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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.

Network234.167.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
234.167.0.0
Broadcast address
234.167.127.255
First usable
234.167.0.1
Last usable
234.167.127.254
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 EAA70000 · Integer 3936813056 to 3936845823
Reverse DNS zones
0.167.234.in-addr.arpa
1.167.234.in-addr.arpa
2.167.234.in-addr.arpa
3.167.234.in-addr.arpa
4.167.234.in-addr.arpa
5.167.234.in-addr.arpa
6.167.234.in-addr.arpa
7.167.234.in-addr.arpa
8.167.234.in-addr.arpa
9.167.234.in-addr.arpa
10.167.234.in-addr.arpa
11.167.234.in-addr.arpa
12.167.234.in-addr.arpa
13.167.234.in-addr.arpa
14.167.234.in-addr.arpa
15.167.234.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
Address11101010.10100111.00000000.00000000234.167.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network11101010.10100111.00000000.00000000234.167.0.0
Broadcast11101010.10100111.01111111.11111111234.167.127.255
Split into smaller subnets/28
/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)

234.167.0.0/17 makes 2,048 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1234.167.0.0/28234.167.0.1 to 234.167.0.14234.167.0.1514
2234.167.0.16/28234.167.0.17 to 234.167.0.30234.167.0.3114
3234.167.0.32/28234.167.0.33 to 234.167.0.46234.167.0.4714
4234.167.0.48/28234.167.0.49 to 234.167.0.62234.167.0.6314
5234.167.0.64/28234.167.0.65 to 234.167.0.78234.167.0.7914
6234.167.0.80/28234.167.0.81 to 234.167.0.94234.167.0.9514
7234.167.0.96/28234.167.0.97 to 234.167.0.110234.167.0.11114
8234.167.0.112/28234.167.0.113 to 234.167.0.126234.167.0.12714
9234.167.0.128/28234.167.0.129 to 234.167.0.142234.167.0.14314
10234.167.0.144/28234.167.0.145 to 234.167.0.158234.167.0.15914
11234.167.0.160/28234.167.0.161 to 234.167.0.174234.167.0.17514
12234.167.0.176/28234.167.0.177 to 234.167.0.190234.167.0.19114
13234.167.0.192/28234.167.0.193 to 234.167.0.206234.167.0.20714
14234.167.0.208/28234.167.0.209 to 234.167.0.222234.167.0.22314
15234.167.0.224/28234.167.0.225 to 234.167.0.238234.167.0.23914
16234.167.0.240/28234.167.0.241 to 234.167.0.254234.167.0.25514
17234.167.1.0/28234.167.1.1 to 234.167.1.14234.167.1.1514
18234.167.1.16/28234.167.1.17 to 234.167.1.30234.167.1.3114
19234.167.1.32/28234.167.1.33 to 234.167.1.46234.167.1.4714
20234.167.1.48/28234.167.1.49 to 234.167.1.62234.167.1.6314
21234.167.1.64/28234.167.1.65 to 234.167.1.78234.167.1.7914
22234.167.1.80/28234.167.1.81 to 234.167.1.94234.167.1.9514
23234.167.1.96/28234.167.1.97 to 234.167.1.110234.167.1.11114
24234.167.1.112/28234.167.1.113 to 234.167.1.126234.167.1.12714
25234.167.1.128/28234.167.1.129 to 234.167.1.142234.167.1.14314
26234.167.1.144/28234.167.1.145 to 234.167.1.158234.167.1.15914
27234.167.1.160/28234.167.1.161 to 234.167.1.174234.167.1.17514
28234.167.1.176/28234.167.1.177 to 234.167.1.190234.167.1.19114
29234.167.1.192/28234.167.1.193 to 234.167.1.206234.167.1.20714
