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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.

Network192.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
192.0.0.0
Broadcast address
193.255.255.255
First usable
192.0.0.1
Last usable
193.255.255.254
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 C0000000 · Integer 3221225472 to 3254779903
Reverse DNS zones
192.in-addr.arpa
193.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
Address11000000.00000000.00000000.00000000192.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network11000000.00000000.00000000.00000000192.0.0.0
Broadcast11000001.11111111.11111111.11111111193.255.255.255
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)

192.0.0.0/7 makes 4,096 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1192.0.0.0/19192.0.0.1 to 192.0.31.254192.0.31.2558,190
2192.0.32.0/19192.0.32.1 to 192.0.63.254192.0.63.2558,190
3192.0.64.0/19192.0.64.1 to 192.0.95.254192.0.95.2558,190
4192.0.96.0/19192.0.96.1 to 192.0.127.254192.0.127.2558,190
5192.0.128.0/19192.0.128.1 to 192.0.159.254192.0.159.2558,190
6192.0.160.0/19192.0.160.1 to 192.0.191.254192.0.191.2558,190
7192.0.192.0/19192.0.192.1 to 192.0.223.254192.0.223.2558,190
8192.0.224.0/19192.0.224.1 to 192.0.255.254192.0.255.2558,190
9192.1.0.0/19192.1.0.1 to 192.1.31.254192.1.31.2558,190
10192.1.32.0/19192.1.32.1 to 192.1.63.254192.1.63.2558,190
11192.1.64.0/19192.1.64.1 to 192.1.95.254192.1.95.2558,190
12192.1.96.0/19192.1.96.1 to 192.1.127.254192.1.127.2558,190
13192.1.128.0/19192.1.128.1 to 192.1.159.254192.1.159.2558,190
14192.1.160.0/19192.1.160.1 to 192.1.191.254192.1.191.2558,190
15192.1.192.0/19192.1.192.1 to 192.1.223.254192.1.223.2558,190
16192.1.224.0/19192.1.224.1 to 192.1.255.254192.1.255.2558,190
17192.2.0.0/19192.2.0.1 to 192.2.31.254192.2.31.2558,190
18192.2.32.0/19192.2.32.1 to 192.2.63.254192.2.63.2558,190
19192.2.64.0/19192.2.64.1 to 192.2.95.254192.2.95.2558,190
20192.2.96.0/19192.2.96.1 to 192.2.127.254192.2.127.2558,190
21192.2.128.0/19192.2.128.1 to 192.2.159.254192.2.159.2558,190
22192.2.160.0/19192.2.160.1 to 192.2.191.254192.2.191.2558,190
23192.2.192.0/19192.2.192.1 to 192.2.223.254192.2.223.2558,190
24192.2.224.0/19192.2.224.1 to 192.2.255.254192.2.255.2558,190
25192.3.0.0/19192.3.0.1 to 192.3.31.254192.3.31.2558,190
26192.3.32.0/19192.3.32.1 to 192.3.63.254192.3.63.2558,190
27192.3.64.0/19192.3.64.1 to 192.3.95.254192.3.95.2558,190
28192.3.96.0/19192.3.96.1 to 192.3.127.254192.3.127.2558,190
29192.3.128.0/19192.3.128.1 to 192.3.159.254192.3.159.2558,190
30192.3.160.0/19192.3.160.1 to 192.3.191.254192.3.191.2558,190
31192.3.192.0/19192.3.192.1 to 192.3.223.254192.3.223.2558,190
32192.3.224.0/19192.3.224.1 to 192.3.255.254192.3.255.2558,190
33192.4.0.0/19192.4.0.1 to 192.4.31.254192.4.31.2558,190
34192.4.32.0/19192.4.32.1 to 192.4.63.254192.4.63.2558,190
