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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.

Network182.3.64.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
182.3.64.0
Broadcast address
182.3.95.255
First usable
182.3.64.1
Last usable
182.3.95.254
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
Public public
Old class
B (default /16)
As numbers
Hex B6034000 · Integer 3053666304 to 3053674495
Reverse DNS zones
64.3.182.in-addr.arpa
65.3.182.in-addr.arpa
66.3.182.in-addr.arpa
67.3.182.in-addr.arpa
68.3.182.in-addr.arpa
69.3.182.in-addr.arpa
70.3.182.in-addr.arpa
71.3.182.in-addr.arpa
72.3.182.in-addr.arpa
73.3.182.in-addr.arpa
74.3.182.in-addr.arpa
75.3.182.in-addr.arpa
76.3.182.in-addr.arpa
77.3.182.in-addr.arpa
78.3.182.in-addr.arpa
79.3.182.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
Address10110110.00000011.01000000.00000000182.3.64.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network10110110.00000011.01000000.00000000182.3.64.0
Broadcast10110110.00000011.01011111.11111111182.3.95.255
Split into smaller subnets/30
/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)

182.3.64.0/19 makes 2,048 subnets of /30; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1182.3.64.0/30182.3.64.1 to 182.3.64.2182.3.64.32
2182.3.64.4/30182.3.64.5 to 182.3.64.6182.3.64.72
3182.3.64.8/30182.3.64.9 to 182.3.64.10182.3.64.112
4182.3.64.12/30182.3.64.13 to 182.3.64.14182.3.64.152
5182.3.64.16/30182.3.64.17 to 182.3.64.18182.3.64.192
6182.3.64.20/30182.3.64.21 to 182.3.64.22182.3.64.232
7182.3.64.24/30182.3.64.25 to 182.3.64.26182.3.64.272
8182.3.64.28/30182.3.64.29 to 182.3.64.30182.3.64.312
9182.3.64.32/30182.3.64.33 to 182.3.64.34182.3.64.352
10182.3.64.36/30182.3.64.37 to 182.3.64.38182.3.64.392
11182.3.64.40/30182.3.64.41 to 182.3.64.42182.3.64.432
12182.3.64.44/30182.3.64.45 to 182.3.64.46182.3.64.472
13182.3.64.48/30182.3.64.49 to 182.3.64.50182.3.64.512
14182.3.64.52/30182.3.64.53 to 182.3.64.54182.3.64.552
15182.3.64.56/30182.3.64.57 to 182.3.64.58182.3.64.592
16182.3.64.60/30182.3.64.61 to 182.3.64.62182.3.64.632
17182.3.64.64/30182.3.64.65 to 182.3.64.66182.3.64.672
18182.3.64.68/30182.3.64.69 to 182.3.64.70182.3.64.712
19182.3.64.72/30182.3.64.73 to 182.3.64.74182.3.64.752
20182.3.64.76/30182.3.64.77 to 182.3.64.78182.3.64.792
21182.3.64.80/30182.3.64.81 to 182.3.64.82182.3.64.832
22182.3.64.84/30182.3.64.85 to 182.3.64.86182.3.64.872
23182.3.64.88/30182.3.64.89 to 182.3.64.90182.3.64.912
24182.3.64.92/30182.3.64.93 to 182.3.64.94182.3.64.952
25182.3.64.96/30182.3.64.97 to 182.3.64.98182.3.64.992
26182.3.64.100/30182.3.64.101 to 182.3.64.102182.3.64.1032
27182.3.64.104/30182.3.64.105 to 182.3.64.106182.3.64.1072
