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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.

Network174.2.192.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
174.2.192.0
Broadcast address
174.2.223.255
First usable
174.2.192.1
Last usable
174.2.223.254
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
B (default /16)
As numbers
Hex AE02C000 · Integer 2919415808 to 2919423999
Reverse DNS zones
192.2.174.in-addr.arpa
193.2.174.in-addr.arpa
194.2.174.in-addr.arpa
195.2.174.in-addr.arpa
196.2.174.in-addr.arpa
197.2.174.in-addr.arpa
198.2.174.in-addr.arpa
199.2.174.in-addr.arpa
200.2.174.in-addr.arpa
201.2.174.in-addr.arpa
202.2.174.in-addr.arpa
203.2.174.in-addr.arpa
204.2.174.in-addr.arpa
205.2.174.in-addr.arpa
206.2.174.in-addr.arpa
207.2.174.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
Address10101110.00000010.11000000.00000000174.2.192.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network10101110.00000010.11000000.00000000174.2.192.0
Broadcast10101110.00000010.11011111.11111111174.2.223.255
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)

174.2.192.0/19 makes 1,024 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1174.2.192.0/29174.2.192.1 to 174.2.192.6174.2.192.76
2174.2.192.8/29174.2.192.9 to 174.2.192.14174.2.192.156
3174.2.192.16/29174.2.192.17 to 174.2.192.22174.2.192.236
4174.2.192.24/29174.2.192.25 to 174.2.192.30174.2.192.316
5174.2.192.32/29174.2.192.33 to 174.2.192.38174.2.192.396
6174.2.192.40/29174.2.192.41 to 174.2.192.46174.2.192.476
7174.2.192.48/29174.2.192.49 to 174.2.192.54174.2.192.556
8174.2.192.56/29174.2.192.57 to 174.2.192.62174.2.192.636
9174.2.192.64/29174.2.192.65 to 174.2.192.70174.2.192.716
10174.2.192.72/29174.2.192.73 to 174.2.192.78174.2.192.796
11174.2.192.80/29174.2.192.81 to 174.2.192.86174.2.192.876
12174.2.192.88/29174.2.192.89 to 174.2.192.94174.2.192.956
13174.2.192.96/29174.2.192.97 to 174.2.192.102174.2.192.1036
14174.2.192.104/29174.2.192.105 to 174.2.192.110174.2.192.1116
15174.2.192.112/29174.2.192.113 to 174.2.192.118174.2.192.1196
16174.2.192.120/29174.2.192.121 to 174.2.192.126174.2.192.1276
17174.2.192.128/29174.2.192.129 to 174.2.192.134174.2.192.1356
18174.2.192.136/29174.2.192.137 to 174.2.192.142174.2.192.1436
19174.2.192.144/29174.2.192.145 to 174.2.192.150174.2.192.1516
20174.2.192.152/29174.2.192.153 to 174.2.192.158174.2.192.1596
21174.2.192.160/29174.2.192.161 to 174.2.192.166174.2.192.1676
22174.2.192.168/29174.2.192.169 to 174.2.192.174174.2.192.1756
23174.2.192.176/29174.2.192.177 to 174.2.192.182174.2.192.1836
24174.2.192.184/29174.2.192.185 to 174.2.192.190174.2.192.1916
25174.2.192.192/29174.2.192.193 to 174.2.192.198174.2.192.1996
26174.2.192.200/29174.2.192.201 to 174.2.192.206174.2.192.2076
27174.2.192.208/29174.2.192.209 to 174.2.192.214174.2.192.2156
