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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.

Network246.2.64.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
246.2.64.0
Broadcast address
246.2.95.255
First usable
246.2.64.1
Last usable
246.2.95.254
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
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F6024000 · Integer 4127342592 to 4127350783
Reverse DNS zones
64.2.246.in-addr.arpa
65.2.246.in-addr.arpa
66.2.246.in-addr.arpa
67.2.246.in-addr.arpa
68.2.246.in-addr.arpa
69.2.246.in-addr.arpa
70.2.246.in-addr.arpa
71.2.246.in-addr.arpa
72.2.246.in-addr.arpa
73.2.246.in-addr.arpa
74.2.246.in-addr.arpa
75.2.246.in-addr.arpa
76.2.246.in-addr.arpa
77.2.246.in-addr.arpa
78.2.246.in-addr.arpa
79.2.246.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
Address11110110.00000010.01000000.00000000246.2.64.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network11110110.00000010.01000000.00000000246.2.64.0
Broadcast11110110.00000010.01011111.11111111246.2.95.255
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)

246.2.64.0/19 makes 1,024 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1246.2.64.0/29246.2.64.1 to 246.2.64.6246.2.64.76
2246.2.64.8/29246.2.64.9 to 246.2.64.14246.2.64.156
3246.2.64.16/29246.2.64.17 to 246.2.64.22246.2.64.236
4246.2.64.24/29246.2.64.25 to 246.2.64.30246.2.64.316
5246.2.64.32/29246.2.64.33 to 246.2.64.38246.2.64.396
6246.2.64.40/29246.2.64.41 to 246.2.64.46246.2.64.476
7246.2.64.48/29246.2.64.49 to 246.2.64.54246.2.64.556
8246.2.64.56/29246.2.64.57 to 246.2.64.62246.2.64.636
9246.2.64.64/29246.2.64.65 to 246.2.64.70246.2.64.716
10246.2.64.72/29246.2.64.73 to 246.2.64.78246.2.64.796
11246.2.64.80/29246.2.64.81 to 246.2.64.86246.2.64.876
12246.2.64.88/29246.2.64.89 to 246.2.64.94246.2.64.956
13246.2.64.96/29246.2.64.97 to 246.2.64.102246.2.64.1036
14246.2.64.104/29246.2.64.105 to 246.2.64.110246.2.64.1116
15246.2.64.112/29246.2.64.113 to 246.2.64.118246.2.64.1196
16246.2.64.120/29246.2.64.121 to 246.2.64.126246.2.64.1276
17246.2.64.128/29246.2.64.129 to 246.2.64.134246.2.64.1356
18246.2.64.136/29246.2.64.137 to 246.2.64.142246.2.64.1436
19246.2.64.144/29246.2.64.145 to 246.2.64.150246.2.64.1516
20246.2.64.152/29246.2.64.153 to 246.2.64.158246.2.64.1596
21246.2.64.160/29246.2.64.161 to 246.2.64.166246.2.64.1676
22246.2.64.168/29246.2.64.169 to 246.2.64.174246.2.64.1756
23246.2.64.176/29246.2.64.177 to 246.2.64.182246.2.64.1836
24246.2.64.184/29246.2.64.185 to 246.2.64.190246.2.64.1916
25246.2.64.192/29246.2.64.193 to 246.2.64.198246.2.64.1996
26246.2.64.200/29246.2.64.201 to 246.2.64.206246.2.64.2076
