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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.

Network160.0.0.0/4
Usable hosts268,435,454
Subnet mask240.0.0.0
Addresses268,435,456
Network address
160.0.0.0
Broadcast address
175.255.255.255
First usable
160.0.0.1
Last usable
175.255.255.254
Usable hosts
268,435,454 (268,435,456 less the network and broadcast addresses)
Subnet mask
240.0.0.0
Wildcard mask
15.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/4
Type
Public public
Old class
B (default /16)
As numbers
Hex A0000000 · Integer 2684354560 to 2952790015
Reverse DNS zones
160.in-addr.arpa
161.in-addr.arpa
162.in-addr.arpa
163.in-addr.arpa
164.in-addr.arpa
165.in-addr.arpa
166.in-addr.arpa
167.in-addr.arpa
168.in-addr.arpa
169.in-addr.arpa
170.in-addr.arpa
171.in-addr.arpa
172.in-addr.arpa
173.in-addr.arpa
174.in-addr.arpa
175.in-addr.arpa
/4 is not on a 8-bit boundary, so it takes 16 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10100000.00000000.00000000.00000000160.0.0.0
Subnet mask11110000.00000000.00000000.00000000240.0.0.0
Network10100000.00000000.00000000.00000000160.0.0.0
Broadcast10101111.11111111.11111111.11111111175.255.255.255
Split into smaller subnets/12
/5 (2)/6 (4)/7 (8)/8 (16)/9 (32)/10 (64)/11 (128)/12 (256)/13 (512)/14 (1,024)/15 (2,048)/16 (4,096)

160.0.0.0/4 makes 256 subnets of /12.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1160.0.0.0/12160.0.0.1 to 160.15.255.254160.15.255.2551,048,574
2160.16.0.0/12160.16.0.1 to 160.31.255.254160.31.255.2551,048,574
3160.32.0.0/12160.32.0.1 to 160.47.255.254160.47.255.2551,048,574
4160.48.0.0/12160.48.0.1 to 160.63.255.254160.63.255.2551,048,574
5160.64.0.0/12160.64.0.1 to 160.79.255.254160.79.255.2551,048,574
6160.80.0.0/12160.80.0.1 to 160.95.255.254160.95.255.2551,048,574
7160.96.0.0/12160.96.0.1 to 160.111.255.254160.111.255.2551,048,574
8160.112.0.0/12160.112.0.1 to 160.127.255.254160.127.255.2551,048,574
9160.128.0.0/12160.128.0.1 to 160.143.255.254160.143.255.2551,048,574
10160.144.0.0/12160.144.0.1 to 160.159.255.254160.159.255.2551,048,574
11160.160.0.0/12160.160.0.1 to 160.175.255.254160.175.255.2551,048,574
12160.176.0.0/12160.176.0.1 to 160.191.255.254160.191.255.2551,048,574
13160.192.0.0/12160.192.0.1 to 160.207.255.254160.207.255.2551,048,574
14160.208.0.0/12160.208.0.1 to 160.223.255.254160.223.255.2551,048,574
15160.224.0.0/12160.224.0.1 to 160.239.255.254160.239.255.2551,048,574
16160.240.0.0/12160.240.0.1 to 160.255.255.254160.255.255.2551,048,574
17161.0.0.0/12161.0.0.1 to 161.15.255.254161.15.255.2551,048,574
18161.16.0.0/12161.16.0.1 to 161.31.255.254161.31.255.2551,048,574
19161.32.0.0/12161.32.0.1 to 161.47.255.254161.47.255.2551,048,574
20161.48.0.0/12161.48.0.1 to 161.63.255.254161.63.255.2551,048,574
