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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.

Network255.92.0.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
255.92.0.0
Broadcast address
255.92.63.255
First usable
255.92.0.1
Last usable
255.92.63.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex FF5C0000 · Integer 4284219392 to 4284235775
Reverse DNS zones
0.92.255.in-addr.arpa
1.92.255.in-addr.arpa
2.92.255.in-addr.arpa
3.92.255.in-addr.arpa
4.92.255.in-addr.arpa
5.92.255.in-addr.arpa
6.92.255.in-addr.arpa
7.92.255.in-addr.arpa
8.92.255.in-addr.arpa
9.92.255.in-addr.arpa
10.92.255.in-addr.arpa
11.92.255.in-addr.arpa
12.92.255.in-addr.arpa
13.92.255.in-addr.arpa
14.92.255.in-addr.arpa
15.92.255.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11111111.01011100.00000000.00000000255.92.0.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network11111111.01011100.00000000.00000000255.92.0.0
Broadcast11111111.01011100.00111111.11111111255.92.63.255
Split into smaller subnets/30
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

255.92.0.0/18 makes 4,096 subnets of /30; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1255.92.0.0/30255.92.0.1 to 255.92.0.2255.92.0.32
2255.92.0.4/30255.92.0.5 to 255.92.0.6255.92.0.72
3255.92.0.8/30255.92.0.9 to 255.92.0.10255.92.0.112
4255.92.0.12/30255.92.0.13 to 255.92.0.14255.92.0.152
5255.92.0.16/30255.92.0.17 to 255.92.0.18255.92.0.192
6255.92.0.20/30255.92.0.21 to 255.92.0.22255.92.0.232
7255.92.0.24/30255.92.0.25 to 255.92.0.26255.92.0.272
8255.92.0.28/30255.92.0.29 to 255.92.0.30255.92.0.312
9255.92.0.32/30255.92.0.33 to 255.92.0.34255.92.0.352
10255.92.0.36/30255.92.0.37 to 255.92.0.38255.92.0.392
11255.92.0.40/30255.92.0.41 to 255.92.0.42255.92.0.432
12255.92.0.44/30255.92.0.45 to 255.92.0.46255.92.0.472
13255.92.0.48/30255.92.0.49 to 255.92.0.50255.92.0.512
14255.92.0.52/30255.92.0.53 to 255.92.0.54255.92.0.552
15255.92.0.56/30255.92.0.57 to 255.92.0.58255.92.0.592
16255.92.0.60/30255.92.0.61 to 255.92.0.62255.92.0.632
17255.92.0.64/30255.92.0.65 to 255.92.0.66255.92.0.672
18255.92.0.68/30255.92.0.69 to 255.92.0.70255.92.0.712
19255.92.0.72/30255.92.0.73 to 255.92.0.74255.92.0.752
20255.92.0.76/30255.92.0.77 to 255.92.0.78255.92.0.792
21255.92.0.80/30255.92.0.81 to 255.92.0.82255.92.0.832
22255.92.0.84/30255.92.0.85 to 255.92.0.86255.92.0.872
23255.92.0.88/30255.92.0.89 to 255.92.0.90255.92.0.912
24255.92.0.92/30255.92.0.93 to 255.92.0.94255.92.0.952
25255.92.0.96/30255.92.0.97 to 255.92.0.98255.92.0.992
26255.92.0.100/30255.92.0.101 to 255.92.0.102255.92.0.1032
27255.92.0.104/30255.92.0.105 to 255.92.0.106255.92.0.1072
