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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.

Network148.7.0.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
148.7.0.0
Broadcast address
148.7.31.255
First usable
148.7.0.1
Last usable
148.7.31.254
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
B (default /16)
As numbers
Hex 94070000 · Integer 2483486720 to 2483494911
Reverse DNS zones
0.7.148.in-addr.arpa
1.7.148.in-addr.arpa
2.7.148.in-addr.arpa
3.7.148.in-addr.arpa
4.7.148.in-addr.arpa
5.7.148.in-addr.arpa
6.7.148.in-addr.arpa
7.7.148.in-addr.arpa
8.7.148.in-addr.arpa
9.7.148.in-addr.arpa
10.7.148.in-addr.arpa
11.7.148.in-addr.arpa
12.7.148.in-addr.arpa
13.7.148.in-addr.arpa
14.7.148.in-addr.arpa
15.7.148.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
Address10010100.00000111.00000000.00000000148.7.0.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network10010100.00000111.00000000.00000000148.7.0.0
Broadcast10010100.00000111.00011111.11111111148.7.31.255
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)

148.7.0.0/19 makes 1,024 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1148.7.0.0/29148.7.0.1 to 148.7.0.6148.7.0.76
2148.7.0.8/29148.7.0.9 to 148.7.0.14148.7.0.156
3148.7.0.16/29148.7.0.17 to 148.7.0.22148.7.0.236
4148.7.0.24/29148.7.0.25 to 148.7.0.30148.7.0.316
5148.7.0.32/29148.7.0.33 to 148.7.0.38148.7.0.396
6148.7.0.40/29148.7.0.41 to 148.7.0.46148.7.0.476
7148.7.0.48/29148.7.0.49 to 148.7.0.54148.7.0.556
8148.7.0.56/29148.7.0.57 to 148.7.0.62148.7.0.636
9148.7.0.64/29148.7.0.65 to 148.7.0.70148.7.0.716
10148.7.0.72/29148.7.0.73 to 148.7.0.78148.7.0.796
11148.7.0.80/29148.7.0.81 to 148.7.0.86148.7.0.876
12148.7.0.88/29148.7.0.89 to 148.7.0.94148.7.0.956
13148.7.0.96/29148.7.0.97 to 148.7.0.102148.7.0.1036
14148.7.0.104/29148.7.0.105 to 148.7.0.110148.7.0.1116
15148.7.0.112/29148.7.0.113 to 148.7.0.118148.7.0.1196
16148.7.0.120/29148.7.0.121 to 148.7.0.126148.7.0.1276
17148.7.0.128/29148.7.0.129 to 148.7.0.134148.7.0.1356
18148.7.0.136/29148.7.0.137 to 148.7.0.142148.7.0.1436
19148.7.0.144/29148.7.0.145 to 148.7.0.150148.7.0.1516
20148.7.0.152/29148.7.0.153 to 148.7.0.158148.7.0.1596
21148.7.0.160/29148.7.0.161 to 148.7.0.166148.7.0.1676
22148.7.0.168/29148.7.0.169 to 148.7.0.174148.7.0.1756
23148.7.0.176/29148.7.0.177 to 148.7.0.182148.7.0.1836
24148.7.0.184/29148.7.0.185 to 148.7.0.190148.7.0.1916
25148.7.0.192/29148.7.0.193 to 148.7.0.198148.7.0.1996
26148.7.0.200/29148.7.0.201 to 148.7.0.206148.7.0.2076