21161.64.0.0/12161.64.0.1 to 161.79.255.254161.79.255.2551,048,574
22161.80.0.0/12161.80.0.1 to 161.95.255.254161.95.255.2551,048,574
23161.96.0.0/12161.96.0.1 to 161.111.255.254161.111.255.2551,048,574
24161.112.0.0/12161.112.0.1 to 161.127.255.254161.127.255.2551,048,574
25161.128.0.0/12161.128.0.1 to 161.143.255.254161.143.255.2551,048,574
26161.144.0.0/12161.144.0.1 to 161.159.255.254161.159.255.2551,048,574
27161.160.0.0/12161.160.0.1 to 161.175.255.254161.175.255.2551,048,574
28161.176.0.0/12161.176.0.1 to 161.191.255.254161.191.255.2551,048,574
29161.192.0.0/12161.192.0.1 to 161.207.255.254161.207.255.2551,048,574
30161.208.0.0/12161.208.0.1 to 161.223.255.254161.223.255.2551,048,574
31161.224.0.0/12161.224.0.1 to 161.239.255.254161.239.255.2551,048,574
32161.240.0.0/12161.240.0.1 to 161.255.255.254161.255.255.2551,048,574
33162.0.0.0/12162.0.0.1 to 162.15.255.254162.15.255.2551,048,574
34162.16.0.0/12162.16.0.1 to 162.31.255.254162.31.255.2551,048,574
35162.32.0.0/12162.32.0.1 to 162.47.255.254162.47.255.2551,048,574
36162.48.0.0/12162.48.0.1 to 162.63.255.254162.63.255.2551,048,574
37162.64.0.0/12162.64.0.1 to 162.79.255.254162.79.255.2551,048,574
38162.80.0.0/12162.80.0.1 to 162.95.255.254162.95.255.2551,048,574
39162.96.0.0/12162.96.0.1 to 162.111.255.254162.111.255.2551,048,574
40162.112.0.0/12162.112.0.1 to 162.127.255.254162.127.255.2551,048,574
41162.128.0.0/12162.128.0.1 to 162.143.255.254162.143.255.2551,048,574
42162.144.0.0/12162.144.0.1 to 162.159.255.254162.159.255.2551,048,574
43162.160.0.0/12162.160.0.1 to 162.175.255.254162.175.255.2551,048,574
44162.176.0.0/12162.176.0.1 to 162.191.255.254162.191.255.2551,048,574
45162.192.0.0/12162.192.0.1 to 162.207.255.254162.207.255.2551,048,574
46162.208.0.0/12162.208.0.1 to 162.223.255.254162.223.255.2551,048,574
47162.224.0.0/12162.224.0.1 to 162.239.255.254162.239.255.2551,048,574
48162.240.0.0/12162.240.0.1 to 162.255.255.254162.255.255.2551,048,574
49163.0.0.0/12163.0.0.1 to 163.15.255.254163.15.255.2551,048,574
50163.16.0.0/12163.16.0.1 to 163.31.255.254163.31.255.2551,048,574
51163.32.0.0/12163.32.0.1 to 163.47.255.254163.47.255.2551,048,574
52163.48.0.0/12163.48.0.1 to 163.63.255.254163.63.255.2551,048,574
53163.64.0.0/12163.64.0.1 to 163.79.255.254163.79.255.2551,048,574
54163.80.0.0/12163.80.0.1 to 163.95.255.254163.95.255.2551,048,574
55163.96.0.0/12163.96.0.1 to 163.111.255.254163.111.255.2551,048,574
56163.112.0.0/12163.112.0.1 to 163.127.255.254163.127.255.2551,048,574
57163.128.0.0/12163.128.0.1 to 163.143.255.254163.143.255.2551,048,574
58163.144.0.0/12163.144.0.1 to 163.159.255.254163.159.255.2551,048,574
59163.160.0.0/12163.160.0.1 to 163.175.255.254163.175.255.2551,048,574
60163.176.0.0/12163.176.0.1 to 163.191.255.254163.191.255.2551,048,574