30234.167.1.208/28234.167.1.209 to 234.167.1.222234.167.1.22314
31234.167.1.224/28234.167.1.225 to 234.167.1.238234.167.1.23914
32234.167.1.240/28234.167.1.241 to 234.167.1.254234.167.1.25514
33234.167.2.0/28234.167.2.1 to 234.167.2.14234.167.2.1514
34234.167.2.16/28234.167.2.17 to 234.167.2.30234.167.2.3114
35234.167.2.32/28234.167.2.33 to 234.167.2.46234.167.2.4714
36234.167.2.48/28234.167.2.49 to 234.167.2.62234.167.2.6314
37234.167.2.64/28234.167.2.65 to 234.167.2.78234.167.2.7914
38234.167.2.80/28234.167.2.81 to 234.167.2.94234.167.2.9514
39234.167.2.96/28234.167.2.97 to 234.167.2.110234.167.2.11114
40234.167.2.112/28234.167.2.113 to 234.167.2.126234.167.2.12714
41234.167.2.128/28234.167.2.129 to 234.167.2.142234.167.2.14314
42234.167.2.144/28234.167.2.145 to 234.167.2.158234.167.2.15914
43234.167.2.160/28234.167.2.161 to 234.167.2.174234.167.2.17514
44234.167.2.176/28234.167.2.177 to 234.167.2.190234.167.2.19114
45234.167.2.192/28234.167.2.193 to 234.167.2.206234.167.2.20714
46234.167.2.208/28234.167.2.209 to 234.167.2.222234.167.2.22314
47234.167.2.224/28234.167.2.225 to 234.167.2.238234.167.2.23914
48234.167.2.240/28234.167.2.241 to 234.167.2.254234.167.2.25514
49234.167.3.0/28234.167.3.1 to 234.167.3.14234.167.3.1514
50234.167.3.16/28234.167.3.17 to 234.167.3.30234.167.3.3114
51234.167.3.32/28234.167.3.33 to 234.167.3.46234.167.3.4714
52234.167.3.48/28234.167.3.49 to 234.167.3.62234.167.3.6314
53234.167.3.64/28234.167.3.65 to 234.167.3.78234.167.3.7914
54234.167.3.80/28234.167.3.81 to 234.167.3.94234.167.3.9514
55234.167.3.96/28234.167.3.97 to 234.167.3.110234.167.3.11114
56234.167.3.112/28234.167.3.113 to 234.167.3.126234.167.3.12714
57234.167.3.128/28234.167.3.129 to 234.167.3.142234.167.3.14314
58234.167.3.144/28234.167.3.145 to 234.167.3.158234.167.3.15914
59234.167.3.160/28234.167.3.161 to 234.167.3.174234.167.3.17514
60234.167.3.176/28234.167.3.177 to 234.167.3.190234.167.3.19114
61234.167.3.192/28234.167.3.193 to 234.167.3.206234.167.3.20714
62234.167.3.208/28234.167.3.209 to 234.167.3.222234.167.3.22314
63234.167.3.224/28234.167.3.225 to 234.167.3.238234.167.3.23914
64234.167.3.240/28234.167.3.241 to 234.167.3.254234.167.3.25514
65234.167.4.0/28234.167.4.1 to 234.167.4.14234.167.4.1514
66234.167.4.16/28234.167.4.17 to 234.167.4.30234.167.4.3114
67234.167.4.32/28234.167.4.33 to 234.167.4.46234.167.4.4714
68234.167.4.48/28234.167.4.49 to 234.167.4.62234.167.4.6314
69234.167.4.64/28234.167.4.65 to 234.167.4.78234.167.4.7914
70234.167.4.80/28234.167.4.81 to 234.167.4.94234.167.4.9514
71234.167.4.96/28234.167.4.97 to 234.167.4.110234.167.4.11114
72234.167.4.112/28234.167.4.113 to 234.167.4.126234.167.4.12714
73234.167.4.128/28234.167.4.129 to 234.167.4.142234.167.4.14314
74234.167.4.144/28234.167.4.145 to 234.167.4.158234.167.4.15914
75234.167.4.160/28234.167.4.161 to 234.167.4.174234.167.4.17514
76234.167.4.176/28234.167.4.177 to 234.167.4.190234.167.4.19114
