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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.

Network248.2.0.0/22
Usable hosts1,022
Subnet mask255.255.252.0
Addresses1,024
Network address
248.2.0.0
Broadcast address
248.2.3.255
First usable
248.2.0.1
Last usable
248.2.3.254
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 F8020000 · Integer 4160880640 to 4160881663
Reverse DNS zones
0.2.248.in-addr.arpa
1.2.248.in-addr.arpa
2.2.248.in-addr.arpa
3.2.248.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
Address11111000.00000010.00000000.00000000248.2.0.0
Subnet mask11111111.11111111.11111100.00000000255.255.252.0
Network11111000.00000010.00000000.00000000248.2.0.0
Broadcast11111000.00000010.00000011.11111111248.2.3.255
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)

248.2.0.0/22 makes 256 subnets of /30.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1248.2.0.0/30248.2.0.1 to 248.2.0.2248.2.0.32
2248.2.0.4/30248.2.0.5 to 248.2.0.6248.2.0.72
3248.2.0.8/30248.2.0.9 to 248.2.0.10248.2.0.112
4248.2.0.12/30248.2.0.13 to 248.2.0.14248.2.0.152
5248.2.0.16/30248.2.0.17 to 248.2.0.18248.2.0.192
6248.2.0.20/30248.2.0.21 to 248.2.0.22248.2.0.232
7248.2.0.24/30248.2.0.25 to 248.2.0.26248.2.0.272
8248.2.0.28/30248.2.0.29 to 248.2.0.30248.2.0.312
9248.2.0.32/30248.2.0.33 to 248.2.0.34248.2.0.352
10248.2.0.36/30248.2.0.37 to 248.2.0.38248.2.0.392
11248.2.0.40/30248.2.0.41 to 248.2.0.42248.2.0.432
12248.2.0.44/30248.2.0.45 to 248.2.0.46248.2.0.472
13248.2.0.48/30248.2.0.49 to 248.2.0.50248.2.0.512
14248.2.0.52/30248.2.0.53 to 248.2.0.54248.2.0.552
15248.2.0.56/30248.2.0.57 to 248.2.0.58248.2.0.592
16248.2.0.60/30248.2.0.61 to 248.2.0.62248.2.0.632
17248.2.0.64/30248.2.0.65 to 248.2.0.66248.2.0.672
18248.2.0.68/30248.2.0.69 to 248.2.0.70248.2.0.712
19248.2.0.72/30248.2.0.73 to 248.2.0.74248.2.0.752
20248.2.0.76/30248.2.0.77 to 248.2.0.78248.2.0.792
21248.2.0.80/30248.2.0.81 to 248.2.0.82248.2.0.832
22248.2.0.84/30248.2.0.85 to 248.2.0.86248.2.0.872
23248.2.0.88/30248.2.0.89 to 248.2.0.90248.2.0.912
24248.2.0.92/30248.2.0.93 to 248.2.0.94248.2.0.952
25248.2.0.96/30248.2.0.97 to 248.2.0.98248.2.0.992
26248.2.0.100/30248.2.0.101 to 248.2.0.102248.2.0.1032
27248.2.0.104/30248.2.0.105 to 248.2.0.106248.2.0.1072
28248.2.0.108/30248.2.0.109 to 248.2.0.110248.2.0.1112
29248.2.0.112/30248.2.0.113 to 248.2.0.114248.2.0.1152
30248.2.0.116/30248.2.0.117 to 248.2.0.118248.2.0.1192
31248.2.0.120/30248.2.0.121 to 248.2.0.122248.2.0.1232