35192.4.64.0/19192.4.64.1 to 192.4.95.254192.4.95.2558,190
36192.4.96.0/19192.4.96.1 to 192.4.127.254192.4.127.2558,190
37192.4.128.0/19192.4.128.1 to 192.4.159.254192.4.159.2558,190
38192.4.160.0/19192.4.160.1 to 192.4.191.254192.4.191.2558,190
39192.4.192.0/19192.4.192.1 to 192.4.223.254192.4.223.2558,190
40192.4.224.0/19192.4.224.1 to 192.4.255.254192.4.255.2558,190
41192.5.0.0/19192.5.0.1 to 192.5.31.254192.5.31.2558,190
42192.5.32.0/19192.5.32.1 to 192.5.63.254192.5.63.2558,190
43192.5.64.0/19192.5.64.1 to 192.5.95.254192.5.95.2558,190
44192.5.96.0/19192.5.96.1 to 192.5.127.254192.5.127.2558,190
45192.5.128.0/19192.5.128.1 to 192.5.159.254192.5.159.2558,190
46192.5.160.0/19192.5.160.1 to 192.5.191.254192.5.191.2558,190
47192.5.192.0/19192.5.192.1 to 192.5.223.254192.5.223.2558,190
48192.5.224.0/19192.5.224.1 to 192.5.255.254192.5.255.2558,190
49192.6.0.0/19192.6.0.1 to 192.6.31.254192.6.31.2558,190
50192.6.32.0/19192.6.32.1 to 192.6.63.254192.6.63.2558,190
51192.6.64.0/19192.6.64.1 to 192.6.95.254192.6.95.2558,190
52192.6.96.0/19192.6.96.1 to 192.6.127.254192.6.127.2558,190
53192.6.128.0/19192.6.128.1 to 192.6.159.254192.6.159.2558,190
54192.6.160.0/19192.6.160.1 to 192.6.191.254192.6.191.2558,190
55192.6.192.0/19192.6.192.1 to 192.6.223.254192.6.223.2558,190
56192.6.224.0/19192.6.224.1 to 192.6.255.254192.6.255.2558,190
57192.7.0.0/19192.7.0.1 to 192.7.31.254192.7.31.2558,190
58192.7.32.0/19192.7.32.1 to 192.7.63.254192.7.63.2558,190
59192.7.64.0/19192.7.64.1 to 192.7.95.254192.7.95.2558,190
60192.7.96.0/19192.7.96.1 to 192.7.127.254192.7.127.2558,190
61192.7.128.0/19192.7.128.1 to 192.7.159.254192.7.159.2558,190
62192.7.160.0/19192.7.160.1 to 192.7.191.254192.7.191.2558,190
63192.7.192.0/19192.7.192.1 to 192.7.223.254192.7.223.2558,190
64192.7.224.0/19192.7.224.1 to 192.7.255.254192.7.255.2558,190
65192.8.0.0/19192.8.0.1 to 192.8.31.254192.8.31.2558,190
66192.8.32.0/19192.8.32.1 to 192.8.63.254192.8.63.2558,190
67192.8.64.0/19192.8.64.1 to 192.8.95.254192.8.95.2558,190
68192.8.96.0/19192.8.96.1 to 192.8.127.254192.8.127.2558,190
69192.8.128.0/19192.8.128.1 to 192.8.159.254192.8.159.2558,190
70192.8.160.0/19192.8.160.1 to 192.8.191.254192.8.191.2558,190
71192.8.192.0/19192.8.192.1 to 192.8.223.254192.8.223.2558,190
72192.8.224.0/19192.8.224.1 to 192.8.255.254192.8.255.2558,190
73192.9.0.0/19192.9.0.1 to 192.9.31.254192.9.31.2558,190
74192.9.32.0/19192.9.32.1 to 192.9.63.254192.9.63.2558,190
75192.9.64.0/19192.9.64.1 to 192.9.95.254192.9.95.2558,190
76192.9.96.0/19192.9.96.1 to 192.9.127.254192.9.127.2558,190
77192.9.128.0/19192.9.128.1 to 192.9.159.254192.9.159.2558,190
78192.9.160.0/19192.9.160.1 to 192.9.191.254192.9.191.2558,190
79192.9.192.0/19192.9.192.1 to 192.9.223.254192.9.223.2558,190
80192.9.224.0/19192.9.224.1 to 192.9.255.254192.9.255.2558,190
81192.10.0.0/19192.10.0.1 to 192.10.31.254192.10.31.2558,190
82192.10.32.0/19192.10.32.1 to 192.10.63.254192.10.63.2558,190