77234.167.4.192/28234.167.4.193 to 234.167.4.206234.167.4.20714
78234.167.4.208/28234.167.4.209 to 234.167.4.222234.167.4.22314
79234.167.4.224/28234.167.4.225 to 234.167.4.238234.167.4.23914
80234.167.4.240/28234.167.4.241 to 234.167.4.254234.167.4.25514
81234.167.5.0/28234.167.5.1 to 234.167.5.14234.167.5.1514
82234.167.5.16/28234.167.5.17 to 234.167.5.30234.167.5.3114
83234.167.5.32/28234.167.5.33 to 234.167.5.46234.167.5.4714
84234.167.5.48/28234.167.5.49 to 234.167.5.62234.167.5.6314
85234.167.5.64/28234.167.5.65 to 234.167.5.78234.167.5.7914
86234.167.5.80/28234.167.5.81 to 234.167.5.94234.167.5.9514
87234.167.5.96/28234.167.5.97 to 234.167.5.110234.167.5.11114
88234.167.5.112/28234.167.5.113 to 234.167.5.126234.167.5.12714
89234.167.5.128/28234.167.5.129 to 234.167.5.142234.167.5.14314
90234.167.5.144/28234.167.5.145 to 234.167.5.158234.167.5.15914
91234.167.5.160/28234.167.5.161 to 234.167.5.174234.167.5.17514
92234.167.5.176/28234.167.5.177 to 234.167.5.190234.167.5.19114
93234.167.5.192/28234.167.5.193 to 234.167.5.206234.167.5.20714
94234.167.5.208/28234.167.5.209 to 234.167.5.222234.167.5.22314
95234.167.5.224/28234.167.5.225 to 234.167.5.238234.167.5.23914
96234.167.5.240/28234.167.5.241 to 234.167.5.254234.167.5.25514
97234.167.6.0/28234.167.6.1 to 234.167.6.14234.167.6.1514
98234.167.6.16/28234.167.6.17 to 234.167.6.30234.167.6.3114
99234.167.6.32/28234.167.6.33 to 234.167.6.46234.167.6.4714
100234.167.6.48/28234.167.6.49 to 234.167.6.62234.167.6.6314
101234.167.6.64/28234.167.6.65 to 234.167.6.78234.167.6.7914
102234.167.6.80/28234.167.6.81 to 234.167.6.94234.167.6.9514
103234.167.6.96/28234.167.6.97 to 234.167.6.110234.167.6.11114
104234.167.6.112/28234.167.6.113 to 234.167.6.126234.167.6.12714
105234.167.6.128/28234.167.6.129 to 234.167.6.142234.167.6.14314
106234.167.6.144/28234.167.6.145 to 234.167.6.158234.167.6.15914
107234.167.6.160/28234.167.6.161 to 234.167.6.174234.167.6.17514
108234.167.6.176/28234.167.6.177 to 234.167.6.190234.167.6.19114
109234.167.6.192/28234.167.6.193 to 234.167.6.206234.167.6.20714
110234.167.6.208/28234.167.6.209 to 234.167.6.222234.167.6.22314
111234.167.6.224/28234.167.6.225 to 234.167.6.238234.167.6.23914
112234.167.6.240/28234.167.6.241 to 234.167.6.254234.167.6.25514
113234.167.7.0/28234.167.7.1 to 234.167.7.14234.167.7.1514
114234.167.7.16/28234.167.7.17 to 234.167.7.30234.167.7.3114
115234.167.7.32/28234.167.7.33 to 234.167.7.46234.167.7.4714
116234.167.7.48/28234.167.7.49 to 234.167.7.62234.167.7.6314
117234.167.7.64/28234.167.7.65 to 234.167.7.78234.167.7.7914
118234.167.7.80/28234.167.7.81 to 234.167.7.94234.167.7.9514
119234.167.7.96/28234.167.7.97 to 234.167.7.110234.167.7.11114
120234.167.7.112/28234.167.7.113 to 234.167.7.126234.167.7.12714
121234.167.7.128/28234.167.7.129 to 234.167.7.142234.167.7.14314
122234.167.7.144/28234.167.7.145 to 234.167.7.158234.167.7.15914
123234.167.7.160/28234.167.7.161 to 234.167.7.174234.167.7.17514
