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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.

Network246.2.0.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
246.2.0.0
Broadcast address
246.2.3.255
First usable
246.2.0.1
Last usable
246.2.3.254
Usable hosts
1,022 (1,024 less the network and broadcast addresses)
Subnet mask
255.255.252.0
Wildcard mask
0.0.3.255 (Cisco ACLs, OSPF)
Prefix length
/22
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F6020000 · Integer 4127326208 to 4127327231
Reverse DNS zones
0.2.246.in-addr.arpa
1.2.246.in-addr.arpa
2.2.246.in-addr.arpa
3.2.246.in-addr.arpa
/22 is not on a 8-bit boundary, so it takes 4 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11110110.00000010.00000000.00000000246.2.0.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network11110110.00000010.00000000.00000000246.2.0.0
Broadcast11110110.00000010.00000011.11111111246.2.3.255
Split into smaller subnets/30
/23 (2)/24 (4)/25 (8)/26 (16)/27 (32)/28 (64)/29 (128)/30 (256)/31 (512)/32 (1,024)

246.2.0.0/22 makes 256 subnets of /30.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1246.2.0.0/30246.2.0.1 to 246.2.0.2246.2.0.32
2246.2.0.4/30246.2.0.5 to 246.2.0.6246.2.0.72
3246.2.0.8/30246.2.0.9 to 246.2.0.10246.2.0.112
4246.2.0.12/30246.2.0.13 to 246.2.0.14246.2.0.152
5246.2.0.16/30246.2.0.17 to 246.2.0.18246.2.0.192
6246.2.0.20/30246.2.0.21 to 246.2.0.22246.2.0.232
7246.2.0.24/30246.2.0.25 to 246.2.0.26246.2.0.272
8246.2.0.28/30246.2.0.29 to 246.2.0.30246.2.0.312
9246.2.0.32/30246.2.0.33 to 246.2.0.34246.2.0.352
10246.2.0.36/30246.2.0.37 to 246.2.0.38246.2.0.392
11246.2.0.40/30246.2.0.41 to 246.2.0.42246.2.0.432
12246.2.0.44/30246.2.0.45 to 246.2.0.46246.2.0.472
13246.2.0.48/30246.2.0.49 to 246.2.0.50246.2.0.512
14246.2.0.52/30246.2.0.53 to 246.2.0.54246.2.0.552
15246.2.0.56/30246.2.0.57 to 246.2.0.58246.2.0.592
16246.2.0.60/30246.2.0.61 to 246.2.0.62246.2.0.632
17246.2.0.64/30246.2.0.65 to 246.2.0.66246.2.0.672
18246.2.0.68/30246.2.0.69 to 246.2.0.70246.2.0.712
19246.2.0.72/30246.2.0.73 to 246.2.0.74246.2.0.752
20246.2.0.76/30246.2.0.77 to 246.2.0.78246.2.0.792
21246.2.0.80/30246.2.0.81 to 246.2.0.82246.2.0.832
22246.2.0.84/30246.2.0.85 to 246.2.0.86246.2.0.872
23246.2.0.88/30246.2.0.89 to 246.2.0.90246.2.0.912
24246.2.0.92/30246.2.0.93 to 246.2.0.94246.2.0.952
25246.2.0.96/30246.2.0.97 to 246.2.0.98246.2.0.992
26246.2.0.100/30246.2.0.101 to 246.2.0.102246.2.0.1032
27246.2.0.104/30246.2.0.105 to 246.2.0.106246.2.0.1072
