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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.

Network234.167.128.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
234.167.128.0
Broadcast address
234.167.255.255
First usable
234.167.128.1
Last usable
234.167.255.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex EAA78000 · Integer 3936845824 to 3936878591
Reverse DNS zones
128.167.234.in-addr.arpa
129.167.234.in-addr.arpa
130.167.234.in-addr.arpa
131.167.234.in-addr.arpa
132.167.234.in-addr.arpa
133.167.234.in-addr.arpa
134.167.234.in-addr.arpa
135.167.234.in-addr.arpa
136.167.234.in-addr.arpa
137.167.234.in-addr.arpa
138.167.234.in-addr.arpa
139.167.234.in-addr.arpa
140.167.234.in-addr.arpa
141.167.234.in-addr.arpa
142.167.234.in-addr.arpa
143.167.234.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11101010.10100111.10000000.00000000234.167.128.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network11101010.10100111.10000000.00000000234.167.128.0
Broadcast11101010.10100111.11111111.11111111234.167.255.255
Split into smaller subnets/26
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

234.167.128.0/17 makes 512 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1234.167.128.0/26234.167.128.1 to 234.167.128.62234.167.128.6362
2234.167.128.64/26234.167.128.65 to 234.167.128.126234.167.128.12762
3234.167.128.128/26234.167.128.129 to 234.167.128.190234.167.128.19162
4234.167.128.192/26234.167.128.193 to 234.167.128.254234.167.128.25562
5234.167.129.0/26234.167.129.1 to 234.167.129.62234.167.129.6362
6234.167.129.64/26234.167.129.65 to 234.167.129.126234.167.129.12762
7234.167.129.128/26234.167.129.129 to 234.167.129.190234.167.129.19162
8234.167.129.192/26234.167.129.193 to 234.167.129.254234.167.129.25562
9234.167.130.0/26234.167.130.1 to 234.167.130.62234.167.130.6362
10234.167.130.64/26234.167.130.65 to 234.167.130.126234.167.130.12762
11234.167.130.128/26234.167.130.129 to 234.167.130.190234.167.130.19162
12234.167.130.192/26234.167.130.193 to 234.167.130.254234.167.130.25562
13234.167.131.0/26234.167.131.1 to 234.167.131.62234.167.131.6362
14234.167.131.64/26234.167.131.65 to 234.167.131.126234.167.131.12762
15234.167.131.128/26234.167.131.129 to 234.167.131.190234.167.131.19162
16234.167.131.192/26234.167.131.193 to 234.167.131.254234.167.131.25562
17234.167.132.0/26234.167.132.1 to 234.167.132.62234.167.132.6362
18234.167.132.64/26234.167.132.65 to 234.167.132.126234.167.132.12762
19234.167.132.128/26234.167.132.129 to 234.167.132.190234.167.132.19162
20234.167.132.192/26234.167.132.193 to 234.167.132.254234.167.132.25562
21234.167.133.0/26234.167.133.1 to 234.167.133.62234.167.133.6362
22234.167.133.64/26234.167.133.65 to 234.167.133.126234.167.133.12762
23234.167.133.128/26234.167.133.129 to 234.167.133.190234.167.133.19162
24234.167.133.192/26234.167.133.193 to 234.167.133.254234.167.133.25562
25234.167.134.0/26234.167.134.1 to 234.167.134.62234.167.134.6362
26234.167.134.64/26234.167.134.65 to 234.167.134.126234.167.134.12762
27234.167.134.128/26234.167.134.129 to 234.167.134.190234.167.134.19162
28234.167.134.192/26234.167.134.193 to 234.167.134.254234.167.134.25562
29234.167.135.0/26234.167.135.1 to 234.167.135.62234.167.135.6362