28174.2.192.216/29174.2.192.217 to 174.2.192.222174.2.192.2236
29174.2.192.224/29174.2.192.225 to 174.2.192.230174.2.192.2316
30174.2.192.232/29174.2.192.233 to 174.2.192.238174.2.192.2396
31174.2.192.240/29174.2.192.241 to 174.2.192.246174.2.192.2476
32174.2.192.248/29174.2.192.249 to 174.2.192.254174.2.192.2556
33174.2.193.0/29174.2.193.1 to 174.2.193.6174.2.193.76
34174.2.193.8/29174.2.193.9 to 174.2.193.14174.2.193.156
35174.2.193.16/29174.2.193.17 to 174.2.193.22174.2.193.236
36174.2.193.24/29174.2.193.25 to 174.2.193.30174.2.193.316
37174.2.193.32/29174.2.193.33 to 174.2.193.38174.2.193.396
38174.2.193.40/29174.2.193.41 to 174.2.193.46174.2.193.476
39174.2.193.48/29174.2.193.49 to 174.2.193.54174.2.193.556
40174.2.193.56/29174.2.193.57 to 174.2.193.62174.2.193.636
41174.2.193.64/29174.2.193.65 to 174.2.193.70174.2.193.716
42174.2.193.72/29174.2.193.73 to 174.2.193.78174.2.193.796
43174.2.193.80/29174.2.193.81 to 174.2.193.86174.2.193.876
44174.2.193.88/29174.2.193.89 to 174.2.193.94174.2.193.956
45174.2.193.96/29174.2.193.97 to 174.2.193.102174.2.193.1036
46174.2.193.104/29174.2.193.105 to 174.2.193.110174.2.193.1116
47174.2.193.112/29174.2.193.113 to 174.2.193.118174.2.193.1196
48174.2.193.120/29174.2.193.121 to 174.2.193.126174.2.193.1276
49174.2.193.128/29174.2.193.129 to 174.2.193.134174.2.193.1356
50174.2.193.136/29174.2.193.137 to 174.2.193.142174.2.193.1436
51174.2.193.144/29174.2.193.145 to 174.2.193.150174.2.193.1516
52174.2.193.152/29174.2.193.153 to 174.2.193.158174.2.193.1596
53174.2.193.160/29174.2.193.161 to 174.2.193.166174.2.193.1676
54174.2.193.168/29174.2.193.169 to 174.2.193.174174.2.193.1756
55174.2.193.176/29174.2.193.177 to 174.2.193.182174.2.193.1836
56174.2.193.184/29174.2.193.185 to 174.2.193.190174.2.193.1916
57174.2.193.192/29174.2.193.193 to 174.2.193.198174.2.193.1996
58174.2.193.200/29174.2.193.201 to 174.2.193.206174.2.193.2076
59174.2.193.208/29174.2.193.209 to 174.2.193.214174.2.193.2156
60174.2.193.216/29174.2.193.217 to 174.2.193.222174.2.193.2236
61174.2.193.224/29174.2.193.225 to 174.2.193.230174.2.193.2316
62174.2.193.232/29174.2.193.233 to 174.2.193.238174.2.193.2396
63174.2.193.240/29174.2.193.241 to 174.2.193.246174.2.193.2476
64174.2.193.248/29174.2.193.249 to 174.2.193.254174.2.193.2556
65174.2.194.0/29174.2.194.1 to 174.2.194.6174.2.194.76
66174.2.194.8/29174.2.194.9 to 174.2.194.14174.2.194.156
67174.2.194.16/29174.2.194.17 to 174.2.194.22174.2.194.236
68174.2.194.24/29174.2.194.25 to 174.2.194.30174.2.194.316
69174.2.194.32/29174.2.194.33 to 174.2.194.38174.2.194.396
70174.2.194.40/29174.2.194.41 to 174.2.194.46174.2.194.476
71174.2.194.48/29174.2.194.49 to 174.2.194.54174.2.194.556
72174.2.194.56/29174.2.194.57 to 174.2.194.62174.2.194.636
73174.2.194.64/29174.2.194.65 to 174.2.194.70174.2.194.716
74174.2.194.72/29174.2.194.73 to 174.2.194.78174.2.194.796
