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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.

Network222.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
222.0.0.0
Broadcast address
223.255.255.255
First usable
222.0.0.1
Last usable
223.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
C (default /24)
As numbers
Hex DE000000 · Integer 3724541952 to 3758096383
Reverse DNS zones
222.in-addr.arpa
223.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11011110.00000000.00000000.00000000222.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network11011110.00000000.00000000.00000000222.0.0.0
Broadcast11011111.11111111.11111111.11111111223.255.255.255
Split into smaller subnets/19
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

222.0.0.0/7 makes 4,096 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1222.0.0.0/19222.0.0.1 to 222.0.31.254222.0.31.2558,190
2222.0.32.0/19222.0.32.1 to 222.0.63.254222.0.63.2558,190
3222.0.64.0/19222.0.64.1 to 222.0.95.254222.0.95.2558,190
4222.0.96.0/19222.0.96.1 to 222.0.127.254222.0.127.2558,190
5222.0.128.0/19222.0.128.1 to 222.0.159.254222.0.159.2558,190
6222.0.160.0/19222.0.160.1 to 222.0.191.254222.0.191.2558,190
7222.0.192.0/19222.0.192.1 to 222.0.223.254222.0.223.2558,190
8222.0.224.0/19222.0.224.1 to 222.0.255.254222.0.255.2558,190
9222.1.0.0/19222.1.0.1 to 222.1.31.254222.1.31.2558,190
10222.1.32.0/19222.1.32.1 to 222.1.63.254222.1.63.2558,190
11222.1.64.0/19222.1.64.1 to 222.1.95.254222.1.95.2558,190
12222.1.96.0/19222.1.96.1 to 222.1.127.254222.1.127.2558,190
13222.1.128.0/19222.1.128.1 to 222.1.159.254222.1.159.2558,190
14222.1.160.0/19222.1.160.1 to 222.1.191.254222.1.191.2558,190
15222.1.192.0/19222.1.192.1 to 222.1.223.254222.1.223.2558,190
16222.1.224.0/19222.1.224.1 to 222.1.255.254222.1.255.2558,190
17222.2.0.0/19222.2.0.1 to 222.2.31.254222.2.31.2558,190
18222.2.32.0/19222.2.32.1 to 222.2.63.254222.2.63.2558,190
19222.2.64.0/19222.2.64.1 to 222.2.95.254222.2.95.2558,190
20222.2.96.0/19222.2.96.1 to 222.2.127.254222.2.127.2558,190
21222.2.128.0/19222.2.128.1 to 222.2.159.254222.2.159.2558,190
22222.2.160.0/19222.2.160.1 to 222.2.191.254222.2.191.2558,190
23222.2.192.0/19222.2.192.1 to 222.2.223.254222.2.223.2558,190
24222.2.224.0/19222.2.224.1 to 222.2.255.254222.2.255.2558,190
25222.3.0.0/19222.3.0.1 to 222.3.31.254222.3.31.2558,190
26222.3.32.0/19222.3.32.1 to 222.3.63.254222.3.63.2558,190
27222.3.64.0/19222.3.64.1 to 222.3.95.254222.3.95.2558,190
28222.3.96.0/19222.3.96.1 to 222.3.127.254222.3.127.2558,190
29222.3.128.0/19222.3.128.1 to 222.3.159.254222.3.159.2558,190
30222.3.160.0/19222.3.160.1 to 222.3.191.254222.3.191.2558,190
31222.3.192.0/19222.3.192.1 to 222.3.223.254222.3.223.2558,190
32222.3.224.0/19222.3.224.1 to 222.3.255.254222.3.255.2558,190
33222.4.0.0/19222.4.0.1 to 222.4.31.254222.4.31.2558,190
34222.4.32.0/19222.4.32.1 to 222.4.63.254222.4.63.2558,190