30234.167.135.64/26234.167.135.65 to 234.167.135.126234.167.135.12762
31234.167.135.128/26234.167.135.129 to 234.167.135.190234.167.135.19162
32234.167.135.192/26234.167.135.193 to 234.167.135.254234.167.135.25562
33234.167.136.0/26234.167.136.1 to 234.167.136.62234.167.136.6362
34234.167.136.64/26234.167.136.65 to 234.167.136.126234.167.136.12762
35234.167.136.128/26234.167.136.129 to 234.167.136.190234.167.136.19162
36234.167.136.192/26234.167.136.193 to 234.167.136.254234.167.136.25562
37234.167.137.0/26234.167.137.1 to 234.167.137.62234.167.137.6362
38234.167.137.64/26234.167.137.65 to 234.167.137.126234.167.137.12762
39234.167.137.128/26234.167.137.129 to 234.167.137.190234.167.137.19162
40234.167.137.192/26234.167.137.193 to 234.167.137.254234.167.137.25562
41234.167.138.0/26234.167.138.1 to 234.167.138.62234.167.138.6362
42234.167.138.64/26234.167.138.65 to 234.167.138.126234.167.138.12762
43234.167.138.128/26234.167.138.129 to 234.167.138.190234.167.138.19162
44234.167.138.192/26234.167.138.193 to 234.167.138.254234.167.138.25562
45234.167.139.0/26234.167.139.1 to 234.167.139.62234.167.139.6362
46234.167.139.64/26234.167.139.65 to 234.167.139.126234.167.139.12762
47234.167.139.128/26234.167.139.129 to 234.167.139.190234.167.139.19162
48234.167.139.192/26234.167.139.193 to 234.167.139.254234.167.139.25562
49234.167.140.0/26234.167.140.1 to 234.167.140.62234.167.140.6362
50234.167.140.64/26234.167.140.65 to 234.167.140.126234.167.140.12762
51234.167.140.128/26234.167.140.129 to 234.167.140.190234.167.140.19162
52234.167.140.192/26234.167.140.193 to 234.167.140.254234.167.140.25562
53234.167.141.0/26234.167.141.1 to 234.167.141.62234.167.141.6362
54234.167.141.64/26234.167.141.65 to 234.167.141.126234.167.141.12762
55234.167.141.128/26234.167.141.129 to 234.167.141.190234.167.141.19162
56234.167.141.192/26234.167.141.193 to 234.167.141.254234.167.141.25562
57234.167.142.0/26234.167.142.1 to 234.167.142.62234.167.142.6362
58234.167.142.64/26234.167.142.65 to 234.167.142.126234.167.142.12762
59234.167.142.128/26234.167.142.129 to 234.167.142.190234.167.142.19162
60234.167.142.192/26234.167.142.193 to 234.167.142.254234.167.142.25562
61234.167.143.0/26234.167.143.1 to 234.167.143.62234.167.143.6362
62234.167.143.64/26234.167.143.65 to 234.167.143.126234.167.143.12762
63234.167.143.128/26234.167.143.129 to 234.167.143.190234.167.143.19162
64234.167.143.192/26234.167.143.193 to 234.167.143.254234.167.143.25562
65234.167.144.0/26234.167.144.1 to 234.167.144.62234.167.144.6362
66234.167.144.64/26234.167.144.65 to 234.167.144.126234.167.144.12762
67234.167.144.128/26234.167.144.129 to 234.167.144.190234.167.144.19162
68234.167.144.192/26234.167.144.193 to 234.167.144.254234.167.144.25562
69234.167.145.0/26234.167.145.1 to 234.167.145.62234.167.145.6362
70234.167.145.64/26234.167.145.65 to 234.167.145.126234.167.145.12762
71234.167.145.128/26234.167.145.129 to 234.167.145.190234.167.145.19162
72234.167.145.192/26234.167.145.193 to 234.167.145.254234.167.145.25562
73234.167.146.0/26234.167.146.1 to 234.167.146.62234.167.146.6362
74234.167.146.64/26234.167.146.65 to 234.167.146.126234.167.146.12762
75234.167.146.128/26234.167.146.129 to 234.167.146.190234.167.146.19162
