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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.

Network115.6.0.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
115.6.0.0
Broadcast address
115.6.31.255
First usable
115.6.0.1
Last usable
115.6.31.254
Usable hosts
8,190 (8,192 less the network and broadcast addresses)
Subnet mask
255.255.224.0
Wildcard mask
0.0.31.255 (Cisco ACLs, OSPF)
Prefix length
/19
Type
Public public
Old class
A (default /8)
As numbers
Hex 73060000 · Integer 1929773056 to 1929781247
Reverse DNS zones
0.6.115.in-addr.arpa
1.6.115.in-addr.arpa
2.6.115.in-addr.arpa
3.6.115.in-addr.arpa
4.6.115.in-addr.arpa
5.6.115.in-addr.arpa
6.6.115.in-addr.arpa
7.6.115.in-addr.arpa
8.6.115.in-addr.arpa
9.6.115.in-addr.arpa
10.6.115.in-addr.arpa
11.6.115.in-addr.arpa
12.6.115.in-addr.arpa
13.6.115.in-addr.arpa
14.6.115.in-addr.arpa
15.6.115.in-addr.arpa
and 16 more
/19 is not on a 8-bit boundary, so it takes 32 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110011.00000110.00000000.00000000115.6.0.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network01110011.00000110.00000000.00000000115.6.0.0
Broadcast01110011.00000110.00011111.11111111115.6.31.255
Split into smaller subnets/29
/20 (2)/21 (4)/22 (8)/23 (16)/24 (32)/25 (64)/26 (128)/27 (256)/28 (512)/29 (1,024)/30 (2,048)/31 (4,096)

115.6.0.0/19 makes 1,024 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1115.6.0.0/29115.6.0.1 to 115.6.0.6115.6.0.76
2115.6.0.8/29115.6.0.9 to 115.6.0.14115.6.0.156
3115.6.0.16/29115.6.0.17 to 115.6.0.22115.6.0.236
4115.6.0.24/29115.6.0.25 to 115.6.0.30115.6.0.316
5115.6.0.32/29115.6.0.33 to 115.6.0.38115.6.0.396
6115.6.0.40/29115.6.0.41 to 115.6.0.46115.6.0.476
7115.6.0.48/29115.6.0.49 to 115.6.0.54115.6.0.556
8115.6.0.56/29115.6.0.57 to 115.6.0.62115.6.0.636
9115.6.0.64/29115.6.0.65 to 115.6.0.70115.6.0.716
10115.6.0.72/29115.6.0.73 to 115.6.0.78115.6.0.796
11115.6.0.80/29115.6.0.81 to 115.6.0.86115.6.0.876
12115.6.0.88/29115.6.0.89 to 115.6.0.94115.6.0.956
13115.6.0.96/29115.6.0.97 to 115.6.0.102115.6.0.1036
14115.6.0.104/29115.6.0.105 to 115.6.0.110115.6.0.1116
15115.6.0.112/29115.6.0.113 to 115.6.0.118115.6.0.1196
16115.6.0.120/29115.6.0.121 to 115.6.0.126115.6.0.1276
17115.6.0.128/29115.6.0.129 to 115.6.0.134115.6.0.1356
18115.6.0.136/29115.6.0.137 to 115.6.0.142115.6.0.1436
19115.6.0.144/29115.6.0.145 to 115.6.0.150115.6.0.1516
20115.6.0.152/29115.6.0.153 to 115.6.0.158115.6.0.1596
21115.6.0.160/29115.6.0.161 to 115.6.0.166115.6.0.1676
22115.6.0.168/29115.6.0.169 to 115.6.0.174115.6.0.1756