75174.2.194.80/29174.2.194.81 to 174.2.194.86174.2.194.876
76174.2.194.88/29174.2.194.89 to 174.2.194.94174.2.194.956
77174.2.194.96/29174.2.194.97 to 174.2.194.102174.2.194.1036
78174.2.194.104/29174.2.194.105 to 174.2.194.110174.2.194.1116
79174.2.194.112/29174.2.194.113 to 174.2.194.118174.2.194.1196
80174.2.194.120/29174.2.194.121 to 174.2.194.126174.2.194.1276
81174.2.194.128/29174.2.194.129 to 174.2.194.134174.2.194.1356
82174.2.194.136/29174.2.194.137 to 174.2.194.142174.2.194.1436
83174.2.194.144/29174.2.194.145 to 174.2.194.150174.2.194.1516
84174.2.194.152/29174.2.194.153 to 174.2.194.158174.2.194.1596
85174.2.194.160/29174.2.194.161 to 174.2.194.166174.2.194.1676
86174.2.194.168/29174.2.194.169 to 174.2.194.174174.2.194.1756
87174.2.194.176/29174.2.194.177 to 174.2.194.182174.2.194.1836
88174.2.194.184/29174.2.194.185 to 174.2.194.190174.2.194.1916
89174.2.194.192/29174.2.194.193 to 174.2.194.198174.2.194.1996
90174.2.194.200/29174.2.194.201 to 174.2.194.206174.2.194.2076
91174.2.194.208/29174.2.194.209 to 174.2.194.214174.2.194.2156
92174.2.194.216/29174.2.194.217 to 174.2.194.222174.2.194.2236
93174.2.194.224/29174.2.194.225 to 174.2.194.230174.2.194.2316
94174.2.194.232/29174.2.194.233 to 174.2.194.238174.2.194.2396
95174.2.194.240/29174.2.194.241 to 174.2.194.246174.2.194.2476
96174.2.194.248/29174.2.194.249 to 174.2.194.254174.2.194.2556
97174.2.195.0/29174.2.195.1 to 174.2.195.6174.2.195.76
98174.2.195.8/29174.2.195.9 to 174.2.195.14174.2.195.156
99174.2.195.16/29174.2.195.17 to 174.2.195.22174.2.195.236
100174.2.195.24/29174.2.195.25 to 174.2.195.30174.2.195.316
101174.2.195.32/29174.2.195.33 to 174.2.195.38174.2.195.396
102174.2.195.40/29174.2.195.41 to 174.2.195.46174.2.195.476
103174.2.195.48/29174.2.195.49 to 174.2.195.54174.2.195.556
104174.2.195.56/29174.2.195.57 to 174.2.195.62174.2.195.636
105174.2.195.64/29174.2.195.65 to 174.2.195.70174.2.195.716
106174.2.195.72/29174.2.195.73 to 174.2.195.78174.2.195.796
107174.2.195.80/29174.2.195.81 to 174.2.195.86174.2.195.876
108174.2.195.88/29174.2.195.89 to 174.2.195.94174.2.195.956
109174.2.195.96/29174.2.195.97 to 174.2.195.102174.2.195.1036
110174.2.195.104/29174.2.195.105 to 174.2.195.110174.2.195.1116
111174.2.195.112/29174.2.195.113 to 174.2.195.118174.2.195.1196
112174.2.195.120/29174.2.195.121 to 174.2.195.126174.2.195.1276
113174.2.195.128/29174.2.195.129 to 174.2.195.134174.2.195.1356
114174.2.195.136/29174.2.195.137 to 174.2.195.142174.2.195.1436
115174.2.195.144/29174.2.195.145 to 174.2.195.150174.2.195.1516
116174.2.195.152/29174.2.195.153 to 174.2.195.158174.2.195.1596
117174.2.195.160/29174.2.195.161 to 174.2.195.166174.2.195.1676
118174.2.195.168/29174.2.195.169 to 174.2.195.174174.2.195.1756
119174.2.195.176/29174.2.195.177 to 174.2.195.182174.2.195.1836
120174.2.195.184/29174.2.195.185 to 174.2.195.190174.2.195.1916