27246.2.64.208/29246.2.64.209 to 246.2.64.214246.2.64.2156
28246.2.64.216/29246.2.64.217 to 246.2.64.222246.2.64.2236
29246.2.64.224/29246.2.64.225 to 246.2.64.230246.2.64.2316
30246.2.64.232/29246.2.64.233 to 246.2.64.238246.2.64.2396
31246.2.64.240/29246.2.64.241 to 246.2.64.246246.2.64.2476
32246.2.64.248/29246.2.64.249 to 246.2.64.254246.2.64.2556
33246.2.65.0/29246.2.65.1 to 246.2.65.6246.2.65.76
34246.2.65.8/29246.2.65.9 to 246.2.65.14246.2.65.156
35246.2.65.16/29246.2.65.17 to 246.2.65.22246.2.65.236
36246.2.65.24/29246.2.65.25 to 246.2.65.30246.2.65.316
37246.2.65.32/29246.2.65.33 to 246.2.65.38246.2.65.396
38246.2.65.40/29246.2.65.41 to 246.2.65.46246.2.65.476
39246.2.65.48/29246.2.65.49 to 246.2.65.54246.2.65.556
40246.2.65.56/29246.2.65.57 to 246.2.65.62246.2.65.636
41246.2.65.64/29246.2.65.65 to 246.2.65.70246.2.65.716
42246.2.65.72/29246.2.65.73 to 246.2.65.78246.2.65.796
43246.2.65.80/29246.2.65.81 to 246.2.65.86246.2.65.876
44246.2.65.88/29246.2.65.89 to 246.2.65.94246.2.65.956
45246.2.65.96/29246.2.65.97 to 246.2.65.102246.2.65.1036
46246.2.65.104/29246.2.65.105 to 246.2.65.110246.2.65.1116
47246.2.65.112/29246.2.65.113 to 246.2.65.118246.2.65.1196
48246.2.65.120/29246.2.65.121 to 246.2.65.126246.2.65.1276
49246.2.65.128/29246.2.65.129 to 246.2.65.134246.2.65.1356
50246.2.65.136/29246.2.65.137 to 246.2.65.142246.2.65.1436
51246.2.65.144/29246.2.65.145 to 246.2.65.150246.2.65.1516
52246.2.65.152/29246.2.65.153 to 246.2.65.158246.2.65.1596
53246.2.65.160/29246.2.65.161 to 246.2.65.166246.2.65.1676
54246.2.65.168/29246.2.65.169 to 246.2.65.174246.2.65.1756
55246.2.65.176/29246.2.65.177 to 246.2.65.182246.2.65.1836
56246.2.65.184/29246.2.65.185 to 246.2.65.190246.2.65.1916
57246.2.65.192/29246.2.65.193 to 246.2.65.198246.2.65.1996
58246.2.65.200/29246.2.65.201 to 246.2.65.206246.2.65.2076
59246.2.65.208/29246.2.65.209 to 246.2.65.214246.2.65.2156
60246.2.65.216/29246.2.65.217 to 246.2.65.222246.2.65.2236
61246.2.65.224/29246.2.65.225 to 246.2.65.230246.2.65.2316
62246.2.65.232/29246.2.65.233 to 246.2.65.238246.2.65.2396
63246.2.65.240/29246.2.65.241 to 246.2.65.246246.2.65.2476
64246.2.65.248/29246.2.65.249 to 246.2.65.254246.2.65.2556
65246.2.66.0/29246.2.66.1 to 246.2.66.6246.2.66.76
66246.2.66.8/29246.2.66.9 to 246.2.66.14246.2.66.156
67246.2.66.16/29246.2.66.17 to 246.2.66.22246.2.66.236
68246.2.66.24/29246.2.66.25 to 246.2.66.30246.2.66.316
69246.2.66.32/29246.2.66.33 to 246.2.66.38246.2.66.396
70246.2.66.40/29246.2.66.41 to 246.2.66.46246.2.66.476
71246.2.66.48/29246.2.66.49 to 246.2.66.54246.2.66.556
72246.2.66.56/29246.2.66.57 to 246.2.66.62246.2.66.636
73246.2.66.64/29246.2.66.65 to 246.2.66.70246.2.66.716