32248.2.0.124/30248.2.0.125 to 248.2.0.126248.2.0.1272
33248.2.0.128/30248.2.0.129 to 248.2.0.130248.2.0.1312
34248.2.0.132/30248.2.0.133 to 248.2.0.134248.2.0.1352
35248.2.0.136/30248.2.0.137 to 248.2.0.138248.2.0.1392
36248.2.0.140/30248.2.0.141 to 248.2.0.142248.2.0.1432
37248.2.0.144/30248.2.0.145 to 248.2.0.146248.2.0.1472
38248.2.0.148/30248.2.0.149 to 248.2.0.150248.2.0.1512
39248.2.0.152/30248.2.0.153 to 248.2.0.154248.2.0.1552
40248.2.0.156/30248.2.0.157 to 248.2.0.158248.2.0.1592
41248.2.0.160/30248.2.0.161 to 248.2.0.162248.2.0.1632
42248.2.0.164/30248.2.0.165 to 248.2.0.166248.2.0.1672
43248.2.0.168/30248.2.0.169 to 248.2.0.170248.2.0.1712
44248.2.0.172/30248.2.0.173 to 248.2.0.174248.2.0.1752
45248.2.0.176/30248.2.0.177 to 248.2.0.178248.2.0.1792
46248.2.0.180/30248.2.0.181 to 248.2.0.182248.2.0.1832
47248.2.0.184/30248.2.0.185 to 248.2.0.186248.2.0.1872
48248.2.0.188/30248.2.0.189 to 248.2.0.190248.2.0.1912
49248.2.0.192/30248.2.0.193 to 248.2.0.194248.2.0.1952
50248.2.0.196/30248.2.0.197 to 248.2.0.198248.2.0.1992
51248.2.0.200/30248.2.0.201 to 248.2.0.202248.2.0.2032
52248.2.0.204/30248.2.0.205 to 248.2.0.206248.2.0.2072
53248.2.0.208/30248.2.0.209 to 248.2.0.210248.2.0.2112
54248.2.0.212/30248.2.0.213 to 248.2.0.214248.2.0.2152
55248.2.0.216/30248.2.0.217 to 248.2.0.218248.2.0.2192
56248.2.0.220/30248.2.0.221 to 248.2.0.222248.2.0.2232
57248.2.0.224/30248.2.0.225 to 248.2.0.226248.2.0.2272
58248.2.0.228/30248.2.0.229 to 248.2.0.230248.2.0.2312
59248.2.0.232/30248.2.0.233 to 248.2.0.234248.2.0.2352
60248.2.0.236/30248.2.0.237 to 248.2.0.238248.2.0.2392
61248.2.0.240/30248.2.0.241 to 248.2.0.242248.2.0.2432
62248.2.0.244/30248.2.0.245 to 248.2.0.246248.2.0.2472
63248.2.0.248/30248.2.0.249 to 248.2.0.250248.2.0.2512
64248.2.0.252/30248.2.0.253 to 248.2.0.254248.2.0.2552
65248.2.1.0/30248.2.1.1 to 248.2.1.2248.2.1.32
66248.2.1.4/30248.2.1.5 to 248.2.1.6248.2.1.72
67248.2.1.8/30248.2.1.9 to 248.2.1.10248.2.1.112
68248.2.1.12/30248.2.1.13 to 248.2.1.14248.2.1.152
69248.2.1.16/30248.2.1.17 to 248.2.1.18248.2.1.192
70248.2.1.20/30248.2.1.21 to 248.2.1.22248.2.1.232
71248.2.1.24/30248.2.1.25 to 248.2.1.26248.2.1.272
72248.2.1.28/30248.2.1.29 to 248.2.1.30248.2.1.312
73248.2.1.32/30248.2.1.33 to 248.2.1.34248.2.1.352
74248.2.1.36/30248.2.1.37 to 248.2.1.38248.2.1.392
75248.2.1.40/30248.2.1.41 to 248.2.1.42248.2.1.432
76248.2.1.44/30248.2.1.45 to 248.2.1.46248.2.1.472
