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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.

Network160.64.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
160.64.0.0
Broadcast address
160.79.255.255
First usable
160.64.0.1
Last usable
160.79.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Public public
Old class
B (default /16)
As numbers
Hex A0400000 · Integer 2688548864 to 2689597439
Reverse DNS zones
64.160.in-addr.arpa
65.160.in-addr.arpa
66.160.in-addr.arpa
67.160.in-addr.arpa
68.160.in-addr.arpa
69.160.in-addr.arpa
70.160.in-addr.arpa
71.160.in-addr.arpa
72.160.in-addr.arpa
73.160.in-addr.arpa
74.160.in-addr.arpa
75.160.in-addr.arpa
76.160.in-addr.arpa
77.160.in-addr.arpa
78.160.in-addr.arpa
79.160.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10100000.01000000.00000000.00000000160.64.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network10100000.01000000.00000000.00000000160.64.0.0
Broadcast10100000.01001111.11111111.11111111160.79.255.255
Split into smaller subnets/20
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

160.64.0.0/12 makes 256 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1160.64.0.0/20160.64.0.1 to 160.64.15.254160.64.15.2554,094
2160.64.16.0/20160.64.16.1 to 160.64.31.254160.64.31.2554,094
3160.64.32.0/20160.64.32.1 to 160.64.47.254160.64.47.2554,094
4160.64.48.0/20160.64.48.1 to 160.64.63.254160.64.63.2554,094
5160.64.64.0/20160.64.64.1 to 160.64.79.254160.64.79.2554,094
6160.64.80.0/20160.64.80.1 to 160.64.95.254160.64.95.2554,094
7160.64.96.0/20160.64.96.1 to 160.64.111.254160.64.111.2554,094
8160.64.112.0/20160.64.112.1 to 160.64.127.254160.64.127.2554,094
9160.64.128.0/20160.64.128.1 to 160.64.143.254160.64.143.2554,094
10160.64.144.0/20160.64.144.1 to 160.64.159.254160.64.159.2554,094
11160.64.160.0/20160.64.160.1 to 160.64.175.254160.64.175.2554,094
12160.64.176.0/20160.64.176.1 to 160.64.191.254160.64.191.2554,094
13160.64.192.0/20160.64.192.1 to 160.64.207.254160.64.207.2554,094
14160.64.208.0/20160.64.208.1 to 160.64.223.254160.64.223.2554,094
15160.64.224.0/20160.64.224.1 to 160.64.239.254160.64.239.2554,094
16160.64.240.0/20160.64.240.1 to 160.64.255.254160.64.255.2554,094
17160.65.0.0/20160.65.0.1 to 160.65.15.254160.65.15.2554,094
18160.65.16.0/20160.65.16.1 to 160.65.31.254160.65.31.2554,094
19160.65.32.0/20160.65.32.1 to 160.65.47.254160.65.47.2554,094
20160.65.48.0/20160.65.48.1 to 160.65.63.254160.65.63.2554,094
21160.65.64.0/20160.65.64.1 to 160.65.79.254160.65.79.2554,094
22160.65.80.0/20160.65.80.1 to 160.65.95.254160.65.95.2554,094
23160.65.96.0/20160.65.96.1 to 160.65.111.254160.65.111.2554,094
24160.65.112.0/20160.65.112.1 to 160.65.127.254160.65.127.2554,094
25160.65.128.0/20160.65.128.1 to 160.65.143.254160.65.143.2554,094
26160.65.144.0/20160.65.144.1 to 160.65.159.254160.65.159.2554,094
27160.65.160.0/20160.65.160.1 to 160.65.175.254160.65.175.2554,094
28160.65.176.0/20160.65.176.1 to 160.65.191.254160.65.191.2554,094
29160.65.192.0/20160.65.192.1 to 160.65.207.254160.65.207.2554,094