61163.192.0.0/12163.192.0.1 to 163.207.255.254163.207.255.2551,048,574
62163.208.0.0/12163.208.0.1 to 163.223.255.254163.223.255.2551,048,574
63163.224.0.0/12163.224.0.1 to 163.239.255.254163.239.255.2551,048,574
64163.240.0.0/12163.240.0.1 to 163.255.255.254163.255.255.2551,048,574
65164.0.0.0/12164.0.0.1 to 164.15.255.254164.15.255.2551,048,574
66164.16.0.0/12164.16.0.1 to 164.31.255.254164.31.255.2551,048,574
67164.32.0.0/12164.32.0.1 to 164.47.255.254164.47.255.2551,048,574
68164.48.0.0/12164.48.0.1 to 164.63.255.254164.63.255.2551,048,574
69164.64.0.0/12164.64.0.1 to 164.79.255.254164.79.255.2551,048,574
70164.80.0.0/12164.80.0.1 to 164.95.255.254164.95.255.2551,048,574
71164.96.0.0/12164.96.0.1 to 164.111.255.254164.111.255.2551,048,574
72164.112.0.0/12164.112.0.1 to 164.127.255.254164.127.255.2551,048,574
73164.128.0.0/12164.128.0.1 to 164.143.255.254164.143.255.2551,048,574
74164.144.0.0/12164.144.0.1 to 164.159.255.254164.159.255.2551,048,574
75164.160.0.0/12164.160.0.1 to 164.175.255.254164.175.255.2551,048,574
76164.176.0.0/12164.176.0.1 to 164.191.255.254164.191.255.2551,048,574
77164.192.0.0/12164.192.0.1 to 164.207.255.254164.207.255.2551,048,574
78164.208.0.0/12164.208.0.1 to 164.223.255.254164.223.255.2551,048,574
79164.224.0.0/12164.224.0.1 to 164.239.255.254164.239.255.2551,048,574
80164.240.0.0/12164.240.0.1 to 164.255.255.254164.255.255.2551,048,574
81165.0.0.0/12165.0.0.1 to 165.15.255.254165.15.255.2551,048,574
82165.16.0.0/12165.16.0.1 to 165.31.255.254165.31.255.2551,048,574
83165.32.0.0/12165.32.0.1 to 165.47.255.254165.47.255.2551,048,574
84165.48.0.0/12165.48.0.1 to 165.63.255.254165.63.255.2551,048,574
85165.64.0.0/12165.64.0.1 to 165.79.255.254165.79.255.2551,048,574
86165.80.0.0/12165.80.0.1 to 165.95.255.254165.95.255.2551,048,574
87165.96.0.0/12165.96.0.1 to 165.111.255.254165.111.255.2551,048,574
88165.112.0.0/12165.112.0.1 to 165.127.255.254165.127.255.2551,048,574
89165.128.0.0/12165.128.0.1 to 165.143.255.254165.143.255.2551,048,574
90165.144.0.0/12165.144.0.1 to 165.159.255.254165.159.255.2551,048,574
91165.160.0.0/12165.160.0.1 to 165.175.255.254165.175.255.2551,048,574
92165.176.0.0/12165.176.0.1 to 165.191.255.254165.191.255.2551,048,574
93165.192.0.0/12165.192.0.1 to 165.207.255.254165.207.255.2551,048,574
94165.208.0.0/12165.208.0.1 to 165.223.255.254165.223.255.2551,048,574
95165.224.0.0/12165.224.0.1 to 165.239.255.254165.239.255.2551,048,574
96165.240.0.0/12165.240.0.1 to 165.255.255.254165.255.255.2551,048,574
97166.0.0.0/12166.0.0.1 to 166.15.255.254166.15.255.2551,048,574
98166.16.0.0/12166.16.0.1 to 166.31.255.254166.31.255.2551,048,574
99166.32.0.0/12166.32.0.1 to 166.47.255.254166.47.255.2551,048,574
100166.48.0.0/12166.48.0.1 to 166.63.255.254166.63.255.2551,048,574