28255.92.0.108/30255.92.0.109 to 255.92.0.110255.92.0.1112
29255.92.0.112/30255.92.0.113 to 255.92.0.114255.92.0.1152
30255.92.0.116/30255.92.0.117 to 255.92.0.118255.92.0.1192
31255.92.0.120/30255.92.0.121 to 255.92.0.122255.92.0.1232
32255.92.0.124/30255.92.0.125 to 255.92.0.126255.92.0.1272
33255.92.0.128/30255.92.0.129 to 255.92.0.130255.92.0.1312
34255.92.0.132/30255.92.0.133 to 255.92.0.134255.92.0.1352
35255.92.0.136/30255.92.0.137 to 255.92.0.138255.92.0.1392
36255.92.0.140/30255.92.0.141 to 255.92.0.142255.92.0.1432
37255.92.0.144/30255.92.0.145 to 255.92.0.146255.92.0.1472
38255.92.0.148/30255.92.0.149 to 255.92.0.150255.92.0.1512
39255.92.0.152/30255.92.0.153 to 255.92.0.154255.92.0.1552
40255.92.0.156/30255.92.0.157 to 255.92.0.158255.92.0.1592
41255.92.0.160/30255.92.0.161 to 255.92.0.162255.92.0.1632
42255.92.0.164/30255.92.0.165 to 255.92.0.166255.92.0.1672
43255.92.0.168/30255.92.0.169 to 255.92.0.170255.92.0.1712
44255.92.0.172/30255.92.0.173 to 255.92.0.174255.92.0.1752
45255.92.0.176/30255.92.0.177 to 255.92.0.178255.92.0.1792
46255.92.0.180/30255.92.0.181 to 255.92.0.182255.92.0.1832
47255.92.0.184/30255.92.0.185 to 255.92.0.186255.92.0.1872
48255.92.0.188/30255.92.0.189 to 255.92.0.190255.92.0.1912
49255.92.0.192/30255.92.0.193 to 255.92.0.194255.92.0.1952
50255.92.0.196/30255.92.0.197 to 255.92.0.198255.92.0.1992
51255.92.0.200/30255.92.0.201 to 255.92.0.202255.92.0.2032
52255.92.0.204/30255.92.0.205 to 255.92.0.206255.92.0.2072
53255.92.0.208/30255.92.0.209 to 255.92.0.210255.92.0.2112
54255.92.0.212/30255.92.0.213 to 255.92.0.214255.92.0.2152
55255.92.0.216/30255.92.0.217 to 255.92.0.218255.92.0.2192
56255.92.0.220/30255.92.0.221 to 255.92.0.222255.92.0.2232
57255.92.0.224/30255.92.0.225 to 255.92.0.226255.92.0.2272
58255.92.0.228/30255.92.0.229 to 255.92.0.230255.92.0.2312
59255.92.0.232/30255.92.0.233 to 255.92.0.234255.92.0.2352
60255.92.0.236/30255.92.0.237 to 255.92.0.238255.92.0.2392
61255.92.0.240/30255.92.0.241 to 255.92.0.242255.92.0.2432
62255.92.0.244/30255.92.0.245 to 255.92.0.246255.92.0.2472
63255.92.0.248/30255.92.0.249 to 255.92.0.250255.92.0.2512
64255.92.0.252/30255.92.0.253 to 255.92.0.254255.92.0.2552
65255.92.1.0/30255.92.1.1 to 255.92.1.2255.92.1.32
66255.92.1.4/30255.92.1.5 to 255.92.1.6255.92.1.72
67255.92.1.8/30255.92.1.9 to 255.92.1.10255.92.1.112
68255.92.1.12/30255.92.1.13 to 255.92.1.14255.92.1.152
69255.92.1.16/30255.92.1.17 to 255.92.1.18255.92.1.192
70255.92.1.20/30255.92.1.21 to 255.92.1.22255.92.1.232
71255.92.1.24/30255.92.1.25 to 255.92.1.26255.92.1.272
72255.92.1.28/30255.92.1.29 to 255.92.1.30255.92.1.312
73255.92.1.32/30255.92.1.33 to 255.92.1.34255.92.1.352
74255.92.1.36/30255.92.1.37 to 255.92.1.38255.92.1.392