28246.2.0.108/30246.2.0.109 to 246.2.0.110246.2.0.1112
29246.2.0.112/30246.2.0.113 to 246.2.0.114246.2.0.1152
30246.2.0.116/30246.2.0.117 to 246.2.0.118246.2.0.1192
31246.2.0.120/30246.2.0.121 to 246.2.0.122246.2.0.1232
32246.2.0.124/30246.2.0.125 to 246.2.0.126246.2.0.1272
33246.2.0.128/30246.2.0.129 to 246.2.0.130246.2.0.1312
34246.2.0.132/30246.2.0.133 to 246.2.0.134246.2.0.1352
35246.2.0.136/30246.2.0.137 to 246.2.0.138246.2.0.1392
36246.2.0.140/30246.2.0.141 to 246.2.0.142246.2.0.1432
37246.2.0.144/30246.2.0.145 to 246.2.0.146246.2.0.1472
38246.2.0.148/30246.2.0.149 to 246.2.0.150246.2.0.1512
39246.2.0.152/30246.2.0.153 to 246.2.0.154246.2.0.1552
40246.2.0.156/30246.2.0.157 to 246.2.0.158246.2.0.1592
41246.2.0.160/30246.2.0.161 to 246.2.0.162246.2.0.1632
42246.2.0.164/30246.2.0.165 to 246.2.0.166246.2.0.1672
43246.2.0.168/30246.2.0.169 to 246.2.0.170246.2.0.1712
44246.2.0.172/30246.2.0.173 to 246.2.0.174246.2.0.1752
45246.2.0.176/30246.2.0.177 to 246.2.0.178246.2.0.1792
46246.2.0.180/30246.2.0.181 to 246.2.0.182246.2.0.1832
47246.2.0.184/30246.2.0.185 to 246.2.0.186246.2.0.1872
48246.2.0.188/30246.2.0.189 to 246.2.0.190246.2.0.1912
49246.2.0.192/30246.2.0.193 to 246.2.0.194246.2.0.1952
50246.2.0.196/30246.2.0.197 to 246.2.0.198246.2.0.1992
51246.2.0.200/30246.2.0.201 to 246.2.0.202246.2.0.2032
52246.2.0.204/30246.2.0.205 to 246.2.0.206246.2.0.2072
53246.2.0.208/30246.2.0.209 to 246.2.0.210246.2.0.2112
54246.2.0.212/30246.2.0.213 to 246.2.0.214246.2.0.2152
55246.2.0.216/30246.2.0.217 to 246.2.0.218246.2.0.2192
56246.2.0.220/30246.2.0.221 to 246.2.0.222246.2.0.2232
57246.2.0.224/30246.2.0.225 to 246.2.0.226246.2.0.2272
58246.2.0.228/30246.2.0.229 to 246.2.0.230246.2.0.2312
59246.2.0.232/30246.2.0.233 to 246.2.0.234246.2.0.2352
60246.2.0.236/30246.2.0.237 to 246.2.0.238246.2.0.2392
61246.2.0.240/30246.2.0.241 to 246.2.0.242246.2.0.2432
62246.2.0.244/30246.2.0.245 to 246.2.0.246246.2.0.2472
63246.2.0.248/30246.2.0.249 to 246.2.0.250246.2.0.2512
64246.2.0.252/30246.2.0.253 to 246.2.0.254246.2.0.2552
65246.2.1.0/30246.2.1.1 to 246.2.1.2246.2.1.32
66246.2.1.4/30246.2.1.5 to 246.2.1.6246.2.1.72
67246.2.1.8/30246.2.1.9 to 246.2.1.10246.2.1.112
68246.2.1.12/30246.2.1.13 to 246.2.1.14246.2.1.152
69246.2.1.16/30246.2.1.17 to 246.2.1.18246.2.1.192
70246.2.1.20/30246.2.1.21 to 246.2.1.22246.2.1.232
71246.2.1.24/30246.2.1.25 to 246.2.1.26246.2.1.272
72246.2.1.28/30246.2.1.29 to 246.2.1.30246.2.1.312
73246.2.1.32/30246.2.1.33 to 246.2.1.34246.2.1.352