83192.10.64.0/19192.10.64.1 to 192.10.95.254192.10.95.2558,190
84192.10.96.0/19192.10.96.1 to 192.10.127.254192.10.127.2558,190
85192.10.128.0/19192.10.128.1 to 192.10.159.254192.10.159.2558,190
86192.10.160.0/19192.10.160.1 to 192.10.191.254192.10.191.2558,190
87192.10.192.0/19192.10.192.1 to 192.10.223.254192.10.223.2558,190
88192.10.224.0/19192.10.224.1 to 192.10.255.254192.10.255.2558,190
89192.11.0.0/19192.11.0.1 to 192.11.31.254192.11.31.2558,190
90192.11.32.0/19192.11.32.1 to 192.11.63.254192.11.63.2558,190
91192.11.64.0/19192.11.64.1 to 192.11.95.254192.11.95.2558,190
92192.11.96.0/19192.11.96.1 to 192.11.127.254192.11.127.2558,190
93192.11.128.0/19192.11.128.1 to 192.11.159.254192.11.159.2558,190
94192.11.160.0/19192.11.160.1 to 192.11.191.254192.11.191.2558,190
95192.11.192.0/19192.11.192.1 to 192.11.223.254192.11.223.2558,190
96192.11.224.0/19192.11.224.1 to 192.11.255.254192.11.255.2558,190
97192.12.0.0/19192.12.0.1 to 192.12.31.254192.12.31.2558,190
98192.12.32.0/19192.12.32.1 to 192.12.63.254192.12.63.2558,190
99192.12.64.0/19192.12.64.1 to 192.12.95.254192.12.95.2558,190
100192.12.96.0/19192.12.96.1 to 192.12.127.254192.12.127.2558,190
101192.12.128.0/19192.12.128.1 to 192.12.159.254192.12.159.2558,190
102192.12.160.0/19192.12.160.1 to 192.12.191.254192.12.191.2558,190
103192.12.192.0/19192.12.192.1 to 192.12.223.254192.12.223.2558,190
104192.12.224.0/19192.12.224.1 to 192.12.255.254192.12.255.2558,190
105192.13.0.0/19192.13.0.1 to 192.13.31.254192.13.31.2558,190
106192.13.32.0/19192.13.32.1 to 192.13.63.254192.13.63.2558,190
107192.13.64.0/19192.13.64.1 to 192.13.95.254192.13.95.2558,190
108192.13.96.0/19192.13.96.1 to 192.13.127.254192.13.127.2558,190
109192.13.128.0/19192.13.128.1 to 192.13.159.254192.13.159.2558,190
110192.13.160.0/19192.13.160.1 to 192.13.191.254192.13.191.2558,190
111192.13.192.0/19192.13.192.1 to 192.13.223.254192.13.223.2558,190
112192.13.224.0/19192.13.224.1 to 192.13.255.254192.13.255.2558,190
113192.14.0.0/19192.14.0.1 to 192.14.31.254192.14.31.2558,190
114192.14.32.0/19192.14.32.1 to 192.14.63.254192.14.63.2558,190
115192.14.64.0/19192.14.64.1 to 192.14.95.254192.14.95.2558,190
116192.14.96.0/19192.14.96.1 to 192.14.127.254192.14.127.2558,190
117192.14.128.0/19192.14.128.1 to 192.14.159.254192.14.159.2558,190
118192.14.160.0/19192.14.160.1 to 192.14.191.254192.14.191.2558,190
119192.14.192.0/19192.14.192.1 to 192.14.223.254192.14.223.2558,190
120192.14.224.0/19192.14.224.1 to 192.14.255.254192.14.255.2558,190
121192.15.0.0/19192.15.0.1 to 192.15.31.254192.15.31.2558,190
122192.15.32.0/19192.15.32.1 to 192.15.63.254192.15.63.2558,190
123192.15.64.0/19192.15.64.1 to 192.15.95.254192.15.95.2558,190
124192.15.96.0/19192.15.96.1 to 192.15.127.254192.15.127.2558,190
125192.15.128.0/19192.15.128.1 to 192.15.159.254192.15.159.2558,190
126192.15.160.0/19192.15.160.1 to 192.15.191.254192.15.191.2558,190