77248.2.1.48/30248.2.1.49 to 248.2.1.50248.2.1.512
78248.2.1.52/30248.2.1.53 to 248.2.1.54248.2.1.552
79248.2.1.56/30248.2.1.57 to 248.2.1.58248.2.1.592
80248.2.1.60/30248.2.1.61 to 248.2.1.62248.2.1.632
81248.2.1.64/30248.2.1.65 to 248.2.1.66248.2.1.672
82248.2.1.68/30248.2.1.69 to 248.2.1.70248.2.1.712
83248.2.1.72/30248.2.1.73 to 248.2.1.74248.2.1.752
84248.2.1.76/30248.2.1.77 to 248.2.1.78248.2.1.792
85248.2.1.80/30248.2.1.81 to 248.2.1.82248.2.1.832
86248.2.1.84/30248.2.1.85 to 248.2.1.86248.2.1.872
87248.2.1.88/30248.2.1.89 to 248.2.1.90248.2.1.912
88248.2.1.92/30248.2.1.93 to 248.2.1.94248.2.1.952
89248.2.1.96/30248.2.1.97 to 248.2.1.98248.2.1.992
90248.2.1.100/30248.2.1.101 to 248.2.1.102248.2.1.1032
91248.2.1.104/30248.2.1.105 to 248.2.1.106248.2.1.1072
92248.2.1.108/30248.2.1.109 to 248.2.1.110248.2.1.1112
93248.2.1.112/30248.2.1.113 to 248.2.1.114248.2.1.1152
94248.2.1.116/30248.2.1.117 to 248.2.1.118248.2.1.1192
95248.2.1.120/30248.2.1.121 to 248.2.1.122248.2.1.1232
96248.2.1.124/30248.2.1.125 to 248.2.1.126248.2.1.1272
97248.2.1.128/30248.2.1.129 to 248.2.1.130248.2.1.1312
98248.2.1.132/30248.2.1.133 to 248.2.1.134248.2.1.1352
99248.2.1.136/30248.2.1.137 to 248.2.1.138248.2.1.1392
100248.2.1.140/30248.2.1.141 to 248.2.1.142248.2.1.1432
101248.2.1.144/30248.2.1.145 to 248.2.1.146248.2.1.1472
102248.2.1.148/30248.2.1.149 to 248.2.1.150248.2.1.1512
103248.2.1.152/30248.2.1.153 to 248.2.1.154248.2.1.1552
104248.2.1.156/30248.2.1.157 to 248.2.1.158248.2.1.1592
105248.2.1.160/30248.2.1.161 to 248.2.1.162248.2.1.1632
106248.2.1.164/30248.2.1.165 to 248.2.1.166248.2.1.1672
107248.2.1.168/30248.2.1.169 to 248.2.1.170248.2.1.1712
108248.2.1.172/30248.2.1.173 to 248.2.1.174248.2.1.1752
109248.2.1.176/30248.2.1.177 to 248.2.1.178248.2.1.1792
110248.2.1.180/30248.2.1.181 to 248.2.1.182248.2.1.1832
111248.2.1.184/30248.2.1.185 to 248.2.1.186248.2.1.1872
112248.2.1.188/30248.2.1.189 to 248.2.1.190248.2.1.1912
113248.2.1.192/30248.2.1.193 to 248.2.1.194248.2.1.1952
114248.2.1.196/30248.2.1.197 to 248.2.1.198248.2.1.1992
115248.2.1.200/30248.2.1.201 to 248.2.1.202248.2.1.2032
116248.2.1.204/30248.2.1.205 to 248.2.1.206248.2.1.2072
117248.2.1.208/30248.2.1.209 to 248.2.1.210248.2.1.2112
118248.2.1.212/30248.2.1.213 to 248.2.1.214248.2.1.2152
119248.2.1.216/30248.2.1.217 to 248.2.1.218248.2.1.2192
120248.2.1.220/30248.2.1.221 to 248.2.1.222248.2.1.2232
121248.2.1.224/30248.2.1.225 to 248.2.1.226248.2.1.2272
