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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/29
/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 4,096 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1234.167.128.0/29234.167.128.1 to 234.167.128.6234.167.128.76
2234.167.128.8/29234.167.128.9 to 234.167.128.14234.167.128.156
3234.167.128.16/29234.167.128.17 to 234.167.128.22234.167.128.236
4234.167.128.24/29234.167.128.25 to 234.167.128.30234.167.128.316
5234.167.128.32/29234.167.128.33 to 234.167.128.38234.167.128.396
6234.167.128.40/29234.167.128.41 to 234.167.128.46234.167.128.476
7234.167.128.48/29234.167.128.49 to 234.167.128.54234.167.128.556
8234.167.128.56/29234.167.128.57 to 234.167.128.62234.167.128.636
9234.167.128.64/29234.167.128.65 to 234.167.128.70234.167.128.716
10234.167.128.72/29234.167.128.73 to 234.167.128.78234.167.128.796
11234.167.128.80/29234.167.128.81 to 234.167.128.86234.167.128.876
12234.167.128.88/29234.167.128.89 to 234.167.128.94234.167.128.956
13234.167.128.96/29234.167.128.97 to 234.167.128.102234.167.128.1036
14234.167.128.104/29234.167.128.105 to 234.167.128.110234.167.128.1116
15234.167.128.112/29234.167.128.113 to 234.167.128.118234.167.128.1196
16234.167.128.120/29234.167.128.121 to 234.167.128.126234.167.128.1276
17234.167.128.128/29234.167.128.129 to 234.167.128.134234.167.128.1356
18234.167.128.136/29234.167.128.137 to 234.167.128.142234.167.128.1436
19234.167.128.144/29234.167.128.145 to 234.167.128.150234.167.128.1516
20234.167.128.152/29234.167.128.153 to 234.167.128.158234.167.128.1596
21234.167.128.160/29234.167.128.161 to 234.167.128.166234.167.128.1676
22234.167.128.168/29234.167.128.169 to 234.167.128.174234.167.128.1756
23234.167.128.176/29234.167.128.177 to 234.167.128.182234.167.128.1836
24234.167.128.184/29234.167.128.185 to 234.167.128.190234.167.128.1916
25234.167.128.192/29234.167.128.193 to 234.167.128.198234.167.128.1996
26234.167.128.200/29234.167.128.201 to 234.167.128.206234.167.128.2076
27234.167.128.208/29234.167.128.209 to 234.167.128.214234.167.128.2156
28234.167.128.216/29234.167.128.217 to 234.167.128.222234.167.128.2236
29234.167.128.224/29234.167.128.225 to 234.167.128.230234.167.128.2316
30234.167.128.232/29234.167.128.233 to 234.167.128.238234.167.128.2396
31234.167.128.240/29234.167.128.241 to 234.167.128.246234.167.128.2476
32234.167.128.248/29234.167.128.249 to 234.167.128.254234.167.128.2556
33234.167.129.0/29234.167.129.1 to 234.167.129.6234.167.129.76
34234.167.129.8/29234.167.129.9 to 234.167.129.14234.167.129.156
35234.167.129.16/29234.167.129.17 to 234.167.129.22234.167.129.236
36234.167.129.24/29234.167.129.25 to 234.167.129.30234.167.129.316
37234.167.129.32/29234.167.129.33 to 234.167.129.38234.167.129.396
38234.167.129.40/29234.167.129.41 to 234.167.129.46234.167.129.476
39234.167.129.48/29234.167.129.49 to 234.167.129.54234.167.129.556
40234.167.129.56/29234.167.129.57 to 234.167.129.62234.167.129.636
41234.167.129.64/29234.167.129.65 to 234.167.129.70234.167.129.716
42234.167.129.72/29234.167.129.73 to 234.167.129.78234.167.129.796
43234.167.129.80/29234.167.129.81 to 234.167.129.86234.167.129.876
44234.167.129.88/29234.167.129.89 to 234.167.129.94234.167.129.956
45234.167.129.96/29234.167.129.97 to 234.167.129.102234.167.129.1036
46234.167.129.104/29234.167.129.105 to 234.167.129.110234.167.129.1116
47234.167.129.112/29234.167.129.113 to 234.167.129.118234.167.129.1196
48234.167.129.120/29234.167.129.121 to 234.167.129.126234.167.129.1276
49234.167.129.128/29234.167.129.129 to 234.167.129.134234.167.129.1356
50234.167.129.136/29234.167.129.137 to 234.167.129.142234.167.129.1436