23115.6.0.176/29115.6.0.177 to 115.6.0.182115.6.0.1836
24115.6.0.184/29115.6.0.185 to 115.6.0.190115.6.0.1916
25115.6.0.192/29115.6.0.193 to 115.6.0.198115.6.0.1996
26115.6.0.200/29115.6.0.201 to 115.6.0.206115.6.0.2076
27115.6.0.208/29115.6.0.209 to 115.6.0.214115.6.0.2156
28115.6.0.216/29115.6.0.217 to 115.6.0.222115.6.0.2236
29115.6.0.224/29115.6.0.225 to 115.6.0.230115.6.0.2316
30115.6.0.232/29115.6.0.233 to 115.6.0.238115.6.0.2396
31115.6.0.240/29115.6.0.241 to 115.6.0.246115.6.0.2476
32115.6.0.248/29115.6.0.249 to 115.6.0.254115.6.0.2556
33115.6.1.0/29115.6.1.1 to 115.6.1.6115.6.1.76
34115.6.1.8/29115.6.1.9 to 115.6.1.14115.6.1.156
35115.6.1.16/29115.6.1.17 to 115.6.1.22115.6.1.236
36115.6.1.24/29115.6.1.25 to 115.6.1.30115.6.1.316
37115.6.1.32/29115.6.1.33 to 115.6.1.38115.6.1.396
38115.6.1.40/29115.6.1.41 to 115.6.1.46115.6.1.476
39115.6.1.48/29115.6.1.49 to 115.6.1.54115.6.1.556
40115.6.1.56/29115.6.1.57 to 115.6.1.62115.6.1.636
41115.6.1.64/29115.6.1.65 to 115.6.1.70115.6.1.716
42115.6.1.72/29115.6.1.73 to 115.6.1.78115.6.1.796
43115.6.1.80/29115.6.1.81 to 115.6.1.86115.6.1.876
44115.6.1.88/29115.6.1.89 to 115.6.1.94115.6.1.956
45115.6.1.96/29115.6.1.97 to 115.6.1.102115.6.1.1036
46115.6.1.104/29115.6.1.105 to 115.6.1.110115.6.1.1116
47115.6.1.112/29115.6.1.113 to 115.6.1.118115.6.1.1196
48115.6.1.120/29115.6.1.121 to 115.6.1.126115.6.1.1276
49115.6.1.128/29115.6.1.129 to 115.6.1.134115.6.1.1356
50115.6.1.136/29115.6.1.137 to 115.6.1.142115.6.1.1436
51115.6.1.144/29115.6.1.145 to 115.6.1.150115.6.1.1516
52115.6.1.152/29115.6.1.153 to 115.6.1.158115.6.1.1596
53115.6.1.160/29115.6.1.161 to 115.6.1.166115.6.1.1676
54115.6.1.168/29115.6.1.169 to 115.6.1.174115.6.1.1756
55115.6.1.176/29115.6.1.177 to 115.6.1.182115.6.1.1836
56115.6.1.184/29115.6.1.185 to 115.6.1.190115.6.1.1916
57115.6.1.192/29115.6.1.193 to 115.6.1.198115.6.1.1996
58115.6.1.200/29115.6.1.201 to 115.6.1.206115.6.1.2076
59115.6.1.208/29115.6.1.209 to 115.6.1.214115.6.1.2156
60115.6.1.216/29115.6.1.217 to 115.6.1.222115.6.1.2236
61115.6.1.224/29115.6.1.225 to 115.6.1.230115.6.1.2316
62115.6.1.232/29115.6.1.233 to 115.6.1.238115.6.1.2396
63115.6.1.240/29115.6.1.241 to 115.6.1.246115.6.1.2476
64115.6.1.248/29115.6.1.249 to 115.6.1.254115.6.1.2556
65115.6.2.0/29115.6.2.1 to 115.6.2.6115.6.2.76
66115.6.2.8/29115.6.2.9 to 115.6.2.14115.6.2.156
67115.6.2.16/29115.6.2.17 to 115.6.2.22115.6.2.236
68115.6.2.24/29115.6.2.25 to 115.6.2.30115.6.2.316
69115.6.2.32/29115.6.2.33 to 115.6.2.38115.6.2.396
