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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.

Network96.0.0.0/3
Usable hosts536,870,910
Subnet mask224.0.0.0
Addresses536,870,912
Network address
96.0.0.0
Broadcast address
127.255.255.255
First usable
96.0.0.1
Last usable
127.255.255.254
Usable hosts
536,870,910 (536,870,912 less the network and broadcast addresses)
Subnet mask
224.0.0.0
Wildcard mask
31.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/3
Type
Public public
Old class
A (default /8)
As numbers
Hex 60000000 · Integer 1610612736 to 2147483647
Reverse DNS zones
96.in-addr.arpa
97.in-addr.arpa
98.in-addr.arpa
99.in-addr.arpa
100.in-addr.arpa
101.in-addr.arpa
102.in-addr.arpa
103.in-addr.arpa
104.in-addr.arpa
105.in-addr.arpa
106.in-addr.arpa
107.in-addr.arpa
108.in-addr.arpa
109.in-addr.arpa
110.in-addr.arpa
111.in-addr.arpa
and 16 more
/3 is not on a 8-bit boundary, so it takes 32 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01100000.00000000.00000000.0000000096.0.0.0
Subnet mask11100000.00000000.00000000.00000000224.0.0.0
Network01100000.00000000.00000000.0000000096.0.0.0
Broadcast01111111.11111111.11111111.11111111127.255.255.255
Split into smaller subnets/12
/4 (2)/5 (4)/6 (8)/7 (16)/8 (32)/9 (64)/10 (128)/11 (256)/12 (512)/13 (1,024)/14 (2,048)/15 (4,096)

96.0.0.0/3 makes 512 subnets of /12; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
196.0.0.0/1296.0.0.1 to 96.15.255.25496.15.255.2551,048,574
296.16.0.0/1296.16.0.1 to 96.31.255.25496.31.255.2551,048,574
396.32.0.0/1296.32.0.1 to 96.47.255.25496.47.255.2551,048,574
496.48.0.0/1296.48.0.1 to 96.63.255.25496.63.255.2551,048,574
596.64.0.0/1296.64.0.1 to 96.79.255.25496.79.255.2551,048,574
696.80.0.0/1296.80.0.1 to 96.95.255.25496.95.255.2551,048,574
796.96.0.0/1296.96.0.1 to 96.111.255.25496.111.255.2551,048,574
896.112.0.0/1296.112.0.1 to 96.127.255.25496.127.255.2551,048,574
996.128.0.0/1296.128.0.1 to 96.143.255.25496.143.255.2551,048,574
1096.144.0.0/1296.144.0.1 to 96.159.255.25496.159.255.2551,048,574
1196.160.0.0/1296.160.0.1 to 96.175.255.25496.175.255.2551,048,574
1296.176.0.0/1296.176.0.1 to 96.191.255.25496.191.255.2551,048,574
1396.192.0.0/1296.192.0.1 to 96.207.255.25496.207.255.2551,048,574
1496.208.0.0/1296.208.0.1 to 96.223.255.25496.223.255.2551,048,574
1596.224.0.0/1296.224.0.1 to 96.239.255.25496.239.255.2551,048,574
1696.240.0.0/1296.240.0.1 to 96.255.255.25496.255.255.2551,048,574
1797.0.0.0/1297.0.0.1 to 97.15.255.25497.15.255.2551,048,574
1897.16.0.0/1297.16.0.1 to 97.31.255.25497.31.255.2551,048,574
1997.32.0.0/1297.32.0.1 to 97.47.255.25497.47.255.2551,048,574
2097.48.0.0/1297.48.0.1 to 97.63.255.25497.63.255.2551,048,574
2197.64.0.0/1297.64.0.1 to 97.79.255.25497.79.255.2551,048,574