28182.3.64.108/30182.3.64.109 to 182.3.64.110182.3.64.1112
29182.3.64.112/30182.3.64.113 to 182.3.64.114182.3.64.1152
30182.3.64.116/30182.3.64.117 to 182.3.64.118182.3.64.1192
31182.3.64.120/30182.3.64.121 to 182.3.64.122182.3.64.1232
32182.3.64.124/30182.3.64.125 to 182.3.64.126182.3.64.1272
33182.3.64.128/30182.3.64.129 to 182.3.64.130182.3.64.1312
34182.3.64.132/30182.3.64.133 to 182.3.64.134182.3.64.1352
35182.3.64.136/30182.3.64.137 to 182.3.64.138182.3.64.1392
36182.3.64.140/30182.3.64.141 to 182.3.64.142182.3.64.1432
37182.3.64.144/30182.3.64.145 to 182.3.64.146182.3.64.1472
38182.3.64.148/30182.3.64.149 to 182.3.64.150182.3.64.1512
39182.3.64.152/30182.3.64.153 to 182.3.64.154182.3.64.1552
40182.3.64.156/30182.3.64.157 to 182.3.64.158182.3.64.1592
41182.3.64.160/30182.3.64.161 to 182.3.64.162182.3.64.1632
42182.3.64.164/30182.3.64.165 to 182.3.64.166182.3.64.1672
43182.3.64.168/30182.3.64.169 to 182.3.64.170182.3.64.1712
44182.3.64.172/30182.3.64.173 to 182.3.64.174182.3.64.1752
45182.3.64.176/30182.3.64.177 to 182.3.64.178182.3.64.1792
46182.3.64.180/30182.3.64.181 to 182.3.64.182182.3.64.1832
47182.3.64.184/30182.3.64.185 to 182.3.64.186182.3.64.1872
48182.3.64.188/30182.3.64.189 to 182.3.64.190182.3.64.1912
49182.3.64.192/30182.3.64.193 to 182.3.64.194182.3.64.1952
50182.3.64.196/30182.3.64.197 to 182.3.64.198182.3.64.1992
51182.3.64.200/30182.3.64.201 to 182.3.64.202182.3.64.2032
52182.3.64.204/30182.3.64.205 to 182.3.64.206182.3.64.2072
53182.3.64.208/30182.3.64.209 to 182.3.64.210182.3.64.2112
54182.3.64.212/30182.3.64.213 to 182.3.64.214182.3.64.2152
55182.3.64.216/30182.3.64.217 to 182.3.64.218182.3.64.2192
56182.3.64.220/30182.3.64.221 to 182.3.64.222182.3.64.2232
57182.3.64.224/30182.3.64.225 to 182.3.64.226182.3.64.2272
58182.3.64.228/30182.3.64.229 to 182.3.64.230182.3.64.2312
59182.3.64.232/30182.3.64.233 to 182.3.64.234182.3.64.2352
60182.3.64.236/30182.3.64.237 to 182.3.64.238182.3.64.2392
61182.3.64.240/30182.3.64.241 to 182.3.64.242182.3.64.2432
62182.3.64.244/30182.3.64.245 to 182.3.64.246182.3.64.2472
63182.3.64.248/30182.3.64.249 to 182.3.64.250182.3.64.2512
64182.3.64.252/30182.3.64.253 to 182.3.64.254182.3.64.2552
65182.3.65.0/30182.3.65.1 to 182.3.65.2182.3.65.32
66182.3.65.4/30182.3.65.5 to 182.3.65.6182.3.65.72
67182.3.65.8/30182.3.65.9 to 182.3.65.10182.3.65.112
68182.3.65.12/30182.3.65.13 to 182.3.65.14182.3.65.152
69182.3.65.16/30182.3.65.17 to 182.3.65.18182.3.65.192
70182.3.65.20/30182.3.65.21 to 182.3.65.22182.3.65.232
71182.3.65.24/30182.3.65.25 to 182.3.65.26182.3.65.272
72182.3.65.28/30182.3.65.29 to 182.3.65.30182.3.65.312
73182.3.65.32/30182.3.65.33 to 182.3.65.34182.3.65.352