75255.92.1.40/30255.92.1.41 to 255.92.1.42255.92.1.432
76255.92.1.44/30255.92.1.45 to 255.92.1.46255.92.1.472
77255.92.1.48/30255.92.1.49 to 255.92.1.50255.92.1.512
78255.92.1.52/30255.92.1.53 to 255.92.1.54255.92.1.552
79255.92.1.56/30255.92.1.57 to 255.92.1.58255.92.1.592
80255.92.1.60/30255.92.1.61 to 255.92.1.62255.92.1.632
81255.92.1.64/30255.92.1.65 to 255.92.1.66255.92.1.672
82255.92.1.68/30255.92.1.69 to 255.92.1.70255.92.1.712
83255.92.1.72/30255.92.1.73 to 255.92.1.74255.92.1.752
84255.92.1.76/30255.92.1.77 to 255.92.1.78255.92.1.792
85255.92.1.80/30255.92.1.81 to 255.92.1.82255.92.1.832
86255.92.1.84/30255.92.1.85 to 255.92.1.86255.92.1.872
87255.92.1.88/30255.92.1.89 to 255.92.1.90255.92.1.912
88255.92.1.92/30255.92.1.93 to 255.92.1.94255.92.1.952
89255.92.1.96/30255.92.1.97 to 255.92.1.98255.92.1.992
90255.92.1.100/30255.92.1.101 to 255.92.1.102255.92.1.1032
91255.92.1.104/30255.92.1.105 to 255.92.1.106255.92.1.1072
92255.92.1.108/30255.92.1.109 to 255.92.1.110255.92.1.1112
93255.92.1.112/30255.92.1.113 to 255.92.1.114255.92.1.1152
94255.92.1.116/30255.92.1.117 to 255.92.1.118255.92.1.1192
95255.92.1.120/30255.92.1.121 to 255.92.1.122255.92.1.1232
96255.92.1.124/30255.92.1.125 to 255.92.1.126255.92.1.1272
97255.92.1.128/30255.92.1.129 to 255.92.1.130255.92.1.1312
98255.92.1.132/30255.92.1.133 to 255.92.1.134255.92.1.1352
99255.92.1.136/30255.92.1.137 to 255.92.1.138255.92.1.1392
100255.92.1.140/30255.92.1.141 to 255.92.1.142255.92.1.1432
101255.92.1.144/30255.92.1.145 to 255.92.1.146255.92.1.1472
102255.92.1.148/30255.92.1.149 to 255.92.1.150255.92.1.1512
103255.92.1.152/30255.92.1.153 to 255.92.1.154255.92.1.1552
104255.92.1.156/30255.92.1.157 to 255.92.1.158255.92.1.1592
105255.92.1.160/30255.92.1.161 to 255.92.1.162255.92.1.1632
106255.92.1.164/30255.92.1.165 to 255.92.1.166255.92.1.1672
107255.92.1.168/30255.92.1.169 to 255.92.1.170255.92.1.1712
108255.92.1.172/30255.92.1.173 to 255.92.1.174255.92.1.1752
109255.92.1.176/30255.92.1.177 to 255.92.1.178255.92.1.1792
110255.92.1.180/30255.92.1.181 to 255.92.1.182255.92.1.1832
111255.92.1.184/30255.92.1.185 to 255.92.1.186255.92.1.1872
112255.92.1.188/30255.92.1.189 to 255.92.1.190255.92.1.1912
113255.92.1.192/30255.92.1.193 to 255.92.1.194255.92.1.1952
114255.92.1.196/30255.92.1.197 to 255.92.1.198255.92.1.1992
115255.92.1.200/30255.92.1.201 to 255.92.1.202255.92.1.2032
116255.92.1.204/30255.92.1.205 to 255.92.1.206255.92.1.2072
117255.92.1.208/30255.92.1.209 to 255.92.1.210255.92.1.2112
118255.92.1.212/30255.92.1.213 to 255.92.1.214255.92.1.2152
119255.92.1.216/30255.92.1.217 to 255.92.1.218255.92.1.2192
120255.92.1.220/30255.92.1.221 to 255.92.1.222255.92.1.2232