74246.2.1.36/30246.2.1.37 to 246.2.1.38246.2.1.392
75246.2.1.40/30246.2.1.41 to 246.2.1.42246.2.1.432
76246.2.1.44/30246.2.1.45 to 246.2.1.46246.2.1.472
77246.2.1.48/30246.2.1.49 to 246.2.1.50246.2.1.512
78246.2.1.52/30246.2.1.53 to 246.2.1.54246.2.1.552
79246.2.1.56/30246.2.1.57 to 246.2.1.58246.2.1.592
80246.2.1.60/30246.2.1.61 to 246.2.1.62246.2.1.632
81246.2.1.64/30246.2.1.65 to 246.2.1.66246.2.1.672
82246.2.1.68/30246.2.1.69 to 246.2.1.70246.2.1.712
83246.2.1.72/30246.2.1.73 to 246.2.1.74246.2.1.752
84246.2.1.76/30246.2.1.77 to 246.2.1.78246.2.1.792
85246.2.1.80/30246.2.1.81 to 246.2.1.82246.2.1.832
86246.2.1.84/30246.2.1.85 to 246.2.1.86246.2.1.872
87246.2.1.88/30246.2.1.89 to 246.2.1.90246.2.1.912
88246.2.1.92/30246.2.1.93 to 246.2.1.94246.2.1.952
89246.2.1.96/30246.2.1.97 to 246.2.1.98246.2.1.992
90246.2.1.100/30246.2.1.101 to 246.2.1.102246.2.1.1032
91246.2.1.104/30246.2.1.105 to 246.2.1.106246.2.1.1072
92246.2.1.108/30246.2.1.109 to 246.2.1.110246.2.1.1112
93246.2.1.112/30246.2.1.113 to 246.2.1.114246.2.1.1152
94246.2.1.116/30246.2.1.117 to 246.2.1.118246.2.1.1192
95246.2.1.120/30246.2.1.121 to 246.2.1.122246.2.1.1232
96246.2.1.124/30246.2.1.125 to 246.2.1.126246.2.1.1272
97246.2.1.128/30246.2.1.129 to 246.2.1.130246.2.1.1312
98246.2.1.132/30246.2.1.133 to 246.2.1.134246.2.1.1352
99246.2.1.136/30246.2.1.137 to 246.2.1.138246.2.1.1392
100246.2.1.140/30246.2.1.141 to 246.2.1.142246.2.1.1432
101246.2.1.144/30246.2.1.145 to 246.2.1.146246.2.1.1472
102246.2.1.148/30246.2.1.149 to 246.2.1.150246.2.1.1512
103246.2.1.152/30246.2.1.153 to 246.2.1.154246.2.1.1552
104246.2.1.156/30246.2.1.157 to 246.2.1.158246.2.1.1592
105246.2.1.160/30246.2.1.161 to 246.2.1.162246.2.1.1632
106246.2.1.164/30246.2.1.165 to 246.2.1.166246.2.1.1672
107246.2.1.168/30246.2.1.169 to 246.2.1.170246.2.1.1712
108246.2.1.172/30246.2.1.173 to 246.2.1.174246.2.1.1752
109246.2.1.176/30246.2.1.177 to 246.2.1.178246.2.1.1792
110246.2.1.180/30246.2.1.181 to 246.2.1.182246.2.1.1832
111246.2.1.184/30246.2.1.185 to 246.2.1.186246.2.1.1872
112246.2.1.188/30246.2.1.189 to 246.2.1.190246.2.1.1912
113246.2.1.192/30246.2.1.193 to 246.2.1.194246.2.1.1952
114246.2.1.196/30246.2.1.197 to 246.2.1.198246.2.1.1992
115246.2.1.200/30246.2.1.201 to 246.2.1.202246.2.1.2032
116246.2.1.204/30246.2.1.205 to 246.2.1.206246.2.1.2072
117246.2.1.208/30246.2.1.209 to 246.2.1.210246.2.1.2112
118246.2.1.212/30246.2.1.213 to 246.2.1.214246.2.1.2152
119246.2.1.216/30246.2.1.217 to 246.2.1.218246.2.1.2192
