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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.

Network200.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
200.0.0.0
Broadcast address
201.255.255.255
First usable
200.0.0.1
Last usable
201.255.255.254
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 C8000000 · Integer 3355443200 to 3388997631
Reverse DNS zones
200.in-addr.arpa
201.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
Address11001000.00000000.00000000.00000000200.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network11001000.00000000.00000000.00000000200.0.0.0
Broadcast11001001.11111111.11111111.11111111201.255.255.255
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)

200.0.0.0/7 makes 4,096 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1200.0.0.0/19200.0.0.1 to 200.0.31.254200.0.31.2558,190
2200.0.32.0/19200.0.32.1 to 200.0.63.254200.0.63.2558,190
3200.0.64.0/19200.0.64.1 to 200.0.95.254200.0.95.2558,190
4200.0.96.0/19200.0.96.1 to 200.0.127.254200.0.127.2558,190
5200.0.128.0/19200.0.128.1 to 200.0.159.254200.0.159.2558,190
6200.0.160.0/19200.0.160.1 to 200.0.191.254200.0.191.2558,190
7200.0.192.0/19200.0.192.1 to 200.0.223.254200.0.223.2558,190
8200.0.224.0/19200.0.224.1 to 200.0.255.254200.0.255.2558,190
9200.1.0.0/19200.1.0.1 to 200.1.31.254200.1.31.2558,190
10200.1.32.0/19200.1.32.1 to 200.1.63.254200.1.63.2558,190
11200.1.64.0/19200.1.64.1 to 200.1.95.254200.1.95.2558,190
12200.1.96.0/19200.1.96.1 to 200.1.127.254200.1.127.2558,190
13200.1.128.0/19200.1.128.1 to 200.1.159.254200.1.159.2558,190
14200.1.160.0/19200.1.160.1 to 200.1.191.254200.1.191.2558,190
15200.1.192.0/19200.1.192.1 to 200.1.223.254200.1.223.2558,190
16200.1.224.0/19200.1.224.1 to 200.1.255.254200.1.255.2558,190
17200.2.0.0/19200.2.0.1 to 200.2.31.254200.2.31.2558,190
18200.2.32.0/19200.2.32.1 to 200.2.63.254200.2.63.2558,190
19200.2.64.0/19200.2.64.1 to 200.2.95.254200.2.95.2558,190
20200.2.96.0/19200.2.96.1 to 200.2.127.254200.2.127.2558,190
21200.2.128.0/19200.2.128.1 to 200.2.159.254200.2.159.2558,190
22200.2.160.0/19200.2.160.1 to 200.2.191.254200.2.191.2558,190
23200.2.192.0/19200.2.192.1 to 200.2.223.254200.2.223.2558,190
24200.2.224.0/19200.2.224.1 to 200.2.255.254200.2.255.2558,190
25200.3.0.0/19200.3.0.1 to 200.3.31.254200.3.31.2558,190
26200.3.32.0/19200.3.32.1 to 200.3.63.254200.3.63.2558,190
27200.3.64.0/19200.3.64.1 to 200.3.95.254200.3.95.2558,190
28200.3.96.0/19200.3.96.1 to 200.3.127.254200.3.127.2558,190
29200.3.128.0/19200.3.128.1 to 200.3.159.254200.3.159.2558,190
30200.3.160.0/19200.3.160.1 to 200.3.191.254200.3.191.2558,190
31200.3.192.0/19200.3.192.1 to 200.3.223.254200.3.223.2558,190
32200.3.224.0/19200.3.224.1 to 200.3.255.254200.3.255.2558,190
33200.4.0.0/19200.4.0.1 to 200.4.31.254200.4.31.2558,190
34200.4.32.0/19200.4.32.1 to 200.4.63.254200.4.63.2558,190