74246.2.66.72/29246.2.66.73 to 246.2.66.78246.2.66.796
75246.2.66.80/29246.2.66.81 to 246.2.66.86246.2.66.876
76246.2.66.88/29246.2.66.89 to 246.2.66.94246.2.66.956
77246.2.66.96/29246.2.66.97 to 246.2.66.102246.2.66.1036
78246.2.66.104/29246.2.66.105 to 246.2.66.110246.2.66.1116
79246.2.66.112/29246.2.66.113 to 246.2.66.118246.2.66.1196
80246.2.66.120/29246.2.66.121 to 246.2.66.126246.2.66.1276
81246.2.66.128/29246.2.66.129 to 246.2.66.134246.2.66.1356
82246.2.66.136/29246.2.66.137 to 246.2.66.142246.2.66.1436
83246.2.66.144/29246.2.66.145 to 246.2.66.150246.2.66.1516
84246.2.66.152/29246.2.66.153 to 246.2.66.158246.2.66.1596
85246.2.66.160/29246.2.66.161 to 246.2.66.166246.2.66.1676
86246.2.66.168/29246.2.66.169 to 246.2.66.174246.2.66.1756
87246.2.66.176/29246.2.66.177 to 246.2.66.182246.2.66.1836
88246.2.66.184/29246.2.66.185 to 246.2.66.190246.2.66.1916
89246.2.66.192/29246.2.66.193 to 246.2.66.198246.2.66.1996
90246.2.66.200/29246.2.66.201 to 246.2.66.206246.2.66.2076
91246.2.66.208/29246.2.66.209 to 246.2.66.214246.2.66.2156
92246.2.66.216/29246.2.66.217 to 246.2.66.222246.2.66.2236
93246.2.66.224/29246.2.66.225 to 246.2.66.230246.2.66.2316
94246.2.66.232/29246.2.66.233 to 246.2.66.238246.2.66.2396
95246.2.66.240/29246.2.66.241 to 246.2.66.246246.2.66.2476
96246.2.66.248/29246.2.66.249 to 246.2.66.254246.2.66.2556
97246.2.67.0/29246.2.67.1 to 246.2.67.6246.2.67.76
98246.2.67.8/29246.2.67.9 to 246.2.67.14246.2.67.156
99246.2.67.16/29246.2.67.17 to 246.2.67.22246.2.67.236
100246.2.67.24/29246.2.67.25 to 246.2.67.30246.2.67.316
101246.2.67.32/29246.2.67.33 to 246.2.67.38246.2.67.396
102246.2.67.40/29246.2.67.41 to 246.2.67.46246.2.67.476
103246.2.67.48/29246.2.67.49 to 246.2.67.54246.2.67.556
104246.2.67.56/29246.2.67.57 to 246.2.67.62246.2.67.636
105246.2.67.64/29246.2.67.65 to 246.2.67.70246.2.67.716
106246.2.67.72/29246.2.67.73 to 246.2.67.78246.2.67.796
107246.2.67.80/29246.2.67.81 to 246.2.67.86246.2.67.876
108246.2.67.88/29246.2.67.89 to 246.2.67.94246.2.67.956
109246.2.67.96/29246.2.67.97 to 246.2.67.102246.2.67.1036
110246.2.67.104/29246.2.67.105 to 246.2.67.110246.2.67.1116
111246.2.67.112/29246.2.67.113 to 246.2.67.118246.2.67.1196
112246.2.67.120/29246.2.67.121 to 246.2.67.126246.2.67.1276
113246.2.67.128/29246.2.67.129 to 246.2.67.134246.2.67.1356
114246.2.67.136/29246.2.67.137 to 246.2.67.142246.2.67.1436
115246.2.67.144/29246.2.67.145 to 246.2.67.150246.2.67.1516
116246.2.67.152/29246.2.67.153 to 246.2.67.158246.2.67.1596
117246.2.67.160/29246.2.67.161 to 246.2.67.166246.2.67.1676
118246.2.67.168/29246.2.67.169 to 246.2.67.174246.2.67.1756
119246.2.67.176/29246.2.67.177 to 246.2.67.182246.2.67.1836
120246.2.67.184/29246.2.67.185 to 246.2.67.190246.2.67.1916