120246.2.1.220/30246.2.1.221 to 246.2.1.222246.2.1.2232
121246.2.1.224/30246.2.1.225 to 246.2.1.226246.2.1.2272
122246.2.1.228/30246.2.1.229 to 246.2.1.230246.2.1.2312
123246.2.1.232/30246.2.1.233 to 246.2.1.234246.2.1.2352
124246.2.1.236/30246.2.1.237 to 246.2.1.238246.2.1.2392
125246.2.1.240/30246.2.1.241 to 246.2.1.242246.2.1.2432
126246.2.1.244/30246.2.1.245 to 246.2.1.246246.2.1.2472
127246.2.1.248/30246.2.1.249 to 246.2.1.250246.2.1.2512
128246.2.1.252/30246.2.1.253 to 246.2.1.254246.2.1.2552
129246.2.2.0/30246.2.2.1 to 246.2.2.2246.2.2.32
130246.2.2.4/30246.2.2.5 to 246.2.2.6246.2.2.72
131246.2.2.8/30246.2.2.9 to 246.2.2.10246.2.2.112
132246.2.2.12/30246.2.2.13 to 246.2.2.14246.2.2.152
133246.2.2.16/30246.2.2.17 to 246.2.2.18246.2.2.192
134246.2.2.20/30246.2.2.21 to 246.2.2.22246.2.2.232
135246.2.2.24/30246.2.2.25 to 246.2.2.26246.2.2.272
136246.2.2.28/30246.2.2.29 to 246.2.2.30246.2.2.312
137246.2.2.32/30246.2.2.33 to 246.2.2.34246.2.2.352
138246.2.2.36/30246.2.2.37 to 246.2.2.38246.2.2.392
139246.2.2.40/30246.2.2.41 to 246.2.2.42246.2.2.432
140246.2.2.44/30246.2.2.45 to 246.2.2.46246.2.2.472
141246.2.2.48/30246.2.2.49 to 246.2.2.50246.2.2.512
142246.2.2.52/30246.2.2.53 to 246.2.2.54246.2.2.552
143246.2.2.56/30246.2.2.57 to 246.2.2.58246.2.2.592
144246.2.2.60/30246.2.2.61 to 246.2.2.62246.2.2.632
145246.2.2.64/30246.2.2.65 to 246.2.2.66246.2.2.672
146246.2.2.68/30246.2.2.69 to 246.2.2.70246.2.2.712
147246.2.2.72/30246.2.2.73 to 246.2.2.74246.2.2.752
148246.2.2.76/30246.2.2.77 to 246.2.2.78246.2.2.792
149246.2.2.80/30246.2.2.81 to 246.2.2.82246.2.2.832
150246.2.2.84/30246.2.2.85 to 246.2.2.86246.2.2.872
151246.2.2.88/30246.2.2.89 to 246.2.2.90246.2.2.912
152246.2.2.92/30246.2.2.93 to 246.2.2.94246.2.2.952
153246.2.2.96/30246.2.2.97 to 246.2.2.98246.2.2.992
154246.2.2.100/30246.2.2.101 to 246.2.2.102246.2.2.1032
155246.2.2.104/30246.2.2.105 to 246.2.2.106246.2.2.1072
156246.2.2.108/30246.2.2.109 to 246.2.2.110246.2.2.1112
157246.2.2.112/30246.2.2.113 to 246.2.2.114246.2.2.1152
158246.2.2.116/30246.2.2.117 to 246.2.2.118246.2.2.1192
159246.2.2.120/30246.2.2.121 to 246.2.2.122246.2.2.1232
160246.2.2.124/30246.2.2.125 to 246.2.2.126246.2.2.1272
161246.2.2.128/30246.2.2.129 to 246.2.2.130246.2.2.1312
162246.2.2.132/30246.2.2.133 to 246.2.2.134246.2.2.1352
163246.2.2.136/30246.2.2.137 to 246.2.2.138246.2.2.1392
164246.2.2.140/30246.2.2.141 to 246.2.2.142246.2.2.1432
165246.2.2.144/30246.2.2.145 to 246.2.2.146246.2.2.1472
166246.2.2.148/30246.2.2.149 to 246.2.2.150246.2.2.1512