27148.7.0.208/29148.7.0.209 to 148.7.0.214148.7.0.2156
28148.7.0.216/29148.7.0.217 to 148.7.0.222148.7.0.2236
29148.7.0.224/29148.7.0.225 to 148.7.0.230148.7.0.2316
30148.7.0.232/29148.7.0.233 to 148.7.0.238148.7.0.2396
31148.7.0.240/29148.7.0.241 to 148.7.0.246148.7.0.2476
32148.7.0.248/29148.7.0.249 to 148.7.0.254148.7.0.2556
33148.7.1.0/29148.7.1.1 to 148.7.1.6148.7.1.76
34148.7.1.8/29148.7.1.9 to 148.7.1.14148.7.1.156
35148.7.1.16/29148.7.1.17 to 148.7.1.22148.7.1.236
36148.7.1.24/29148.7.1.25 to 148.7.1.30148.7.1.316
37148.7.1.32/29148.7.1.33 to 148.7.1.38148.7.1.396
38148.7.1.40/29148.7.1.41 to 148.7.1.46148.7.1.476
39148.7.1.48/29148.7.1.49 to 148.7.1.54148.7.1.556
40148.7.1.56/29148.7.1.57 to 148.7.1.62148.7.1.636
41148.7.1.64/29148.7.1.65 to 148.7.1.70148.7.1.716
42148.7.1.72/29148.7.1.73 to 148.7.1.78148.7.1.796
43148.7.1.80/29148.7.1.81 to 148.7.1.86148.7.1.876
44148.7.1.88/29148.7.1.89 to 148.7.1.94148.7.1.956
45148.7.1.96/29148.7.1.97 to 148.7.1.102148.7.1.1036
46148.7.1.104/29148.7.1.105 to 148.7.1.110148.7.1.1116
47148.7.1.112/29148.7.1.113 to 148.7.1.118148.7.1.1196
48148.7.1.120/29148.7.1.121 to 148.7.1.126148.7.1.1276
49148.7.1.128/29148.7.1.129 to 148.7.1.134148.7.1.1356
50148.7.1.136/29148.7.1.137 to 148.7.1.142148.7.1.1436
51148.7.1.144/29148.7.1.145 to 148.7.1.150148.7.1.1516
52148.7.1.152/29148.7.1.153 to 148.7.1.158148.7.1.1596
53148.7.1.160/29148.7.1.161 to 148.7.1.166148.7.1.1676
54148.7.1.168/29148.7.1.169 to 148.7.1.174148.7.1.1756
55148.7.1.176/29148.7.1.177 to 148.7.1.182148.7.1.1836
56148.7.1.184/29148.7.1.185 to 148.7.1.190148.7.1.1916
57148.7.1.192/29148.7.1.193 to 148.7.1.198148.7.1.1996
58148.7.1.200/29148.7.1.201 to 148.7.1.206148.7.1.2076
59148.7.1.208/29148.7.1.209 to 148.7.1.214148.7.1.2156
60148.7.1.216/29148.7.1.217 to 148.7.1.222148.7.1.2236
61148.7.1.224/29148.7.1.225 to 148.7.1.230148.7.1.2316
62148.7.1.232/29148.7.1.233 to 148.7.1.238148.7.1.2396
63148.7.1.240/29148.7.1.241 to 148.7.1.246148.7.1.2476
64148.7.1.248/29148.7.1.249 to 148.7.1.254148.7.1.2556
65148.7.2.0/29148.7.2.1 to 148.7.2.6148.7.2.76
66148.7.2.8/29148.7.2.9 to 148.7.2.14148.7.2.156
67148.7.2.16/29148.7.2.17 to 148.7.2.22148.7.2.236
68148.7.2.24/29148.7.2.25 to 148.7.2.30148.7.2.316
69148.7.2.32/29148.7.2.33 to 148.7.2.38148.7.2.396
70148.7.2.40/29148.7.2.41 to 148.7.2.46148.7.2.476
71148.7.2.48/29148.7.2.49 to 148.7.2.54148.7.2.556
72148.7.2.56/29148.7.2.57 to 148.7.2.62148.7.2.636
73148.7.2.64/29148.7.2.65 to 148.7.2.70148.7.2.716