121174.2.195.192/29174.2.195.193 to 174.2.195.198174.2.195.1996
122174.2.195.200/29174.2.195.201 to 174.2.195.206174.2.195.2076
123174.2.195.208/29174.2.195.209 to 174.2.195.214174.2.195.2156
124174.2.195.216/29174.2.195.217 to 174.2.195.222174.2.195.2236
125174.2.195.224/29174.2.195.225 to 174.2.195.230174.2.195.2316
126174.2.195.232/29174.2.195.233 to 174.2.195.238174.2.195.2396
127174.2.195.240/29174.2.195.241 to 174.2.195.246174.2.195.2476
128174.2.195.248/29174.2.195.249 to 174.2.195.254174.2.195.2556
129174.2.196.0/29174.2.196.1 to 174.2.196.6174.2.196.76
130174.2.196.8/29174.2.196.9 to 174.2.196.14174.2.196.156
131174.2.196.16/29174.2.196.17 to 174.2.196.22174.2.196.236
132174.2.196.24/29174.2.196.25 to 174.2.196.30174.2.196.316
133174.2.196.32/29174.2.196.33 to 174.2.196.38174.2.196.396
134174.2.196.40/29174.2.196.41 to 174.2.196.46174.2.196.476
135174.2.196.48/29174.2.196.49 to 174.2.196.54174.2.196.556
136174.2.196.56/29174.2.196.57 to 174.2.196.62174.2.196.636
137174.2.196.64/29174.2.196.65 to 174.2.196.70174.2.196.716
138174.2.196.72/29174.2.196.73 to 174.2.196.78174.2.196.796
139174.2.196.80/29174.2.196.81 to 174.2.196.86174.2.196.876
140174.2.196.88/29174.2.196.89 to 174.2.196.94174.2.196.956
141174.2.196.96/29174.2.196.97 to 174.2.196.102174.2.196.1036
142174.2.196.104/29174.2.196.105 to 174.2.196.110174.2.196.1116
143174.2.196.112/29174.2.196.113 to 174.2.196.118174.2.196.1196
144174.2.196.120/29174.2.196.121 to 174.2.196.126174.2.196.1276
145174.2.196.128/29174.2.196.129 to 174.2.196.134174.2.196.1356
146174.2.196.136/29174.2.196.137 to 174.2.196.142174.2.196.1436
147174.2.196.144/29174.2.196.145 to 174.2.196.150174.2.196.1516
148174.2.196.152/29174.2.196.153 to 174.2.196.158174.2.196.1596
149174.2.196.160/29174.2.196.161 to 174.2.196.166174.2.196.1676
150174.2.196.168/29174.2.196.169 to 174.2.196.174174.2.196.1756
151174.2.196.176/29174.2.196.177 to 174.2.196.182174.2.196.1836
152174.2.196.184/29174.2.196.185 to 174.2.196.190174.2.196.1916
153174.2.196.192/29174.2.196.193 to 174.2.196.198174.2.196.1996
154174.2.196.200/29174.2.196.201 to 174.2.196.206174.2.196.2076
155174.2.196.208/29174.2.196.209 to 174.2.196.214174.2.196.2156
156174.2.196.216/29174.2.196.217 to 174.2.196.222174.2.196.2236
157174.2.196.224/29174.2.196.225 to 174.2.196.230174.2.196.2316
158174.2.196.232/29174.2.196.233 to 174.2.196.238174.2.196.2396
159174.2.196.240/29174.2.196.241 to 174.2.196.246174.2.196.2476
160174.2.196.248/29174.2.196.249 to 174.2.196.254174.2.196.2556
161174.2.197.0/29174.2.197.1 to 174.2.197.6174.2.197.76
162174.2.197.8/29174.2.197.9 to 174.2.197.14174.2.197.156
163174.2.197.16/29174.2.197.17 to 174.2.197.22174.2.197.236
164174.2.197.24/29174.2.197.25 to 174.2.197.30174.2.197.316
165174.2.197.32/29174.2.197.33 to 174.2.197.38174.2.197.396
166174.2.197.40/29174.2.197.41 to 174.2.197.46174.2.197.476