30160.65.208.0/20160.65.208.1 to 160.65.223.254160.65.223.2554,094
31160.65.224.0/20160.65.224.1 to 160.65.239.254160.65.239.2554,094
32160.65.240.0/20160.65.240.1 to 160.65.255.254160.65.255.2554,094
33160.66.0.0/20160.66.0.1 to 160.66.15.254160.66.15.2554,094
34160.66.16.0/20160.66.16.1 to 160.66.31.254160.66.31.2554,094
35160.66.32.0/20160.66.32.1 to 160.66.47.254160.66.47.2554,094
36160.66.48.0/20160.66.48.1 to 160.66.63.254160.66.63.2554,094
37160.66.64.0/20160.66.64.1 to 160.66.79.254160.66.79.2554,094
38160.66.80.0/20160.66.80.1 to 160.66.95.254160.66.95.2554,094
39160.66.96.0/20160.66.96.1 to 160.66.111.254160.66.111.2554,094
40160.66.112.0/20160.66.112.1 to 160.66.127.254160.66.127.2554,094
41160.66.128.0/20160.66.128.1 to 160.66.143.254160.66.143.2554,094
42160.66.144.0/20160.66.144.1 to 160.66.159.254160.66.159.2554,094
43160.66.160.0/20160.66.160.1 to 160.66.175.254160.66.175.2554,094
44160.66.176.0/20160.66.176.1 to 160.66.191.254160.66.191.2554,094
45160.66.192.0/20160.66.192.1 to 160.66.207.254160.66.207.2554,094
46160.66.208.0/20160.66.208.1 to 160.66.223.254160.66.223.2554,094
47160.66.224.0/20160.66.224.1 to 160.66.239.254160.66.239.2554,094
48160.66.240.0/20160.66.240.1 to 160.66.255.254160.66.255.2554,094
49160.67.0.0/20160.67.0.1 to 160.67.15.254160.67.15.2554,094
50160.67.16.0/20160.67.16.1 to 160.67.31.254160.67.31.2554,094
51160.67.32.0/20160.67.32.1 to 160.67.47.254160.67.47.2554,094
52160.67.48.0/20160.67.48.1 to 160.67.63.254160.67.63.2554,094
53160.67.64.0/20160.67.64.1 to 160.67.79.254160.67.79.2554,094
54160.67.80.0/20160.67.80.1 to 160.67.95.254160.67.95.2554,094
55160.67.96.0/20160.67.96.1 to 160.67.111.254160.67.111.2554,094
56160.67.112.0/20160.67.112.1 to 160.67.127.254160.67.127.2554,094
57160.67.128.0/20160.67.128.1 to 160.67.143.254160.67.143.2554,094
58160.67.144.0/20160.67.144.1 to 160.67.159.254160.67.159.2554,094
59160.67.160.0/20160.67.160.1 to 160.67.175.254160.67.175.2554,094
60160.67.176.0/20160.67.176.1 to 160.67.191.254160.67.191.2554,094
61160.67.192.0/20160.67.192.1 to 160.67.207.254160.67.207.2554,094
62160.67.208.0/20160.67.208.1 to 160.67.223.254160.67.223.2554,094
63160.67.224.0/20160.67.224.1 to 160.67.239.254160.67.239.2554,094
64160.67.240.0/20160.67.240.1 to 160.67.255.254160.67.255.2554,094
65160.68.0.0/20160.68.0.1 to 160.68.15.254160.68.15.2554,094
66160.68.16.0/20160.68.16.1 to 160.68.31.254160.68.31.2554,094
67160.68.32.0/20160.68.32.1 to 160.68.47.254160.68.47.2554,094
68160.68.48.0/20160.68.48.1 to 160.68.63.254160.68.63.2554,094
69160.68.64.0/20160.68.64.1 to 160.68.79.254160.68.79.2554,094
70160.68.80.0/20160.68.80.1 to 160.68.95.254160.68.95.2554,094
71160.68.96.0/20160.68.96.1 to 160.68.111.254160.68.111.2554,094
72160.68.112.0/20160.68.112.1 to 160.68.127.254160.68.127.2554,094
73160.68.128.0/20160.68.128.1 to 160.68.143.254160.68.143.2554,094
74160.68.144.0/20160.68.144.1 to 160.68.159.254160.68.159.2554,094
75160.68.160.0/20160.68.160.1 to 160.68.175.254160.68.175.2554,094