76234.167.146.192/26234.167.146.193 to 234.167.146.254234.167.146.25562
77234.167.147.0/26234.167.147.1 to 234.167.147.62234.167.147.6362
78234.167.147.64/26234.167.147.65 to 234.167.147.126234.167.147.12762
79234.167.147.128/26234.167.147.129 to 234.167.147.190234.167.147.19162
80234.167.147.192/26234.167.147.193 to 234.167.147.254234.167.147.25562
81234.167.148.0/26234.167.148.1 to 234.167.148.62234.167.148.6362
82234.167.148.64/26234.167.148.65 to 234.167.148.126234.167.148.12762
83234.167.148.128/26234.167.148.129 to 234.167.148.190234.167.148.19162
84234.167.148.192/26234.167.148.193 to 234.167.148.254234.167.148.25562
85234.167.149.0/26234.167.149.1 to 234.167.149.62234.167.149.6362
86234.167.149.64/26234.167.149.65 to 234.167.149.126234.167.149.12762
87234.167.149.128/26234.167.149.129 to 234.167.149.190234.167.149.19162
88234.167.149.192/26234.167.149.193 to 234.167.149.254234.167.149.25562
89234.167.150.0/26234.167.150.1 to 234.167.150.62234.167.150.6362
90234.167.150.64/26234.167.150.65 to 234.167.150.126234.167.150.12762
91234.167.150.128/26234.167.150.129 to 234.167.150.190234.167.150.19162
92234.167.150.192/26234.167.150.193 to 234.167.150.254234.167.150.25562
93234.167.151.0/26234.167.151.1 to 234.167.151.62234.167.151.6362
94234.167.151.64/26234.167.151.65 to 234.167.151.126234.167.151.12762
95234.167.151.128/26234.167.151.129 to 234.167.151.190234.167.151.19162
96234.167.151.192/26234.167.151.193 to 234.167.151.254234.167.151.25562
97234.167.152.0/26234.167.152.1 to 234.167.152.62234.167.152.6362
98234.167.152.64/26234.167.152.65 to 234.167.152.126234.167.152.12762
99234.167.152.128/26234.167.152.129 to 234.167.152.190234.167.152.19162
100234.167.152.192/26234.167.152.193 to 234.167.152.254234.167.152.25562
101234.167.153.0/26234.167.153.1 to 234.167.153.62234.167.153.6362
102234.167.153.64/26234.167.153.65 to 234.167.153.126234.167.153.12762
103234.167.153.128/26234.167.153.129 to 234.167.153.190234.167.153.19162
104234.167.153.192/26234.167.153.193 to 234.167.153.254234.167.153.25562
105234.167.154.0/26234.167.154.1 to 234.167.154.62234.167.154.6362
106234.167.154.64/26234.167.154.65 to 234.167.154.126234.167.154.12762
107234.167.154.128/26234.167.154.129 to 234.167.154.190234.167.154.19162
108234.167.154.192/26234.167.154.193 to 234.167.154.254234.167.154.25562
109234.167.155.0/26234.167.155.1 to 234.167.155.62234.167.155.6362
110234.167.155.64/26234.167.155.65 to 234.167.155.126234.167.155.12762
111234.167.155.128/26234.167.155.129 to 234.167.155.190234.167.155.19162
112234.167.155.192/26234.167.155.193 to 234.167.155.254234.167.155.25562
113234.167.156.0/26234.167.156.1 to 234.167.156.62234.167.156.6362
114234.167.156.64/26234.167.156.65 to 234.167.156.126234.167.156.12762
115234.167.156.128/26234.167.156.129 to 234.167.156.190234.167.156.19162
116234.167.156.192/26234.167.156.193 to 234.167.156.254234.167.156.25562
117234.167.157.0/26234.167.157.1 to 234.167.157.62234.167.157.6362
118234.167.157.64/26234.167.157.65 to 234.167.157.126234.167.157.12762
119234.167.157.128/26234.167.157.129 to 234.167.157.190234.167.157.19162
120234.167.157.192/26234.167.157.193 to 234.167.157.254234.167.157.25562
121234.167.158.0/26234.167.158.1 to 234.167.158.62234.167.158.6362