121255.92.1.224/30255.92.1.225 to 255.92.1.226255.92.1.2272
122255.92.1.228/30255.92.1.229 to 255.92.1.230255.92.1.2312
123255.92.1.232/30255.92.1.233 to 255.92.1.234255.92.1.2352
124255.92.1.236/30255.92.1.237 to 255.92.1.238255.92.1.2392
125255.92.1.240/30255.92.1.241 to 255.92.1.242255.92.1.2432
126255.92.1.244/30255.92.1.245 to 255.92.1.246255.92.1.2472
127255.92.1.248/30255.92.1.249 to 255.92.1.250255.92.1.2512
128255.92.1.252/30255.92.1.253 to 255.92.1.254255.92.1.2552
129255.92.2.0/30255.92.2.1 to 255.92.2.2255.92.2.32
130255.92.2.4/30255.92.2.5 to 255.92.2.6255.92.2.72
131255.92.2.8/30255.92.2.9 to 255.92.2.10255.92.2.112
132255.92.2.12/30255.92.2.13 to 255.92.2.14255.92.2.152
133255.92.2.16/30255.92.2.17 to 255.92.2.18255.92.2.192
134255.92.2.20/30255.92.2.21 to 255.92.2.22255.92.2.232
135255.92.2.24/30255.92.2.25 to 255.92.2.26255.92.2.272
136255.92.2.28/30255.92.2.29 to 255.92.2.30255.92.2.312
137255.92.2.32/30255.92.2.33 to 255.92.2.34255.92.2.352
138255.92.2.36/30255.92.2.37 to 255.92.2.38255.92.2.392
139255.92.2.40/30255.92.2.41 to 255.92.2.42255.92.2.432
140255.92.2.44/30255.92.2.45 to 255.92.2.46255.92.2.472
141255.92.2.48/30255.92.2.49 to 255.92.2.50255.92.2.512
142255.92.2.52/30255.92.2.53 to 255.92.2.54255.92.2.552
143255.92.2.56/30255.92.2.57 to 255.92.2.58255.92.2.592
144255.92.2.60/30255.92.2.61 to 255.92.2.62255.92.2.632
145255.92.2.64/30255.92.2.65 to 255.92.2.66255.92.2.672
146255.92.2.68/30255.92.2.69 to 255.92.2.70255.92.2.712
147255.92.2.72/30255.92.2.73 to 255.92.2.74255.92.2.752
148255.92.2.76/30255.92.2.77 to 255.92.2.78255.92.2.792
149255.92.2.80/30255.92.2.81 to 255.92.2.82255.92.2.832
150255.92.2.84/30255.92.2.85 to 255.92.2.86255.92.2.872
151255.92.2.88/30255.92.2.89 to 255.92.2.90255.92.2.912
152255.92.2.92/30255.92.2.93 to 255.92.2.94255.92.2.952
153255.92.2.96/30255.92.2.97 to 255.92.2.98255.92.2.992
154255.92.2.100/30255.92.2.101 to 255.92.2.102255.92.2.1032
155255.92.2.104/30255.92.2.105 to 255.92.2.106255.92.2.1072
156255.92.2.108/30255.92.2.109 to 255.92.2.110255.92.2.1112
157255.92.2.112/30255.92.2.113 to 255.92.2.114255.92.2.1152
158255.92.2.116/30255.92.2.117 to 255.92.2.118255.92.2.1192
159255.92.2.120/30255.92.2.121 to 255.92.2.122255.92.2.1232
160255.92.2.124/30255.92.2.125 to 255.92.2.126255.92.2.1272
161255.92.2.128/30255.92.2.129 to 255.92.2.130255.92.2.1312
162255.92.2.132/30255.92.2.133 to 255.92.2.134255.92.2.1352
163255.92.2.136/30255.92.2.137 to 255.92.2.138255.92.2.1392
164255.92.2.140/30255.92.2.141 to 255.92.2.142255.92.2.1432
165255.92.2.144/30255.92.2.145 to 255.92.2.146255.92.2.1472
166255.92.2.148/30255.92.2.149 to 255.92.2.150255.92.2.1512