35200.4.64.0/19200.4.64.1 to 200.4.95.254200.4.95.2558,190
36200.4.96.0/19200.4.96.1 to 200.4.127.254200.4.127.2558,190
37200.4.128.0/19200.4.128.1 to 200.4.159.254200.4.159.2558,190
38200.4.160.0/19200.4.160.1 to 200.4.191.254200.4.191.2558,190
39200.4.192.0/19200.4.192.1 to 200.4.223.254200.4.223.2558,190
40200.4.224.0/19200.4.224.1 to 200.4.255.254200.4.255.2558,190
41200.5.0.0/19200.5.0.1 to 200.5.31.254200.5.31.2558,190
42200.5.32.0/19200.5.32.1 to 200.5.63.254200.5.63.2558,190
43200.5.64.0/19200.5.64.1 to 200.5.95.254200.5.95.2558,190
44200.5.96.0/19200.5.96.1 to 200.5.127.254200.5.127.2558,190
45200.5.128.0/19200.5.128.1 to 200.5.159.254200.5.159.2558,190
46200.5.160.0/19200.5.160.1 to 200.5.191.254200.5.191.2558,190
47200.5.192.0/19200.5.192.1 to 200.5.223.254200.5.223.2558,190
48200.5.224.0/19200.5.224.1 to 200.5.255.254200.5.255.2558,190
49200.6.0.0/19200.6.0.1 to 200.6.31.254200.6.31.2558,190
50200.6.32.0/19200.6.32.1 to 200.6.63.254200.6.63.2558,190
51200.6.64.0/19200.6.64.1 to 200.6.95.254200.6.95.2558,190
52200.6.96.0/19200.6.96.1 to 200.6.127.254200.6.127.2558,190
53200.6.128.0/19200.6.128.1 to 200.6.159.254200.6.159.2558,190
54200.6.160.0/19200.6.160.1 to 200.6.191.254200.6.191.2558,190
55200.6.192.0/19200.6.192.1 to 200.6.223.254200.6.223.2558,190
56200.6.224.0/19200.6.224.1 to 200.6.255.254200.6.255.2558,190
57200.7.0.0/19200.7.0.1 to 200.7.31.254200.7.31.2558,190
58200.7.32.0/19200.7.32.1 to 200.7.63.254200.7.63.2558,190
59200.7.64.0/19200.7.64.1 to 200.7.95.254200.7.95.2558,190
60200.7.96.0/19200.7.96.1 to 200.7.127.254200.7.127.2558,190
61200.7.128.0/19200.7.128.1 to 200.7.159.254200.7.159.2558,190
62200.7.160.0/19200.7.160.1 to 200.7.191.254200.7.191.2558,190
63200.7.192.0/19200.7.192.1 to 200.7.223.254200.7.223.2558,190
64200.7.224.0/19200.7.224.1 to 200.7.255.254200.7.255.2558,190
65200.8.0.0/19200.8.0.1 to 200.8.31.254200.8.31.2558,190
66200.8.32.0/19200.8.32.1 to 200.8.63.254200.8.63.2558,190
67200.8.64.0/19200.8.64.1 to 200.8.95.254200.8.95.2558,190
68200.8.96.0/19200.8.96.1 to 200.8.127.254200.8.127.2558,190
69200.8.128.0/19200.8.128.1 to 200.8.159.254200.8.159.2558,190
70200.8.160.0/19200.8.160.1 to 200.8.191.254200.8.191.2558,190
71200.8.192.0/19200.8.192.1 to 200.8.223.254200.8.223.2558,190
72200.8.224.0/19200.8.224.1 to 200.8.255.254200.8.255.2558,190
73200.9.0.0/19200.9.0.1 to 200.9.31.254200.9.31.2558,190
74200.9.32.0/19200.9.32.1 to 200.9.63.254200.9.63.2558,190
75200.9.64.0/19200.9.64.1 to 200.9.95.254200.9.95.2558,190
76200.9.96.0/19200.9.96.1 to 200.9.127.254200.9.127.2558,190
77200.9.128.0/19200.9.128.1 to 200.9.159.254200.9.159.2558,190
78200.9.160.0/19200.9.160.1 to 200.9.191.254200.9.191.2558,190
79200.9.192.0/19200.9.192.1 to 200.9.223.254200.9.223.2558,190
80200.9.224.0/19200.9.224.1 to 200.9.255.254200.9.255.2558,190
81200.10.0.0/19200.10.0.1 to 200.10.31.254200.10.31.2558,190
82200.10.32.0/19200.10.32.1 to 200.10.63.254200.10.63.2558,190