74182.3.65.36/30182.3.65.37 to 182.3.65.38182.3.65.392
75182.3.65.40/30182.3.65.41 to 182.3.65.42182.3.65.432
76182.3.65.44/30182.3.65.45 to 182.3.65.46182.3.65.472
77182.3.65.48/30182.3.65.49 to 182.3.65.50182.3.65.512
78182.3.65.52/30182.3.65.53 to 182.3.65.54182.3.65.552
79182.3.65.56/30182.3.65.57 to 182.3.65.58182.3.65.592
80182.3.65.60/30182.3.65.61 to 182.3.65.62182.3.65.632
81182.3.65.64/30182.3.65.65 to 182.3.65.66182.3.65.672
82182.3.65.68/30182.3.65.69 to 182.3.65.70182.3.65.712
83182.3.65.72/30182.3.65.73 to 182.3.65.74182.3.65.752
84182.3.65.76/30182.3.65.77 to 182.3.65.78182.3.65.792
85182.3.65.80/30182.3.65.81 to 182.3.65.82182.3.65.832
86182.3.65.84/30182.3.65.85 to 182.3.65.86182.3.65.872
87182.3.65.88/30182.3.65.89 to 182.3.65.90182.3.65.912
88182.3.65.92/30182.3.65.93 to 182.3.65.94182.3.65.952
89182.3.65.96/30182.3.65.97 to 182.3.65.98182.3.65.992
90182.3.65.100/30182.3.65.101 to 182.3.65.102182.3.65.1032
91182.3.65.104/30182.3.65.105 to 182.3.65.106182.3.65.1072
92182.3.65.108/30182.3.65.109 to 182.3.65.110182.3.65.1112
93182.3.65.112/30182.3.65.113 to 182.3.65.114182.3.65.1152
94182.3.65.116/30182.3.65.117 to 182.3.65.118182.3.65.1192
95182.3.65.120/30182.3.65.121 to 182.3.65.122182.3.65.1232
96182.3.65.124/30182.3.65.125 to 182.3.65.126182.3.65.1272
97182.3.65.128/30182.3.65.129 to 182.3.65.130182.3.65.1312
98182.3.65.132/30182.3.65.133 to 182.3.65.134182.3.65.1352
99182.3.65.136/30182.3.65.137 to 182.3.65.138182.3.65.1392
100182.3.65.140/30182.3.65.141 to 182.3.65.142182.3.65.1432
101182.3.65.144/30182.3.65.145 to 182.3.65.146182.3.65.1472
102182.3.65.148/30182.3.65.149 to 182.3.65.150182.3.65.1512
103182.3.65.152/30182.3.65.153 to 182.3.65.154182.3.65.1552
104182.3.65.156/30182.3.65.157 to 182.3.65.158182.3.65.1592
105182.3.65.160/30182.3.65.161 to 182.3.65.162182.3.65.1632
106182.3.65.164/30182.3.65.165 to 182.3.65.166182.3.65.1672
107182.3.65.168/30182.3.65.169 to 182.3.65.170182.3.65.1712
108182.3.65.172/30182.3.65.173 to 182.3.65.174182.3.65.1752
109182.3.65.176/30182.3.65.177 to 182.3.65.178182.3.65.1792
110182.3.65.180/30182.3.65.181 to 182.3.65.182182.3.65.1832
111182.3.65.184/30182.3.65.185 to 182.3.65.186182.3.65.1872
112182.3.65.188/30182.3.65.189 to 182.3.65.190182.3.65.1912
113182.3.65.192/30182.3.65.193 to 182.3.65.194182.3.65.1952
114182.3.65.196/30182.3.65.197 to 182.3.65.198182.3.65.1992
115182.3.65.200/30182.3.65.201 to 182.3.65.202182.3.65.2032
116182.3.65.204/30182.3.65.205 to 182.3.65.206182.3.65.2072
117182.3.65.208/30182.3.65.209 to 182.3.65.210182.3.65.2112
118182.3.65.212/30182.3.65.213 to 182.3.65.214182.3.65.2152
119182.3.65.216/30182.3.65.217 to 182.3.65.218182.3.65.2192