51234.167.129.144/29234.167.129.145 to 234.167.129.150234.167.129.1516
52234.167.129.152/29234.167.129.153 to 234.167.129.158234.167.129.1596
53234.167.129.160/29234.167.129.161 to 234.167.129.166234.167.129.1676
54234.167.129.168/29234.167.129.169 to 234.167.129.174234.167.129.1756
55234.167.129.176/29234.167.129.177 to 234.167.129.182234.167.129.1836
56234.167.129.184/29234.167.129.185 to 234.167.129.190234.167.129.1916
57234.167.129.192/29234.167.129.193 to 234.167.129.198234.167.129.1996
58234.167.129.200/29234.167.129.201 to 234.167.129.206234.167.129.2076
59234.167.129.208/29234.167.129.209 to 234.167.129.214234.167.129.2156
60234.167.129.216/29234.167.129.217 to 234.167.129.222234.167.129.2236
61234.167.129.224/29234.167.129.225 to 234.167.129.230234.167.129.2316
62234.167.129.232/29234.167.129.233 to 234.167.129.238234.167.129.2396
63234.167.129.240/29234.167.129.241 to 234.167.129.246234.167.129.2476
64234.167.129.248/29234.167.129.249 to 234.167.129.254234.167.129.2556
65234.167.130.0/29234.167.130.1 to 234.167.130.6234.167.130.76
66234.167.130.8/29234.167.130.9 to 234.167.130.14234.167.130.156
67234.167.130.16/29234.167.130.17 to 234.167.130.22234.167.130.236
68234.167.130.24/29234.167.130.25 to 234.167.130.30234.167.130.316
69234.167.130.32/29234.167.130.33 to 234.167.130.38234.167.130.396
70234.167.130.40/29234.167.130.41 to 234.167.130.46234.167.130.476
71234.167.130.48/29234.167.130.49 to 234.167.130.54234.167.130.556
72234.167.130.56/29234.167.130.57 to 234.167.130.62234.167.130.636
73234.167.130.64/29234.167.130.65 to 234.167.130.70234.167.130.716
74234.167.130.72/29234.167.130.73 to 234.167.130.78234.167.130.796
75234.167.130.80/29234.167.130.81 to 234.167.130.86234.167.130.876
76234.167.130.88/29234.167.130.89 to 234.167.130.94234.167.130.956
77234.167.130.96/29234.167.130.97 to 234.167.130.102234.167.130.1036
78234.167.130.104/29234.167.130.105 to 234.167.130.110234.167.130.1116
79234.167.130.112/29234.167.130.113 to 234.167.130.118234.167.130.1196
80234.167.130.120/29234.167.130.121 to 234.167.130.126234.167.130.1276
81234.167.130.128/29234.167.130.129 to 234.167.130.134234.167.130.1356
82234.167.130.136/29234.167.130.137 to 234.167.130.142234.167.130.1436
83234.167.130.144/29234.167.130.145 to 234.167.130.150234.167.130.1516
84234.167.130.152/29234.167.130.153 to 234.167.130.158234.167.130.1596
85234.167.130.160/29234.167.130.161 to 234.167.130.166234.167.130.1676
86234.167.130.168/29234.167.130.169 to 234.167.130.174234.167.130.1756
87234.167.130.176/29234.167.130.177 to 234.167.130.182234.167.130.1836
88234.167.130.184/29234.167.130.185 to 234.167.130.190234.167.130.1916
89234.167.130.192/29234.167.130.193 to 234.167.130.198234.167.130.1996
90234.167.130.200/29234.167.130.201 to 234.167.130.206234.167.130.2076
91234.167.130.208/29234.167.130.209 to 234.167.130.214234.167.130.2156
92234.167.130.216/29234.167.130.217 to 234.167.130.222234.167.130.2236
93234.167.130.224/29234.167.130.225 to 234.167.130.230234.167.130.2316
94234.167.130.232/29234.167.130.233 to 234.167.130.238234.167.130.2396
95234.167.130.240/29234.167.130.241 to 234.167.130.246234.167.130.2476
96234.167.130.248/29234.167.130.249 to 234.167.130.254234.167.130.2556
97234.167.131.0/29234.167.131.1 to 234.167.131.6234.167.131.76
98234.167.131.8/29234.167.131.9 to 234.167.131.14234.167.131.156
99234.167.131.16/29234.167.131.17 to 234.167.131.22234.167.131.236
100234.167.131.24/29234.167.131.25 to 234.167.131.30234.167.131.316
101234.167.131.32/29234.167.131.33 to 234.167.131.38234.167.131.396
102234.167.131.40/29234.167.131.41 to 234.167.131.46234.167.131.476