83200.10.64.0/19200.10.64.1 to 200.10.95.254200.10.95.2558,190
84200.10.96.0/19200.10.96.1 to 200.10.127.254200.10.127.2558,190
85200.10.128.0/19200.10.128.1 to 200.10.159.254200.10.159.2558,190
86200.10.160.0/19200.10.160.1 to 200.10.191.254200.10.191.2558,190
87200.10.192.0/19200.10.192.1 to 200.10.223.254200.10.223.2558,190
88200.10.224.0/19200.10.224.1 to 200.10.255.254200.10.255.2558,190
89200.11.0.0/19200.11.0.1 to 200.11.31.254200.11.31.2558,190
90200.11.32.0/19200.11.32.1 to 200.11.63.254200.11.63.2558,190
91200.11.64.0/19200.11.64.1 to 200.11.95.254200.11.95.2558,190
92200.11.96.0/19200.11.96.1 to 200.11.127.254200.11.127.2558,190
93200.11.128.0/19200.11.128.1 to 200.11.159.254200.11.159.2558,190
94200.11.160.0/19200.11.160.1 to 200.11.191.254200.11.191.2558,190
95200.11.192.0/19200.11.192.1 to 200.11.223.254200.11.223.2558,190
96200.11.224.0/19200.11.224.1 to 200.11.255.254200.11.255.2558,190
97200.12.0.0/19200.12.0.1 to 200.12.31.254200.12.31.2558,190
98200.12.32.0/19200.12.32.1 to 200.12.63.254200.12.63.2558,190
99200.12.64.0/19200.12.64.1 to 200.12.95.254200.12.95.2558,190
100200.12.96.0/19200.12.96.1 to 200.12.127.254200.12.127.2558,190
101200.12.128.0/19200.12.128.1 to 200.12.159.254200.12.159.2558,190
102200.12.160.0/19200.12.160.1 to 200.12.191.254200.12.191.2558,190
103200.12.192.0/19200.12.192.1 to 200.12.223.254200.12.223.2558,190
104200.12.224.0/19200.12.224.1 to 200.12.255.254200.12.255.2558,190
105200.13.0.0/19200.13.0.1 to 200.13.31.254200.13.31.2558,190
106200.13.32.0/19200.13.32.1 to 200.13.63.254200.13.63.2558,190
107200.13.64.0/19200.13.64.1 to 200.13.95.254200.13.95.2558,190
108200.13.96.0/19200.13.96.1 to 200.13.127.254200.13.127.2558,190
109200.13.128.0/19200.13.128.1 to 200.13.159.254200.13.159.2558,190
110200.13.160.0/19200.13.160.1 to 200.13.191.254200.13.191.2558,190
111200.13.192.0/19200.13.192.1 to 200.13.223.254200.13.223.2558,190
112200.13.224.0/19200.13.224.1 to 200.13.255.254200.13.255.2558,190
113200.14.0.0/19200.14.0.1 to 200.14.31.254200.14.31.2558,190
114200.14.32.0/19200.14.32.1 to 200.14.63.254200.14.63.2558,190
115200.14.64.0/19200.14.64.1 to 200.14.95.254200.14.95.2558,190
116200.14.96.0/19200.14.96.1 to 200.14.127.254200.14.127.2558,190
117200.14.128.0/19200.14.128.1 to 200.14.159.254200.14.159.2558,190
118200.14.160.0/19200.14.160.1 to 200.14.191.254200.14.191.2558,190
119200.14.192.0/19200.14.192.1 to 200.14.223.254200.14.223.2558,190
120200.14.224.0/19200.14.224.1 to 200.14.255.254200.14.255.2558,190
121200.15.0.0/19200.15.0.1 to 200.15.31.254200.15.31.2558,190
122200.15.32.0/19200.15.32.1 to 200.15.63.254200.15.63.2558,190
123200.15.64.0/19200.15.64.1 to 200.15.95.254200.15.95.2558,190
124200.15.96.0/19200.15.96.1 to 200.15.127.254200.15.127.2558,190
125200.15.128.0/19200.15.128.1 to 200.15.159.254200.15.159.2558,190
126200.15.160.0/19200.15.160.1 to 200.15.191.254200.15.191.2558,190