35222.4.64.0/19222.4.64.1 to 222.4.95.254222.4.95.2558,190
36222.4.96.0/19222.4.96.1 to 222.4.127.254222.4.127.2558,190
37222.4.128.0/19222.4.128.1 to 222.4.159.254222.4.159.2558,190
38222.4.160.0/19222.4.160.1 to 222.4.191.254222.4.191.2558,190
39222.4.192.0/19222.4.192.1 to 222.4.223.254222.4.223.2558,190
40222.4.224.0/19222.4.224.1 to 222.4.255.254222.4.255.2558,190
41222.5.0.0/19222.5.0.1 to 222.5.31.254222.5.31.2558,190
42222.5.32.0/19222.5.32.1 to 222.5.63.254222.5.63.2558,190
43222.5.64.0/19222.5.64.1 to 222.5.95.254222.5.95.2558,190
44222.5.96.0/19222.5.96.1 to 222.5.127.254222.5.127.2558,190
45222.5.128.0/19222.5.128.1 to 222.5.159.254222.5.159.2558,190
46222.5.160.0/19222.5.160.1 to 222.5.191.254222.5.191.2558,190
47222.5.192.0/19222.5.192.1 to 222.5.223.254222.5.223.2558,190
48222.5.224.0/19222.5.224.1 to 222.5.255.254222.5.255.2558,190
49222.6.0.0/19222.6.0.1 to 222.6.31.254222.6.31.2558,190
50222.6.32.0/19222.6.32.1 to 222.6.63.254222.6.63.2558,190
51222.6.64.0/19222.6.64.1 to 222.6.95.254222.6.95.2558,190
52222.6.96.0/19222.6.96.1 to 222.6.127.254222.6.127.2558,190
53222.6.128.0/19222.6.128.1 to 222.6.159.254222.6.159.2558,190
54222.6.160.0/19222.6.160.1 to 222.6.191.254222.6.191.2558,190
55222.6.192.0/19222.6.192.1 to 222.6.223.254222.6.223.2558,190
56222.6.224.0/19222.6.224.1 to 222.6.255.254222.6.255.2558,190
57222.7.0.0/19222.7.0.1 to 222.7.31.254222.7.31.2558,190
58222.7.32.0/19222.7.32.1 to 222.7.63.254222.7.63.2558,190
59222.7.64.0/19222.7.64.1 to 222.7.95.254222.7.95.2558,190
60222.7.96.0/19222.7.96.1 to 222.7.127.254222.7.127.2558,190
61222.7.128.0/19222.7.128.1 to 222.7.159.254222.7.159.2558,190
62222.7.160.0/19222.7.160.1 to 222.7.191.254222.7.191.2558,190
63222.7.192.0/19222.7.192.1 to 222.7.223.254222.7.223.2558,190
64222.7.224.0/19222.7.224.1 to 222.7.255.254222.7.255.2558,190
65222.8.0.0/19222.8.0.1 to 222.8.31.254222.8.31.2558,190
66222.8.32.0/19222.8.32.1 to 222.8.63.254222.8.63.2558,190
67222.8.64.0/19222.8.64.1 to 222.8.95.254222.8.95.2558,190
68222.8.96.0/19222.8.96.1 to 222.8.127.254222.8.127.2558,190
69222.8.128.0/19222.8.128.1 to 222.8.159.254222.8.159.2558,190
70222.8.160.0/19222.8.160.1 to 222.8.191.254222.8.191.2558,190
71222.8.192.0/19222.8.192.1 to 222.8.223.254222.8.223.2558,190
72222.8.224.0/19222.8.224.1 to 222.8.255.254222.8.255.2558,190
73222.9.0.0/19222.9.0.1 to 222.9.31.254222.9.31.2558,190
74222.9.32.0/19222.9.32.1 to 222.9.63.254222.9.63.2558,190
75222.9.64.0/19222.9.64.1 to 222.9.95.254222.9.95.2558,190
76222.9.96.0/19222.9.96.1 to 222.9.127.254222.9.127.2558,190
77222.9.128.0/19222.9.128.1 to 222.9.159.254222.9.159.2558,190
78222.9.160.0/19222.9.160.1 to 222.9.191.254222.9.191.2558,190
79222.9.192.0/19222.9.192.1 to 222.9.223.254222.9.223.2558,190
80222.9.224.0/19222.9.224.1 to 222.9.255.254222.9.255.2558,190
81222.10.0.0/19222.10.0.1 to 222.10.31.254222.10.31.2558,190