2297.80.0.0/1297.80.0.1 to 97.95.255.25497.95.255.2551,048,574
2397.96.0.0/1297.96.0.1 to 97.111.255.25497.111.255.2551,048,574
2497.112.0.0/1297.112.0.1 to 97.127.255.25497.127.255.2551,048,574
2597.128.0.0/1297.128.0.1 to 97.143.255.25497.143.255.2551,048,574
2697.144.0.0/1297.144.0.1 to 97.159.255.25497.159.255.2551,048,574
2797.160.0.0/1297.160.0.1 to 97.175.255.25497.175.255.2551,048,574
2897.176.0.0/1297.176.0.1 to 97.191.255.25497.191.255.2551,048,574
2997.192.0.0/1297.192.0.1 to 97.207.255.25497.207.255.2551,048,574
3097.208.0.0/1297.208.0.1 to 97.223.255.25497.223.255.2551,048,574
3197.224.0.0/1297.224.0.1 to 97.239.255.25497.239.255.2551,048,574
3297.240.0.0/1297.240.0.1 to 97.255.255.25497.255.255.2551,048,574
3398.0.0.0/1298.0.0.1 to 98.15.255.25498.15.255.2551,048,574
3498.16.0.0/1298.16.0.1 to 98.31.255.25498.31.255.2551,048,574
3598.32.0.0/1298.32.0.1 to 98.47.255.25498.47.255.2551,048,574
3698.48.0.0/1298.48.0.1 to 98.63.255.25498.63.255.2551,048,574
3798.64.0.0/1298.64.0.1 to 98.79.255.25498.79.255.2551,048,574
3898.80.0.0/1298.80.0.1 to 98.95.255.25498.95.255.2551,048,574
3998.96.0.0/1298.96.0.1 to 98.111.255.25498.111.255.2551,048,574
4098.112.0.0/1298.112.0.1 to 98.127.255.25498.127.255.2551,048,574
4198.128.0.0/1298.128.0.1 to 98.143.255.25498.143.255.2551,048,574
4298.144.0.0/1298.144.0.1 to 98.159.255.25498.159.255.2551,048,574
4398.160.0.0/1298.160.0.1 to 98.175.255.25498.175.255.2551,048,574
4498.176.0.0/1298.176.0.1 to 98.191.255.25498.191.255.2551,048,574
4598.192.0.0/1298.192.0.1 to 98.207.255.25498.207.255.2551,048,574
4698.208.0.0/1298.208.0.1 to 98.223.255.25498.223.255.2551,048,574
4798.224.0.0/1298.224.0.1 to 98.239.255.25498.239.255.2551,048,574
4898.240.0.0/1298.240.0.1 to 98.255.255.25498.255.255.2551,048,574
4999.0.0.0/1299.0.0.1 to 99.15.255.25499.15.255.2551,048,574
5099.16.0.0/1299.16.0.1 to 99.31.255.25499.31.255.2551,048,574
5199.32.0.0/1299.32.0.1 to 99.47.255.25499.47.255.2551,048,574
5299.48.0.0/1299.48.0.1 to 99.63.255.25499.63.255.2551,048,574
5399.64.0.0/1299.64.0.1 to 99.79.255.25499.79.255.2551,048,574
5499.80.0.0/1299.80.0.1 to 99.95.255.25499.95.255.2551,048,574
5599.96.0.0/1299.96.0.1 to 99.111.255.25499.111.255.2551,048,574
5699.112.0.0/1299.112.0.1 to 99.127.255.25499.127.255.2551,048,574
5799.128.0.0/1299.128.0.1 to 99.143.255.25499.143.255.2551,048,574
5899.144.0.0/1299.144.0.1 to 99.159.255.25499.159.255.2551,048,574
5999.160.0.0/1299.160.0.1 to 99.175.255.25499.175.255.2551,048,574
6099.176.0.0/1299.176.0.1 to 99.191.255.25499.191.255.2551,048,574
6199.192.0.0/1299.192.0.1 to 99.207.255.25499.207.255.2551,048,574
6299.208.0.0/1299.208.0.1 to 99.223.255.25499.223.255.2551,048,574