120182.3.65.220/30182.3.65.221 to 182.3.65.222182.3.65.2232
121182.3.65.224/30182.3.65.225 to 182.3.65.226182.3.65.2272
122182.3.65.228/30182.3.65.229 to 182.3.65.230182.3.65.2312
123182.3.65.232/30182.3.65.233 to 182.3.65.234182.3.65.2352
124182.3.65.236/30182.3.65.237 to 182.3.65.238182.3.65.2392
125182.3.65.240/30182.3.65.241 to 182.3.65.242182.3.65.2432
126182.3.65.244/30182.3.65.245 to 182.3.65.246182.3.65.2472
127182.3.65.248/30182.3.65.249 to 182.3.65.250182.3.65.2512
128182.3.65.252/30182.3.65.253 to 182.3.65.254182.3.65.2552
129182.3.66.0/30182.3.66.1 to 182.3.66.2182.3.66.32
130182.3.66.4/30182.3.66.5 to 182.3.66.6182.3.66.72
131182.3.66.8/30182.3.66.9 to 182.3.66.10182.3.66.112
132182.3.66.12/30182.3.66.13 to 182.3.66.14182.3.66.152
133182.3.66.16/30182.3.66.17 to 182.3.66.18182.3.66.192
134182.3.66.20/30182.3.66.21 to 182.3.66.22182.3.66.232
135182.3.66.24/30182.3.66.25 to 182.3.66.26182.3.66.272
136182.3.66.28/30182.3.66.29 to 182.3.66.30182.3.66.312
137182.3.66.32/30182.3.66.33 to 182.3.66.34182.3.66.352
138182.3.66.36/30182.3.66.37 to 182.3.66.38182.3.66.392
139182.3.66.40/30182.3.66.41 to 182.3.66.42182.3.66.432
140182.3.66.44/30182.3.66.45 to 182.3.66.46182.3.66.472
141182.3.66.48/30182.3.66.49 to 182.3.66.50182.3.66.512
142182.3.66.52/30182.3.66.53 to 182.3.66.54182.3.66.552
143182.3.66.56/30182.3.66.57 to 182.3.66.58182.3.66.592
144182.3.66.60/30182.3.66.61 to 182.3.66.62182.3.66.632
145182.3.66.64/30182.3.66.65 to 182.3.66.66182.3.66.672
146182.3.66.68/30182.3.66.69 to 182.3.66.70182.3.66.712
147182.3.66.72/30182.3.66.73 to 182.3.66.74182.3.66.752
148182.3.66.76/30182.3.66.77 to 182.3.66.78182.3.66.792
149182.3.66.80/30182.3.66.81 to 182.3.66.82182.3.66.832
150182.3.66.84/30182.3.66.85 to 182.3.66.86182.3.66.872
151182.3.66.88/30182.3.66.89 to 182.3.66.90182.3.66.912
152182.3.66.92/30182.3.66.93 to 182.3.66.94182.3.66.952
153182.3.66.96/30182.3.66.97 to 182.3.66.98182.3.66.992
154182.3.66.100/30182.3.66.101 to 182.3.66.102182.3.66.1032
155182.3.66.104/30182.3.66.105 to 182.3.66.106182.3.66.1072
156182.3.66.108/30182.3.66.109 to 182.3.66.110182.3.66.1112
157182.3.66.112/30182.3.66.113 to 182.3.66.114182.3.66.1152
158182.3.66.116/30182.3.66.117 to 182.3.66.118182.3.66.1192
159182.3.66.120/30182.3.66.121 to 182.3.66.122182.3.66.1232
160182.3.66.124/30182.3.66.125 to 182.3.66.126182.3.66.1272
161182.3.66.128/30182.3.66.129 to 182.3.66.130182.3.66.1312
162182.3.66.132/30182.3.66.133 to 182.3.66.134182.3.66.1352
163182.3.66.136/30182.3.66.137 to 182.3.66.138182.3.66.1392
164182.3.66.140/30182.3.66.141 to 182.3.66.142182.3.66.1432
165182.3.66.144/30182.3.66.145 to 182.3.66.146182.3.66.1472
166182.3.66.148/30182.3.66.149 to 182.3.66.150182.3.66.1512