74148.7.2.72/29148.7.2.73 to 148.7.2.78148.7.2.796
75148.7.2.80/29148.7.2.81 to 148.7.2.86148.7.2.876
76148.7.2.88/29148.7.2.89 to 148.7.2.94148.7.2.956
77148.7.2.96/29148.7.2.97 to 148.7.2.102148.7.2.1036
78148.7.2.104/29148.7.2.105 to 148.7.2.110148.7.2.1116
79148.7.2.112/29148.7.2.113 to 148.7.2.118148.7.2.1196
80148.7.2.120/29148.7.2.121 to 148.7.2.126148.7.2.1276
81148.7.2.128/29148.7.2.129 to 148.7.2.134148.7.2.1356
82148.7.2.136/29148.7.2.137 to 148.7.2.142148.7.2.1436
83148.7.2.144/29148.7.2.145 to 148.7.2.150148.7.2.1516
84148.7.2.152/29148.7.2.153 to 148.7.2.158148.7.2.1596
85148.7.2.160/29148.7.2.161 to 148.7.2.166148.7.2.1676
86148.7.2.168/29148.7.2.169 to 148.7.2.174148.7.2.1756
87148.7.2.176/29148.7.2.177 to 148.7.2.182148.7.2.1836
88148.7.2.184/29148.7.2.185 to 148.7.2.190148.7.2.1916
89148.7.2.192/29148.7.2.193 to 148.7.2.198148.7.2.1996
90148.7.2.200/29148.7.2.201 to 148.7.2.206148.7.2.2076
91148.7.2.208/29148.7.2.209 to 148.7.2.214148.7.2.2156
92148.7.2.216/29148.7.2.217 to 148.7.2.222148.7.2.2236
93148.7.2.224/29148.7.2.225 to 148.7.2.230148.7.2.2316
94148.7.2.232/29148.7.2.233 to 148.7.2.238148.7.2.2396
95148.7.2.240/29148.7.2.241 to 148.7.2.246148.7.2.2476
96148.7.2.248/29148.7.2.249 to 148.7.2.254148.7.2.2556
97148.7.3.0/29148.7.3.1 to 148.7.3.6148.7.3.76
98148.7.3.8/29148.7.3.9 to 148.7.3.14148.7.3.156
99148.7.3.16/29148.7.3.17 to 148.7.3.22148.7.3.236
100148.7.3.24/29148.7.3.25 to 148.7.3.30148.7.3.316
101148.7.3.32/29148.7.3.33 to 148.7.3.38148.7.3.396
102148.7.3.40/29148.7.3.41 to 148.7.3.46148.7.3.476
103148.7.3.48/29148.7.3.49 to 148.7.3.54148.7.3.556
104148.7.3.56/29148.7.3.57 to 148.7.3.62148.7.3.636
105148.7.3.64/29148.7.3.65 to 148.7.3.70148.7.3.716
106148.7.3.72/29148.7.3.73 to 148.7.3.78148.7.3.796
107148.7.3.80/29148.7.3.81 to 148.7.3.86148.7.3.876
108148.7.3.88/29148.7.3.89 to 148.7.3.94148.7.3.956
109148.7.3.96/29148.7.3.97 to 148.7.3.102148.7.3.1036
110148.7.3.104/29148.7.3.105 to 148.7.3.110148.7.3.1116
111148.7.3.112/29148.7.3.113 to 148.7.3.118148.7.3.1196
112148.7.3.120/29148.7.3.121 to 148.7.3.126148.7.3.1276
113148.7.3.128/29148.7.3.129 to 148.7.3.134148.7.3.1356
114148.7.3.136/29148.7.3.137 to 148.7.3.142148.7.3.1436
115148.7.3.144/29148.7.3.145 to 148.7.3.150148.7.3.1516
116148.7.3.152/29148.7.3.153 to 148.7.3.158148.7.3.1596
117148.7.3.160/29148.7.3.161 to 148.7.3.166148.7.3.1676
118148.7.3.168/29148.7.3.169 to 148.7.3.174148.7.3.1756
119148.7.3.176/29148.7.3.177 to 148.7.3.182148.7.3.1836