167255.92.2.152/30255.92.2.153 to 255.92.2.154255.92.2.1552
168255.92.2.156/30255.92.2.157 to 255.92.2.158255.92.2.1592
169255.92.2.160/30255.92.2.161 to 255.92.2.162255.92.2.1632
170255.92.2.164/30255.92.2.165 to 255.92.2.166255.92.2.1672
171255.92.2.168/30255.92.2.169 to 255.92.2.170255.92.2.1712
172255.92.2.172/30255.92.2.173 to 255.92.2.174255.92.2.1752
173255.92.2.176/30255.92.2.177 to 255.92.2.178255.92.2.1792
174255.92.2.180/30255.92.2.181 to 255.92.2.182255.92.2.1832
175255.92.2.184/30255.92.2.185 to 255.92.2.186255.92.2.1872
176255.92.2.188/30255.92.2.189 to 255.92.2.190255.92.2.1912
177255.92.2.192/30255.92.2.193 to 255.92.2.194255.92.2.1952
178255.92.2.196/30255.92.2.197 to 255.92.2.198255.92.2.1992
179255.92.2.200/30255.92.2.201 to 255.92.2.202255.92.2.2032
180255.92.2.204/30255.92.2.205 to 255.92.2.206255.92.2.2072
181255.92.2.208/30255.92.2.209 to 255.92.2.210255.92.2.2112
182255.92.2.212/30255.92.2.213 to 255.92.2.214255.92.2.2152
183255.92.2.216/30255.92.2.217 to 255.92.2.218255.92.2.2192
184255.92.2.220/30255.92.2.221 to 255.92.2.222255.92.2.2232
185255.92.2.224/30255.92.2.225 to 255.92.2.226255.92.2.2272
186255.92.2.228/30255.92.2.229 to 255.92.2.230255.92.2.2312
187255.92.2.232/30255.92.2.233 to 255.92.2.234255.92.2.2352
188255.92.2.236/30255.92.2.237 to 255.92.2.238255.92.2.2392
189255.92.2.240/30255.92.2.241 to 255.92.2.242255.92.2.2432
190255.92.2.244/30255.92.2.245 to 255.92.2.246255.92.2.2472
191255.92.2.248/30255.92.2.249 to 255.92.2.250255.92.2.2512
192255.92.2.252/30255.92.2.253 to 255.92.2.254255.92.2.2552
193255.92.3.0/30255.92.3.1 to 255.92.3.2255.92.3.32
194255.92.3.4/30255.92.3.5 to 255.92.3.6255.92.3.72
195255.92.3.8/30255.92.3.9 to 255.92.3.10255.92.3.112
196255.92.3.12/30255.92.3.13 to 255.92.3.14255.92.3.152
197255.92.3.16/30255.92.3.17 to 255.92.3.18255.92.3.192
198255.92.3.20/30255.92.3.21 to 255.92.3.22255.92.3.232
199255.92.3.24/30255.92.3.25 to 255.92.3.26255.92.3.272
200255.92.3.28/30255.92.3.29 to 255.92.3.30255.92.3.312
201255.92.3.32/30255.92.3.33 to 255.92.3.34255.92.3.352
202255.92.3.36/30255.92.3.37 to 255.92.3.38255.92.3.392
203255.92.3.40/30255.92.3.41 to 255.92.3.42255.92.3.432
204255.92.3.44/30255.92.3.45 to 255.92.3.46255.92.3.472
205255.92.3.48/30255.92.3.49 to 255.92.3.50255.92.3.512
206255.92.3.52/30255.92.3.53 to 255.92.3.54255.92.3.552
207255.92.3.56/30255.92.3.57 to 255.92.3.58255.92.3.592
208255.92.3.60/30255.92.3.61 to 255.92.3.62255.92.3.632
209255.92.3.64/30255.92.3.65 to 255.92.3.66255.92.3.672
210255.92.3.68/30255.92.3.69 to 255.92.3.70255.92.3.712
211255.92.3.72/30255.92.3.73 to 255.92.3.74255.92.3.752
212255.92.3.76/30255.92.3.77 to 255.92.3.78255.92.3.792