122248.2.1.228/30248.2.1.229 to 248.2.1.230248.2.1.2312
123248.2.1.232/30248.2.1.233 to 248.2.1.234248.2.1.2352
124248.2.1.236/30248.2.1.237 to 248.2.1.238248.2.1.2392
125248.2.1.240/30248.2.1.241 to 248.2.1.242248.2.1.2432
126248.2.1.244/30248.2.1.245 to 248.2.1.246248.2.1.2472
127248.2.1.248/30248.2.1.249 to 248.2.1.250248.2.1.2512
128248.2.1.252/30248.2.1.253 to 248.2.1.254248.2.1.2552
129248.2.2.0/30248.2.2.1 to 248.2.2.2248.2.2.32
130248.2.2.4/30248.2.2.5 to 248.2.2.6248.2.2.72
131248.2.2.8/30248.2.2.9 to 248.2.2.10248.2.2.112
132248.2.2.12/30248.2.2.13 to 248.2.2.14248.2.2.152
133248.2.2.16/30248.2.2.17 to 248.2.2.18248.2.2.192
134248.2.2.20/30248.2.2.21 to 248.2.2.22248.2.2.232
135248.2.2.24/30248.2.2.25 to 248.2.2.26248.2.2.272
136248.2.2.28/30248.2.2.29 to 248.2.2.30248.2.2.312
137248.2.2.32/30248.2.2.33 to 248.2.2.34248.2.2.352
138248.2.2.36/30248.2.2.37 to 248.2.2.38248.2.2.392
139248.2.2.40/30248.2.2.41 to 248.2.2.42248.2.2.432
140248.2.2.44/30248.2.2.45 to 248.2.2.46248.2.2.472
141248.2.2.48/30248.2.2.49 to 248.2.2.50248.2.2.512
142248.2.2.52/30248.2.2.53 to 248.2.2.54248.2.2.552
143248.2.2.56/30248.2.2.57 to 248.2.2.58248.2.2.592
144248.2.2.60/30248.2.2.61 to 248.2.2.62248.2.2.632
145248.2.2.64/30248.2.2.65 to 248.2.2.66248.2.2.672
146248.2.2.68/30248.2.2.69 to 248.2.2.70248.2.2.712
147248.2.2.72/30248.2.2.73 to 248.2.2.74248.2.2.752
148248.2.2.76/30248.2.2.77 to 248.2.2.78248.2.2.792
149248.2.2.80/30248.2.2.81 to 248.2.2.82248.2.2.832
150248.2.2.84/30248.2.2.85 to 248.2.2.86248.2.2.872
151248.2.2.88/30248.2.2.89 to 248.2.2.90248.2.2.912
152248.2.2.92/30248.2.2.93 to 248.2.2.94248.2.2.952
153248.2.2.96/30248.2.2.97 to 248.2.2.98248.2.2.992
154248.2.2.100/30248.2.2.101 to 248.2.2.102248.2.2.1032
155248.2.2.104/30248.2.2.105 to 248.2.2.106248.2.2.1072
156248.2.2.108/30248.2.2.109 to 248.2.2.110248.2.2.1112
157248.2.2.112/30248.2.2.113 to 248.2.2.114248.2.2.1152
158248.2.2.116/30248.2.2.117 to 248.2.2.118248.2.2.1192
159248.2.2.120/30248.2.2.121 to 248.2.2.122248.2.2.1232
160248.2.2.124/30248.2.2.125 to 248.2.2.126248.2.2.1272
161248.2.2.128/30248.2.2.129 to 248.2.2.130248.2.2.1312
162248.2.2.132/30248.2.2.133 to 248.2.2.134248.2.2.1352
163248.2.2.136/30248.2.2.137 to 248.2.2.138248.2.2.1392
164248.2.2.140/30248.2.2.141 to 248.2.2.142248.2.2.1432
165248.2.2.144/30248.2.2.145 to 248.2.2.146248.2.2.1472
166248.2.2.148/30248.2.2.149 to 248.2.2.150248.2.2.1512
167248.2.2.152/30248.2.2.153 to 248.2.2.154248.2.2.1552