6399.224.0.0/1299.224.0.1 to 99.239.255.25499.239.255.2551,048,574
6499.240.0.0/1299.240.0.1 to 99.255.255.25499.255.255.2551,048,574
65100.0.0.0/12100.0.0.1 to 100.15.255.254100.15.255.2551,048,574
66100.16.0.0/12100.16.0.1 to 100.31.255.254100.31.255.2551,048,574
67100.32.0.0/12100.32.0.1 to 100.47.255.254100.47.255.2551,048,574
68100.48.0.0/12100.48.0.1 to 100.63.255.254100.63.255.2551,048,574
69100.64.0.0/12100.64.0.1 to 100.79.255.254100.79.255.2551,048,574
70100.80.0.0/12100.80.0.1 to 100.95.255.254100.95.255.2551,048,574
71100.96.0.0/12100.96.0.1 to 100.111.255.254100.111.255.2551,048,574
72100.112.0.0/12100.112.0.1 to 100.127.255.254100.127.255.2551,048,574
73100.128.0.0/12100.128.0.1 to 100.143.255.254100.143.255.2551,048,574
74100.144.0.0/12100.144.0.1 to 100.159.255.254100.159.255.2551,048,574
75100.160.0.0/12100.160.0.1 to 100.175.255.254100.175.255.2551,048,574
76100.176.0.0/12100.176.0.1 to 100.191.255.254100.191.255.2551,048,574
77100.192.0.0/12100.192.0.1 to 100.207.255.254100.207.255.2551,048,574
78100.208.0.0/12100.208.0.1 to 100.223.255.254100.223.255.2551,048,574
79100.224.0.0/12100.224.0.1 to 100.239.255.254100.239.255.2551,048,574
80100.240.0.0/12100.240.0.1 to 100.255.255.254100.255.255.2551,048,574
81101.0.0.0/12101.0.0.1 to 101.15.255.254101.15.255.2551,048,574
82101.16.0.0/12101.16.0.1 to 101.31.255.254101.31.255.2551,048,574
83101.32.0.0/12101.32.0.1 to 101.47.255.254101.47.255.2551,048,574
84101.48.0.0/12101.48.0.1 to 101.63.255.254101.63.255.2551,048,574
85101.64.0.0/12101.64.0.1 to 101.79.255.254101.79.255.2551,048,574
86101.80.0.0/12101.80.0.1 to 101.95.255.254101.95.255.2551,048,574
87101.96.0.0/12101.96.0.1 to 101.111.255.254101.111.255.2551,048,574
88101.112.0.0/12101.112.0.1 to 101.127.255.254101.127.255.2551,048,574
89101.128.0.0/12101.128.0.1 to 101.143.255.254101.143.255.2551,048,574
90101.144.0.0/12101.144.0.1 to 101.159.255.254101.159.255.2551,048,574
91101.160.0.0/12101.160.0.1 to 101.175.255.254101.175.255.2551,048,574
92101.176.0.0/12101.176.0.1 to 101.191.255.254101.191.255.2551,048,574
93101.192.0.0/12101.192.0.1 to 101.207.255.254101.207.255.2551,048,574
94101.208.0.0/12101.208.0.1 to 101.223.255.254101.223.255.2551,048,574
95101.224.0.0/12101.224.0.1 to 101.239.255.254101.239.255.2551,048,574
96101.240.0.0/12101.240.0.1 to 101.255.255.254101.255.255.2551,048,574
97102.0.0.0/12102.0.0.1 to 102.15.255.254102.15.255.2551,048,574
98102.16.0.0/12102.16.0.1 to 102.31.255.254102.31.255.2551,048,574
99102.32.0.0/12102.32.0.1 to 102.47.255.254102.47.255.2551,048,574
100102.48.0.0/12102.48.0.1 to 102.63.255.254102.63.255.2551,048,574
101102.64.0.0/12102.64.0.1 to 102.79.255.254102.79.255.2551,048,574
102102.80.0.0/12102.80.0.1 to 102.95.255.254102.95.255.2551,048,574