70115.6.2.40/29115.6.2.41 to 115.6.2.46115.6.2.476
71115.6.2.48/29115.6.2.49 to 115.6.2.54115.6.2.556
72115.6.2.56/29115.6.2.57 to 115.6.2.62115.6.2.636
73115.6.2.64/29115.6.2.65 to 115.6.2.70115.6.2.716
74115.6.2.72/29115.6.2.73 to 115.6.2.78115.6.2.796
75115.6.2.80/29115.6.2.81 to 115.6.2.86115.6.2.876
76115.6.2.88/29115.6.2.89 to 115.6.2.94115.6.2.956
77115.6.2.96/29115.6.2.97 to 115.6.2.102115.6.2.1036
78115.6.2.104/29115.6.2.105 to 115.6.2.110115.6.2.1116
79115.6.2.112/29115.6.2.113 to 115.6.2.118115.6.2.1196
80115.6.2.120/29115.6.2.121 to 115.6.2.126115.6.2.1276
81115.6.2.128/29115.6.2.129 to 115.6.2.134115.6.2.1356
82115.6.2.136/29115.6.2.137 to 115.6.2.142115.6.2.1436
83115.6.2.144/29115.6.2.145 to 115.6.2.150115.6.2.1516
84115.6.2.152/29115.6.2.153 to 115.6.2.158115.6.2.1596
85115.6.2.160/29115.6.2.161 to 115.6.2.166115.6.2.1676
86115.6.2.168/29115.6.2.169 to 115.6.2.174115.6.2.1756
87115.6.2.176/29115.6.2.177 to 115.6.2.182115.6.2.1836
88115.6.2.184/29115.6.2.185 to 115.6.2.190115.6.2.1916
89115.6.2.192/29115.6.2.193 to 115.6.2.198115.6.2.1996
90115.6.2.200/29115.6.2.201 to 115.6.2.206115.6.2.2076
91115.6.2.208/29115.6.2.209 to 115.6.2.214115.6.2.2156
92115.6.2.216/29115.6.2.217 to 115.6.2.222115.6.2.2236
93115.6.2.224/29115.6.2.225 to 115.6.2.230115.6.2.2316
94115.6.2.232/29115.6.2.233 to 115.6.2.238115.6.2.2396
95115.6.2.240/29115.6.2.241 to 115.6.2.246115.6.2.2476
96115.6.2.248/29115.6.2.249 to 115.6.2.254115.6.2.2556
97115.6.3.0/29115.6.3.1 to 115.6.3.6115.6.3.76
98115.6.3.8/29115.6.3.9 to 115.6.3.14115.6.3.156
99115.6.3.16/29115.6.3.17 to 115.6.3.22115.6.3.236
100115.6.3.24/29115.6.3.25 to 115.6.3.30115.6.3.316
101115.6.3.32/29115.6.3.33 to 115.6.3.38115.6.3.396
102115.6.3.40/29115.6.3.41 to 115.6.3.46115.6.3.476
103115.6.3.48/29115.6.3.49 to 115.6.3.54115.6.3.556
104115.6.3.56/29115.6.3.57 to 115.6.3.62115.6.3.636
105115.6.3.64/29115.6.3.65 to 115.6.3.70115.6.3.716
106115.6.3.72/29115.6.3.73 to 115.6.3.78115.6.3.796
107115.6.3.80/29115.6.3.81 to 115.6.3.86115.6.3.876
108115.6.3.88/29115.6.3.89 to 115.6.3.94115.6.3.956
109115.6.3.96/29115.6.3.97 to 115.6.3.102115.6.3.1036
110115.6.3.104/29115.6.3.105 to 115.6.3.110115.6.3.1116
111115.6.3.112/29115.6.3.113 to 115.6.3.118115.6.3.1196
112115.6.3.120/29115.6.3.121 to 115.6.3.126115.6.3.1276
113115.6.3.128/29115.6.3.129 to 115.6.3.134115.6.3.1356
114115.6.3.136/29115.6.3.137 to 115.6.3.142115.6.3.1436
115115.6.3.144/29115.6.3.145 to 115.6.3.150115.6.3.1516
116115.6.3.152/29115.6.3.153 to 115.6.3.158115.6.3.1596
117115.6.3.160/29115.6.3.161 to 115.6.3.166115.6.3.1676