82222.10.32.0/19222.10.32.1 to 222.10.63.254222.10.63.2558,190
83222.10.64.0/19222.10.64.1 to 222.10.95.254222.10.95.2558,190
84222.10.96.0/19222.10.96.1 to 222.10.127.254222.10.127.2558,190
85222.10.128.0/19222.10.128.1 to 222.10.159.254222.10.159.2558,190
86222.10.160.0/19222.10.160.1 to 222.10.191.254222.10.191.2558,190
87222.10.192.0/19222.10.192.1 to 222.10.223.254222.10.223.2558,190
88222.10.224.0/19222.10.224.1 to 222.10.255.254222.10.255.2558,190
89222.11.0.0/19222.11.0.1 to 222.11.31.254222.11.31.2558,190
90222.11.32.0/19222.11.32.1 to 222.11.63.254222.11.63.2558,190
91222.11.64.0/19222.11.64.1 to 222.11.95.254222.11.95.2558,190
92222.11.96.0/19222.11.96.1 to 222.11.127.254222.11.127.2558,190
93222.11.128.0/19222.11.128.1 to 222.11.159.254222.11.159.2558,190
94222.11.160.0/19222.11.160.1 to 222.11.191.254222.11.191.2558,190
95222.11.192.0/19222.11.192.1 to 222.11.223.254222.11.223.2558,190
96222.11.224.0/19222.11.224.1 to 222.11.255.254222.11.255.2558,190
97222.12.0.0/19222.12.0.1 to 222.12.31.254222.12.31.2558,190
98222.12.32.0/19222.12.32.1 to 222.12.63.254222.12.63.2558,190
99222.12.64.0/19222.12.64.1 to 222.12.95.254222.12.95.2558,190
100222.12.96.0/19222.12.96.1 to 222.12.127.254222.12.127.2558,190
101222.12.128.0/19222.12.128.1 to 222.12.159.254222.12.159.2558,190
102222.12.160.0/19222.12.160.1 to 222.12.191.254222.12.191.2558,190
103222.12.192.0/19222.12.192.1 to 222.12.223.254222.12.223.2558,190
104222.12.224.0/19222.12.224.1 to 222.12.255.254222.12.255.2558,190
105222.13.0.0/19222.13.0.1 to 222.13.31.254222.13.31.2558,190
106222.13.32.0/19222.13.32.1 to 222.13.63.254222.13.63.2558,190
107222.13.64.0/19222.13.64.1 to 222.13.95.254222.13.95.2558,190
108222.13.96.0/19222.13.96.1 to 222.13.127.254222.13.127.2558,190
109222.13.128.0/19222.13.128.1 to 222.13.159.254222.13.159.2558,190
110222.13.160.0/19222.13.160.1 to 222.13.191.254222.13.191.2558,190
111222.13.192.0/19222.13.192.1 to 222.13.223.254222.13.223.2558,190
112222.13.224.0/19222.13.224.1 to 222.13.255.254222.13.255.2558,190
113222.14.0.0/19222.14.0.1 to 222.14.31.254222.14.31.2558,190
114222.14.32.0/19222.14.32.1 to 222.14.63.254222.14.63.2558,190
115222.14.64.0/19222.14.64.1 to 222.14.95.254222.14.95.2558,190
116222.14.96.0/19222.14.96.1 to 222.14.127.254222.14.127.2558,190
117222.14.128.0/19222.14.128.1 to 222.14.159.254222.14.159.2558,190
118222.14.160.0/19222.14.160.1 to 222.14.191.254222.14.191.2558,190
119222.14.192.0/19222.14.192.1 to 222.14.223.254222.14.223.2558,190
120222.14.224.0/19222.14.224.1 to 222.14.255.254222.14.255.2558,190
121222.15.0.0/19222.15.0.1 to 222.15.31.254222.15.31.2558,190
122222.15.32.0/19222.15.32.1 to 222.15.63.254222.15.63.2558,190
123222.15.64.0/19222.15.64.1 to 222.15.95.254222.15.95.2558,190
124222.15.96.0/19222.15.96.1 to 222.15.127.254222.15.127.2558,190
125222.15.128.0/19222.15.128.1 to 222.15.159.254222.15.159.2558,190