103102.96.0.0/12102.96.0.1 to 102.111.255.254102.111.255.2551,048,574
104102.112.0.0/12102.112.0.1 to 102.127.255.254102.127.255.2551,048,574
105102.128.0.0/12102.128.0.1 to 102.143.255.254102.143.255.2551,048,574
106102.144.0.0/12102.144.0.1 to 102.159.255.254102.159.255.2551,048,574
107102.160.0.0/12102.160.0.1 to 102.175.255.254102.175.255.2551,048,574
108102.176.0.0/12102.176.0.1 to 102.191.255.254102.191.255.2551,048,574
109102.192.0.0/12102.192.0.1 to 102.207.255.254102.207.255.2551,048,574
110102.208.0.0/12102.208.0.1 to 102.223.255.254102.223.255.2551,048,574
111102.224.0.0/12102.224.0.1 to 102.239.255.254102.239.255.2551,048,574
112102.240.0.0/12102.240.0.1 to 102.255.255.254102.255.255.2551,048,574
113103.0.0.0/12103.0.0.1 to 103.15.255.254103.15.255.2551,048,574
114103.16.0.0/12103.16.0.1 to 103.31.255.254103.31.255.2551,048,574
115103.32.0.0/12103.32.0.1 to 103.47.255.254103.47.255.2551,048,574
116103.48.0.0/12103.48.0.1 to 103.63.255.254103.63.255.2551,048,574
117103.64.0.0/12103.64.0.1 to 103.79.255.254103.79.255.2551,048,574
118103.80.0.0/12103.80.0.1 to 103.95.255.254103.95.255.2551,048,574
119103.96.0.0/12103.96.0.1 to 103.111.255.254103.111.255.2551,048,574
120103.112.0.0/12103.112.0.1 to 103.127.255.254103.127.255.2551,048,574
121103.128.0.0/12103.128.0.1 to 103.143.255.254103.143.255.2551,048,574
122103.144.0.0/12103.144.0.1 to 103.159.255.254103.159.255.2551,048,574
123103.160.0.0/12103.160.0.1 to 103.175.255.254103.175.255.2551,048,574
124103.176.0.0/12103.176.0.1 to 103.191.255.254103.191.255.2551,048,574
125103.192.0.0/12103.192.0.1 to 103.207.255.254103.207.255.2551,048,574
126103.208.0.0/12103.208.0.1 to 103.223.255.254103.223.255.2551,048,574
127103.224.0.0/12103.224.0.1 to 103.239.255.254103.239.255.2551,048,574
128103.240.0.0/12103.240.0.1 to 103.255.255.254103.255.255.2551,048,574
129104.0.0.0/12104.0.0.1 to 104.15.255.254104.15.255.2551,048,574
130104.16.0.0/12104.16.0.1 to 104.31.255.254104.31.255.2551,048,574
131104.32.0.0/12104.32.0.1 to 104.47.255.254104.47.255.2551,048,574
132104.48.0.0/12104.48.0.1 to 104.63.255.254104.63.255.2551,048,574
133104.64.0.0/12104.64.0.1 to 104.79.255.254104.79.255.2551,048,574
134104.80.0.0/12104.80.0.1 to 104.95.255.254104.95.255.2551,048,574
135104.96.0.0/12104.96.0.1 to 104.111.255.254104.111.255.2551,048,574
136104.112.0.0/12104.112.0.1 to 104.127.255.254104.127.255.2551,048,574
137104.128.0.0/12104.128.0.1 to 104.143.255.254104.143.255.2551,048,574
138104.144.0.0/12104.144.0.1 to 104.159.255.254104.159.255.2551,048,574
139104.160.0.0/12104.160.0.1 to 104.175.255.254104.175.255.2551,048,574
140104.176.0.0/12104.176.0.1 to 104.191.255.254104.191.255.2551,048,574