122234.167.158.64/26234.167.158.65 to 234.167.158.126234.167.158.12762
123234.167.158.128/26234.167.158.129 to 234.167.158.190234.167.158.19162
124234.167.158.192/26234.167.158.193 to 234.167.158.254234.167.158.25562
125234.167.159.0/26234.167.159.1 to 234.167.159.62234.167.159.6362
126234.167.159.64/26234.167.159.65 to 234.167.159.126234.167.159.12762
127234.167.159.128/26234.167.159.129 to 234.167.159.190234.167.159.19162
128234.167.159.192/26234.167.159.193 to 234.167.159.254234.167.159.25562
129234.167.160.0/26234.167.160.1 to 234.167.160.62234.167.160.6362
130234.167.160.64/26234.167.160.65 to 234.167.160.126234.167.160.12762
131234.167.160.128/26234.167.160.129 to 234.167.160.190234.167.160.19162
132234.167.160.192/26234.167.160.193 to 234.167.160.254234.167.160.25562
133234.167.161.0/26234.167.161.1 to 234.167.161.62234.167.161.6362
134234.167.161.64/26234.167.161.65 to 234.167.161.126234.167.161.12762
135234.167.161.128/26234.167.161.129 to 234.167.161.190234.167.161.19162
136234.167.161.192/26234.167.161.193 to 234.167.161.254234.167.161.25562
137234.167.162.0/26234.167.162.1 to 234.167.162.62234.167.162.6362
138234.167.162.64/26234.167.162.65 to 234.167.162.126234.167.162.12762
139234.167.162.128/26234.167.162.129 to 234.167.162.190234.167.162.19162
140234.167.162.192/26234.167.162.193 to 234.167.162.254234.167.162.25562
141234.167.163.0/26234.167.163.1 to 234.167.163.62234.167.163.6362
142234.167.163.64/26234.167.163.65 to 234.167.163.126234.167.163.12762
143234.167.163.128/26234.167.163.129 to 234.167.163.190234.167.163.19162
144234.167.163.192/26234.167.163.193 to 234.167.163.254234.167.163.25562
145234.167.164.0/26234.167.164.1 to 234.167.164.62234.167.164.6362
146234.167.164.64/26234.167.164.65 to 234.167.164.126234.167.164.12762
147234.167.164.128/26234.167.164.129 to 234.167.164.190234.167.164.19162
148234.167.164.192/26234.167.164.193 to 234.167.164.254234.167.164.25562
149234.167.165.0/26234.167.165.1 to 234.167.165.62234.167.165.6362
150234.167.165.64/26234.167.165.65 to 234.167.165.126234.167.165.12762
151234.167.165.128/26234.167.165.129 to 234.167.165.190234.167.165.19162
152234.167.165.192/26234.167.165.193 to 234.167.165.254234.167.165.25562
153234.167.166.0/26234.167.166.1 to 234.167.166.62234.167.166.6362
154234.167.166.64/26234.167.166.65 to 234.167.166.126234.167.166.12762
155234.167.166.128/26234.167.166.129 to 234.167.166.190234.167.166.19162
156234.167.166.192/26234.167.166.193 to 234.167.166.254234.167.166.25562
157234.167.167.0/26234.167.167.1 to 234.167.167.62234.167.167.6362
158234.167.167.64/26234.167.167.65 to 234.167.167.126234.167.167.12762
159234.167.167.128/26234.167.167.129 to 234.167.167.190234.167.167.19162
160234.167.167.192/26234.167.167.193 to 234.167.167.254234.167.167.25562
161234.167.168.0/26234.167.168.1 to 234.167.168.62234.167.168.6362
162234.167.168.64/26234.167.168.65 to 234.167.168.126234.167.168.12762
163234.167.168.128/26234.167.168.129 to 234.167.168.190234.167.168.19162
164234.167.168.192/26234.167.168.193 to 234.167.168.254234.167.168.25562
165234.167.169.0/26234.167.169.1 to 234.167.169.62234.167.169.6362
166234.167.169.64/26234.167.169.65 to 234.167.169.126234.167.169.12762