120148.7.3.184/29148.7.3.185 to 148.7.3.190148.7.3.1916
121148.7.3.192/29148.7.3.193 to 148.7.3.198148.7.3.1996
122148.7.3.200/29148.7.3.201 to 148.7.3.206148.7.3.2076
123148.7.3.208/29148.7.3.209 to 148.7.3.214148.7.3.2156
124148.7.3.216/29148.7.3.217 to 148.7.3.222148.7.3.2236
125148.7.3.224/29148.7.3.225 to 148.7.3.230148.7.3.2316
126148.7.3.232/29148.7.3.233 to 148.7.3.238148.7.3.2396
127148.7.3.240/29148.7.3.241 to 148.7.3.246148.7.3.2476
128148.7.3.248/29148.7.3.249 to 148.7.3.254148.7.3.2556
129148.7.4.0/29148.7.4.1 to 148.7.4.6148.7.4.76
130148.7.4.8/29148.7.4.9 to 148.7.4.14148.7.4.156
131148.7.4.16/29148.7.4.17 to 148.7.4.22148.7.4.236
132148.7.4.24/29148.7.4.25 to 148.7.4.30148.7.4.316
133148.7.4.32/29148.7.4.33 to 148.7.4.38148.7.4.396
134148.7.4.40/29148.7.4.41 to 148.7.4.46148.7.4.476
135148.7.4.48/29148.7.4.49 to 148.7.4.54148.7.4.556
136148.7.4.56/29148.7.4.57 to 148.7.4.62148.7.4.636
137148.7.4.64/29148.7.4.65 to 148.7.4.70148.7.4.716
138148.7.4.72/29148.7.4.73 to 148.7.4.78148.7.4.796
139148.7.4.80/29148.7.4.81 to 148.7.4.86148.7.4.876
140148.7.4.88/29148.7.4.89 to 148.7.4.94148.7.4.956
141148.7.4.96/29148.7.4.97 to 148.7.4.102148.7.4.1036
142148.7.4.104/29148.7.4.105 to 148.7.4.110148.7.4.1116
143148.7.4.112/29148.7.4.113 to 148.7.4.118148.7.4.1196
144148.7.4.120/29148.7.4.121 to 148.7.4.126148.7.4.1276
145148.7.4.128/29148.7.4.129 to 148.7.4.134148.7.4.1356
146148.7.4.136/29148.7.4.137 to 148.7.4.142148.7.4.1436
147148.7.4.144/29148.7.4.145 to 148.7.4.150148.7.4.1516
148148.7.4.152/29148.7.4.153 to 148.7.4.158148.7.4.1596
149148.7.4.160/29148.7.4.161 to 148.7.4.166148.7.4.1676
150148.7.4.168/29148.7.4.169 to 148.7.4.174148.7.4.1756
151148.7.4.176/29148.7.4.177 to 148.7.4.182148.7.4.1836
152148.7.4.184/29148.7.4.185 to 148.7.4.190148.7.4.1916
153148.7.4.192/29148.7.4.193 to 148.7.4.198148.7.4.1996
154148.7.4.200/29148.7.4.201 to 148.7.4.206148.7.4.2076
155148.7.4.208/29148.7.4.209 to 148.7.4.214148.7.4.2156
156148.7.4.216/29148.7.4.217 to 148.7.4.222148.7.4.2236
157148.7.4.224/29148.7.4.225 to 148.7.4.230148.7.4.2316
158148.7.4.232/29148.7.4.233 to 148.7.4.238148.7.4.2396
159148.7.4.240/29148.7.4.241 to 148.7.4.246148.7.4.2476
160148.7.4.248/29148.7.4.249 to 148.7.4.254148.7.4.2556
161148.7.5.0/29148.7.5.1 to 148.7.5.6148.7.5.76
162148.7.5.8/29148.7.5.9 to 148.7.5.14148.7.5.156
163148.7.5.16/29148.7.5.17 to 148.7.5.22148.7.5.236
164148.7.5.24/29148.7.5.25 to 148.7.5.30148.7.5.316
165148.7.5.32/29148.7.5.33 to 148.7.5.38148.7.5.396