141104.192.0.0/12104.192.0.1 to 104.207.255.254104.207.255.2551,048,574
142104.208.0.0/12104.208.0.1 to 104.223.255.254104.223.255.2551,048,574
143104.224.0.0/12104.224.0.1 to 104.239.255.254104.239.255.2551,048,574
144104.240.0.0/12104.240.0.1 to 104.255.255.254104.255.255.2551,048,574
145105.0.0.0/12105.0.0.1 to 105.15.255.254105.15.255.2551,048,574
146105.16.0.0/12105.16.0.1 to 105.31.255.254105.31.255.2551,048,574
147105.32.0.0/12105.32.0.1 to 105.47.255.254105.47.255.2551,048,574
148105.48.0.0/12105.48.0.1 to 105.63.255.254105.63.255.2551,048,574
149105.64.0.0/12105.64.0.1 to 105.79.255.254105.79.255.2551,048,574
150105.80.0.0/12105.80.0.1 to 105.95.255.254105.95.255.2551,048,574
151105.96.0.0/12105.96.0.1 to 105.111.255.254105.111.255.2551,048,574
152105.112.0.0/12105.112.0.1 to 105.127.255.254105.127.255.2551,048,574
153105.128.0.0/12105.128.0.1 to 105.143.255.254105.143.255.2551,048,574
154105.144.0.0/12105.144.0.1 to 105.159.255.254105.159.255.2551,048,574
155105.160.0.0/12105.160.0.1 to 105.175.255.254105.175.255.2551,048,574
156105.176.0.0/12105.176.0.1 to 105.191.255.254105.191.255.2551,048,574
157105.192.0.0/12105.192.0.1 to 105.207.255.254105.207.255.2551,048,574
158105.208.0.0/12105.208.0.1 to 105.223.255.254105.223.255.2551,048,574
159105.224.0.0/12105.224.0.1 to 105.239.255.254105.239.255.2551,048,574
160105.240.0.0/12105.240.0.1 to 105.255.255.254105.255.255.2551,048,574
161106.0.0.0/12106.0.0.1 to 106.15.255.254106.15.255.2551,048,574
162106.16.0.0/12106.16.0.1 to 106.31.255.254106.31.255.2551,048,574
163106.32.0.0/12106.32.0.1 to 106.47.255.254106.47.255.2551,048,574
164106.48.0.0/12106.48.0.1 to 106.63.255.254106.63.255.2551,048,574
165106.64.0.0/12106.64.0.1 to 106.79.255.254106.79.255.2551,048,574
166106.80.0.0/12106.80.0.1 to 106.95.255.254106.95.255.2551,048,574
167106.96.0.0/12106.96.0.1 to 106.111.255.254106.111.255.2551,048,574
168106.112.0.0/12106.112.0.1 to 106.127.255.254106.127.255.2551,048,574
169106.128.0.0/12106.128.0.1 to 106.143.255.254106.143.255.2551,048,574
170106.144.0.0/12106.144.0.1 to 106.159.255.254106.159.255.2551,048,574
171106.160.0.0/12106.160.0.1 to 106.175.255.254106.175.255.2551,048,574
172106.176.0.0/12106.176.0.1 to 106.191.255.254106.191.255.2551,048,574
173106.192.0.0/12106.192.0.1 to 106.207.255.254106.207.255.2551,048,574
174106.208.0.0/12106.208.0.1 to 106.223.255.254106.223.255.2551,048,574
175106.224.0.0/12106.224.0.1 to 106.239.255.254106.239.255.2551,048,574
176106.240.0.0/12106.240.0.1 to 106.255.255.254106.255.255.2551,048,574
177107.0.0.0/12107.0.0.1 to 107.15.255.254107.15.255.2551,048,574
178107.16.0.0/12107.16.0.1 to 107.31.255.254107.31.255.2551,048,574
179107.32.0.0/12107.32.0.1 to 107.47.255.254107.47.255.2551,048,574