121246.2.67.192/29246.2.67.193 to 246.2.67.198246.2.67.1996
122246.2.67.200/29246.2.67.201 to 246.2.67.206246.2.67.2076
123246.2.67.208/29246.2.67.209 to 246.2.67.214246.2.67.2156
124246.2.67.216/29246.2.67.217 to 246.2.67.222246.2.67.2236
125246.2.67.224/29246.2.67.225 to 246.2.67.230246.2.67.2316
126246.2.67.232/29246.2.67.233 to 246.2.67.238246.2.67.2396
127246.2.67.240/29246.2.67.241 to 246.2.67.246246.2.67.2476
128246.2.67.248/29246.2.67.249 to 246.2.67.254246.2.67.2556
129246.2.68.0/29246.2.68.1 to 246.2.68.6246.2.68.76
130246.2.68.8/29246.2.68.9 to 246.2.68.14246.2.68.156
131246.2.68.16/29246.2.68.17 to 246.2.68.22246.2.68.236
132246.2.68.24/29246.2.68.25 to 246.2.68.30246.2.68.316
133246.2.68.32/29246.2.68.33 to 246.2.68.38246.2.68.396
134246.2.68.40/29246.2.68.41 to 246.2.68.46246.2.68.476
135246.2.68.48/29246.2.68.49 to 246.2.68.54246.2.68.556
136246.2.68.56/29246.2.68.57 to 246.2.68.62246.2.68.636
137246.2.68.64/29246.2.68.65 to 246.2.68.70246.2.68.716
138246.2.68.72/29246.2.68.73 to 246.2.68.78246.2.68.796
139246.2.68.80/29246.2.68.81 to 246.2.68.86246.2.68.876
140246.2.68.88/29246.2.68.89 to 246.2.68.94246.2.68.956
141246.2.68.96/29246.2.68.97 to 246.2.68.102246.2.68.1036
142246.2.68.104/29246.2.68.105 to 246.2.68.110246.2.68.1116
143246.2.68.112/29246.2.68.113 to 246.2.68.118246.2.68.1196
144246.2.68.120/29246.2.68.121 to 246.2.68.126246.2.68.1276
145246.2.68.128/29246.2.68.129 to 246.2.68.134246.2.68.1356
146246.2.68.136/29246.2.68.137 to 246.2.68.142246.2.68.1436
147246.2.68.144/29246.2.68.145 to 246.2.68.150246.2.68.1516
148246.2.68.152/29246.2.68.153 to 246.2.68.158246.2.68.1596
149246.2.68.160/29246.2.68.161 to 246.2.68.166246.2.68.1676
150246.2.68.168/29246.2.68.169 to 246.2.68.174246.2.68.1756
151246.2.68.176/29246.2.68.177 to 246.2.68.182246.2.68.1836
152246.2.68.184/29246.2.68.185 to 246.2.68.190246.2.68.1916
153246.2.68.192/29246.2.68.193 to 246.2.68.198246.2.68.1996
154246.2.68.200/29246.2.68.201 to 246.2.68.206246.2.68.2076
155246.2.68.208/29246.2.68.209 to 246.2.68.214246.2.68.2156
156246.2.68.216/29246.2.68.217 to 246.2.68.222246.2.68.2236
157246.2.68.224/29246.2.68.225 to 246.2.68.230246.2.68.2316
158246.2.68.232/29246.2.68.233 to 246.2.68.238246.2.68.2396
159246.2.68.240/29246.2.68.241 to 246.2.68.246246.2.68.2476
160246.2.68.248/29246.2.68.249 to 246.2.68.254246.2.68.2556
161246.2.69.0/29246.2.69.1 to 246.2.69.6246.2.69.76
162246.2.69.8/29246.2.69.9 to 246.2.69.14246.2.69.156
163246.2.69.16/29246.2.69.17 to 246.2.69.22246.2.69.236
164246.2.69.24/29246.2.69.25 to 246.2.69.30246.2.69.316
165246.2.69.32/29246.2.69.33 to 246.2.69.38246.2.69.396
