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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.

Network193.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
193.0.0.0
Broadcast address
193.127.255.255
First usable
193.0.0.1
Last usable
193.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
C (default /24)
As numbers
Hex C1000000 · Integer 3238002688 to 3246391295
Reverse DNS zones
0.193.in-addr.arpa
1.193.in-addr.arpa
2.193.in-addr.arpa
3.193.in-addr.arpa
4.193.in-addr.arpa
5.193.in-addr.arpa
6.193.in-addr.arpa
7.193.in-addr.arpa
8.193.in-addr.arpa
9.193.in-addr.arpa
10.193.in-addr.arpa
11.193.in-addr.arpa
12.193.in-addr.arpa
13.193.in-addr.arpa
14.193.in-addr.arpa
15.193.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000001.00000000.00000000.00000000193.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network11000001.00000000.00000000.00000000193.0.0.0
Broadcast11000001.01111111.11111111.11111111193.127.255.255
Split into smaller subnets/20
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

193.0.0.0/9 makes 2,048 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1193.0.0.0/20193.0.0.1 to 193.0.15.254193.0.15.2554,094
2193.0.16.0/20193.0.16.1 to 193.0.31.254193.0.31.2554,094
3193.0.32.0/20193.0.32.1 to 193.0.47.254193.0.47.2554,094
4193.0.48.0/20193.0.48.1 to 193.0.63.254193.0.63.2554,094
5193.0.64.0/20193.0.64.1 to 193.0.79.254193.0.79.2554,094
6193.0.80.0/20193.0.80.1 to 193.0.95.254193.0.95.2554,094
7193.0.96.0/20193.0.96.1 to 193.0.111.254193.0.111.2554,094
8193.0.112.0/20193.0.112.1 to 193.0.127.254193.0.127.2554,094
9193.0.128.0/20193.0.128.1 to 193.0.143.254193.0.143.2554,094
10193.0.144.0/20193.0.144.1 to 193.0.159.254193.0.159.2554,094
11193.0.160.0/20193.0.160.1 to 193.0.175.254193.0.175.2554,094
12193.0.176.0/20193.0.176.1 to 193.0.191.254193.0.191.2554,094
13193.0.192.0/20193.0.192.1 to 193.0.207.254193.0.207.2554,094
14193.0.208.0/20193.0.208.1 to 193.0.223.254193.0.223.2554,094
15193.0.224.0/20193.0.224.1 to 193.0.239.254193.0.239.2554,094
16193.0.240.0/20193.0.240.1 to 193.0.255.254193.0.255.2554,094
17193.1.0.0/20193.1.0.1 to 193.1.15.254193.1.15.2554,094
18193.1.16.0/20193.1.16.1 to 193.1.31.254193.1.31.2554,094
19193.1.32.0/20193.1.32.1 to 193.1.47.254193.1.47.2554,094
20193.1.48.0/20193.1.48.1 to 193.1.63.254193.1.63.2554,094
21193.1.64.0/20193.1.64.1 to 193.1.79.254193.1.79.2554,094
22193.1.80.0/20193.1.80.1 to 193.1.95.254193.1.95.2554,094
23193.1.96.0/20193.1.96.1 to 193.1.111.254193.1.111.2554,094
24193.1.112.0/20193.1.112.1 to 193.1.127.254193.1.127.2554,094
25193.1.128.0/20193.1.128.1 to 193.1.143.254193.1.143.2554,094
26193.1.144.0/20193.1.144.1 to 193.1.159.254193.1.159.2554,094
27193.1.160.0/20193.1.160.1 to 193.1.175.254193.1.175.2554,094
28193.1.176.0/20193.1.176.1 to 193.1.191.254193.1.191.2554,094