167234.167.169.128/26234.167.169.129 to 234.167.169.190234.167.169.19162
168234.167.169.192/26234.167.169.193 to 234.167.169.254234.167.169.25562
169234.167.170.0/26234.167.170.1 to 234.167.170.62234.167.170.6362
170234.167.170.64/26234.167.170.65 to 234.167.170.126234.167.170.12762
171234.167.170.128/26234.167.170.129 to 234.167.170.190234.167.170.19162
172234.167.170.192/26234.167.170.193 to 234.167.170.254234.167.170.25562
173234.167.171.0/26234.167.171.1 to 234.167.171.62234.167.171.6362
174234.167.171.64/26234.167.171.65 to 234.167.171.126234.167.171.12762
175234.167.171.128/26234.167.171.129 to 234.167.171.190234.167.171.19162
176234.167.171.192/26234.167.171.193 to 234.167.171.254234.167.171.25562
177234.167.172.0/26234.167.172.1 to 234.167.172.62234.167.172.6362
178234.167.172.64/26234.167.172.65 to 234.167.172.126234.167.172.12762
179234.167.172.128/26234.167.172.129 to 234.167.172.190234.167.172.19162
180234.167.172.192/26234.167.172.193 to 234.167.172.254234.167.172.25562
181234.167.173.0/26234.167.173.1 to 234.167.173.62234.167.173.6362
182234.167.173.64/26234.167.173.65 to 234.167.173.126234.167.173.12762
183234.167.173.128/26234.167.173.129 to 234.167.173.190234.167.173.19162
184234.167.173.192/26234.167.173.193 to 234.167.173.254234.167.173.25562
185234.167.174.0/26234.167.174.1 to 234.167.174.62234.167.174.6362
186234.167.174.64/26234.167.174.65 to 234.167.174.126234.167.174.12762
187234.167.174.128/26234.167.174.129 to 234.167.174.190234.167.174.19162
188234.167.174.192/26234.167.174.193 to 234.167.174.254234.167.174.25562
189234.167.175.0/26234.167.175.1 to 234.167.175.62234.167.175.6362
190234.167.175.64/26234.167.175.65 to 234.167.175.126234.167.175.12762
191234.167.175.128/26234.167.175.129 to 234.167.175.190234.167.175.19162
192234.167.175.192/26234.167.175.193 to 234.167.175.254234.167.175.25562
193234.167.176.0/26234.167.176.1 to 234.167.176.62234.167.176.6362
194234.167.176.64/26234.167.176.65 to 234.167.176.126234.167.176.12762
195234.167.176.128/26234.167.176.129 to 234.167.176.190234.167.176.19162
196234.167.176.192/26234.167.176.193 to 234.167.176.254234.167.176.25562
197234.167.177.0/26234.167.177.1 to 234.167.177.62234.167.177.6362
198234.167.177.64/26234.167.177.65 to 234.167.177.126234.167.177.12762
199234.167.177.128/26234.167.177.129 to 234.167.177.190234.167.177.19162
200234.167.177.192/26234.167.177.193 to 234.167.177.254234.167.177.25562
201234.167.178.0/26234.167.178.1 to 234.167.178.62234.167.178.6362
202234.167.178.64/26234.167.178.65 to 234.167.178.126234.167.178.12762
203234.167.178.128/26234.167.178.129 to 234.167.178.190234.167.178.19162
204234.167.178.192/26234.167.178.193 to 234.167.178.254234.167.178.25562
205234.167.179.0/26234.167.179.1 to 234.167.179.62234.167.179.6362
206234.167.179.64/26234.167.179.65 to 234.167.179.126234.167.179.12762
207234.167.179.128/26234.167.179.129 to 234.167.179.190234.167.179.19162
208234.167.179.192/26234.167.179.193 to 234.167.179.254234.167.179.25562
209234.167.180.0/26234.167.180.1 to 234.167.180.62234.167.180.6362
210234.167.180.64/26234.167.180.65 to 234.167.180.126234.167.180.12762
211234.167.180.128/26234.167.180.129 to 234.167.180.190234.167.180.19162