101166.64.0.0/12166.64.0.1 to 166.79.255.254166.79.255.2551,048,574
102166.80.0.0/12166.80.0.1 to 166.95.255.254166.95.255.2551,048,574
103166.96.0.0/12166.96.0.1 to 166.111.255.254166.111.255.2551,048,574
104166.112.0.0/12166.112.0.1 to 166.127.255.254166.127.255.2551,048,574
105166.128.0.0/12166.128.0.1 to 166.143.255.254166.143.255.2551,048,574
106166.144.0.0/12166.144.0.1 to 166.159.255.254166.159.255.2551,048,574
107166.160.0.0/12166.160.0.1 to 166.175.255.254166.175.255.2551,048,574
108166.176.0.0/12166.176.0.1 to 166.191.255.254166.191.255.2551,048,574
109166.192.0.0/12166.192.0.1 to 166.207.255.254166.207.255.2551,048,574
110166.208.0.0/12166.208.0.1 to 166.223.255.254166.223.255.2551,048,574
111166.224.0.0/12166.224.0.1 to 166.239.255.254166.239.255.2551,048,574
112166.240.0.0/12166.240.0.1 to 166.255.255.254166.255.255.2551,048,574
113167.0.0.0/12167.0.0.1 to 167.15.255.254167.15.255.2551,048,574
114167.16.0.0/12167.16.0.1 to 167.31.255.254167.31.255.2551,048,574
115167.32.0.0/12167.32.0.1 to 167.47.255.254167.47.255.2551,048,574
116167.48.0.0/12167.48.0.1 to 167.63.255.254167.63.255.2551,048,574
117167.64.0.0/12167.64.0.1 to 167.79.255.254167.79.255.2551,048,574
118167.80.0.0/12167.80.0.1 to 167.95.255.254167.95.255.2551,048,574
119167.96.0.0/12167.96.0.1 to 167.111.255.254167.111.255.2551,048,574
120167.112.0.0/12167.112.0.1 to 167.127.255.254167.127.255.2551,048,574
121167.128.0.0/12167.128.0.1 to 167.143.255.254167.143.255.2551,048,574
122167.144.0.0/12167.144.0.1 to 167.159.255.254167.159.255.2551,048,574
123167.160.0.0/12167.160.0.1 to 167.175.255.254167.175.255.2551,048,574
124167.176.0.0/12167.176.0.1 to 167.191.255.254167.191.255.2551,048,574
125167.192.0.0/12167.192.0.1 to 167.207.255.254167.207.255.2551,048,574
126167.208.0.0/12167.208.0.1 to 167.223.255.254167.223.255.2551,048,574
127167.224.0.0/12167.224.0.1 to 167.239.255.254167.239.255.2551,048,574
128167.240.0.0/12167.240.0.1 to 167.255.255.254167.255.255.2551,048,574
129168.0.0.0/12168.0.0.1 to 168.15.255.254168.15.255.2551,048,574
130168.16.0.0/12168.16.0.1 to 168.31.255.254168.31.255.2551,048,574
131168.32.0.0/12168.32.0.1 to 168.47.255.254168.47.255.2551,048,574
132168.48.0.0/12168.48.0.1 to 168.63.255.254168.63.255.2551,048,574
133168.64.0.0/12168.64.0.1 to 168.79.255.254168.79.255.2551,048,574
134168.80.0.0/12168.80.0.1 to 168.95.255.254168.95.255.2551,048,574
135168.96.0.0/12168.96.0.1 to 168.111.255.254168.111.255.2551,048,574
136168.112.0.0/12168.112.0.1 to 168.127.255.254168.127.255.2551,048,574
137168.128.0.0/12168.128.0.1 to 168.143.255.254168.143.255.2551,048,574
138168.144.0.0/12168.144.0.1 to 168.159.255.254168.159.255.2551,048,574
139168.160.0.0/12168.160.0.1 to 168.175.255.254168.175.255.2551,048,574