127192.15.192.0/19192.15.192.1 to 192.15.223.254192.15.223.2558,190
128192.15.224.0/19192.15.224.1 to 192.15.255.254192.15.255.2558,190
129192.16.0.0/19192.16.0.1 to 192.16.31.254192.16.31.2558,190
130192.16.32.0/19192.16.32.1 to 192.16.63.254192.16.63.2558,190
131192.16.64.0/19192.16.64.1 to 192.16.95.254192.16.95.2558,190
132192.16.96.0/19192.16.96.1 to 192.16.127.254192.16.127.2558,190
133192.16.128.0/19192.16.128.1 to 192.16.159.254192.16.159.2558,190
134192.16.160.0/19192.16.160.1 to 192.16.191.254192.16.191.2558,190
135192.16.192.0/19192.16.192.1 to 192.16.223.254192.16.223.2558,190
136192.16.224.0/19192.16.224.1 to 192.16.255.254192.16.255.2558,190
137192.17.0.0/19192.17.0.1 to 192.17.31.254192.17.31.2558,190
138192.17.32.0/19192.17.32.1 to 192.17.63.254192.17.63.2558,190
139192.17.64.0/19192.17.64.1 to 192.17.95.254192.17.95.2558,190
140192.17.96.0/19192.17.96.1 to 192.17.127.254192.17.127.2558,190
141192.17.128.0/19192.17.128.1 to 192.17.159.254192.17.159.2558,190
142192.17.160.0/19192.17.160.1 to 192.17.191.254192.17.191.2558,190
143192.17.192.0/19192.17.192.1 to 192.17.223.254192.17.223.2558,190
144192.17.224.0/19192.17.224.1 to 192.17.255.254192.17.255.2558,190
145192.18.0.0/19192.18.0.1 to 192.18.31.254192.18.31.2558,190
146192.18.32.0/19192.18.32.1 to 192.18.63.254192.18.63.2558,190
147192.18.64.0/19192.18.64.1 to 192.18.95.254192.18.95.2558,190
148192.18.96.0/19192.18.96.1 to 192.18.127.254192.18.127.2558,190
149192.18.128.0/19192.18.128.1 to 192.18.159.254192.18.159.2558,190
150192.18.160.0/19192.18.160.1 to 192.18.191.254192.18.191.2558,190
151192.18.192.0/19192.18.192.1 to 192.18.223.254192.18.223.2558,190
152192.18.224.0/19192.18.224.1 to 192.18.255.254192.18.255.2558,190
153192.19.0.0/19192.19.0.1 to 192.19.31.254192.19.31.2558,190
154192.19.32.0/19192.19.32.1 to 192.19.63.254192.19.63.2558,190
155192.19.64.0/19192.19.64.1 to 192.19.95.254192.19.95.2558,190
156192.19.96.0/19192.19.96.1 to 192.19.127.254192.19.127.2558,190
157192.19.128.0/19192.19.128.1 to 192.19.159.254192.19.159.2558,190
158192.19.160.0/19192.19.160.1 to 192.19.191.254192.19.191.2558,190
159192.19.192.0/19192.19.192.1 to 192.19.223.254192.19.223.2558,190
160192.19.224.0/19192.19.224.1 to 192.19.255.254192.19.255.2558,190
161192.20.0.0/19192.20.0.1 to 192.20.31.254192.20.31.2558,190
162192.20.32.0/19192.20.32.1 to 192.20.63.254192.20.63.2558,190
163192.20.64.0/19192.20.64.1 to 192.20.95.254192.20.95.2558,190
164192.20.96.0/19192.20.96.1 to 192.20.127.254192.20.127.2558,190
165192.20.128.0/19192.20.128.1 to 192.20.159.254192.20.159.2558,190
166192.20.160.0/19192.20.160.1 to 192.20.191.254192.20.191.2558,190
167192.20.192.0/19192.20.192.1 to 192.20.223.254192.20.223.2558,190
168192.20.224.0/19192.20.224.1 to 192.20.255.254192.20.255.2558,190
169192.21.0.0/19192.21.0.1 to 192.21.31.254192.21.31.2558,190