103234.167.131.48/29234.167.131.49 to 234.167.131.54234.167.131.556
104234.167.131.56/29234.167.131.57 to 234.167.131.62234.167.131.636
105234.167.131.64/29234.167.131.65 to 234.167.131.70234.167.131.716
106234.167.131.72/29234.167.131.73 to 234.167.131.78234.167.131.796
107234.167.131.80/29234.167.131.81 to 234.167.131.86234.167.131.876
108234.167.131.88/29234.167.131.89 to 234.167.131.94234.167.131.956
109234.167.131.96/29234.167.131.97 to 234.167.131.102234.167.131.1036
110234.167.131.104/29234.167.131.105 to 234.167.131.110234.167.131.1116
111234.167.131.112/29234.167.131.113 to 234.167.131.118234.167.131.1196
112234.167.131.120/29234.167.131.121 to 234.167.131.126234.167.131.1276
113234.167.131.128/29234.167.131.129 to 234.167.131.134234.167.131.1356
114234.167.131.136/29234.167.131.137 to 234.167.131.142234.167.131.1436
115234.167.131.144/29234.167.131.145 to 234.167.131.150234.167.131.1516
116234.167.131.152/29234.167.131.153 to 234.167.131.158234.167.131.1596
117234.167.131.160/29234.167.131.161 to 234.167.131.166234.167.131.1676
118234.167.131.168/29234.167.131.169 to 234.167.131.174234.167.131.1756
119234.167.131.176/29234.167.131.177 to 234.167.131.182234.167.131.1836
120234.167.131.184/29234.167.131.185 to 234.167.131.190234.167.131.1916
121234.167.131.192/29234.167.131.193 to 234.167.131.198234.167.131.1996
122234.167.131.200/29234.167.131.201 to 234.167.131.206234.167.131.2076
123234.167.131.208/29234.167.131.209 to 234.167.131.214234.167.131.2156
124234.167.131.216/29234.167.131.217 to 234.167.131.222234.167.131.2236
125234.167.131.224/29234.167.131.225 to 234.167.131.230234.167.131.2316
126234.167.131.232/29234.167.131.233 to 234.167.131.238234.167.131.2396
127234.167.131.240/29234.167.131.241 to 234.167.131.246234.167.131.2476
128234.167.131.248/29234.167.131.249 to 234.167.131.254234.167.131.2556
129234.167.132.0/29234.167.132.1 to 234.167.132.6234.167.132.76
130234.167.132.8/29234.167.132.9 to 234.167.132.14234.167.132.156
131234.167.132.16/29234.167.132.17 to 234.167.132.22234.167.132.236
132234.167.132.24/29234.167.132.25 to 234.167.132.30234.167.132.316
133234.167.132.32/29234.167.132.33 to 234.167.132.38234.167.132.396
134234.167.132.40/29234.167.132.41 to 234.167.132.46234.167.132.476
135234.167.132.48/29234.167.132.49 to 234.167.132.54234.167.132.556
136234.167.132.56/29234.167.132.57 to 234.167.132.62234.167.132.636
137234.167.132.64/29234.167.132.65 to 234.167.132.70234.167.132.716
138234.167.132.72/29234.167.132.73 to 234.167.132.78234.167.132.796
139234.167.132.80/29234.167.132.81 to 234.167.132.86234.167.132.876
140234.167.132.88/29234.167.132.89 to 234.167.132.94234.167.132.956
141234.167.132.96/29234.167.132.97 to 234.167.132.102234.167.132.1036
142234.167.132.104/29234.167.132.105 to 234.167.132.110234.167.132.1116
143234.167.132.112/29234.167.132.113 to 234.167.132.118234.167.132.1196
144234.167.132.120/29234.167.132.121 to 234.167.132.126234.167.132.1276
145234.167.132.128/29234.167.132.129 to 234.167.132.134234.167.132.1356
146234.167.132.136/29234.167.132.137 to 234.167.132.142234.167.132.1436
147234.167.132.144/29234.167.132.145 to 234.167.132.150234.167.132.1516
148234.167.132.152/29234.167.132.153 to 234.167.132.158234.167.132.1596
149234.167.132.160/29234.167.132.161 to 234.167.132.166234.167.132.1676
150234.167.132.168/29234.167.132.169 to 234.167.132.174234.167.132.1756
151234.167.132.176/29234.167.132.177 to 234.167.132.182234.167.132.1836
152234.167.132.184/29234.167.132.185 to 234.167.132.190234.167.132.1916
153234.167.132.192/29234.167.132.193 to 234.167.132.198234.167.132.1996
154234.167.132.200/29234.167.132.201 to 234.167.132.206234.167.132.2076