127200.15.192.0/19200.15.192.1 to 200.15.223.254200.15.223.2558,190
128200.15.224.0/19200.15.224.1 to 200.15.255.254200.15.255.2558,190
129200.16.0.0/19200.16.0.1 to 200.16.31.254200.16.31.2558,190
130200.16.32.0/19200.16.32.1 to 200.16.63.254200.16.63.2558,190
131200.16.64.0/19200.16.64.1 to 200.16.95.254200.16.95.2558,190
132200.16.96.0/19200.16.96.1 to 200.16.127.254200.16.127.2558,190
133200.16.128.0/19200.16.128.1 to 200.16.159.254200.16.159.2558,190
134200.16.160.0/19200.16.160.1 to 200.16.191.254200.16.191.2558,190
135200.16.192.0/19200.16.192.1 to 200.16.223.254200.16.223.2558,190
136200.16.224.0/19200.16.224.1 to 200.16.255.254200.16.255.2558,190
137200.17.0.0/19200.17.0.1 to 200.17.31.254200.17.31.2558,190
138200.17.32.0/19200.17.32.1 to 200.17.63.254200.17.63.2558,190
139200.17.64.0/19200.17.64.1 to 200.17.95.254200.17.95.2558,190
140200.17.96.0/19200.17.96.1 to 200.17.127.254200.17.127.2558,190
141200.17.128.0/19200.17.128.1 to 200.17.159.254200.17.159.2558,190
142200.17.160.0/19200.17.160.1 to 200.17.191.254200.17.191.2558,190
143200.17.192.0/19200.17.192.1 to 200.17.223.254200.17.223.2558,190
144200.17.224.0/19200.17.224.1 to 200.17.255.254200.17.255.2558,190
145200.18.0.0/19200.18.0.1 to 200.18.31.254200.18.31.2558,190
146200.18.32.0/19200.18.32.1 to 200.18.63.254200.18.63.2558,190
147200.18.64.0/19200.18.64.1 to 200.18.95.254200.18.95.2558,190
148200.18.96.0/19200.18.96.1 to 200.18.127.254200.18.127.2558,190
149200.18.128.0/19200.18.128.1 to 200.18.159.254200.18.159.2558,190
150200.18.160.0/19200.18.160.1 to 200.18.191.254200.18.191.2558,190
151200.18.192.0/19200.18.192.1 to 200.18.223.254200.18.223.2558,190
152200.18.224.0/19200.18.224.1 to 200.18.255.254200.18.255.2558,190
153200.19.0.0/19200.19.0.1 to 200.19.31.254200.19.31.2558,190
154200.19.32.0/19200.19.32.1 to 200.19.63.254200.19.63.2558,190
155200.19.64.0/19200.19.64.1 to 200.19.95.254200.19.95.2558,190
156200.19.96.0/19200.19.96.1 to 200.19.127.254200.19.127.2558,190
157200.19.128.0/19200.19.128.1 to 200.19.159.254200.19.159.2558,190
158200.19.160.0/19200.19.160.1 to 200.19.191.254200.19.191.2558,190
159200.19.192.0/19200.19.192.1 to 200.19.223.254200.19.223.2558,190
160200.19.224.0/19200.19.224.1 to 200.19.255.254200.19.255.2558,190
161200.20.0.0/19200.20.0.1 to 200.20.31.254200.20.31.2558,190
162200.20.32.0/19200.20.32.1 to 200.20.63.254200.20.63.2558,190
163200.20.64.0/19200.20.64.1 to 200.20.95.254200.20.95.2558,190
164200.20.96.0/19200.20.96.1 to 200.20.127.254200.20.127.2558,190
165200.20.128.0/19200.20.128.1 to 200.20.159.254200.20.159.2558,190
166200.20.160.0/19200.20.160.1 to 200.20.191.254200.20.191.2558,190
167200.20.192.0/19200.20.192.1 to 200.20.223.254200.20.223.2558,190
168200.20.224.0/19200.20.224.1 to 200.20.255.254200.20.255.2558,190
169200.21.0.0/19200.21.0.1 to 200.21.31.254200.21.31.2558,190