126222.15.160.0/19222.15.160.1 to 222.15.191.254222.15.191.2558,190
127222.15.192.0/19222.15.192.1 to 222.15.223.254222.15.223.2558,190
128222.15.224.0/19222.15.224.1 to 222.15.255.254222.15.255.2558,190
129222.16.0.0/19222.16.0.1 to 222.16.31.254222.16.31.2558,190
130222.16.32.0/19222.16.32.1 to 222.16.63.254222.16.63.2558,190
131222.16.64.0/19222.16.64.1 to 222.16.95.254222.16.95.2558,190
132222.16.96.0/19222.16.96.1 to 222.16.127.254222.16.127.2558,190
133222.16.128.0/19222.16.128.1 to 222.16.159.254222.16.159.2558,190
134222.16.160.0/19222.16.160.1 to 222.16.191.254222.16.191.2558,190
135222.16.192.0/19222.16.192.1 to 222.16.223.254222.16.223.2558,190
136222.16.224.0/19222.16.224.1 to 222.16.255.254222.16.255.2558,190
137222.17.0.0/19222.17.0.1 to 222.17.31.254222.17.31.2558,190
138222.17.32.0/19222.17.32.1 to 222.17.63.254222.17.63.2558,190
139222.17.64.0/19222.17.64.1 to 222.17.95.254222.17.95.2558,190
140222.17.96.0/19222.17.96.1 to 222.17.127.254222.17.127.2558,190
141222.17.128.0/19222.17.128.1 to 222.17.159.254222.17.159.2558,190
142222.17.160.0/19222.17.160.1 to 222.17.191.254222.17.191.2558,190
143222.17.192.0/19222.17.192.1 to 222.17.223.254222.17.223.2558,190
144222.17.224.0/19222.17.224.1 to 222.17.255.254222.17.255.2558,190
145222.18.0.0/19222.18.0.1 to 222.18.31.254222.18.31.2558,190
146222.18.32.0/19222.18.32.1 to 222.18.63.254222.18.63.2558,190
147222.18.64.0/19222.18.64.1 to 222.18.95.254222.18.95.2558,190
148222.18.96.0/19222.18.96.1 to 222.18.127.254222.18.127.2558,190
149222.18.128.0/19222.18.128.1 to 222.18.159.254222.18.159.2558,190
150222.18.160.0/19222.18.160.1 to 222.18.191.254222.18.191.2558,190
151222.18.192.0/19222.18.192.1 to 222.18.223.254222.18.223.2558,190
152222.18.224.0/19222.18.224.1 to 222.18.255.254222.18.255.2558,190
153222.19.0.0/19222.19.0.1 to 222.19.31.254222.19.31.2558,190
154222.19.32.0/19222.19.32.1 to 222.19.63.254222.19.63.2558,190
155222.19.64.0/19222.19.64.1 to 222.19.95.254222.19.95.2558,190
156222.19.96.0/19222.19.96.1 to 222.19.127.254222.19.127.2558,190
157222.19.128.0/19222.19.128.1 to 222.19.159.254222.19.159.2558,190
158222.19.160.0/19222.19.160.1 to 222.19.191.254222.19.191.2558,190
159222.19.192.0/19222.19.192.1 to 222.19.223.254222.19.223.2558,190
160222.19.224.0/19222.19.224.1 to 222.19.255.254222.19.255.2558,190
161222.20.0.0/19222.20.0.1 to 222.20.31.254222.20.31.2558,190
162222.20.32.0/19222.20.32.1 to 222.20.63.254222.20.63.2558,190
163222.20.64.0/19222.20.64.1 to 222.20.95.254222.20.95.2558,190
164222.20.96.0/19222.20.96.1 to 222.20.127.254222.20.127.2558,190
165222.20.128.0/19222.20.128.1 to 222.20.159.254222.20.159.2558,190
166222.20.160.0/19222.20.160.1 to 222.20.191.254222.20.191.2558,190
167222.20.192.0/19222.20.192.1 to 222.20.223.254222.20.223.2558,190
168222.20.224.0/19222.20.224.1 to 222.20.255.254222.20.255.2558,190
169222.21.0.0/19222.21.0.1 to 222.21.31.254222.21.31.2558,190