118115.6.3.168/29115.6.3.169 to 115.6.3.174115.6.3.1756
119115.6.3.176/29115.6.3.177 to 115.6.3.182115.6.3.1836
120115.6.3.184/29115.6.3.185 to 115.6.3.190115.6.3.1916
121115.6.3.192/29115.6.3.193 to 115.6.3.198115.6.3.1996
122115.6.3.200/29115.6.3.201 to 115.6.3.206115.6.3.2076
123115.6.3.208/29115.6.3.209 to 115.6.3.214115.6.3.2156
124115.6.3.216/29115.6.3.217 to 115.6.3.222115.6.3.2236
125115.6.3.224/29115.6.3.225 to 115.6.3.230115.6.3.2316
126115.6.3.232/29115.6.3.233 to 115.6.3.238115.6.3.2396
127115.6.3.240/29115.6.3.241 to 115.6.3.246115.6.3.2476
128115.6.3.248/29115.6.3.249 to 115.6.3.254115.6.3.2556
129115.6.4.0/29115.6.4.1 to 115.6.4.6115.6.4.76
130115.6.4.8/29115.6.4.9 to 115.6.4.14115.6.4.156
131115.6.4.16/29115.6.4.17 to 115.6.4.22115.6.4.236
132115.6.4.24/29115.6.4.25 to 115.6.4.30115.6.4.316
133115.6.4.32/29115.6.4.33 to 115.6.4.38115.6.4.396
134115.6.4.40/29115.6.4.41 to 115.6.4.46115.6.4.476
135115.6.4.48/29115.6.4.49 to 115.6.4.54115.6.4.556
136115.6.4.56/29115.6.4.57 to 115.6.4.62115.6.4.636
137115.6.4.64/29115.6.4.65 to 115.6.4.70115.6.4.716
138115.6.4.72/29115.6.4.73 to 115.6.4.78115.6.4.796
139115.6.4.80/29115.6.4.81 to 115.6.4.86115.6.4.876
140115.6.4.88/29115.6.4.89 to 115.6.4.94115.6.4.956
141115.6.4.96/29115.6.4.97 to 115.6.4.102115.6.4.1036
142115.6.4.104/29115.6.4.105 to 115.6.4.110115.6.4.1116
143115.6.4.112/29115.6.4.113 to 115.6.4.118115.6.4.1196
144115.6.4.120/29115.6.4.121 to 115.6.4.126115.6.4.1276
145115.6.4.128/29115.6.4.129 to 115.6.4.134115.6.4.1356
146115.6.4.136/29115.6.4.137 to 115.6.4.142115.6.4.1436
147115.6.4.144/29115.6.4.145 to 115.6.4.150115.6.4.1516
148115.6.4.152/29115.6.4.153 to 115.6.4.158115.6.4.1596
149115.6.4.160/29115.6.4.161 to 115.6.4.166115.6.4.1676
150115.6.4.168/29115.6.4.169 to 115.6.4.174115.6.4.1756
151115.6.4.176/29115.6.4.177 to 115.6.4.182115.6.4.1836
152115.6.4.184/29115.6.4.185 to 115.6.4.190115.6.4.1916
153115.6.4.192/29115.6.4.193 to 115.6.4.198115.6.4.1996
154115.6.4.200/29115.6.4.201 to 115.6.4.206115.6.4.2076
155115.6.4.208/29115.6.4.209 to 115.6.4.214115.6.4.2156
156115.6.4.216/29115.6.4.217 to 115.6.4.222115.6.4.2236
157115.6.4.224/29115.6.4.225 to 115.6.4.230115.6.4.2316
158115.6.4.232/29115.6.4.233 to 115.6.4.238115.6.4.2396
159115.6.4.240/29115.6.4.241 to 115.6.4.246115.6.4.2476
160115.6.4.248/29115.6.4.249 to 115.6.4.254115.6.4.2556
161115.6.5.0/29115.6.5.1 to 115.6.5.6115.6.5.76
162115.6.5.8/29115.6.5.9 to 115.6.5.14115.6.5.156
163115.6.5.16/29115.6.5.17 to 115.6.5.22115.6.5.236
164115.6.5.24/29115.6.5.25 to 115.6.5.30115.6.5.316