155234.167.132.208/29234.167.132.209 to 234.167.132.214234.167.132.2156
156234.167.132.216/29234.167.132.217 to 234.167.132.222234.167.132.2236
157234.167.132.224/29234.167.132.225 to 234.167.132.230234.167.132.2316
158234.167.132.232/29234.167.132.233 to 234.167.132.238234.167.132.2396
159234.167.132.240/29234.167.132.241 to 234.167.132.246234.167.132.2476
160234.167.132.248/29234.167.132.249 to 234.167.132.254234.167.132.2556
161234.167.133.0/29234.167.133.1 to 234.167.133.6234.167.133.76
162234.167.133.8/29234.167.133.9 to 234.167.133.14234.167.133.156
163234.167.133.16/29234.167.133.17 to 234.167.133.22234.167.133.236
164234.167.133.24/29234.167.133.25 to 234.167.133.30234.167.133.316
165234.167.133.32/29234.167.133.33 to 234.167.133.38234.167.133.396
166234.167.133.40/29234.167.133.41 to 234.167.133.46234.167.133.476
167234.167.133.48/29234.167.133.49 to 234.167.133.54234.167.133.556
168234.167.133.56/29234.167.133.57 to 234.167.133.62234.167.133.636
169234.167.133.64/29234.167.133.65 to 234.167.133.70234.167.133.716
170234.167.133.72/29234.167.133.73 to 234.167.133.78234.167.133.796
171234.167.133.80/29234.167.133.81 to 234.167.133.86234.167.133.876
172234.167.133.88/29234.167.133.89 to 234.167.133.94234.167.133.956
173234.167.133.96/29234.167.133.97 to 234.167.133.102234.167.133.1036
174234.167.133.104/29234.167.133.105 to 234.167.133.110234.167.133.1116
175234.167.133.112/29234.167.133.113 to 234.167.133.118234.167.133.1196
176234.167.133.120/29234.167.133.121 to 234.167.133.126234.167.133.1276
177234.167.133.128/29234.167.133.129 to 234.167.133.134234.167.133.1356
178234.167.133.136/29234.167.133.137 to 234.167.133.142234.167.133.1436
179234.167.133.144/29234.167.133.145 to 234.167.133.150234.167.133.1516
180234.167.133.152/29234.167.133.153 to 234.167.133.158234.167.133.1596
181234.167.133.160/29234.167.133.161 to 234.167.133.166234.167.133.1676
182234.167.133.168/29234.167.133.169 to 234.167.133.174234.167.133.1756
183234.167.133.176/29234.167.133.177 to 234.167.133.182234.167.133.1836
184234.167.133.184/29234.167.133.185 to 234.167.133.190234.167.133.1916
185234.167.133.192/29234.167.133.193 to 234.167.133.198234.167.133.1996
186234.167.133.200/29234.167.133.201 to 234.167.133.206234.167.133.2076
187234.167.133.208/29234.167.133.209 to 234.167.133.214234.167.133.2156
188234.167.133.216/29234.167.133.217 to 234.167.133.222234.167.133.2236
189234.167.133.224/29234.167.133.225 to 234.167.133.230234.167.133.2316
190234.167.133.232/29234.167.133.233 to 234.167.133.238234.167.133.2396
191234.167.133.240/29234.167.133.241 to 234.167.133.246234.167.133.2476
192234.167.133.248/29234.167.133.249 to 234.167.133.254234.167.133.2556
193234.167.134.0/29234.167.134.1 to 234.167.134.6234.167.134.76
194234.167.134.8/29234.167.134.9 to 234.167.134.14234.167.134.156
195234.167.134.16/29234.167.134.17 to 234.167.134.22234.167.134.236
196234.167.134.24/29234.167.134.25 to 234.167.134.30234.167.134.316
197234.167.134.32/29234.167.134.33 to 234.167.134.38234.167.134.396
198234.167.134.40/29234.167.134.41 to 234.167.134.46234.167.134.476
199234.167.134.48/29234.167.134.49 to 234.167.134.54234.167.134.556
200234.167.134.56/29234.167.134.57 to 234.167.134.62234.167.134.636
201234.167.134.64/29234.167.134.65 to 234.167.134.70234.167.134.716
202234.167.134.72/29234.167.134.73 to 234.167.134.78234.167.134.796
203234.167.134.80/29234.167.134.81 to 234.167.134.86234.167.134.876
204234.167.134.88/29234.167.134.89 to 234.167.134.94234.167.134.956
205234.167.134.96/29234.167.134.97 to 234.167.134.102234.167.134.1036
206234.167.134.104/29234.167.134.105 to 234.167.134.110234.167.134.1116