167246.2.2.152/30246.2.2.153 to 246.2.2.154246.2.2.1552
168246.2.2.156/30246.2.2.157 to 246.2.2.158246.2.2.1592
169246.2.2.160/30246.2.2.161 to 246.2.2.162246.2.2.1632
170246.2.2.164/30246.2.2.165 to 246.2.2.166246.2.2.1672
171246.2.2.168/30246.2.2.169 to 246.2.2.170246.2.2.1712
172246.2.2.172/30246.2.2.173 to 246.2.2.174246.2.2.1752
173246.2.2.176/30246.2.2.177 to 246.2.2.178246.2.2.1792
174246.2.2.180/30246.2.2.181 to 246.2.2.182246.2.2.1832
175246.2.2.184/30246.2.2.185 to 246.2.2.186246.2.2.1872
176246.2.2.188/30246.2.2.189 to 246.2.2.190246.2.2.1912
177246.2.2.192/30246.2.2.193 to 246.2.2.194246.2.2.1952
178246.2.2.196/30246.2.2.197 to 246.2.2.198246.2.2.1992
179246.2.2.200/30246.2.2.201 to 246.2.2.202246.2.2.2032
180246.2.2.204/30246.2.2.205 to 246.2.2.206246.2.2.2072
181246.2.2.208/30246.2.2.209 to 246.2.2.210246.2.2.2112
182246.2.2.212/30246.2.2.213 to 246.2.2.214246.2.2.2152
183246.2.2.216/30246.2.2.217 to 246.2.2.218246.2.2.2192
184246.2.2.220/30246.2.2.221 to 246.2.2.222246.2.2.2232
185246.2.2.224/30246.2.2.225 to 246.2.2.226246.2.2.2272
186246.2.2.228/30246.2.2.229 to 246.2.2.230246.2.2.2312
187246.2.2.232/30246.2.2.233 to 246.2.2.234246.2.2.2352
188246.2.2.236/30246.2.2.237 to 246.2.2.238246.2.2.2392
189246.2.2.240/30246.2.2.241 to 246.2.2.242246.2.2.2432
190246.2.2.244/30246.2.2.245 to 246.2.2.246246.2.2.2472
191246.2.2.248/30246.2.2.249 to 246.2.2.250246.2.2.2512
192246.2.2.252/30246.2.2.253 to 246.2.2.254246.2.2.2552
193246.2.3.0/30246.2.3.1 to 246.2.3.2246.2.3.32
194246.2.3.4/30246.2.3.5 to 246.2.3.6246.2.3.72
195246.2.3.8/30246.2.3.9 to 246.2.3.10246.2.3.112
196246.2.3.12/30246.2.3.13 to 246.2.3.14246.2.3.152
197246.2.3.16/30246.2.3.17 to 246.2.3.18246.2.3.192
198246.2.3.20/30246.2.3.21 to 246.2.3.22246.2.3.232
199246.2.3.24/30246.2.3.25 to 246.2.3.26246.2.3.272
200246.2.3.28/30246.2.3.29 to 246.2.3.30246.2.3.312
201246.2.3.32/30246.2.3.33 to 246.2.3.34246.2.3.352
202246.2.3.36/30246.2.3.37 to 246.2.3.38246.2.3.392
203246.2.3.40/30246.2.3.41 to 246.2.3.42246.2.3.432
204246.2.3.44/30246.2.3.45 to 246.2.3.46246.2.3.472
205246.2.3.48/30246.2.3.49 to 246.2.3.50246.2.3.512
206246.2.3.52/30246.2.3.53 to 246.2.3.54246.2.3.552
207246.2.3.56/30246.2.3.57 to 246.2.3.58246.2.3.592
208246.2.3.60/30246.2.3.61 to 246.2.3.62246.2.3.632
209246.2.3.64/30246.2.3.65 to 246.2.3.66246.2.3.672
210246.2.3.68/30246.2.3.69 to 246.2.3.70246.2.3.712
211246.2.3.72/30246.2.3.73 to 246.2.3.74246.2.3.752
212246.2.3.76/30246.2.3.77 to 246.2.3.78246.2.3.792