170222.21.32.0/19222.21.32.1 to 222.21.63.254222.21.63.2558,190
171222.21.64.0/19222.21.64.1 to 222.21.95.254222.21.95.2558,190
172222.21.96.0/19222.21.96.1 to 222.21.127.254222.21.127.2558,190
173222.21.128.0/19222.21.128.1 to 222.21.159.254222.21.159.2558,190
174222.21.160.0/19222.21.160.1 to 222.21.191.254222.21.191.2558,190
175222.21.192.0/19222.21.192.1 to 222.21.223.254222.21.223.2558,190
176222.21.224.0/19222.21.224.1 to 222.21.255.254222.21.255.2558,190
177222.22.0.0/19222.22.0.1 to 222.22.31.254222.22.31.2558,190
178222.22.32.0/19222.22.32.1 to 222.22.63.254222.22.63.2558,190
179222.22.64.0/19222.22.64.1 to 222.22.95.254222.22.95.2558,190
180222.22.96.0/19222.22.96.1 to 222.22.127.254222.22.127.2558,190
181222.22.128.0/19222.22.128.1 to 222.22.159.254222.22.159.2558,190
182222.22.160.0/19222.22.160.1 to 222.22.191.254222.22.191.2558,190
183222.22.192.0/19222.22.192.1 to 222.22.223.254222.22.223.2558,190
184222.22.224.0/19222.22.224.1 to 222.22.255.254222.22.255.2558,190
185222.23.0.0/19222.23.0.1 to 222.23.31.254222.23.31.2558,190
186222.23.32.0/19222.23.32.1 to 222.23.63.254222.23.63.2558,190
187222.23.64.0/19222.23.64.1 to 222.23.95.254222.23.95.2558,190
188222.23.96.0/19222.23.96.1 to 222.23.127.254222.23.127.2558,190
189222.23.128.0/19222.23.128.1 to 222.23.159.254222.23.159.2558,190
190222.23.160.0/19222.23.160.1 to 222.23.191.254222.23.191.2558,190
191222.23.192.0/19222.23.192.1 to 222.23.223.254222.23.223.2558,190
192222.23.224.0/19222.23.224.1 to 222.23.255.254222.23.255.2558,190
193222.24.0.0/19222.24.0.1 to 222.24.31.254222.24.31.2558,190
194222.24.32.0/19222.24.32.1 to 222.24.63.254222.24.63.2558,190
195222.24.64.0/19222.24.64.1 to 222.24.95.254222.24.95.2558,190
196222.24.96.0/19222.24.96.1 to 222.24.127.254222.24.127.2558,190
197222.24.128.0/19222.24.128.1 to 222.24.159.254222.24.159.2558,190
198222.24.160.0/19222.24.160.1 to 222.24.191.254222.24.191.2558,190
199222.24.192.0/19222.24.192.1 to 222.24.223.254222.24.223.2558,190
200222.24.224.0/19222.24.224.1 to 222.24.255.254222.24.255.2558,190
201222.25.0.0/19222.25.0.1 to 222.25.31.254222.25.31.2558,190
202222.25.32.0/19222.25.32.1 to 222.25.63.254222.25.63.2558,190
203222.25.64.0/19222.25.64.1 to 222.25.95.254222.25.95.2558,190
204222.25.96.0/19222.25.96.1 to 222.25.127.254222.25.127.2558,190
205222.25.128.0/19222.25.128.1 to 222.25.159.254222.25.159.2558,190
206222.25.160.0/19222.25.160.1 to 222.25.191.254222.25.191.2558,190
207222.25.192.0/19222.25.192.1 to 222.25.223.254222.25.223.2558,190
208222.25.224.0/19222.25.224.1 to 222.25.255.254222.25.255.2558,190
209222.26.0.0/19222.26.0.1 to 222.26.31.254222.26.31.2558,190
210222.26.32.0/19222.26.32.1 to 222.26.63.254222.26.63.2558,190
211222.26.64.0/19222.26.64.1 to 222.26.95.254222.26.95.2558,190
212222.26.96.0/19222.26.96.1 to 222.26.127.254222.26.127.2558,190
213222.26.128.0/19222.26.128.1 to 222.26.159.254222.26.159.2558,190