166148.7.5.40/29148.7.5.41 to 148.7.5.46148.7.5.476
167148.7.5.48/29148.7.5.49 to 148.7.5.54148.7.5.556
168148.7.5.56/29148.7.5.57 to 148.7.5.62148.7.5.636
169148.7.5.64/29148.7.5.65 to 148.7.5.70148.7.5.716
170148.7.5.72/29148.7.5.73 to 148.7.5.78148.7.5.796
171148.7.5.80/29148.7.5.81 to 148.7.5.86148.7.5.876
172148.7.5.88/29148.7.5.89 to 148.7.5.94148.7.5.956
173148.7.5.96/29148.7.5.97 to 148.7.5.102148.7.5.1036
174148.7.5.104/29148.7.5.105 to 148.7.5.110148.7.5.1116
175148.7.5.112/29148.7.5.113 to 148.7.5.118148.7.5.1196
176148.7.5.120/29148.7.5.121 to 148.7.5.126148.7.5.1276
177148.7.5.128/29148.7.5.129 to 148.7.5.134148.7.5.1356
178148.7.5.136/29148.7.5.137 to 148.7.5.142148.7.5.1436
179148.7.5.144/29148.7.5.145 to 148.7.5.150148.7.5.1516
180148.7.5.152/29148.7.5.153 to 148.7.5.158148.7.5.1596
181148.7.5.160/29148.7.5.161 to 148.7.5.166148.7.5.1676
182148.7.5.168/29148.7.5.169 to 148.7.5.174148.7.5.1756
183148.7.5.176/29148.7.5.177 to 148.7.5.182148.7.5.1836
184148.7.5.184/29148.7.5.185 to 148.7.5.190148.7.5.1916
185148.7.5.192/29148.7.5.193 to 148.7.5.198148.7.5.1996
186148.7.5.200/29148.7.5.201 to 148.7.5.206148.7.5.2076
187148.7.5.208/29148.7.5.209 to 148.7.5.214148.7.5.2156
188148.7.5.216/29148.7.5.217 to 148.7.5.222148.7.5.2236
189148.7.5.224/29148.7.5.225 to 148.7.5.230148.7.5.2316
190148.7.5.232/29148.7.5.233 to 148.7.5.238148.7.5.2396
191148.7.5.240/29148.7.5.241 to 148.7.5.246148.7.5.2476
192148.7.5.248/29148.7.5.249 to 148.7.5.254148.7.5.2556
193148.7.6.0/29148.7.6.1 to 148.7.6.6148.7.6.76
194148.7.6.8/29148.7.6.9 to 148.7.6.14148.7.6.156
195148.7.6.16/29148.7.6.17 to 148.7.6.22148.7.6.236
196148.7.6.24/29148.7.6.25 to 148.7.6.30148.7.6.316
197148.7.6.32/29148.7.6.33 to 148.7.6.38148.7.6.396
198148.7.6.40/29148.7.6.41 to 148.7.6.46148.7.6.476
199148.7.6.48/29148.7.6.49 to 148.7.6.54148.7.6.556
200148.7.6.56/29148.7.6.57 to 148.7.6.62148.7.6.636
201148.7.6.64/29148.7.6.65 to 148.7.6.70148.7.6.716
202148.7.6.72/29148.7.6.73 to 148.7.6.78148.7.6.796
203148.7.6.80/29148.7.6.81 to 148.7.6.86148.7.6.876
204148.7.6.88/29148.7.6.89 to 148.7.6.94148.7.6.956
205148.7.6.96/29148.7.6.97 to 148.7.6.102148.7.6.1036
206148.7.6.104/29148.7.6.105 to 148.7.6.110148.7.6.1116
207148.7.6.112/29148.7.6.113 to 148.7.6.118148.7.6.1196
208148.7.6.120/29148.7.6.121 to 148.7.6.126148.7.6.1276
209148.7.6.128/29148.7.6.129 to 148.7.6.134148.7.6.1356
210148.7.6.136/29148.7.6.137 to 148.7.6.142148.7.6.1436
211148.7.6.144/29148.7.6.145 to 148.7.6.150148.7.6.1516