167182.3.66.152/30182.3.66.153 to 182.3.66.154182.3.66.1552
168182.3.66.156/30182.3.66.157 to 182.3.66.158182.3.66.1592
169182.3.66.160/30182.3.66.161 to 182.3.66.162182.3.66.1632
170182.3.66.164/30182.3.66.165 to 182.3.66.166182.3.66.1672
171182.3.66.168/30182.3.66.169 to 182.3.66.170182.3.66.1712
172182.3.66.172/30182.3.66.173 to 182.3.66.174182.3.66.1752
173182.3.66.176/30182.3.66.177 to 182.3.66.178182.3.66.1792
174182.3.66.180/30182.3.66.181 to 182.3.66.182182.3.66.1832
175182.3.66.184/30182.3.66.185 to 182.3.66.186182.3.66.1872
176182.3.66.188/30182.3.66.189 to 182.3.66.190182.3.66.1912
177182.3.66.192/30182.3.66.193 to 182.3.66.194182.3.66.1952
178182.3.66.196/30182.3.66.197 to 182.3.66.198182.3.66.1992
179182.3.66.200/30182.3.66.201 to 182.3.66.202182.3.66.2032
180182.3.66.204/30182.3.66.205 to 182.3.66.206182.3.66.2072
181182.3.66.208/30182.3.66.209 to 182.3.66.210182.3.66.2112
182182.3.66.212/30182.3.66.213 to 182.3.66.214182.3.66.2152
183182.3.66.216/30182.3.66.217 to 182.3.66.218182.3.66.2192
184182.3.66.220/30182.3.66.221 to 182.3.66.222182.3.66.2232
185182.3.66.224/30182.3.66.225 to 182.3.66.226182.3.66.2272
186182.3.66.228/30182.3.66.229 to 182.3.66.230182.3.66.2312
187182.3.66.232/30182.3.66.233 to 182.3.66.234182.3.66.2352
188182.3.66.236/30182.3.66.237 to 182.3.66.238182.3.66.2392
189182.3.66.240/30182.3.66.241 to 182.3.66.242182.3.66.2432
190182.3.66.244/30182.3.66.245 to 182.3.66.246182.3.66.2472
191182.3.66.248/30182.3.66.249 to 182.3.66.250182.3.66.2512
192182.3.66.252/30182.3.66.253 to 182.3.66.254182.3.66.2552
193182.3.67.0/30182.3.67.1 to 182.3.67.2182.3.67.32
194182.3.67.4/30182.3.67.5 to 182.3.67.6182.3.67.72
195182.3.67.8/30182.3.67.9 to 182.3.67.10182.3.67.112
196182.3.67.12/30182.3.67.13 to 182.3.67.14182.3.67.152
197182.3.67.16/30182.3.67.17 to 182.3.67.18182.3.67.192
198182.3.67.20/30182.3.67.21 to 182.3.67.22182.3.67.232
199182.3.67.24/30182.3.67.25 to 182.3.67.26182.3.67.272
200182.3.67.28/30182.3.67.29 to 182.3.67.30182.3.67.312
201182.3.67.32/30182.3.67.33 to 182.3.67.34182.3.67.352
202182.3.67.36/30182.3.67.37 to 182.3.67.38182.3.67.392
203182.3.67.40/30182.3.67.41 to 182.3.67.42182.3.67.432
204182.3.67.44/30182.3.67.45 to 182.3.67.46182.3.67.472
205182.3.67.48/30182.3.67.49 to 182.3.67.50182.3.67.512
206182.3.67.52/30182.3.67.53 to 182.3.67.54182.3.67.552
207182.3.67.56/30182.3.67.57 to 182.3.67.58182.3.67.592
208182.3.67.60/30182.3.67.61 to 182.3.67.62182.3.67.632
209182.3.67.64/30182.3.67.65 to 182.3.67.66182.3.67.672
210182.3.67.68/30182.3.67.69 to 182.3.67.70182.3.67.712
211182.3.67.72/30182.3.67.73 to 182.3.67.74182.3.67.752
212182.3.67.76/30182.3.67.77 to 182.3.67.78182.3.67.792