170192.21.32.0/19192.21.32.1 to 192.21.63.254192.21.63.2558,190
171192.21.64.0/19192.21.64.1 to 192.21.95.254192.21.95.2558,190
172192.21.96.0/19192.21.96.1 to 192.21.127.254192.21.127.2558,190
173192.21.128.0/19192.21.128.1 to 192.21.159.254192.21.159.2558,190
174192.21.160.0/19192.21.160.1 to 192.21.191.254192.21.191.2558,190
175192.21.192.0/19192.21.192.1 to 192.21.223.254192.21.223.2558,190
176192.21.224.0/19192.21.224.1 to 192.21.255.254192.21.255.2558,190
177192.22.0.0/19192.22.0.1 to 192.22.31.254192.22.31.2558,190
178192.22.32.0/19192.22.32.1 to 192.22.63.254192.22.63.2558,190
179192.22.64.0/19192.22.64.1 to 192.22.95.254192.22.95.2558,190
180192.22.96.0/19192.22.96.1 to 192.22.127.254192.22.127.2558,190
181192.22.128.0/19192.22.128.1 to 192.22.159.254192.22.159.2558,190
182192.22.160.0/19192.22.160.1 to 192.22.191.254192.22.191.2558,190
183192.22.192.0/19192.22.192.1 to 192.22.223.254192.22.223.2558,190
184192.22.224.0/19192.22.224.1 to 192.22.255.254192.22.255.2558,190
185192.23.0.0/19192.23.0.1 to 192.23.31.254192.23.31.2558,190
186192.23.32.0/19192.23.32.1 to 192.23.63.254192.23.63.2558,190
187192.23.64.0/19192.23.64.1 to 192.23.95.254192.23.95.2558,190
188192.23.96.0/19192.23.96.1 to 192.23.127.254192.23.127.2558,190
189192.23.128.0/19192.23.128.1 to 192.23.159.254192.23.159.2558,190
190192.23.160.0/19192.23.160.1 to 192.23.191.254192.23.191.2558,190
191192.23.192.0/19192.23.192.1 to 192.23.223.254192.23.223.2558,190
192192.23.224.0/19192.23.224.1 to 192.23.255.254192.23.255.2558,190
193192.24.0.0/19192.24.0.1 to 192.24.31.254192.24.31.2558,190
194192.24.32.0/19192.24.32.1 to 192.24.63.254192.24.63.2558,190
195192.24.64.0/19192.24.64.1 to 192.24.95.254192.24.95.2558,190
196192.24.96.0/19192.24.96.1 to 192.24.127.254192.24.127.2558,190
197192.24.128.0/19192.24.128.1 to 192.24.159.254192.24.159.2558,190
198192.24.160.0/19192.24.160.1 to 192.24.191.254192.24.191.2558,190
199192.24.192.0/19192.24.192.1 to 192.24.223.254192.24.223.2558,190
200192.24.224.0/19192.24.224.1 to 192.24.255.254192.24.255.2558,190
201192.25.0.0/19192.25.0.1 to 192.25.31.254192.25.31.2558,190
202192.25.32.0/19192.25.32.1 to 192.25.63.254192.25.63.2558,190
203192.25.64.0/19192.25.64.1 to 192.25.95.254192.25.95.2558,190
204192.25.96.0/19192.25.96.1 to 192.25.127.254192.25.127.2558,190
205192.25.128.0/19192.25.128.1 to 192.25.159.254192.25.159.2558,190
206192.25.160.0/19192.25.160.1 to 192.25.191.254192.25.191.2558,190
207192.25.192.0/19192.25.192.1 to 192.25.223.254192.25.223.2558,190
208192.25.224.0/19192.25.224.1 to 192.25.255.254192.25.255.2558,190
209192.26.0.0/19192.26.0.1 to 192.26.31.254192.26.31.2558,190
210192.26.32.0/19192.26.32.1 to 192.26.63.254192.26.63.2558,190
211192.26.64.0/19192.26.64.1 to 192.26.95.254192.26.95.2558,190
212192.26.96.0/19192.26.96.1 to 192.26.127.254192.26.127.2558,190
213192.26.128.0/19192.26.128.1 to 192.26.159.254192.26.159.2558,190