76160.68.176.0/20160.68.176.1 to 160.68.191.254160.68.191.2554,094
77160.68.192.0/20160.68.192.1 to 160.68.207.254160.68.207.2554,094
78160.68.208.0/20160.68.208.1 to 160.68.223.254160.68.223.2554,094
79160.68.224.0/20160.68.224.1 to 160.68.239.254160.68.239.2554,094
80160.68.240.0/20160.68.240.1 to 160.68.255.254160.68.255.2554,094
81160.69.0.0/20160.69.0.1 to 160.69.15.254160.69.15.2554,094
82160.69.16.0/20160.69.16.1 to 160.69.31.254160.69.31.2554,094
83160.69.32.0/20160.69.32.1 to 160.69.47.254160.69.47.2554,094
84160.69.48.0/20160.69.48.1 to 160.69.63.254160.69.63.2554,094
85160.69.64.0/20160.69.64.1 to 160.69.79.254160.69.79.2554,094
86160.69.80.0/20160.69.80.1 to 160.69.95.254160.69.95.2554,094
87160.69.96.0/20160.69.96.1 to 160.69.111.254160.69.111.2554,094
88160.69.112.0/20160.69.112.1 to 160.69.127.254160.69.127.2554,094
89160.69.128.0/20160.69.128.1 to 160.69.143.254160.69.143.2554,094
90160.69.144.0/20160.69.144.1 to 160.69.159.254160.69.159.2554,094
91160.69.160.0/20160.69.160.1 to 160.69.175.254160.69.175.2554,094
92160.69.176.0/20160.69.176.1 to 160.69.191.254160.69.191.2554,094
93160.69.192.0/20160.69.192.1 to 160.69.207.254160.69.207.2554,094
94160.69.208.0/20160.69.208.1 to 160.69.223.254160.69.223.2554,094
95160.69.224.0/20160.69.224.1 to 160.69.239.254160.69.239.2554,094
96160.69.240.0/20160.69.240.1 to 160.69.255.254160.69.255.2554,094
97160.70.0.0/20160.70.0.1 to 160.70.15.254160.70.15.2554,094
98160.70.16.0/20160.70.16.1 to 160.70.31.254160.70.31.2554,094
99160.70.32.0/20160.70.32.1 to 160.70.47.254160.70.47.2554,094
100160.70.48.0/20160.70.48.1 to 160.70.63.254160.70.63.2554,094
101160.70.64.0/20160.70.64.1 to 160.70.79.254160.70.79.2554,094
102160.70.80.0/20160.70.80.1 to 160.70.95.254160.70.95.2554,094
103160.70.96.0/20160.70.96.1 to 160.70.111.254160.70.111.2554,094
104160.70.112.0/20160.70.112.1 to 160.70.127.254160.70.127.2554,094
105160.70.128.0/20160.70.128.1 to 160.70.143.254160.70.143.2554,094
106160.70.144.0/20160.70.144.1 to 160.70.159.254160.70.159.2554,094
107160.70.160.0/20160.70.160.1 to 160.70.175.254160.70.175.2554,094
108160.70.176.0/20160.70.176.1 to 160.70.191.254160.70.191.2554,094
109160.70.192.0/20160.70.192.1 to 160.70.207.254160.70.207.2554,094
110160.70.208.0/20160.70.208.1 to 160.70.223.254160.70.223.2554,094
111160.70.224.0/20160.70.224.1 to 160.70.239.254160.70.239.2554,094
112160.70.240.0/20160.70.240.1 to 160.70.255.254160.70.255.2554,094
113160.71.0.0/20160.71.0.1 to 160.71.15.254160.71.15.2554,094
114160.71.16.0/20160.71.16.1 to 160.71.31.254160.71.31.2554,094
115160.71.32.0/20160.71.32.1 to 160.71.47.254160.71.47.2554,094
116160.71.48.0/20160.71.48.1 to 160.71.63.254160.71.63.2554,094
117160.71.64.0/20160.71.64.1 to 160.71.79.254160.71.79.2554,094
118160.71.80.0/20160.71.80.1 to 160.71.95.254160.71.95.2554,094
119160.71.96.0/20160.71.96.1 to 160.71.111.254160.71.111.2554,094
120160.71.112.0/20160.71.112.1 to 160.71.127.254160.71.127.2554,094
121160.71.128.0/20160.71.128.1 to 160.71.143.254160.71.143.2554,094