165115.6.5.32/29115.6.5.33 to 115.6.5.38115.6.5.396
166115.6.5.40/29115.6.5.41 to 115.6.5.46115.6.5.476
167115.6.5.48/29115.6.5.49 to 115.6.5.54115.6.5.556
168115.6.5.56/29115.6.5.57 to 115.6.5.62115.6.5.636
169115.6.5.64/29115.6.5.65 to 115.6.5.70115.6.5.716
170115.6.5.72/29115.6.5.73 to 115.6.5.78115.6.5.796
171115.6.5.80/29115.6.5.81 to 115.6.5.86115.6.5.876
172115.6.5.88/29115.6.5.89 to 115.6.5.94115.6.5.956
173115.6.5.96/29115.6.5.97 to 115.6.5.102115.6.5.1036
174115.6.5.104/29115.6.5.105 to 115.6.5.110115.6.5.1116
175115.6.5.112/29115.6.5.113 to 115.6.5.118115.6.5.1196
176115.6.5.120/29115.6.5.121 to 115.6.5.126115.6.5.1276
177115.6.5.128/29115.6.5.129 to 115.6.5.134115.6.5.1356
178115.6.5.136/29115.6.5.137 to 115.6.5.142115.6.5.1436
179115.6.5.144/29115.6.5.145 to 115.6.5.150115.6.5.1516
180115.6.5.152/29115.6.5.153 to 115.6.5.158115.6.5.1596
181115.6.5.160/29115.6.5.161 to 115.6.5.166115.6.5.1676
182115.6.5.168/29115.6.5.169 to 115.6.5.174115.6.5.1756
183115.6.5.176/29115.6.5.177 to 115.6.5.182115.6.5.1836
184115.6.5.184/29115.6.5.185 to 115.6.5.190115.6.5.1916
185115.6.5.192/29115.6.5.193 to 115.6.5.198115.6.5.1996
186115.6.5.200/29115.6.5.201 to 115.6.5.206115.6.5.2076
187115.6.5.208/29115.6.5.209 to 115.6.5.214115.6.5.2156
188115.6.5.216/29115.6.5.217 to 115.6.5.222115.6.5.2236
189115.6.5.224/29115.6.5.225 to 115.6.5.230115.6.5.2316
190115.6.5.232/29115.6.5.233 to 115.6.5.238115.6.5.2396
191115.6.5.240/29115.6.5.241 to 115.6.5.246115.6.5.2476
192115.6.5.248/29115.6.5.249 to 115.6.5.254115.6.5.2556
193115.6.6.0/29115.6.6.1 to 115.6.6.6115.6.6.76
194115.6.6.8/29115.6.6.9 to 115.6.6.14115.6.6.156
195115.6.6.16/29115.6.6.17 to 115.6.6.22115.6.6.236
196115.6.6.24/29115.6.6.25 to 115.6.6.30115.6.6.316
197115.6.6.32/29115.6.6.33 to 115.6.6.38115.6.6.396
198115.6.6.40/29115.6.6.41 to 115.6.6.46115.6.6.476
199115.6.6.48/29115.6.6.49 to 115.6.6.54115.6.6.556
200115.6.6.56/29115.6.6.57 to 115.6.6.62115.6.6.636
201115.6.6.64/29115.6.6.65 to 115.6.6.70115.6.6.716
202115.6.6.72/29115.6.6.73 to 115.6.6.78115.6.6.796
203115.6.6.80/29115.6.6.81 to 115.6.6.86115.6.6.876
204115.6.6.88/29115.6.6.89 to 115.6.6.94115.6.6.956
205115.6.6.96/29115.6.6.97 to 115.6.6.102115.6.6.1036
206115.6.6.104/29115.6.6.105 to 115.6.6.110115.6.6.1116
207115.6.6.112/29115.6.6.113 to 115.6.6.118115.6.6.1196
208115.6.6.120/29115.6.6.121 to 115.6.6.126115.6.6.1276
209115.6.6.128/29115.6.6.129 to 115.6.6.134115.6.6.1356
210115.6.6.136/29115.6.6.137 to 115.6.6.142115.6.6.1436
211115.6.6.144/29115.6.6.145 to 115.6.6.150115.6.6.1516