166246.2.69.40/29246.2.69.41 to 246.2.69.46246.2.69.476
167246.2.69.48/29246.2.69.49 to 246.2.69.54246.2.69.556
168246.2.69.56/29246.2.69.57 to 246.2.69.62246.2.69.636
169246.2.69.64/29246.2.69.65 to 246.2.69.70246.2.69.716
170246.2.69.72/29246.2.69.73 to 246.2.69.78246.2.69.796
171246.2.69.80/29246.2.69.81 to 246.2.69.86246.2.69.876
172246.2.69.88/29246.2.69.89 to 246.2.69.94246.2.69.956
173246.2.69.96/29246.2.69.97 to 246.2.69.102246.2.69.1036
174246.2.69.104/29246.2.69.105 to 246.2.69.110246.2.69.1116
175246.2.69.112/29246.2.69.113 to 246.2.69.118246.2.69.1196
176246.2.69.120/29246.2.69.121 to 246.2.69.126246.2.69.1276
177246.2.69.128/29246.2.69.129 to 246.2.69.134246.2.69.1356
178246.2.69.136/29246.2.69.137 to 246.2.69.142246.2.69.1436
179246.2.69.144/29246.2.69.145 to 246.2.69.150246.2.69.1516
180246.2.69.152/29246.2.69.153 to 246.2.69.158246.2.69.1596
181246.2.69.160/29246.2.69.161 to 246.2.69.166246.2.69.1676
182246.2.69.168/29246.2.69.169 to 246.2.69.174246.2.69.1756
183246.2.69.176/29246.2.69.177 to 246.2.69.182246.2.69.1836
184246.2.69.184/29246.2.69.185 to 246.2.69.190246.2.69.1916
185246.2.69.192/29246.2.69.193 to 246.2.69.198246.2.69.1996
186246.2.69.200/29246.2.69.201 to 246.2.69.206246.2.69.2076
187246.2.69.208/29246.2.69.209 to 246.2.69.214246.2.69.2156
188246.2.69.216/29246.2.69.217 to 246.2.69.222246.2.69.2236
189246.2.69.224/29246.2.69.225 to 246.2.69.230246.2.69.2316
190246.2.69.232/29246.2.69.233 to 246.2.69.238246.2.69.2396
191246.2.69.240/29246.2.69.241 to 246.2.69.246246.2.69.2476
192246.2.69.248/29246.2.69.249 to 246.2.69.254246.2.69.2556
193246.2.70.0/29246.2.70.1 to 246.2.70.6246.2.70.76
194246.2.70.8/29246.2.70.9 to 246.2.70.14246.2.70.156
195246.2.70.16/29246.2.70.17 to 246.2.70.22246.2.70.236
196246.2.70.24/29246.2.70.25 to 246.2.70.30246.2.70.316
197246.2.70.32/29246.2.70.33 to 246.2.70.38246.2.70.396
198246.2.70.40/29246.2.70.41 to 246.2.70.46246.2.70.476
199246.2.70.48/29246.2.70.49 to 246.2.70.54246.2.70.556
200246.2.70.56/29246.2.70.57 to 246.2.70.62246.2.70.636
201246.2.70.64/29246.2.70.65 to 246.2.70.70246.2.70.716
202246.2.70.72/29246.2.70.73 to 246.2.70.78246.2.70.796
203246.2.70.80/29246.2.70.81 to 246.2.70.86246.2.70.876
204246.2.70.88/29246.2.70.89 to 246.2.70.94246.2.70.956
205246.2.70.96/29246.2.70.97 to 246.2.70.102246.2.70.1036
206246.2.70.104/29246.2.70.105 to 246.2.70.110246.2.70.1116
207246.2.70.112/29246.2.70.113 to 246.2.70.118246.2.70.1196
208246.2.70.120/29246.2.70.121 to 246.2.70.126246.2.70.1276
209246.2.70.128/29246.2.70.129 to 246.2.70.134246.2.70.1356
210246.2.70.136/29246.2.70.137 to 246.2.70.142246.2.70.1436
211246.2.70.144/29246.2.70.145 to 246.2.70.150246.2.70.1516