124234.167.7.176/28234.167.7.177 to 234.167.7.190234.167.7.19114
125234.167.7.192/28234.167.7.193 to 234.167.7.206234.167.7.20714
126234.167.7.208/28234.167.7.209 to 234.167.7.222234.167.7.22314
127234.167.7.224/28234.167.7.225 to 234.167.7.238234.167.7.23914
128234.167.7.240/28234.167.7.241 to 234.167.7.254234.167.7.25514
129234.167.8.0/28234.167.8.1 to 234.167.8.14234.167.8.1514
130234.167.8.16/28234.167.8.17 to 234.167.8.30234.167.8.3114
131234.167.8.32/28234.167.8.33 to 234.167.8.46234.167.8.4714
132234.167.8.48/28234.167.8.49 to 234.167.8.62234.167.8.6314
133234.167.8.64/28234.167.8.65 to 234.167.8.78234.167.8.7914
134234.167.8.80/28234.167.8.81 to 234.167.8.94234.167.8.9514
135234.167.8.96/28234.167.8.97 to 234.167.8.110234.167.8.11114
136234.167.8.112/28234.167.8.113 to 234.167.8.126234.167.8.12714
137234.167.8.128/28234.167.8.129 to 234.167.8.142234.167.8.14314
138234.167.8.144/28234.167.8.145 to 234.167.8.158234.167.8.15914
139234.167.8.160/28234.167.8.161 to 234.167.8.174234.167.8.17514
140234.167.8.176/28234.167.8.177 to 234.167.8.190234.167.8.19114
141234.167.8.192/28234.167.8.193 to 234.167.8.206234.167.8.20714
142234.167.8.208/28234.167.8.209 to 234.167.8.222234.167.8.22314
143234.167.8.224/28234.167.8.225 to 234.167.8.238234.167.8.23914
144234.167.8.240/28234.167.8.241 to 234.167.8.254234.167.8.25514
145234.167.9.0/28234.167.9.1 to 234.167.9.14234.167.9.1514
146234.167.9.16/28234.167.9.17 to 234.167.9.30234.167.9.3114
147234.167.9.32/28234.167.9.33 to 234.167.9.46234.167.9.4714
148234.167.9.48/28234.167.9.49 to 234.167.9.62234.167.9.6314
149234.167.9.64/28234.167.9.65 to 234.167.9.78234.167.9.7914
150234.167.9.80/28234.167.9.81 to 234.167.9.94234.167.9.9514
151234.167.9.96/28234.167.9.97 to 234.167.9.110234.167.9.11114
152234.167.9.112/28234.167.9.113 to 234.167.9.126234.167.9.12714
153234.167.9.128/28234.167.9.129 to 234.167.9.142234.167.9.14314
154234.167.9.144/28234.167.9.145 to 234.167.9.158234.167.9.15914
155234.167.9.160/28234.167.9.161 to 234.167.9.174234.167.9.17514
156234.167.9.176/28234.167.9.177 to 234.167.9.190234.167.9.19114
157234.167.9.192/28234.167.9.193 to 234.167.9.206234.167.9.20714
158234.167.9.208/28234.167.9.209 to 234.167.9.222234.167.9.22314
159234.167.9.224/28234.167.9.225 to 234.167.9.238234.167.9.23914
160234.167.9.240/28234.167.9.241 to 234.167.9.254234.167.9.25514
161234.167.10.0/28234.167.10.1 to 234.167.10.14234.167.10.1514
162234.167.10.16/28234.167.10.17 to 234.167.10.30234.167.10.3114
163234.167.10.32/28234.167.10.33 to 234.167.10.46234.167.10.4714
164234.167.10.48/28234.167.10.49 to 234.167.10.62234.167.10.6314
165234.167.10.64/28234.167.10.65 to 234.167.10.78234.167.10.7914
166234.167.10.80/28234.167.10.81 to 234.167.10.94234.167.10.9514
167234.167.10.96/28234.167.10.97 to 234.167.10.110234.167.10.11114
168234.167.10.112/28234.167.10.113 to 234.167.10.126234.167.10.12714
169234.167.10.128/28234.167.10.129 to 234.167.10.142234.167.10.14314