214222.26.160.0/19222.26.160.1 to 222.26.191.254222.26.191.2558,190
215222.26.192.0/19222.26.192.1 to 222.26.223.254222.26.223.2558,190
216222.26.224.0/19222.26.224.1 to 222.26.255.254222.26.255.2558,190
217222.27.0.0/19222.27.0.1 to 222.27.31.254222.27.31.2558,190
218222.27.32.0/19222.27.32.1 to 222.27.63.254222.27.63.2558,190
219222.27.64.0/19222.27.64.1 to 222.27.95.254222.27.95.2558,190
220222.27.96.0/19222.27.96.1 to 222.27.127.254222.27.127.2558,190
221222.27.128.0/19222.27.128.1 to 222.27.159.254222.27.159.2558,190
222222.27.160.0/19222.27.160.1 to 222.27.191.254222.27.191.2558,190
223222.27.192.0/19222.27.192.1 to 222.27.223.254222.27.223.2558,190
224222.27.224.0/19222.27.224.1 to 222.27.255.254222.27.255.2558,190
225222.28.0.0/19222.28.0.1 to 222.28.31.254222.28.31.2558,190
226222.28.32.0/19222.28.32.1 to 222.28.63.254222.28.63.2558,190
227222.28.64.0/19222.28.64.1 to 222.28.95.254222.28.95.2558,190
228222.28.96.0/19222.28.96.1 to 222.28.127.254222.28.127.2558,190
229222.28.128.0/19222.28.128.1 to 222.28.159.254222.28.159.2558,190
230222.28.160.0/19222.28.160.1 to 222.28.191.254222.28.191.2558,190
231222.28.192.0/19222.28.192.1 to 222.28.223.254222.28.223.2558,190
232222.28.224.0/19222.28.224.1 to 222.28.255.254222.28.255.2558,190
233222.29.0.0/19222.29.0.1 to 222.29.31.254222.29.31.2558,190
234222.29.32.0/19222.29.32.1 to 222.29.63.254222.29.63.2558,190
235222.29.64.0/19222.29.64.1 to 222.29.95.254222.29.95.2558,190
236222.29.96.0/19222.29.96.1 to 222.29.127.254222.29.127.2558,190
237222.29.128.0/19222.29.128.1 to 222.29.159.254222.29.159.2558,190
238222.29.160.0/19222.29.160.1 to 222.29.191.254222.29.191.2558,190
239222.29.192.0/19222.29.192.1 to 222.29.223.254222.29.223.2558,190
240222.29.224.0/19222.29.224.1 to 222.29.255.254222.29.255.2558,190
241222.30.0.0/19222.30.0.1 to 222.30.31.254222.30.31.2558,190
242222.30.32.0/19222.30.32.1 to 222.30.63.254222.30.63.2558,190
243222.30.64.0/19222.30.64.1 to 222.30.95.254222.30.95.2558,190
244222.30.96.0/19222.30.96.1 to 222.30.127.254222.30.127.2558,190
245222.30.128.0/19222.30.128.1 to 222.30.159.254222.30.159.2558,190
246222.30.160.0/19222.30.160.1 to 222.30.191.254222.30.191.2558,190
247222.30.192.0/19222.30.192.1 to 222.30.223.254222.30.223.2558,190
248222.30.224.0/19222.30.224.1 to 222.30.255.254222.30.255.2558,190
249222.31.0.0/19222.31.0.1 to 222.31.31.254222.31.31.2558,190
250222.31.32.0/19222.31.32.1 to 222.31.63.254222.31.63.2558,190
251222.31.64.0/19222.31.64.1 to 222.31.95.254222.31.95.2558,190
252222.31.96.0/19222.31.96.1 to 222.31.127.254222.31.127.2558,190
253222.31.128.0/19222.31.128.1 to 222.31.159.254222.31.159.2558,190
254222.31.160.0/19222.31.160.1 to 222.31.191.254222.31.191.2558,190
255222.31.192.0/19222.31.192.1 to 222.31.223.254222.31.223.2558,190
256222.31.224.0/19222.31.224.1 to 222.31.255.254222.31.255.2558,190

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.