213255.92.3.80/30255.92.3.81 to 255.92.3.82255.92.3.832
214255.92.3.84/30255.92.3.85 to 255.92.3.86255.92.3.872
215255.92.3.88/30255.92.3.89 to 255.92.3.90255.92.3.912
216255.92.3.92/30255.92.3.93 to 255.92.3.94255.92.3.952
217255.92.3.96/30255.92.3.97 to 255.92.3.98255.92.3.992
218255.92.3.100/30255.92.3.101 to 255.92.3.102255.92.3.1032
219255.92.3.104/30255.92.3.105 to 255.92.3.106255.92.3.1072
220255.92.3.108/30255.92.3.109 to 255.92.3.110255.92.3.1112
221255.92.3.112/30255.92.3.113 to 255.92.3.114255.92.3.1152
222255.92.3.116/30255.92.3.117 to 255.92.3.118255.92.3.1192
223255.92.3.120/30255.92.3.121 to 255.92.3.122255.92.3.1232
224255.92.3.124/30255.92.3.125 to 255.92.3.126255.92.3.1272
225255.92.3.128/30255.92.3.129 to 255.92.3.130255.92.3.1312
226255.92.3.132/30255.92.3.133 to 255.92.3.134255.92.3.1352
227255.92.3.136/30255.92.3.137 to 255.92.3.138255.92.3.1392
228255.92.3.140/30255.92.3.141 to 255.92.3.142255.92.3.1432
229255.92.3.144/30255.92.3.145 to 255.92.3.146255.92.3.1472
230255.92.3.148/30255.92.3.149 to 255.92.3.150255.92.3.1512
231255.92.3.152/30255.92.3.153 to 255.92.3.154255.92.3.1552
232255.92.3.156/30255.92.3.157 to 255.92.3.158255.92.3.1592
233255.92.3.160/30255.92.3.161 to 255.92.3.162255.92.3.1632
234255.92.3.164/30255.92.3.165 to 255.92.3.166255.92.3.1672
235255.92.3.168/30255.92.3.169 to 255.92.3.170255.92.3.1712
236255.92.3.172/30255.92.3.173 to 255.92.3.174255.92.3.1752
237255.92.3.176/30255.92.3.177 to 255.92.3.178255.92.3.1792
238255.92.3.180/30255.92.3.181 to 255.92.3.182255.92.3.1832
239255.92.3.184/30255.92.3.185 to 255.92.3.186255.92.3.1872
240255.92.3.188/30255.92.3.189 to 255.92.3.190255.92.3.1912
241255.92.3.192/30255.92.3.193 to 255.92.3.194255.92.3.1952
242255.92.3.196/30255.92.3.197 to 255.92.3.198255.92.3.1992
243255.92.3.200/30255.92.3.201 to 255.92.3.202255.92.3.2032
244255.92.3.204/30255.92.3.205 to 255.92.3.206255.92.3.2072
245255.92.3.208/30255.92.3.209 to 255.92.3.210255.92.3.2112
246255.92.3.212/30255.92.3.213 to 255.92.3.214255.92.3.2152
247255.92.3.216/30255.92.3.217 to 255.92.3.218255.92.3.2192
248255.92.3.220/30255.92.3.221 to 255.92.3.222255.92.3.2232
249255.92.3.224/30255.92.3.225 to 255.92.3.226255.92.3.2272
250255.92.3.228/30255.92.3.229 to 255.92.3.230255.92.3.2312
251255.92.3.232/30255.92.3.233 to 255.92.3.234255.92.3.2352
252255.92.3.236/30255.92.3.237 to 255.92.3.238255.92.3.2392
253255.92.3.240/30255.92.3.241 to 255.92.3.242255.92.3.2432
254255.92.3.244/30255.92.3.245 to 255.92.3.246255.92.3.2472
255255.92.3.248/30255.92.3.249 to 255.92.3.250255.92.3.2512
256255.92.3.252/30255.92.3.253 to 255.92.3.254255.92.3.2552

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.