122160.71.144.0/20160.71.144.1 to 160.71.159.254160.71.159.2554,094
123160.71.160.0/20160.71.160.1 to 160.71.175.254160.71.175.2554,094
124160.71.176.0/20160.71.176.1 to 160.71.191.254160.71.191.2554,094
125160.71.192.0/20160.71.192.1 to 160.71.207.254160.71.207.2554,094
126160.71.208.0/20160.71.208.1 to 160.71.223.254160.71.223.2554,094
127160.71.224.0/20160.71.224.1 to 160.71.239.254160.71.239.2554,094
128160.71.240.0/20160.71.240.1 to 160.71.255.254160.71.255.2554,094
129160.72.0.0/20160.72.0.1 to 160.72.15.254160.72.15.2554,094
130160.72.16.0/20160.72.16.1 to 160.72.31.254160.72.31.2554,094
131160.72.32.0/20160.72.32.1 to 160.72.47.254160.72.47.2554,094
132160.72.48.0/20160.72.48.1 to 160.72.63.254160.72.63.2554,094
133160.72.64.0/20160.72.64.1 to 160.72.79.254160.72.79.2554,094
134160.72.80.0/20160.72.80.1 to 160.72.95.254160.72.95.2554,094
135160.72.96.0/20160.72.96.1 to 160.72.111.254160.72.111.2554,094
136160.72.112.0/20160.72.112.1 to 160.72.127.254160.72.127.2554,094
137160.72.128.0/20160.72.128.1 to 160.72.143.254160.72.143.2554,094
138160.72.144.0/20160.72.144.1 to 160.72.159.254160.72.159.2554,094
139160.72.160.0/20160.72.160.1 to 160.72.175.254160.72.175.2554,094
140160.72.176.0/20160.72.176.1 to 160.72.191.254160.72.191.2554,094
141160.72.192.0/20160.72.192.1 to 160.72.207.254160.72.207.2554,094
142160.72.208.0/20160.72.208.1 to 160.72.223.254160.72.223.2554,094
143160.72.224.0/20160.72.224.1 to 160.72.239.254160.72.239.2554,094
144160.72.240.0/20160.72.240.1 to 160.72.255.254160.72.255.2554,094
145160.73.0.0/20160.73.0.1 to 160.73.15.254160.73.15.2554,094
146160.73.16.0/20160.73.16.1 to 160.73.31.254160.73.31.2554,094
147160.73.32.0/20160.73.32.1 to 160.73.47.254160.73.47.2554,094
148160.73.48.0/20160.73.48.1 to 160.73.63.254160.73.63.2554,094
149160.73.64.0/20160.73.64.1 to 160.73.79.254160.73.79.2554,094
150160.73.80.0/20160.73.80.1 to 160.73.95.254160.73.95.2554,094
151160.73.96.0/20160.73.96.1 to 160.73.111.254160.73.111.2554,094
152160.73.112.0/20160.73.112.1 to 160.73.127.254160.73.127.2554,094
153160.73.128.0/20160.73.128.1 to 160.73.143.254160.73.143.2554,094
154160.73.144.0/20160.73.144.1 to 160.73.159.254160.73.159.2554,094
155160.73.160.0/20160.73.160.1 to 160.73.175.254160.73.175.2554,094
156160.73.176.0/20160.73.176.1 to 160.73.191.254160.73.191.2554,094
157160.73.192.0/20160.73.192.1 to 160.73.207.254160.73.207.2554,094
158160.73.208.0/20160.73.208.1 to 160.73.223.254160.73.223.2554,094
159160.73.224.0/20160.73.224.1 to 160.73.239.254160.73.239.2554,094
160160.73.240.0/20160.73.240.1 to 160.73.255.254160.73.255.2554,094
161160.74.0.0/20160.74.0.1 to 160.74.15.254160.74.15.2554,094
162160.74.16.0/20160.74.16.1 to 160.74.31.254160.74.31.2554,094
163160.74.32.0/20160.74.32.1 to 160.74.47.254160.74.47.2554,094
164160.74.48.0/20160.74.48.1 to 160.74.63.254160.74.63.2554,094
165160.74.64.0/20160.74.64.1 to 160.74.79.254160.74.79.2554,094
166160.74.80.0/20160.74.80.1 to 160.74.95.254160.74.95.2554,094