167174.2.197.48/29174.2.197.49 to 174.2.197.54174.2.197.556
168174.2.197.56/29174.2.197.57 to 174.2.197.62174.2.197.636
169174.2.197.64/29174.2.197.65 to 174.2.197.70174.2.197.716
170174.2.197.72/29174.2.197.73 to 174.2.197.78174.2.197.796
171174.2.197.80/29174.2.197.81 to 174.2.197.86174.2.197.876
172174.2.197.88/29174.2.197.89 to 174.2.197.94174.2.197.956
173174.2.197.96/29174.2.197.97 to 174.2.197.102174.2.197.1036
174174.2.197.104/29174.2.197.105 to 174.2.197.110174.2.197.1116
175174.2.197.112/29174.2.197.113 to 174.2.197.118174.2.197.1196
176174.2.197.120/29174.2.197.121 to 174.2.197.126174.2.197.1276
177174.2.197.128/29174.2.197.129 to 174.2.197.134174.2.197.1356
178174.2.197.136/29174.2.197.137 to 174.2.197.142174.2.197.1436
179174.2.197.144/29174.2.197.145 to 174.2.197.150174.2.197.1516
180174.2.197.152/29174.2.197.153 to 174.2.197.158174.2.197.1596
181174.2.197.160/29174.2.197.161 to 174.2.197.166174.2.197.1676
182174.2.197.168/29174.2.197.169 to 174.2.197.174174.2.197.1756
183174.2.197.176/29174.2.197.177 to 174.2.197.182174.2.197.1836
184174.2.197.184/29174.2.197.185 to 174.2.197.190174.2.197.1916
185174.2.197.192/29174.2.197.193 to 174.2.197.198174.2.197.1996
186174.2.197.200/29174.2.197.201 to 174.2.197.206174.2.197.2076
187174.2.197.208/29174.2.197.209 to 174.2.197.214174.2.197.2156
188174.2.197.216/29174.2.197.217 to 174.2.197.222174.2.197.2236
189174.2.197.224/29174.2.197.225 to 174.2.197.230174.2.197.2316
190174.2.197.232/29174.2.197.233 to 174.2.197.238174.2.197.2396
191174.2.197.240/29174.2.197.241 to 174.2.197.246174.2.197.2476
192174.2.197.248/29174.2.197.249 to 174.2.197.254174.2.197.2556
193174.2.198.0/29174.2.198.1 to 174.2.198.6174.2.198.76
194174.2.198.8/29174.2.198.9 to 174.2.198.14174.2.198.156
195174.2.198.16/29174.2.198.17 to 174.2.198.22174.2.198.236
196174.2.198.24/29174.2.198.25 to 174.2.198.30174.2.198.316
197174.2.198.32/29174.2.198.33 to 174.2.198.38174.2.198.396
198174.2.198.40/29174.2.198.41 to 174.2.198.46174.2.198.476
199174.2.198.48/29174.2.198.49 to 174.2.198.54174.2.198.556
200174.2.198.56/29174.2.198.57 to 174.2.198.62174.2.198.636
201174.2.198.64/29174.2.198.65 to 174.2.198.70174.2.198.716
202174.2.198.72/29174.2.198.73 to 174.2.198.78174.2.198.796
203174.2.198.80/29174.2.198.81 to 174.2.198.86174.2.198.876
204174.2.198.88/29174.2.198.89 to 174.2.198.94174.2.198.956
205174.2.198.96/29174.2.198.97 to 174.2.198.102174.2.198.1036
206174.2.198.104/29174.2.198.105 to 174.2.198.110174.2.198.1116
207174.2.198.112/29174.2.198.113 to 174.2.198.118174.2.198.1196
208174.2.198.120/29174.2.198.121 to 174.2.198.126174.2.198.1276
209174.2.198.128/29174.2.198.129 to 174.2.198.134174.2.198.1356
210174.2.198.136/29174.2.198.137 to 174.2.198.142174.2.198.1436
211174.2.198.144/29174.2.198.145 to 174.2.198.150174.2.198.1516
212174.2.198.152/29174.2.198.153 to 174.2.198.158174.2.198.1596