170234.167.10.144/28234.167.10.145 to 234.167.10.158234.167.10.15914
171234.167.10.160/28234.167.10.161 to 234.167.10.174234.167.10.17514
172234.167.10.176/28234.167.10.177 to 234.167.10.190234.167.10.19114
173234.167.10.192/28234.167.10.193 to 234.167.10.206234.167.10.20714
174234.167.10.208/28234.167.10.209 to 234.167.10.222234.167.10.22314
175234.167.10.224/28234.167.10.225 to 234.167.10.238234.167.10.23914
176234.167.10.240/28234.167.10.241 to 234.167.10.254234.167.10.25514
177234.167.11.0/28234.167.11.1 to 234.167.11.14234.167.11.1514
178234.167.11.16/28234.167.11.17 to 234.167.11.30234.167.11.3114
179234.167.11.32/28234.167.11.33 to 234.167.11.46234.167.11.4714
180234.167.11.48/28234.167.11.49 to 234.167.11.62234.167.11.6314
181234.167.11.64/28234.167.11.65 to 234.167.11.78234.167.11.7914
182234.167.11.80/28234.167.11.81 to 234.167.11.94234.167.11.9514
183234.167.11.96/28234.167.11.97 to 234.167.11.110234.167.11.11114
184234.167.11.112/28234.167.11.113 to 234.167.11.126234.167.11.12714
185234.167.11.128/28234.167.11.129 to 234.167.11.142234.167.11.14314
186234.167.11.144/28234.167.11.145 to 234.167.11.158234.167.11.15914
187234.167.11.160/28234.167.11.161 to 234.167.11.174234.167.11.17514
188234.167.11.176/28234.167.11.177 to 234.167.11.190234.167.11.19114
189234.167.11.192/28234.167.11.193 to 234.167.11.206234.167.11.20714
190234.167.11.208/28234.167.11.209 to 234.167.11.222234.167.11.22314
191234.167.11.224/28234.167.11.225 to 234.167.11.238234.167.11.23914
192234.167.11.240/28234.167.11.241 to 234.167.11.254234.167.11.25514
193234.167.12.0/28234.167.12.1 to 234.167.12.14234.167.12.1514
194234.167.12.16/28234.167.12.17 to 234.167.12.30234.167.12.3114
195234.167.12.32/28234.167.12.33 to 234.167.12.46234.167.12.4714
196234.167.12.48/28234.167.12.49 to 234.167.12.62234.167.12.6314
197234.167.12.64/28234.167.12.65 to 234.167.12.78234.167.12.7914
198234.167.12.80/28234.167.12.81 to 234.167.12.94234.167.12.9514
199234.167.12.96/28234.167.12.97 to 234.167.12.110234.167.12.11114
200234.167.12.112/28234.167.12.113 to 234.167.12.126234.167.12.12714
201234.167.12.128/28234.167.12.129 to 234.167.12.142234.167.12.14314
202234.167.12.144/28234.167.12.145 to 234.167.12.158234.167.12.15914
203234.167.12.160/28234.167.12.161 to 234.167.12.174234.167.12.17514
204234.167.12.176/28234.167.12.177 to 234.167.12.190234.167.12.19114
205234.167.12.192/28234.167.12.193 to 234.167.12.206234.167.12.20714
206234.167.12.208/28234.167.12.209 to 234.167.12.222234.167.12.22314
207234.167.12.224/28234.167.12.225 to 234.167.12.238234.167.12.23914
208234.167.12.240/28234.167.12.241 to 234.167.12.254234.167.12.25514
209234.167.13.0/28234.167.13.1 to 234.167.13.14234.167.13.1514
210234.167.13.16/28234.167.13.17 to 234.167.13.30234.167.13.3114
211234.167.13.32/28234.167.13.33 to 234.167.13.46234.167.13.4714
212234.167.13.48/28234.167.13.49 to 234.167.13.62234.167.13.6314
213234.167.13.64/28234.167.13.65 to 234.167.13.78234.167.13.7914