170200.21.32.0/19200.21.32.1 to 200.21.63.254200.21.63.2558,190
171200.21.64.0/19200.21.64.1 to 200.21.95.254200.21.95.2558,190
172200.21.96.0/19200.21.96.1 to 200.21.127.254200.21.127.2558,190
173200.21.128.0/19200.21.128.1 to 200.21.159.254200.21.159.2558,190
174200.21.160.0/19200.21.160.1 to 200.21.191.254200.21.191.2558,190
175200.21.192.0/19200.21.192.1 to 200.21.223.254200.21.223.2558,190
176200.21.224.0/19200.21.224.1 to 200.21.255.254200.21.255.2558,190
177200.22.0.0/19200.22.0.1 to 200.22.31.254200.22.31.2558,190
178200.22.32.0/19200.22.32.1 to 200.22.63.254200.22.63.2558,190
179200.22.64.0/19200.22.64.1 to 200.22.95.254200.22.95.2558,190
180200.22.96.0/19200.22.96.1 to 200.22.127.254200.22.127.2558,190
181200.22.128.0/19200.22.128.1 to 200.22.159.254200.22.159.2558,190
182200.22.160.0/19200.22.160.1 to 200.22.191.254200.22.191.2558,190
183200.22.192.0/19200.22.192.1 to 200.22.223.254200.22.223.2558,190
184200.22.224.0/19200.22.224.1 to 200.22.255.254200.22.255.2558,190
185200.23.0.0/19200.23.0.1 to 200.23.31.254200.23.31.2558,190
186200.23.32.0/19200.23.32.1 to 200.23.63.254200.23.63.2558,190
187200.23.64.0/19200.23.64.1 to 200.23.95.254200.23.95.2558,190
188200.23.96.0/19200.23.96.1 to 200.23.127.254200.23.127.2558,190
189200.23.128.0/19200.23.128.1 to 200.23.159.254200.23.159.2558,190
190200.23.160.0/19200.23.160.1 to 200.23.191.254200.23.191.2558,190
191200.23.192.0/19200.23.192.1 to 200.23.223.254200.23.223.2558,190
192200.23.224.0/19200.23.224.1 to 200.23.255.254200.23.255.2558,190
193200.24.0.0/19200.24.0.1 to 200.24.31.254200.24.31.2558,190
194200.24.32.0/19200.24.32.1 to 200.24.63.254200.24.63.2558,190
195200.24.64.0/19200.24.64.1 to 200.24.95.254200.24.95.2558,190
196200.24.96.0/19200.24.96.1 to 200.24.127.254200.24.127.2558,190
197200.24.128.0/19200.24.128.1 to 200.24.159.254200.24.159.2558,190
198200.24.160.0/19200.24.160.1 to 200.24.191.254200.24.191.2558,190
199200.24.192.0/19200.24.192.1 to 200.24.223.254200.24.223.2558,190
200200.24.224.0/19200.24.224.1 to 200.24.255.254200.24.255.2558,190
201200.25.0.0/19200.25.0.1 to 200.25.31.254200.25.31.2558,190
202200.25.32.0/19200.25.32.1 to 200.25.63.254200.25.63.2558,190
203200.25.64.0/19200.25.64.1 to 200.25.95.254200.25.95.2558,190
204200.25.96.0/19200.25.96.1 to 200.25.127.254200.25.127.2558,190
205200.25.128.0/19200.25.128.1 to 200.25.159.254200.25.159.2558,190
206200.25.160.0/19200.25.160.1 to 200.25.191.254200.25.191.2558,190
207200.25.192.0/19200.25.192.1 to 200.25.223.254200.25.223.2558,190
208200.25.224.0/19200.25.224.1 to 200.25.255.254200.25.255.2558,190
209200.26.0.0/19200.26.0.1 to 200.26.31.254200.26.31.2558,190
210200.26.32.0/19200.26.32.1 to 200.26.63.254200.26.63.2558,190
211200.26.64.0/19200.26.64.1 to 200.26.95.254200.26.95.2558,190
212200.26.96.0/19200.26.96.1 to 200.26.127.254200.26.127.2558,190
213200.26.128.0/19200.26.128.1 to 200.26.159.254200.26.159.2558,190