213174.2.198.160/29174.2.198.161 to 174.2.198.166174.2.198.1676
214174.2.198.168/29174.2.198.169 to 174.2.198.174174.2.198.1756
215174.2.198.176/29174.2.198.177 to 174.2.198.182174.2.198.1836
216174.2.198.184/29174.2.198.185 to 174.2.198.190174.2.198.1916
217174.2.198.192/29174.2.198.193 to 174.2.198.198174.2.198.1996
218174.2.198.200/29174.2.198.201 to 174.2.198.206174.2.198.2076
219174.2.198.208/29174.2.198.209 to 174.2.198.214174.2.198.2156
220174.2.198.216/29174.2.198.217 to 174.2.198.222174.2.198.2236
221174.2.198.224/29174.2.198.225 to 174.2.198.230174.2.198.2316
222174.2.198.232/29174.2.198.233 to 174.2.198.238174.2.198.2396
223174.2.198.240/29174.2.198.241 to 174.2.198.246174.2.198.2476
224174.2.198.248/29174.2.198.249 to 174.2.198.254174.2.198.2556
225174.2.199.0/29174.2.199.1 to 174.2.199.6174.2.199.76
226174.2.199.8/29174.2.199.9 to 174.2.199.14174.2.199.156
227174.2.199.16/29174.2.199.17 to 174.2.199.22174.2.199.236
228174.2.199.24/29174.2.199.25 to 174.2.199.30174.2.199.316
229174.2.199.32/29174.2.199.33 to 174.2.199.38174.2.199.396
230174.2.199.40/29174.2.199.41 to 174.2.199.46174.2.199.476
231174.2.199.48/29174.2.199.49 to 174.2.199.54174.2.199.556
232174.2.199.56/29174.2.199.57 to 174.2.199.62174.2.199.636
233174.2.199.64/29174.2.199.65 to 174.2.199.70174.2.199.716
234174.2.199.72/29174.2.199.73 to 174.2.199.78174.2.199.796
235174.2.199.80/29174.2.199.81 to 174.2.199.86174.2.199.876
236174.2.199.88/29174.2.199.89 to 174.2.199.94174.2.199.956
237174.2.199.96/29174.2.199.97 to 174.2.199.102174.2.199.1036
238174.2.199.104/29174.2.199.105 to 174.2.199.110174.2.199.1116
239174.2.199.112/29174.2.199.113 to 174.2.199.118174.2.199.1196
240174.2.199.120/29174.2.199.121 to 174.2.199.126174.2.199.1276
241174.2.199.128/29174.2.199.129 to 174.2.199.134174.2.199.1356
242174.2.199.136/29174.2.199.137 to 174.2.199.142174.2.199.1436
243174.2.199.144/29174.2.199.145 to 174.2.199.150174.2.199.1516
244174.2.199.152/29174.2.199.153 to 174.2.199.158174.2.199.1596
245174.2.199.160/29174.2.199.161 to 174.2.199.166174.2.199.1676
246174.2.199.168/29174.2.199.169 to 174.2.199.174174.2.199.1756
247174.2.199.176/29174.2.199.177 to 174.2.199.182174.2.199.1836
248174.2.199.184/29174.2.199.185 to 174.2.199.190174.2.199.1916
249174.2.199.192/29174.2.199.193 to 174.2.199.198174.2.199.1996
250174.2.199.200/29174.2.199.201 to 174.2.199.206174.2.199.2076
251174.2.199.208/29174.2.199.209 to 174.2.199.214174.2.199.2156
252174.2.199.216/29174.2.199.217 to 174.2.199.222174.2.199.2236
253174.2.199.224/29174.2.199.225 to 174.2.199.230174.2.199.2316
254174.2.199.232/29174.2.199.233 to 174.2.199.238174.2.199.2396
255174.2.199.240/29174.2.199.241 to 174.2.199.246174.2.199.2476
256174.2.199.248/29174.2.199.249 to 174.2.199.254174.2.199.2556

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.