212148.7.6.152/29148.7.6.153 to 148.7.6.158148.7.6.1596
213148.7.6.160/29148.7.6.161 to 148.7.6.166148.7.6.1676
214148.7.6.168/29148.7.6.169 to 148.7.6.174148.7.6.1756
215148.7.6.176/29148.7.6.177 to 148.7.6.182148.7.6.1836
216148.7.6.184/29148.7.6.185 to 148.7.6.190148.7.6.1916
217148.7.6.192/29148.7.6.193 to 148.7.6.198148.7.6.1996
218148.7.6.200/29148.7.6.201 to 148.7.6.206148.7.6.2076
219148.7.6.208/29148.7.6.209 to 148.7.6.214148.7.6.2156
220148.7.6.216/29148.7.6.217 to 148.7.6.222148.7.6.2236
221148.7.6.224/29148.7.6.225 to 148.7.6.230148.7.6.2316
222148.7.6.232/29148.7.6.233 to 148.7.6.238148.7.6.2396
223148.7.6.240/29148.7.6.241 to 148.7.6.246148.7.6.2476
224148.7.6.248/29148.7.6.249 to 148.7.6.254148.7.6.2556
225148.7.7.0/29148.7.7.1 to 148.7.7.6148.7.7.76
226148.7.7.8/29148.7.7.9 to 148.7.7.14148.7.7.156
227148.7.7.16/29148.7.7.17 to 148.7.7.22148.7.7.236
228148.7.7.24/29148.7.7.25 to 148.7.7.30148.7.7.316
229148.7.7.32/29148.7.7.33 to 148.7.7.38148.7.7.396
230148.7.7.40/29148.7.7.41 to 148.7.7.46148.7.7.476
231148.7.7.48/29148.7.7.49 to 148.7.7.54148.7.7.556
232148.7.7.56/29148.7.7.57 to 148.7.7.62148.7.7.636
233148.7.7.64/29148.7.7.65 to 148.7.7.70148.7.7.716
234148.7.7.72/29148.7.7.73 to 148.7.7.78148.7.7.796
235148.7.7.80/29148.7.7.81 to 148.7.7.86148.7.7.876
236148.7.7.88/29148.7.7.89 to 148.7.7.94148.7.7.956
237148.7.7.96/29148.7.7.97 to 148.7.7.102148.7.7.1036
238148.7.7.104/29148.7.7.105 to 148.7.7.110148.7.7.1116
239148.7.7.112/29148.7.7.113 to 148.7.7.118148.7.7.1196
240148.7.7.120/29148.7.7.121 to 148.7.7.126148.7.7.1276
241148.7.7.128/29148.7.7.129 to 148.7.7.134148.7.7.1356
242148.7.7.136/29148.7.7.137 to 148.7.7.142148.7.7.1436
243148.7.7.144/29148.7.7.145 to 148.7.7.150148.7.7.1516
244148.7.7.152/29148.7.7.153 to 148.7.7.158148.7.7.1596
245148.7.7.160/29148.7.7.161 to 148.7.7.166148.7.7.1676
246148.7.7.168/29148.7.7.169 to 148.7.7.174148.7.7.1756
247148.7.7.176/29148.7.7.177 to 148.7.7.182148.7.7.1836
248148.7.7.184/29148.7.7.185 to 148.7.7.190148.7.7.1916
249148.7.7.192/29148.7.7.193 to 148.7.7.198148.7.7.1996
250148.7.7.200/29148.7.7.201 to 148.7.7.206148.7.7.2076
251148.7.7.208/29148.7.7.209 to 148.7.7.214148.7.7.2156
252148.7.7.216/29148.7.7.217 to 148.7.7.222148.7.7.2236
253148.7.7.224/29148.7.7.225 to 148.7.7.230148.7.7.2316
254148.7.7.232/29148.7.7.233 to 148.7.7.238148.7.7.2396
255148.7.7.240/29148.7.7.241 to 148.7.7.246148.7.7.2476
256148.7.7.248/29148.7.7.249 to 148.7.7.254148.7.7.2556

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.