2552,046

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.