207234.167.134.112/29234.167.134.113 to 234.167.134.118234.167.134.1196
208234.167.134.120/29234.167.134.121 to 234.167.134.126234.167.134.1276
209234.167.134.128/29234.167.134.129 to 234.167.134.134234.167.134.1356
210234.167.134.136/29234.167.134.137 to 234.167.134.142234.167.134.1436
211234.167.134.144/29234.167.134.145 to 234.167.134.150234.167.134.1516
212234.167.134.152/29234.167.134.153 to 234.167.134.158234.167.134.1596
213234.167.134.160/29234.167.134.161 to 234.167.134.166234.167.134.1676
214234.167.134.168/29234.167.134.169 to 234.167.134.174234.167.134.1756
215234.167.134.176/29234.167.134.177 to 234.167.134.182234.167.134.1836
216234.167.134.184/29234.167.134.185 to 234.167.134.190234.167.134.1916
217234.167.134.192/29234.167.134.193 to 234.167.134.198234.167.134.1996
218234.167.134.200/29234.167.134.201 to 234.167.134.206234.167.134.2076
219234.167.134.208/29234.167.134.209 to 234.167.134.214234.167.134.2156
220234.167.134.216/29234.167.134.217 to 234.167.134.222234.167.134.2236
221234.167.134.224/29234.167.134.225 to 234.167.134.230234.167.134.2316
222234.167.134.232/29234.167.134.233 to 234.167.134.238234.167.134.2396
223234.167.134.240/29234.167.134.241 to 234.167.134.246234.167.134.2476
224234.167.134.248/29234.167.134.249 to 234.167.134.254234.167.134.2556
225234.167.135.0/29234.167.135.1 to 234.167.135.6234.167.135.76
226234.167.135.8/29234.167.135.9 to 234.167.135.14234.167.135.156
227234.167.135.16/29234.167.135.17 to 234.167.135.22234.167.135.236
228234.167.135.24/29234.167.135.25 to 234.167.135.30234.167.135.316
229234.167.135.32/29234.167.135.33 to 234.167.135.38234.167.135.396
230234.167.135.40/29234.167.135.41 to 234.167.135.46234.167.135.476
231234.167.135.48/29234.167.135.49 to 234.167.135.54234.167.135.556
232234.167.135.56/29234.167.135.57 to 234.167.135.62234.167.135.636
233234.167.135.64/29234.167.135.65 to 234.167.135.70234.167.135.716
234234.167.135.72/29234.167.135.73 to 234.167.135.78234.167.135.796
235234.167.135.80/29234.167.135.81 to 234.167.135.86234.167.135.876
236234.167.135.88/29234.167.135.89 to 234.167.135.94234.167.135.956
237234.167.135.96/29234.167.135.97 to 234.167.135.102234.167.135.1036
238234.167.135.104/29234.167.135.105 to 234.167.135.110234.167.135.1116
239234.167.135.112/29234.167.135.113 to 234.167.135.118234.167.135.1196
240234.167.135.120/29234.167.135.121 to 234.167.135.126234.167.135.1276
241234.167.135.128/29234.167.135.129 to 234.167.135.134234.167.135.1356
242234.167.135.136/29234.167.135.137 to 234.167.135.142234.167.135.1436
243234.167.135.144/29234.167.135.145 to 234.167.135.150234.167.135.1516
244234.167.135.152/29234.167.135.153 to 234.167.135.158234.167.135.1596
245234.167.135.160/29234.167.135.161 to 234.167.135.166234.167.135.1676
246234.167.135.168/29234.167.135.169 to 234.167.135.174234.167.135.1756
247234.167.135.176/29234.167.135.177 to 234.167.135.182234.167.135.1836
248234.167.135.184/29234.167.135.185 to 234.167.135.190234.167.135.1916
249234.167.135.192/29234.167.135.193 to 234.167.135.198234.167.135.1996
250234.167.135.200/29234.167.135.201 to 234.167.135.206234.167.135.2076
251234.167.135.208/29234.167.135.209 to 234.167.135.214234.167.135.2156
252234.167.135.216/29234.167.135.217 to 234.167.135.222234.167.135.2236
253234.167.135.224/29234.167.135.225 to 234.167.135.230234.167.135.2316
254234.167.135.232/29234.167.135.233 to 234.167.135.238234.167.135.2396
255234.167.135.240/29234.167.135.241 to 234.167.135.246234.167.135.2476
256234.167.135.248/29234.167.135.249 to 234.167.135.254234.167.135.2556

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.