167160.74.96.0/20160.74.96.1 to 160.74.111.254160.74.111.2554,094
168160.74.112.0/20160.74.112.1 to 160.74.127.254160.74.127.2554,094
169160.74.128.0/20160.74.128.1 to 160.74.143.254160.74.143.2554,094
170160.74.144.0/20160.74.144.1 to 160.74.159.254160.74.159.2554,094
171160.74.160.0/20160.74.160.1 to 160.74.175.254160.74.175.2554,094
172160.74.176.0/20160.74.176.1 to 160.74.191.254160.74.191.2554,094
173160.74.192.0/20160.74.192.1 to 160.74.207.254160.74.207.2554,094
174160.74.208.0/20160.74.208.1 to 160.74.223.254160.74.223.2554,094
175160.74.224.0/20160.74.224.1 to 160.74.239.254160.74.239.2554,094
176160.74.240.0/20160.74.240.1 to 160.74.255.254160.74.255.2554,094
177160.75.0.0/20160.75.0.1 to 160.75.15.254160.75.15.2554,094
178160.75.16.0/20160.75.16.1 to 160.75.31.254160.75.31.2554,094
179160.75.32.0/20160.75.32.1 to 160.75.47.254160.75.47.2554,094
180160.75.48.0/20160.75.48.1 to 160.75.63.254160.75.63.2554,094
181160.75.64.0/20160.75.64.1 to 160.75.79.254160.75.79.2554,094
182160.75.80.0/20160.75.80.1 to 160.75.95.254160.75.95.2554,094
183160.75.96.0/20160.75.96.1 to 160.75.111.254160.75.111.2554,094
184160.75.112.0/20160.75.112.1 to 160.75.127.254160.75.127.2554,094
185160.75.128.0/20160.75.128.1 to 160.75.143.254160.75.143.2554,094
186160.75.144.0/20160.75.144.1 to 160.75.159.254160.75.159.2554,094
187160.75.160.0/20160.75.160.1 to 160.75.175.254160.75.175.2554,094
188160.75.176.0/20160.75.176.1 to 160.75.191.254160.75.191.2554,094
189160.75.192.0/20160.75.192.1 to 160.75.207.254160.75.207.2554,094
190160.75.208.0/20160.75.208.1 to 160.75.223.254160.75.223.2554,094
191160.75.224.0/20160.75.224.1 to 160.75.239.254160.75.239.2554,094
192160.75.240.0/20160.75.240.1 to 160.75.255.254160.75.255.2554,094
193160.76.0.0/20160.76.0.1 to 160.76.15.254160.76.15.2554,094
194160.76.16.0/20160.76.16.1 to 160.76.31.254160.76.31.2554,094
195160.76.32.0/20160.76.32.1 to 160.76.47.254160.76.47.2554,094
196160.76.48.0/20160.76.48.1 to 160.76.63.254160.76.63.2554,094
197160.76.64.0/20160.76.64.1 to 160.76.79.254160.76.79.2554,094
198160.76.80.0/20160.76.80.1 to 160.76.95.254160.76.95.2554,094
199160.76.96.0/20160.76.96.1 to 160.76.111.254160.76.111.2554,094
200160.76.112.0/20160.76.112.1 to 160.76.127.254160.76.127.2554,094
201160.76.128.0/20160.76.128.1 to 160.76.143.254160.76.143.2554,094
202160.76.144.0/20160.76.144.1 to 160.76.159.254160.76.159.2554,094
203160.76.160.0/20160.76.160.1 to 160.76.175.254160.76.175.2554,094
204160.76.176.0/20160.76.176.1 to 160.76.191.254160.76.191.2554,094
205160.76.192.0/20160.76.192.1 to 160.76.207.254160.76.207.2554,094
206160.76.208.0/20160.76.208.1 to 160.76.223.254160.76.223.2554,094
207160.76.224.0/20160.76.224.1 to 160.76.239.254160.76.239.2554,094
208160.76.240.0/20160.76.240.1 to 160.76.255.254160.76.255.2554,094
209160.77.0.0/20160.77.0.1 to 160.77.15.254160.77.15.2554,094
210160.77.16.0/20160.77.16.1 to 160.77.31.254160.77.31.2554,094
211160.77.32.0/20160.77.32.1 to 160.77.47.254160.77.47.2554,094
212160.77.48.0/20160.77.48.1 to 160.77.63.254160.77.63.2554,094