212115.6.6.152/29115.6.6.153 to 115.6.6.158115.6.6.1596
213115.6.6.160/29115.6.6.161 to 115.6.6.166115.6.6.1676
214115.6.6.168/29115.6.6.169 to 115.6.6.174115.6.6.1756
215115.6.6.176/29115.6.6.177 to 115.6.6.182115.6.6.1836
216115.6.6.184/29115.6.6.185 to 115.6.6.190115.6.6.1916
217115.6.6.192/29115.6.6.193 to 115.6.6.198115.6.6.1996
218115.6.6.200/29115.6.6.201 to 115.6.6.206115.6.6.2076
219115.6.6.208/29115.6.6.209 to 115.6.6.214115.6.6.2156
220115.6.6.216/29115.6.6.217 to 115.6.6.222115.6.6.2236
221115.6.6.224/29115.6.6.225 to 115.6.6.230115.6.6.2316
222115.6.6.232/29115.6.6.233 to 115.6.6.238115.6.6.2396
223115.6.6.240/29115.6.6.241 to 115.6.6.246115.6.6.2476
224115.6.6.248/29115.6.6.249 to 115.6.6.254115.6.6.2556
225115.6.7.0/29115.6.7.1 to 115.6.7.6115.6.7.76
226115.6.7.8/29115.6.7.9 to 115.6.7.14115.6.7.156
227115.6.7.16/29115.6.7.17 to 115.6.7.22115.6.7.236
228115.6.7.24/29115.6.7.25 to 115.6.7.30115.6.7.316
229115.6.7.32/29115.6.7.33 to 115.6.7.38115.6.7.396
230115.6.7.40/29115.6.7.41 to 115.6.7.46115.6.7.476
231115.6.7.48/29115.6.7.49 to 115.6.7.54115.6.7.556
232115.6.7.56/29115.6.7.57 to 115.6.7.62115.6.7.636
233115.6.7.64/29115.6.7.65 to 115.6.7.70115.6.7.716
234115.6.7.72/29115.6.7.73 to 115.6.7.78115.6.7.796
235115.6.7.80/29115.6.7.81 to 115.6.7.86115.6.7.876
236115.6.7.88/29115.6.7.89 to 115.6.7.94115.6.7.956
237115.6.7.96/29115.6.7.97 to 115.6.7.102115.6.7.1036
238115.6.7.104/29115.6.7.105 to 115.6.7.110115.6.7.1116
239115.6.7.112/29115.6.7.113 to 115.6.7.118115.6.7.1196
240115.6.7.120/29115.6.7.121 to 115.6.7.126115.6.7.1276
241115.6.7.128/29115.6.7.129 to 115.6.7.134115.6.7.1356
242115.6.7.136/29115.6.7.137 to 115.6.7.142115.6.7.1436
243115.6.7.144/29115.6.7.145 to 115.6.7.150115.6.7.1516
244115.6.7.152/29115.6.7.153 to 115.6.7.158115.6.7.1596
245115.6.7.160/29115.6.7.161 to 115.6.7.166115.6.7.1676
246115.6.7.168/29115.6.7.169 to 115.6.7.174115.6.7.1756
247115.6.7.176/29115.6.7.177 to 115.6.7.182115.6.7.1836
248115.6.7.184/29115.6.7.185 to 115.6.7.190115.6.7.1916
249115.6.7.192/29115.6.7.193 to 115.6.7.198115.6.7.1996
250115.6.7.200/29115.6.7.201 to 115.6.7.206115.6.7.2076
251115.6.7.208/29115.6.7.209 to 115.6.7.214115.6.7.2156
252115.6.7.216/29115.6.7.217 to 115.6.7.222115.6.7.2236
253115.6.7.224/29115.6.7.225 to 115.6.7.230115.6.7.2316
254115.6.7.232/29115.6.7.233 to 115.6.7.238115.6.7.2396
255115.6.7.240/29115.6.7.241 to 115.6.7.246115.6.7.2476
256115.6.7.248/29115.6.7.249 to 115.6.7.254115.6.7.2556

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.