214200.26.160.0/19200.26.160.1 to 200.26.191.254200.26.191.2558,190
215200.26.192.0/19200.26.192.1 to 200.26.223.254200.26.223.2558,190
216200.26.224.0/19200.26.224.1 to 200.26.255.254200.26.255.2558,190
217200.27.0.0/19200.27.0.1 to 200.27.31.254200.27.31.2558,190
218200.27.32.0/19200.27.32.1 to 200.27.63.254200.27.63.2558,190
219200.27.64.0/19200.27.64.1 to 200.27.95.254200.27.95.2558,190
220200.27.96.0/19200.27.96.1 to 200.27.127.254200.27.127.2558,190
221200.27.128.0/19200.27.128.1 to 200.27.159.254200.27.159.2558,190
222200.27.160.0/19200.27.160.1 to 200.27.191.254200.27.191.2558,190
223200.27.192.0/19200.27.192.1 to 200.27.223.254200.27.223.2558,190
224200.27.224.0/19200.27.224.1 to 200.27.255.254200.27.255.2558,190
225200.28.0.0/19200.28.0.1 to 200.28.31.254200.28.31.2558,190
226200.28.32.0/19200.28.32.1 to 200.28.63.254200.28.63.2558,190
227200.28.64.0/19200.28.64.1 to 200.28.95.254200.28.95.2558,190
228200.28.96.0/19200.28.96.1 to 200.28.127.254200.28.127.2558,190
229200.28.128.0/19200.28.128.1 to 200.28.159.254200.28.159.2558,190
230200.28.160.0/19200.28.160.1 to 200.28.191.254200.28.191.2558,190
231200.28.192.0/19200.28.192.1 to 200.28.223.254200.28.223.2558,190
232200.28.224.0/19200.28.224.1 to 200.28.255.254200.28.255.2558,190
233200.29.0.0/19200.29.0.1 to 200.29.31.254200.29.31.2558,190
234200.29.32.0/19200.29.32.1 to 200.29.63.254200.29.63.2558,190
235200.29.64.0/19200.29.64.1 to 200.29.95.254200.29.95.2558,190
236200.29.96.0/19200.29.96.1 to 200.29.127.254200.29.127.2558,190
237200.29.128.0/19200.29.128.1 to 200.29.159.254200.29.159.2558,190
238200.29.160.0/19200.29.160.1 to 200.29.191.254200.29.191.2558,190
239200.29.192.0/19200.29.192.1 to 200.29.223.254200.29.223.2558,190
240200.29.224.0/19200.29.224.1 to 200.29.255.254200.29.255.2558,190
241200.30.0.0/19200.30.0.1 to 200.30.31.254200.30.31.2558,190
242200.30.32.0/19200.30.32.1 to 200.30.63.254200.30.63.2558,190
243200.30.64.0/19200.30.64.1 to 200.30.95.254200.30.95.2558,190
244200.30.96.0/19200.30.96.1 to 200.30.127.254200.30.127.2558,190
245200.30.128.0/19200.30.128.1 to 200.30.159.254200.30.159.2558,190
246200.30.160.0/19200.30.160.1 to 200.30.191.254200.30.191.2558,190
247200.30.192.0/19200.30.192.1 to 200.30.223.254200.30.223.2558,190
248200.30.224.0/19200.30.224.1 to 200.30.255.254200.30.255.2558,190
249200.31.0.0/19200.31.0.1 to 200.31.31.254200.31.31.2558,190
250200.31.32.0/19200.31.32.1 to 200.31.63.254200.31.63.2558,190
251200.31.64.0/19200.31.64.1 to 200.31.95.254200.31.95.2558,190
252200.31.96.0/19200.31.96.1 to 200.31.127.254200.31.127.2558,190
253200.31.128.0/19200.31.128.1 to 200.31.159.254200.31.159.2558,190
254200.31.160.0/19200.31.160.1 to 200.31.191.254200.31.191.2558,190
255200.31.192.0/19200.31.192.1 to 200.31.223.254200.31.223.2558,190
256200.31.224.0/19200.31.224.1 to 200.31.255.254200.31.255.2558,190

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.