180107.48.0.0/12107.48.0.1 to 107.63.255.254107.63.255.2551,048,574
181107.64.0.0/12107.64.0.1 to 107.79.255.254107.79.255.2551,048,574
182107.80.0.0/12107.80.0.1 to 107.95.255.254107.95.255.2551,048,574
183107.96.0.0/12107.96.0.1 to 107.111.255.254107.111.255.2551,048,574
184107.112.0.0/12107.112.0.1 to 107.127.255.254107.127.255.2551,048,574
185107.128.0.0/12107.128.0.1 to 107.143.255.254107.143.255.2551,048,574
186107.144.0.0/12107.144.0.1 to 107.159.255.254107.159.255.2551,048,574
187107.160.0.0/12107.160.0.1 to 107.175.255.254107.175.255.2551,048,574
188107.176.0.0/12107.176.0.1 to 107.191.255.254107.191.255.2551,048,574
189107.192.0.0/12107.192.0.1 to 107.207.255.254107.207.255.2551,048,574
190107.208.0.0/12107.208.0.1 to 107.223.255.254107.223.255.2551,048,574
191107.224.0.0/12107.224.0.1 to 107.239.255.254107.239.255.2551,048,574
192107.240.0.0/12107.240.0.1 to 107.255.255.254107.255.255.2551,048,574
193108.0.0.0/12108.0.0.1 to 108.15.255.254108.15.255.2551,048,574
194108.16.0.0/12108.16.0.1 to 108.31.255.254108.31.255.2551,048,574
195108.32.0.0/12108.32.0.1 to 108.47.255.254108.47.255.2551,048,574
196108.48.0.0/12108.48.0.1 to 108.63.255.254108.63.255.2551,048,574
197108.64.0.0/12108.64.0.1 to 108.79.255.254108.79.255.2551,048,574
198108.80.0.0/12108.80.0.1 to 108.95.255.254108.95.255.2551,048,574
199108.96.0.0/12108.96.0.1 to 108.111.255.254108.111.255.2551,048,574
200108.112.0.0/12108.112.0.1 to 108.127.255.254108.127.255.2551,048,574
201108.128.0.0/12108.128.0.1 to 108.143.255.254108.143.255.2551,048,574
202108.144.0.0/12108.144.0.1 to 108.159.255.254108.159.255.2551,048,574
203108.160.0.0/12108.160.0.1 to 108.175.255.254108.175.255.2551,048,574
204108.176.0.0/12108.176.0.1 to 108.191.255.254108.191.255.2551,048,574
205108.192.0.0/12108.192.0.1 to 108.207.255.254108.207.255.2551,048,574
206108.208.0.0/12108.208.0.1 to 108.223.255.254108.223.255.2551,048,574
207108.224.0.0/12108.224.0.1 to 108.239.255.254108.239.255.2551,048,574
208108.240.0.0/12108.240.0.1 to 108.255.255.254108.255.255.2551,048,574
209109.0.0.0/12109.0.0.1 to 109.15.255.254109.15.255.2551,048,574
210109.16.0.0/12109.16.0.1 to 109.31.255.254109.31.255.2551,048,574
211109.32.0.0/12109.32.0.1 to 109.47.255.254109.47.255.2551,048,574
212109.48.0.0/12109.48.0.1 to 109.63.255.254109.63.255.2551,048,574
213109.64.0.0/12109.64.0.1 to 109.79.255.254109.79.255.2551,048,574
214109.80.0.0/12109.80.0.1 to 109.95.255.254109.95.255.2551,048,574
215109.96.0.0/12109.96.0.1 to 109.111.255.254109.111.255.2551,048,574
216109.112.0.0/12109.112.0.1 to 109.127.255.254109.127.255.2551,048,574
217109.128.0.0/12109.128.0.1 to 109.143.255.254109.143.255.2551,048,574
218109.144.0.0/12109.144.0.1 to 109.159.255.254109.159.255.2551,048,574