213246.2.3.80/30246.2.3.81 to 246.2.3.82246.2.3.832
214246.2.3.84/30246.2.3.85 to 246.2.3.86246.2.3.872
215246.2.3.88/30246.2.3.89 to 246.2.3.90246.2.3.912
216246.2.3.92/30246.2.3.93 to 246.2.3.94246.2.3.952
217246.2.3.96/30246.2.3.97 to 246.2.3.98246.2.3.992
218246.2.3.100/30246.2.3.101 to 246.2.3.102246.2.3.1032
219246.2.3.104/30246.2.3.105 to 246.2.3.106246.2.3.1072
220246.2.3.108/30246.2.3.109 to 246.2.3.110246.2.3.1112
221246.2.3.112/30246.2.3.113 to 246.2.3.114246.2.3.1152
222246.2.3.116/30246.2.3.117 to 246.2.3.118246.2.3.1192
223246.2.3.120/30246.2.3.121 to 246.2.3.122246.2.3.1232
224246.2.3.124/30246.2.3.125 to 246.2.3.126246.2.3.1272
225246.2.3.128/30246.2.3.129 to 246.2.3.130246.2.3.1312
226246.2.3.132/30246.2.3.133 to 246.2.3.134246.2.3.1352
227246.2.3.136/30246.2.3.137 to 246.2.3.138246.2.3.1392
228246.2.3.140/30246.2.3.141 to 246.2.3.142246.2.3.1432
229246.2.3.144/30246.2.3.145 to 246.2.3.146246.2.3.1472
230246.2.3.148/30246.2.3.149 to 246.2.3.150246.2.3.1512
231246.2.3.152/30246.2.3.153 to 246.2.3.154246.2.3.1552
232246.2.3.156/30246.2.3.157 to 246.2.3.158246.2.3.1592
233246.2.3.160/30246.2.3.161 to 246.2.3.162246.2.3.1632
234246.2.3.164/30246.2.3.165 to 246.2.3.166246.2.3.1672
235246.2.3.168/30246.2.3.169 to 246.2.3.170246.2.3.1712
236246.2.3.172/30246.2.3.173 to 246.2.3.174246.2.3.1752
237246.2.3.176/30246.2.3.177 to 246.2.3.178246.2.3.1792
238246.2.3.180/30246.2.3.181 to 246.2.3.182246.2.3.1832
239246.2.3.184/30246.2.3.185 to 246.2.3.186246.2.3.1872
240246.2.3.188/30246.2.3.189 to 246.2.3.190246.2.3.1912
241246.2.3.192/30246.2.3.193 to 246.2.3.194246.2.3.1952
242246.2.3.196/30246.2.3.197 to 246.2.3.198246.2.3.1992
243246.2.3.200/30246.2.3.201 to 246.2.3.202246.2.3.2032
244246.2.3.204/30246.2.3.205 to 246.2.3.206246.2.3.2072
245246.2.3.208/30246.2.3.209 to 246.2.3.210246.2.3.2112
246246.2.3.212/30246.2.3.213 to 246.2.3.214246.2.3.2152
247246.2.3.216/30246.2.3.217 to 246.2.3.218246.2.3.2192
248246.2.3.220/30246.2.3.221 to 246.2.3.222246.2.3.2232
249246.2.3.224/30246.2.3.225 to 246.2.3.226246.2.3.2272
250246.2.3.228/30246.2.3.229 to 246.2.3.230246.2.3.2312
251246.2.3.232/30246.2.3.233 to 246.2.3.234246.2.3.2352
252246.2.3.236/30246.2.3.237 to 246.2.3.238246.2.3.2392
253246.2.3.240/30246.2.3.241 to 246.2.3.242246.2.3.2432
254246.2.3.244/30246.2.3.245 to 246.2.3.246246.2.3.2472
255246.2.3.248/30246.2.3.249 to 246.2.3.250246.2.3.2512
256246.2.3.252/30246.2.3.253 to 246.2.3.254246.2.3.2552

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.