140168.176.0.0/12168.176.0.1 to 168.191.255.254168.191.255.2551,048,574
141168.192.0.0/12168.192.0.1 to 168.207.255.254168.207.255.2551,048,574
142168.208.0.0/12168.208.0.1 to 168.223.255.254168.223.255.2551,048,574
143168.224.0.0/12168.224.0.1 to 168.239.255.254168.239.255.2551,048,574
144168.240.0.0/12168.240.0.1 to 168.255.255.254168.255.255.2551,048,574
145169.0.0.0/12169.0.0.1 to 169.15.255.254169.15.255.2551,048,574
146169.16.0.0/12169.16.0.1 to 169.31.255.254169.31.255.2551,048,574
147169.32.0.0/12169.32.0.1 to 169.47.255.254169.47.255.2551,048,574
148169.48.0.0/12169.48.0.1 to 169.63.255.254169.63.255.2551,048,574
149169.64.0.0/12169.64.0.1 to 169.79.255.254169.79.255.2551,048,574
150169.80.0.0/12169.80.0.1 to 169.95.255.254169.95.255.2551,048,574
151169.96.0.0/12169.96.0.1 to 169.111.255.254169.111.255.2551,048,574
152169.112.0.0/12169.112.0.1 to 169.127.255.254169.127.255.2551,048,574
153169.128.0.0/12169.128.0.1 to 169.143.255.254169.143.255.2551,048,574
154169.144.0.0/12169.144.0.1 to 169.159.255.254169.159.255.2551,048,574
155169.160.0.0/12169.160.0.1 to 169.175.255.254169.175.255.2551,048,574
156169.176.0.0/12169.176.0.1 to 169.191.255.254169.191.255.2551,048,574
157169.192.0.0/12169.192.0.1 to 169.207.255.254169.207.255.2551,048,574
158169.208.0.0/12169.208.0.1 to 169.223.255.254169.223.255.2551,048,574
159169.224.0.0/12169.224.0.1 to 169.239.255.254169.239.255.2551,048,574
160169.240.0.0/12169.240.0.1 to 169.255.255.254169.255.255.2551,048,574
161170.0.0.0/12170.0.0.1 to 170.15.255.254170.15.255.2551,048,574
162170.16.0.0/12170.16.0.1 to 170.31.255.254170.31.255.2551,048,574
163170.32.0.0/12170.32.0.1 to 170.47.255.254170.47.255.2551,048,574
164170.48.0.0/12170.48.0.1 to 170.63.255.254170.63.255.2551,048,574
165170.64.0.0/12170.64.0.1 to 170.79.255.254170.79.255.2551,048,574
166170.80.0.0/12170.80.0.1 to 170.95.255.254170.95.255.2551,048,574
167170.96.0.0/12170.96.0.1 to 170.111.255.254170.111.255.2551,048,574
168170.112.0.0/12170.112.0.1 to 170.127.255.254170.127.255.2551,048,574
169170.128.0.0/12170.128.0.1 to 170.143.255.254170.143.255.2551,048,574
170170.144.0.0/12170.144.0.1 to 170.159.255.254170.159.255.2551,048,574
171170.160.0.0/12170.160.0.1 to 170.175.255.254170.175.255.2551,048,574
172170.176.0.0/12170.176.0.1 to 170.191.255.254170.191.255.2551,048,574
173170.192.0.0/12170.192.0.1 to 170.207.255.254170.207.255.2551,048,574
174170.208.0.0/12170.208.0.1 to 170.223.255.254170.223.255.2551,048,574
175170.224.0.0/12170.224.0.1 to 170.239.255.254170.239.255.2551,048,574
176170.240.0.0/12170.240.0.1 to 170.255.255.254170.255.255.2551,048,574
177171.0.0.0/12171.0.0.1 to 171.15.255.254171.15.255.2551,048,574
178171.16.0.0/12171.16.0.1 to 171.31.255.254171.31.255.2551,048,574