168248.2.2.156/30248.2.2.157 to 248.2.2.158248.2.2.1592
169248.2.2.160/30248.2.2.161 to 248.2.2.162248.2.2.1632
170248.2.2.164/30248.2.2.165 to 248.2.2.166248.2.2.1672
171248.2.2.168/30248.2.2.169 to 248.2.2.170248.2.2.1712
172248.2.2.172/30248.2.2.173 to 248.2.2.174248.2.2.1752
173248.2.2.176/30248.2.2.177 to 248.2.2.178248.2.2.1792
174248.2.2.180/30248.2.2.181 to 248.2.2.182248.2.2.1832
175248.2.2.184/30248.2.2.185 to 248.2.2.186248.2.2.1872
176248.2.2.188/30248.2.2.189 to 248.2.2.190248.2.2.1912
177248.2.2.192/30248.2.2.193 to 248.2.2.194248.2.2.1952
178248.2.2.196/30248.2.2.197 to 248.2.2.198248.2.2.1992
179248.2.2.200/30248.2.2.201 to 248.2.2.202248.2.2.2032
180248.2.2.204/30248.2.2.205 to 248.2.2.206248.2.2.2072
181248.2.2.208/30248.2.2.209 to 248.2.2.210248.2.2.2112
182248.2.2.212/30248.2.2.213 to 248.2.2.214248.2.2.2152
183248.2.2.216/30248.2.2.217 to 248.2.2.218248.2.2.2192
184248.2.2.220/30248.2.2.221 to 248.2.2.222248.2.2.2232
185248.2.2.224/30248.2.2.225 to 248.2.2.226248.2.2.2272
186248.2.2.228/30248.2.2.229 to 248.2.2.230248.2.2.2312
187248.2.2.232/30248.2.2.233 to 248.2.2.234248.2.2.2352
188248.2.2.236/30248.2.2.237 to 248.2.2.238248.2.2.2392
189248.2.2.240/30248.2.2.241 to 248.2.2.242248.2.2.2432
190248.2.2.244/30248.2.2.245 to 248.2.2.246248.2.2.2472
191248.2.2.248/30248.2.2.249 to 248.2.2.250248.2.2.2512
192248.2.2.252/30248.2.2.253 to 248.2.2.254248.2.2.2552
193248.2.3.0/30248.2.3.1 to 248.2.3.2248.2.3.32
194248.2.3.4/30248.2.3.5 to 248.2.3.6248.2.3.72
195248.2.3.8/30248.2.3.9 to 248.2.3.10248.2.3.112
196248.2.3.12/30248.2.3.13 to 248.2.3.14248.2.3.152
197248.2.3.16/30248.2.3.17 to 248.2.3.18248.2.3.192
198248.2.3.20/30248.2.3.21 to 248.2.3.22248.2.3.232
199248.2.3.24/30248.2.3.25 to 248.2.3.26248.2.3.272
200248.2.3.28/30248.2.3.29 to 248.2.3.30248.2.3.312
201248.2.3.32/30248.2.3.33 to 248.2.3.34248.2.3.352
202248.2.3.36/30248.2.3.37 to 248.2.3.38248.2.3.392
203248.2.3.40/30248.2.3.41 to 248.2.3.42248.2.3.432
204248.2.3.44/30248.2.3.45 to 248.2.3.46248.2.3.472
205248.2.3.48/30248.2.3.49 to 248.2.3.50248.2.3.512
206248.2.3.52/30248.2.3.53 to 248.2.3.54248.2.3.552
207248.2.3.56/30248.2.3.57 to 248.2.3.58248.2.3.592
208248.2.3.60/30248.2.3.61 to 248.2.3.62248.2.3.632
209248.2.3.64/30248.2.3.65 to 248.2.3.66248.2.3.672
210248.2.3.68/30248.2.3.69 to 248.2.3.70248.2.3.712
211248.2.3.72/30248.2.3.73 to 248.2.3.74248.2.3.752
212248.2.3.76/30248.2.3.77 to 248.2.3.78248.2.3.792
213248.2.3.80/30248.2.3.81 to 248.2.3.82248.2.3.832