214234.167.13.80/28234.167.13.81 to 234.167.13.94234.167.13.9514
215234.167.13.96/28234.167.13.97 to 234.167.13.110234.167.13.11114
216234.167.13.112/28234.167.13.113 to 234.167.13.126234.167.13.12714
217234.167.13.128/28234.167.13.129 to 234.167.13.142234.167.13.14314
218234.167.13.144/28234.167.13.145 to 234.167.13.158234.167.13.15914
219234.167.13.160/28234.167.13.161 to 234.167.13.174234.167.13.17514
220234.167.13.176/28234.167.13.177 to 234.167.13.190234.167.13.19114
221234.167.13.192/28234.167.13.193 to 234.167.13.206234.167.13.20714
222234.167.13.208/28234.167.13.209 to 234.167.13.222234.167.13.22314
223234.167.13.224/28234.167.13.225 to 234.167.13.238234.167.13.23914
224234.167.13.240/28234.167.13.241 to 234.167.13.254234.167.13.25514
225234.167.14.0/28234.167.14.1 to 234.167.14.14234.167.14.1514
226234.167.14.16/28234.167.14.17 to 234.167.14.30234.167.14.3114
227234.167.14.32/28234.167.14.33 to 234.167.14.46234.167.14.4714
228234.167.14.48/28234.167.14.49 to 234.167.14.62234.167.14.6314
229234.167.14.64/28234.167.14.65 to 234.167.14.78234.167.14.7914
230234.167.14.80/28234.167.14.81 to 234.167.14.94234.167.14.9514
231234.167.14.96/28234.167.14.97 to 234.167.14.110234.167.14.11114
232234.167.14.112/28234.167.14.113 to 234.167.14.126234.167.14.12714
233234.167.14.128/28234.167.14.129 to 234.167.14.142234.167.14.14314
234234.167.14.144/28234.167.14.145 to 234.167.14.158234.167.14.15914
235234.167.14.160/28234.167.14.161 to 234.167.14.174234.167.14.17514
236234.167.14.176/28234.167.14.177 to 234.167.14.190234.167.14.19114
237234.167.14.192/28234.167.14.193 to 234.167.14.206234.167.14.20714
238234.167.14.208/28234.167.14.209 to 234.167.14.222234.167.14.22314
239234.167.14.224/28234.167.14.225 to 234.167.14.238234.167.14.23914
240234.167.14.240/28234.167.14.241 to 234.167.14.254234.167.14.25514
241234.167.15.0/28234.167.15.1 to 234.167.15.14234.167.15.1514
242234.167.15.16/28234.167.15.17 to 234.167.15.30234.167.15.3114
243234.167.15.32/28234.167.15.33 to 234.167.15.46234.167.15.4714
244234.167.15.48/28234.167.15.49 to 234.167.15.62234.167.15.6314
245234.167.15.64/28234.167.15.65 to 234.167.15.78234.167.15.7914
246234.167.15.80/28234.167.15.81 to 234.167.15.94234.167.15.9514
247234.167.15.96/28234.167.15.97 to 234.167.15.110234.167.15.11114
248234.167.15.112/28234.167.15.113 to 234.167.15.126234.167.15.12714
249234.167.15.128/28234.167.15.129 to 234.167.15.142234.167.15.14314
250234.167.15.144/28234.167.15.145 to 234.167.15.158234.167.15.15914
251234.167.15.160/28234.167.15.161 to 234.167.15.174234.167.15.17514
252234.167.15.176/28234.167.15.177 to 234.167.15.190234.167.15.19114
253234.167.15.192/28234.167.15.193 to 234.167.15.206234.167.15.20714
254234.167.15.208/28234.167.15.209 to 234.167.15.222234.167.15.22314
255234.167.15.224/28234.167.15.225 to 234.167.15.238234.167.15.23914
256234.167.15.240/28234.167.15.241 to 234.167.15.254234.167.15.25514

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.