212246.2.70.152/29246.2.70.153 to 246.2.70.158246.2.70.1596
213246.2.70.160/29246.2.70.161 to 246.2.70.166246.2.70.1676
214246.2.70.168/29246.2.70.169 to 246.2.70.174246.2.70.1756
215246.2.70.176/29246.2.70.177 to 246.2.70.182246.2.70.1836
216246.2.70.184/29246.2.70.185 to 246.2.70.190246.2.70.1916
217246.2.70.192/29246.2.70.193 to 246.2.70.198246.2.70.1996
218246.2.70.200/29246.2.70.201 to 246.2.70.206246.2.70.2076
219246.2.70.208/29246.2.70.209 to 246.2.70.214246.2.70.2156
220246.2.70.216/29246.2.70.217 to 246.2.70.222246.2.70.2236
221246.2.70.224/29246.2.70.225 to 246.2.70.230246.2.70.2316
222246.2.70.232/29246.2.70.233 to 246.2.70.238246.2.70.2396
223246.2.70.240/29246.2.70.241 to 246.2.70.246246.2.70.2476
224246.2.70.248/29246.2.70.249 to 246.2.70.254246.2.70.2556
225246.2.71.0/29246.2.71.1 to 246.2.71.6246.2.71.76
226246.2.71.8/29246.2.71.9 to 246.2.71.14246.2.71.156
227246.2.71.16/29246.2.71.17 to 246.2.71.22246.2.71.236
228246.2.71.24/29246.2.71.25 to 246.2.71.30246.2.71.316
229246.2.71.32/29246.2.71.33 to 246.2.71.38246.2.71.396
230246.2.71.40/29246.2.71.41 to 246.2.71.46246.2.71.476
231246.2.71.48/29246.2.71.49 to 246.2.71.54246.2.71.556
232246.2.71.56/29246.2.71.57 to 246.2.71.62246.2.71.636
233246.2.71.64/29246.2.71.65 to 246.2.71.70246.2.71.716
234246.2.71.72/29246.2.71.73 to 246.2.71.78246.2.71.796
235246.2.71.80/29246.2.71.81 to 246.2.71.86246.2.71.876
236246.2.71.88/29246.2.71.89 to 246.2.71.94246.2.71.956
237246.2.71.96/29246.2.71.97 to 246.2.71.102246.2.71.1036
238246.2.71.104/29246.2.71.105 to 246.2.71.110246.2.71.1116
239246.2.71.112/29246.2.71.113 to 246.2.71.118246.2.71.1196
240246.2.71.120/29246.2.71.121 to 246.2.71.126246.2.71.1276
241246.2.71.128/29246.2.71.129 to 246.2.71.134246.2.71.1356
242246.2.71.136/29246.2.71.137 to 246.2.71.142246.2.71.1436
243246.2.71.144/29246.2.71.145 to 246.2.71.150246.2.71.1516
244246.2.71.152/29246.2.71.153 to 246.2.71.158246.2.71.1596
245246.2.71.160/29246.2.71.161 to 246.2.71.166246.2.71.1676
246246.2.71.168/29246.2.71.169 to 246.2.71.174246.2.71.1756
247246.2.71.176/29246.2.71.177 to 246.2.71.182246.2.71.1836
248246.2.71.184/29246.2.71.185 to 246.2.71.190246.2.71.1916
249246.2.71.192/29246.2.71.193 to 246.2.71.198246.2.71.1996
250246.2.71.200/29246.2.71.201 to 246.2.71.206246.2.71.2076
251246.2.71.208/29246.2.71.209 to 246.2.71.214246.2.71.2156
252246.2.71.216/29246.2.71.217 to 246.2.71.222246.2.71.2236
253246.2.71.224/29246.2.71.225 to 246.2.71.230246.2.71.2316
254246.2.71.232/29246.2.71.233 to 246.2.71.238246.2.71.2396
255246.2.71.240/29246.2.71.241 to 246.2.71.246246.2.71.2476
256246.2.71.248/29246.2.71.249 to 246.2.71.254246.2.71.2556

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.