179171.32.0.0/12171.32.0.1 to 171.47.255.254171.47.255.2551,048,574
180171.48.0.0/12171.48.0.1 to 171.63.255.254171.63.255.2551,048,574
181171.64.0.0/12171.64.0.1 to 171.79.255.254171.79.255.2551,048,574
182171.80.0.0/12171.80.0.1 to 171.95.255.254171.95.255.2551,048,574
183171.96.0.0/12171.96.0.1 to 171.111.255.254171.111.255.2551,048,574
184171.112.0.0/12171.112.0.1 to 171.127.255.254171.127.255.2551,048,574
185171.128.0.0/12171.128.0.1 to 171.143.255.254171.143.255.2551,048,574
186171.144.0.0/12171.144.0.1 to 171.159.255.254171.159.255.2551,048,574
187171.160.0.0/12171.160.0.1 to 171.175.255.254171.175.255.2551,048,574
188171.176.0.0/12171.176.0.1 to 171.191.255.254171.191.255.2551,048,574
189171.192.0.0/12171.192.0.1 to 171.207.255.254171.207.255.2551,048,574
190171.208.0.0/12171.208.0.1 to 171.223.255.254171.223.255.2551,048,574
191171.224.0.0/12171.224.0.1 to 171.239.255.254171.239.255.2551,048,574
192171.240.0.0/12171.240.0.1 to 171.255.255.254171.255.255.2551,048,574
193172.0.0.0/12172.0.0.1 to 172.15.255.254172.15.255.2551,048,574
194172.16.0.0/12172.16.0.1 to 172.31.255.254172.31.255.2551,048,574
195172.32.0.0/12172.32.0.1 to 172.47.255.254172.47.255.2551,048,574
196172.48.0.0/12172.48.0.1 to 172.63.255.254172.63.255.2551,048,574
197172.64.0.0/12172.64.0.1 to 172.79.255.254172.79.255.2551,048,574
198172.80.0.0/12172.80.0.1 to 172.95.255.254172.95.255.2551,048,574
199172.96.0.0/12172.96.0.1 to 172.111.255.254172.111.255.2551,048,574
200172.112.0.0/12172.112.0.1 to 172.127.255.254172.127.255.2551,048,574
201172.128.0.0/12172.128.0.1 to 172.143.255.254172.143.255.2551,048,574
202172.144.0.0/12172.144.0.1 to 172.159.255.254172.159.255.2551,048,574
203172.160.0.0/12172.160.0.1 to 172.175.255.254172.175.255.2551,048,574
204172.176.0.0/12172.176.0.1 to 172.191.255.254172.191.255.2551,048,574
205172.192.0.0/12172.192.0.1 to 172.207.255.254172.207.255.2551,048,574
206172.208.0.0/12172.208.0.1 to 172.223.255.254172.223.255.2551,048,574
207172.224.0.0/12172.224.0.1 to 172.239.255.254172.239.255.2551,048,574
208172.240.0.0/12172.240.0.1 to 172.255.255.254172.255.255.2551,048,574
209173.0.0.0/12173.0.0.1 to 173.15.255.254173.15.255.2551,048,574
210173.16.0.0/12173.16.0.1 to 173.31.255.254173.31.255.2551,048,574
211173.32.0.0/12173.32.0.1 to 173.47.255.254173.47.255.2551,048,574
212173.48.0.0/12173.48.0.1 to 173.63.255.254173.63.255.2551,048,574
213173.64.0.0/12173.64.0.1 to 173.79.255.254173.79.255.2551,048,574
214173.80.0.0/12173.80.0.1 to 173.95.255.254173.95.255.2551,048,574
215173.96.0.0/12173.96.0.1 to 173.111.255.254173.111.255.2551,048,574
216173.112.0.0/12173.112.0.1 to 173.127.255.254173.127.255.2551,048,574
217173.128.0.0/12173.128.0.1 to 173.143.255.254173.143.255.2551,048,574
218173.144.0.0/12173.144.0.1 to 173.159.255.254173.159.255.2551,048,574