219109.160.0.0/12109.160.0.1 to 109.175.255.254109.175.255.2551,048,574
220109.176.0.0/12109.176.0.1 to 109.191.255.254109.191.255.2551,048,574
221109.192.0.0/12109.192.0.1 to 109.207.255.254109.207.255.2551,048,574
222109.208.0.0/12109.208.0.1 to 109.223.255.254109.223.255.2551,048,574
223109.224.0.0/12109.224.0.1 to 109.239.255.254109.239.255.2551,048,574
224109.240.0.0/12109.240.0.1 to 109.255.255.254109.255.255.2551,048,574
225110.0.0.0/12110.0.0.1 to 110.15.255.254110.15.255.2551,048,574
226110.16.0.0/12110.16.0.1 to 110.31.255.254110.31.255.2551,048,574
227110.32.0.0/12110.32.0.1 to 110.47.255.254110.47.255.2551,048,574
228110.48.0.0/12110.48.0.1 to 110.63.255.254110.63.255.2551,048,574
229110.64.0.0/12110.64.0.1 to 110.79.255.254110.79.255.2551,048,574
230110.80.0.0/12110.80.0.1 to 110.95.255.254110.95.255.2551,048,574
231110.96.0.0/12110.96.0.1 to 110.111.255.254110.111.255.2551,048,574
232110.112.0.0/12110.112.0.1 to 110.127.255.254110.127.255.2551,048,574
233110.128.0.0/12110.128.0.1 to 110.143.255.254110.143.255.2551,048,574
234110.144.0.0/12110.144.0.1 to 110.159.255.254110.159.255.2551,048,574
235110.160.0.0/12110.160.0.1 to 110.175.255.254110.175.255.2551,048,574
236110.176.0.0/12110.176.0.1 to 110.191.255.254110.191.255.2551,048,574
237110.192.0.0/12110.192.0.1 to 110.207.255.254110.207.255.2551,048,574
238110.208.0.0/12110.208.0.1 to 110.223.255.254110.223.255.2551,048,574
239110.224.0.0/12110.224.0.1 to 110.239.255.254110.239.255.2551,048,574
240110.240.0.0/12110.240.0.1 to 110.255.255.254110.255.255.2551,048,574
241111.0.0.0/12111.0.0.1 to 111.15.255.254111.15.255.2551,048,574
242111.16.0.0/12111.16.0.1 to 111.31.255.254111.31.255.2551,048,574
243111.32.0.0/12111.32.0.1 to 111.47.255.254111.47.255.2551,048,574
244111.48.0.0/12111.48.0.1 to 111.63.255.254111.63.255.2551,048,574
245111.64.0.0/12111.64.0.1 to 111.79.255.254111.79.255.2551,048,574
246111.80.0.0/12111.80.0.1 to 111.95.255.254111.95.255.2551,048,574
247111.96.0.0/12111.96.0.1 to 111.111.255.254111.111.255.2551,048,574
248111.112.0.0/12111.112.0.1 to 111.127.255.254111.127.255.2551,048,574
249111.128.0.0/12111.128.0.1 to 111.143.255.254111.143.255.2551,048,574
250111.144.0.0/12111.144.0.1 to 111.159.255.254111.159.255.2551,048,574
251111.160.0.0/12111.160.0.1 to 111.175.255.254111.175.255.2551,048,574
252111.176.0.0/12111.176.0.1 to 111.191.255.254111.191.255.2551,048,574
253111.192.0.0/12111.192.0.1 to 111.207.255.254111.207.255.2551,048,574
254111.208.0.0/12111.208.0.1 to 111.223.255.254111.223.255.2551,048,574
255111.224.0.0/12111.224.0.1 to 111.239.255.254111.239.255.2551,048,574
256111.240.0.0/12111.240.0.1 to 111.255.255.254111.255.255.2551,048,574

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.