213182.3.67.80/30182.3.67.81 to 182.3.67.82182.3.67.832
214182.3.67.84/30182.3.67.85 to 182.3.67.86182.3.67.872
215182.3.67.88/30182.3.67.89 to 182.3.67.90182.3.67.912
216182.3.67.92/30182.3.67.93 to 182.3.67.94182.3.67.952
217182.3.67.96/30182.3.67.97 to 182.3.67.98182.3.67.992
218182.3.67.100/30182.3.67.101 to 182.3.67.102182.3.67.1032
219182.3.67.104/30182.3.67.105 to 182.3.67.106182.3.67.1072
220182.3.67.108/30182.3.67.109 to 182.3.67.110182.3.67.1112
221182.3.67.112/30182.3.67.113 to 182.3.67.114182.3.67.1152
222182.3.67.116/30182.3.67.117 to 182.3.67.118182.3.67.1192
223182.3.67.120/30182.3.67.121 to 182.3.67.122182.3.67.1232
224182.3.67.124/30182.3.67.125 to 182.3.67.126182.3.67.1272
225182.3.67.128/30182.3.67.129 to 182.3.67.130182.3.67.1312
226182.3.67.132/30182.3.67.133 to 182.3.67.134182.3.67.1352
227182.3.67.136/30182.3.67.137 to 182.3.67.138182.3.67.1392
228182.3.67.140/30182.3.67.141 to 182.3.67.142182.3.67.1432
229182.3.67.144/30182.3.67.145 to 182.3.67.146182.3.67.1472
230182.3.67.148/30182.3.67.149 to 182.3.67.150182.3.67.1512
231182.3.67.152/30182.3.67.153 to 182.3.67.154182.3.67.1552
232182.3.67.156/30182.3.67.157 to 182.3.67.158182.3.67.1592
233182.3.67.160/30182.3.67.161 to 182.3.67.162182.3.67.1632
234182.3.67.164/30182.3.67.165 to 182.3.67.166182.3.67.1672
235182.3.67.168/30182.3.67.169 to 182.3.67.170182.3.67.1712
236182.3.67.172/30182.3.67.173 to 182.3.67.174182.3.67.1752
237182.3.67.176/30182.3.67.177 to 182.3.67.178182.3.67.1792
238182.3.67.180/30182.3.67.181 to 182.3.67.182182.3.67.1832
239182.3.67.184/30182.3.67.185 to 182.3.67.186182.3.67.1872
240182.3.67.188/30182.3.67.189 to 182.3.67.190182.3.67.1912
241182.3.67.192/30182.3.67.193 to 182.3.67.194182.3.67.1952
242182.3.67.196/30182.3.67.197 to 182.3.67.198182.3.67.1992
243182.3.67.200/30182.3.67.201 to 182.3.67.202182.3.67.2032
244182.3.67.204/30182.3.67.205 to 182.3.67.206182.3.67.2072
245182.3.67.208/30182.3.67.209 to 182.3.67.210182.3.67.2112
246182.3.67.212/30182.3.67.213 to 182.3.67.214182.3.67.2152
247182.3.67.216/30182.3.67.217 to 182.3.67.218182.3.67.2192
248182.3.67.220/30182.3.67.221 to 182.3.67.222182.3.67.2232
249182.3.67.224/30182.3.67.225 to 182.3.67.226182.3.67.2272
250182.3.67.228/30182.3.67.229 to 182.3.67.230182.3.67.2312
251182.3.67.232/30182.3.67.233 to 182.3.67.234182.3.67.2352
252182.3.67.236/30182.3.67.237 to 182.3.67.238182.3.67.2392
253182.3.67.240/30182.3.67.241 to 182.3.67.242182.3.67.2432
254182.3.67.244/30182.3.67.245 to 182.3.67.246182.3.67.2472
255182.3.67.248/30182.3.67.249 to 182.3.67.250182.3.67.2512
256182.3.67.252/30182.3.67.253 to 182.3.67.254182.3.67.2552

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.