214248.2.3.84/30248.2.3.85 to 248.2.3.86248.2.3.872
215248.2.3.88/30248.2.3.89 to 248.2.3.90248.2.3.912
216248.2.3.92/30248.2.3.93 to 248.2.3.94248.2.3.952
217248.2.3.96/30248.2.3.97 to 248.2.3.98248.2.3.992
218248.2.3.100/30248.2.3.101 to 248.2.3.102248.2.3.1032
219248.2.3.104/30248.2.3.105 to 248.2.3.106248.2.3.1072
220248.2.3.108/30248.2.3.109 to 248.2.3.110248.2.3.1112
221248.2.3.112/30248.2.3.113 to 248.2.3.114248.2.3.1152
222248.2.3.116/30248.2.3.117 to 248.2.3.118248.2.3.1192
223248.2.3.120/30248.2.3.121 to 248.2.3.122248.2.3.1232
224248.2.3.124/30248.2.3.125 to 248.2.3.126248.2.3.1272
225248.2.3.128/30248.2.3.129 to 248.2.3.130248.2.3.1312
226248.2.3.132/30248.2.3.133 to 248.2.3.134248.2.3.1352
227248.2.3.136/30248.2.3.137 to 248.2.3.138248.2.3.1392
228248.2.3.140/30248.2.3.141 to 248.2.3.142248.2.3.1432
229248.2.3.144/30248.2.3.145 to 248.2.3.146248.2.3.1472
230248.2.3.148/30248.2.3.149 to 248.2.3.150248.2.3.1512
231248.2.3.152/30248.2.3.153 to 248.2.3.154248.2.3.1552
232248.2.3.156/30248.2.3.157 to 248.2.3.158248.2.3.1592
233248.2.3.160/30248.2.3.161 to 248.2.3.162248.2.3.1632
234248.2.3.164/30248.2.3.165 to 248.2.3.166248.2.3.1672
235248.2.3.168/30248.2.3.169 to 248.2.3.170248.2.3.1712
236248.2.3.172/30248.2.3.173 to 248.2.3.174248.2.3.1752
237248.2.3.176/30248.2.3.177 to 248.2.3.178248.2.3.1792
238248.2.3.180/30248.2.3.181 to 248.2.3.182248.2.3.1832
239248.2.3.184/30248.2.3.185 to 248.2.3.186248.2.3.1872
240248.2.3.188/30248.2.3.189 to 248.2.3.190248.2.3.1912
241248.2.3.192/30248.2.3.193 to 248.2.3.194248.2.3.1952
242248.2.3.196/30248.2.3.197 to 248.2.3.198248.2.3.1992
243248.2.3.200/30248.2.3.201 to 248.2.3.202248.2.3.2032
244248.2.3.204/30248.2.3.205 to 248.2.3.206248.2.3.2072
245248.2.3.208/30248.2.3.209 to 248.2.3.210248.2.3.2112
246248.2.3.212/30248.2.3.213 to 248.2.3.214248.2.3.2152
247248.2.3.216/30248.2.3.217 to 248.2.3.218248.2.3.2192
248248.2.3.220/30248.2.3.221 to 248.2.3.222248.2.3.2232
249248.2.3.224/30248.2.3.225 to 248.2.3.226248.2.3.2272
250248.2.3.228/30248.2.3.229 to 248.2.3.230248.2.3.2312
251248.2.3.232/30248.2.3.233 to 248.2.3.234248.2.3.2352
252248.2.3.236/30248.2.3.237 to 248.2.3.238248.2.3.2392
253248.2.3.240/30248.2.3.241 to 248.2.3.242248.2.3.2432
254248.2.3.244/30248.2.3.245 to 248.2.3.246248.2.3.2472
255248.2.3.248/30248.2.3.249 to 248.2.3.250248.2.3.2512
256248.2.3.252/30248.2.3.253 to 248.2.3.254248.2.3.2552

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.