214192.26.160.0/19192.26.160.1 to 192.26.191.254192.26.191.2558,190
215192.26.192.0/19192.26.192.1 to 192.26.223.254192.26.223.2558,190
216192.26.224.0/19192.26.224.1 to 192.26.255.254192.26.255.2558,190
217192.27.0.0/19192.27.0.1 to 192.27.31.254192.27.31.2558,190
218192.27.32.0/19192.27.32.1 to 192.27.63.254192.27.63.2558,190
219192.27.64.0/19192.27.64.1 to 192.27.95.254192.27.95.2558,190
220192.27.96.0/19192.27.96.1 to 192.27.127.254192.27.127.2558,190
221192.27.128.0/19192.27.128.1 to 192.27.159.254192.27.159.2558,190
222192.27.160.0/19192.27.160.1 to 192.27.191.254192.27.191.2558,190
223192.27.192.0/19192.27.192.1 to 192.27.223.254192.27.223.2558,190
224192.27.224.0/19192.27.224.1 to 192.27.255.254192.27.255.2558,190
225192.28.0.0/19192.28.0.1 to 192.28.31.254192.28.31.2558,190
226192.28.32.0/19192.28.32.1 to 192.28.63.254192.28.63.2558,190
227192.28.64.0/19192.28.64.1 to 192.28.95.254192.28.95.2558,190
228192.28.96.0/19192.28.96.1 to 192.28.127.254192.28.127.2558,190
229192.28.128.0/19192.28.128.1 to 192.28.159.254192.28.159.2558,190
230192.28.160.0/19192.28.160.1 to 192.28.191.254192.28.191.2558,190
231192.28.192.0/19192.28.192.1 to 192.28.223.254192.28.223.2558,190
232192.28.224.0/19192.28.224.1 to 192.28.255.254192.28.255.2558,190
233192.29.0.0/19192.29.0.1 to 192.29.31.254192.29.31.2558,190
234192.29.32.0/19192.29.32.1 to 192.29.63.254192.29.63.2558,190
235192.29.64.0/19192.29.64.1 to 192.29.95.254192.29.95.2558,190
236192.29.96.0/19192.29.96.1 to 192.29.127.254192.29.127.2558,190
237192.29.128.0/19192.29.128.1 to 192.29.159.254192.29.159.2558,190
238192.29.160.0/19192.29.160.1 to 192.29.191.254192.29.191.2558,190
239192.29.192.0/19192.29.192.1 to 192.29.223.254192.29.223.2558,190
240192.29.224.0/19192.29.224.1 to 192.29.255.254192.29.255.2558,190
241192.30.0.0/19192.30.0.1 to 192.30.31.254192.30.31.2558,190
242192.30.32.0/19192.30.32.1 to 192.30.63.254192.30.63.2558,190
243192.30.64.0/19192.30.64.1 to 192.30.95.254192.30.95.2558,190
244192.30.96.0/19192.30.96.1 to 192.30.127.254192.30.127.2558,190
245192.30.128.0/19192.30.128.1 to 192.30.159.254192.30.159.2558,190
246192.30.160.0/19192.30.160.1 to 192.30.191.254192.30.191.2558,190
247192.30.192.0/19192.30.192.1 to 192.30.223.254192.30.223.2558,190
248192.30.224.0/19192.30.224.1 to 192.30.255.254192.30.255.2558,190
249192.31.0.0/19192.31.0.1 to 192.31.31.254192.31.31.2558,190
250192.31.32.0/19192.31.32.1 to 192.31.63.254192.31.63.2558,190
251192.31.64.0/19192.31.64.1 to 192.31.95.254192.31.95.2558,190
252192.31.96.0/19192.31.96.1 to 192.31.127.254192.31.127.2558,190
253192.31.128.0/19192.31.128.1 to 192.31.159.254192.31.159.2558,190
254192.31.160.0/19192.31.160.1 to 192.31.191.254192.31.191.2558,190
255192.31.192.0/19192.31.192.1 to 192.31.223.254192.31.223.2558,190
256192.31.224.0/19192.31.224.1 to 192.31.255.254192.31.255.2558,190

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.