213160.77.64.0/20160.77.64.1 to 160.77.79.254160.77.79.2554,094
214160.77.80.0/20160.77.80.1 to 160.77.95.254160.77.95.2554,094
215160.77.96.0/20160.77.96.1 to 160.77.111.254160.77.111.2554,094
216160.77.112.0/20160.77.112.1 to 160.77.127.254160.77.127.2554,094
217160.77.128.0/20160.77.128.1 to 160.77.143.254160.77.143.2554,094
218160.77.144.0/20160.77.144.1 to 160.77.159.254160.77.159.2554,094
219160.77.160.0/20160.77.160.1 to 160.77.175.254160.77.175.2554,094
220160.77.176.0/20160.77.176.1 to 160.77.191.254160.77.191.2554,094
221160.77.192.0/20160.77.192.1 to 160.77.207.254160.77.207.2554,094
222160.77.208.0/20160.77.208.1 to 160.77.223.254160.77.223.2554,094
223160.77.224.0/20160.77.224.1 to 160.77.239.254160.77.239.2554,094
224160.77.240.0/20160.77.240.1 to 160.77.255.254160.77.255.2554,094
225160.78.0.0/20160.78.0.1 to 160.78.15.254160.78.15.2554,094
226160.78.16.0/20160.78.16.1 to 160.78.31.254160.78.31.2554,094
227160.78.32.0/20160.78.32.1 to 160.78.47.254160.78.47.2554,094
228160.78.48.0/20160.78.48.1 to 160.78.63.254160.78.63.2554,094
229160.78.64.0/20160.78.64.1 to 160.78.79.254160.78.79.2554,094
230160.78.80.0/20160.78.80.1 to 160.78.95.254160.78.95.2554,094
231160.78.96.0/20160.78.96.1 to 160.78.111.254160.78.111.2554,094
232160.78.112.0/20160.78.112.1 to 160.78.127.254160.78.127.2554,094
233160.78.128.0/20160.78.128.1 to 160.78.143.254160.78.143.2554,094
234160.78.144.0/20160.78.144.1 to 160.78.159.254160.78.159.2554,094
235160.78.160.0/20160.78.160.1 to 160.78.175.254160.78.175.2554,094
236160.78.176.0/20160.78.176.1 to 160.78.191.254160.78.191.2554,094
237160.78.192.0/20160.78.192.1 to 160.78.207.254160.78.207.2554,094
238160.78.208.0/20160.78.208.1 to 160.78.223.254160.78.223.2554,094
239160.78.224.0/20160.78.224.1 to 160.78.239.254160.78.239.2554,094
240160.78.240.0/20160.78.240.1 to 160.78.255.254160.78.255.2554,094
241160.79.0.0/20160.79.0.1 to 160.79.15.254160.79.15.2554,094
242160.79.16.0/20160.79.16.1 to 160.79.31.254160.79.31.2554,094
243160.79.32.0/20160.79.32.1 to 160.79.47.254160.79.47.2554,094
244160.79.48.0/20160.79.48.1 to 160.79.63.254160.79.63.2554,094
245160.79.64.0/20160.79.64.1 to 160.79.79.254160.79.79.2554,094
246160.79.80.0/20160.79.80.1 to 160.79.95.254160.79.95.2554,094
247160.79.96.0/20160.79.96.1 to 160.79.111.254160.79.111.2554,094
248160.79.112.0/20160.79.112.1 to 160.79.127.254160.79.127.2554,094
249160.79.128.0/20160.79.128.1 to 160.79.143.254160.79.143.2554,094
250160.79.144.0/20160.79.144.1 to 160.79.159.254160.79.159.2554,094
251160.79.160.0/20160.79.160.1 to 160.79.175.254160.79.175.2554,094
252160.79.176.0/20160.79.176.1 to 160.79.191.254160.79.191.2554,094
253160.79.192.0/20160.79.192.1 to 160.79.207.254160.79.207.2554,094
254160.79.208.0/20160.79.208.1 to 160.79.223.254160.79.223.2554,094
255160.79.224.0/20160.79.224.1 to 160.79.239.254160.79.239.2554,094
256160.79.240.0/20160.79.240.1 to 160.79.255.254160.79.255.2554,094

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.