212234.167.180.192/26234.167.180.193 to 234.167.180.254234.167.180.25562
213234.167.181.0/26234.167.181.1 to 234.167.181.62234.167.181.6362
214234.167.181.64/26234.167.181.65 to 234.167.181.126234.167.181.12762
215234.167.181.128/26234.167.181.129 to 234.167.181.190234.167.181.19162
216234.167.181.192/26234.167.181.193 to 234.167.181.254234.167.181.25562
217234.167.182.0/26234.167.182.1 to 234.167.182.62234.167.182.6362
218234.167.182.64/26234.167.182.65 to 234.167.182.126234.167.182.12762
219234.167.182.128/26234.167.182.129 to 234.167.182.190234.167.182.19162
220234.167.182.192/26234.167.182.193 to 234.167.182.254234.167.182.25562
221234.167.183.0/26234.167.183.1 to 234.167.183.62234.167.183.6362
222234.167.183.64/26234.167.183.65 to 234.167.183.126234.167.183.12762
223234.167.183.128/26234.167.183.129 to 234.167.183.190234.167.183.19162
224234.167.183.192/26234.167.183.193 to 234.167.183.254234.167.183.25562
225234.167.184.0/26234.167.184.1 to 234.167.184.62234.167.184.6362
226234.167.184.64/26234.167.184.65 to 234.167.184.126234.167.184.12762
227234.167.184.128/26234.167.184.129 to 234.167.184.190234.167.184.19162
228234.167.184.192/26234.167.184.193 to 234.167.184.254234.167.184.25562
229234.167.185.0/26234.167.185.1 to 234.167.185.62234.167.185.6362
230234.167.185.64/26234.167.185.65 to 234.167.185.126234.167.185.12762
231234.167.185.128/26234.167.185.129 to 234.167.185.190234.167.185.19162
232234.167.185.192/26234.167.185.193 to 234.167.185.254234.167.185.25562
233234.167.186.0/26234.167.186.1 to 234.167.186.62234.167.186.6362
234234.167.186.64/26234.167.186.65 to 234.167.186.126234.167.186.12762
235234.167.186.128/26234.167.186.129 to 234.167.186.190234.167.186.19162
236234.167.186.192/26234.167.186.193 to 234.167.186.254234.167.186.25562
237234.167.187.0/26234.167.187.1 to 234.167.187.62234.167.187.6362
238234.167.187.64/26234.167.187.65 to 234.167.187.126234.167.187.12762
239234.167.187.128/26234.167.187.129 to 234.167.187.190234.167.187.19162
240234.167.187.192/26234.167.187.193 to 234.167.187.254234.167.187.25562
241234.167.188.0/26234.167.188.1 to 234.167.188.62234.167.188.6362
242234.167.188.64/26234.167.188.65 to 234.167.188.126234.167.188.12762
243234.167.188.128/26234.167.188.129 to 234.167.188.190234.167.188.19162
244234.167.188.192/26234.167.188.193 to 234.167.188.254234.167.188.25562
245234.167.189.0/26234.167.189.1 to 234.167.189.62234.167.189.6362
246234.167.189.64/26234.167.189.65 to 234.167.189.126234.167.189.12762
247234.167.189.128/26234.167.189.129 to 234.167.189.190234.167.189.19162
248234.167.189.192/26234.167.189.193 to 234.167.189.254234.167.189.25562
249234.167.190.0/26234.167.190.1 to 234.167.190.62234.167.190.6362
250234.167.190.64/26234.167.190.65 to 234.167.190.126234.167.190.12762
251234.167.190.128/26234.167.190.129 to 234.167.190.190234.167.190.19162
252234.167.190.192/26234.167.190.193 to 234.167.190.254234.167.190.25562
253234.167.191.0/26234.167.191.1 to 234.167.191.62234.167.191.6362
254234.167.191.64/26234.167.191.65 to 234.167.191.126234.167.191.12762
255234.167.191.128/26234.167.191.129 to 234.167.191.190234.167.191.19162
256234.167.191.192/26234.167.191.193 to 234.167.191.254234.167.191.25562

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.