219173.160.0.0/12173.160.0.1 to 173.175.255.254173.175.255.2551,048,574
220173.176.0.0/12173.176.0.1 to 173.191.255.254173.191.255.2551,048,574
221173.192.0.0/12173.192.0.1 to 173.207.255.254173.207.255.2551,048,574
222173.208.0.0/12173.208.0.1 to 173.223.255.254173.223.255.2551,048,574
223173.224.0.0/12173.224.0.1 to 173.239.255.254173.239.255.2551,048,574
224173.240.0.0/12173.240.0.1 to 173.255.255.254173.255.255.2551,048,574
225174.0.0.0/12174.0.0.1 to 174.15.255.254174.15.255.2551,048,574
226174.16.0.0/12174.16.0.1 to 174.31.255.254174.31.255.2551,048,574
227174.32.0.0/12174.32.0.1 to 174.47.255.254174.47.255.2551,048,574
228174.48.0.0/12174.48.0.1 to 174.63.255.254174.63.255.2551,048,574
229174.64.0.0/12174.64.0.1 to 174.79.255.254174.79.255.2551,048,574
230174.80.0.0/12174.80.0.1 to 174.95.255.254174.95.255.2551,048,574
231174.96.0.0/12174.96.0.1 to 174.111.255.254174.111.255.2551,048,574
232174.112.0.0/12174.112.0.1 to 174.127.255.254174.127.255.2551,048,574
233174.128.0.0/12174.128.0.1 to 174.143.255.254174.143.255.2551,048,574
234174.144.0.0/12174.144.0.1 to 174.159.255.254174.159.255.2551,048,574
235174.160.0.0/12174.160.0.1 to 174.175.255.254174.175.255.2551,048,574
236174.176.0.0/12174.176.0.1 to 174.191.255.254174.191.255.2551,048,574
237174.192.0.0/12174.192.0.1 to 174.207.255.254174.207.255.2551,048,574
238174.208.0.0/12174.208.0.1 to 174.223.255.254174.223.255.2551,048,574
239174.224.0.0/12174.224.0.1 to 174.239.255.254174.239.255.2551,048,574
240174.240.0.0/12174.240.0.1 to 174.255.255.254174.255.255.2551,048,574
241175.0.0.0/12175.0.0.1 to 175.15.255.254175.15.255.2551,048,574
242175.16.0.0/12175.16.0.1 to 175.31.255.254175.31.255.2551,048,574
243175.32.0.0/12175.32.0.1 to 175.47.255.254175.47.255.2551,048,574
244175.48.0.0/12175.48.0.1 to 175.63.255.254175.63.255.2551,048,574
245175.64.0.0/12175.64.0.1 to 175.79.255.254175.79.255.2551,048,574
246175.80.0.0/12175.80.0.1 to 175.95.255.254175.95.255.2551,048,574
247175.96.0.0/12175.96.0.1 to 175.111.255.254175.111.255.2551,048,574
248175.112.0.0/12175.112.0.1 to 175.127.255.254175.127.255.2551,048,574
249175.128.0.0/12175.128.0.1 to 175.143.255.254175.143.255.2551,048,574
250175.144.0.0/12175.144.0.1 to 175.159.255.254175.159.255.2551,048,574
251175.160.0.0/12175.160.0.1 to 175.175.255.254175.175.255.2551,048,574
252175.176.0.0/12175.176.0.1 to 175.191.255.254175.191.255.2551,048,574
253175.192.0.0/12175.192.0.1 to 175.207.255.254175.207.255.2551,048,574
254175.208.0.0/12175.208.0.1 to 175.223.255.254175.223.255.2551,048,574
255175.224.0.0/12175.224.0.1 to 175.239.255.254175.239.255.2551,048,574
256175.240.0.0/12175.240.0.1 to 175.255.255.254175.255.255.2551,048,574

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.