29193.1.192.0/20193.1.192.1 to 193.1.207.254193.1.207.2554,094
30193.1.208.0/20193.1.208.1 to 193.1.223.254193.1.223.2554,094
31193.1.224.0/20193.1.224.1 to 193.1.239.254193.1.239.2554,094
32193.1.240.0/20193.1.240.1 to 193.1.255.254193.1.255.2554,094
33193.2.0.0/20193.2.0.1 to 193.2.15.254193.2.15.2554,094
34193.2.16.0/20193.2.16.1 to 193.2.31.254193.2.31.2554,094
35193.2.32.0/20193.2.32.1 to 193.2.47.254193.2.47.2554,094
36193.2.48.0/20193.2.48.1 to 193.2.63.254193.2.63.2554,094
37193.2.64.0/20193.2.64.1 to 193.2.79.254193.2.79.2554,094
38193.2.80.0/20193.2.80.1 to 193.2.95.254193.2.95.2554,094
39193.2.96.0/20193.2.96.1 to 193.2.111.254193.2.111.2554,094
40193.2.112.0/20193.2.112.1 to 193.2.127.254193.2.127.2554,094
41193.2.128.0/20193.2.128.1 to 193.2.143.254193.2.143.2554,094
42193.2.144.0/20193.2.144.1 to 193.2.159.254193.2.159.2554,094
43193.2.160.0/20193.2.160.1 to 193.2.175.254193.2.175.2554,094
44193.2.176.0/20193.2.176.1 to 193.2.191.254193.2.191.2554,094
45193.2.192.0/20193.2.192.1 to 193.2.207.254193.2.207.2554,094
46193.2.208.0/20193.2.208.1 to 193.2.223.254193.2.223.2554,094
47193.2.224.0/20193.2.224.1 to 193.2.239.254193.2.239.2554,094
48193.2.240.0/20193.2.240.1 to 193.2.255.254193.2.255.2554,094
49193.3.0.0/20193.3.0.1 to 193.3.15.254193.3.15.2554,094
50193.3.16.0/20193.3.16.1 to 193.3.31.254193.3.31.2554,094
51193.3.32.0/20193.3.32.1 to 193.3.47.254193.3.47.2554,094
52193.3.48.0/20193.3.48.1 to 193.3.63.254193.3.63.2554,094
53193.3.64.0/20193.3.64.1 to 193.3.79.254193.3.79.2554,094
54193.3.80.0/20193.3.80.1 to 193.3.95.254193.3.95.2554,094
55193.3.96.0/20193.3.96.1 to 193.3.111.254193.3.111.2554,094
56193.3.112.0/20193.3.112.1 to 193.3.127.254193.3.127.2554,094
57193.3.128.0/20193.3.128.1 to 193.3.143.254193.3.143.2554,094
58193.3.144.0/20193.3.144.1 to 193.3.159.254193.3.159.2554,094
59193.3.160.0/20193.3.160.1 to 193.3.175.254193.3.175.2554,094
60193.3.176.0/20193.3.176.1 to 193.3.191.254193.3.191.2554,094
61193.3.192.0/20193.3.192.1 to 193.3.207.254193.3.207.2554,094
62193.3.208.0/20193.3.208.1 to 193.3.223.254193.3.223.2554,094
63193.3.224.0/20193.3.224.1 to 193.3.239.254193.3.239.2554,094
64193.3.240.0/20193.3.240.1 to 193.3.255.254193.3.255.2554,094
65193.4.0.0/20193.4.0.1 to 193.4.15.254193.4.15.2554,094
66193.4.16.0/20193.4.16.1 to 193.4.31.254193.4.31.2554,094
67193.4.32.0/20193.4.32.1 to 193.4.47.254193.4.47.2554,094
68193.4.48.0/20193.4.48.1 to 193.4.63.254193.4.63.2554,094
69193.4.64.0/20193.4.64.1 to 193.4.79.254193.4.79.2554,094
70193.4.80.0/20193.4.80.1 to 193.4.95.254193.4.95.2554,094
71193.4.96.0/20193.4.96.1 to 193.4.111.254193.4.111.2554,094
72193.4.112.0/20193.4.112.1 to 193.4.127.254193.4.127.2554,094
73193.4.128.0/20193.4.128.1 to 193.4.143.254193.4.143.2554,094
74193.4.144.0/20193.4.144.1 to 193.4.159.254193.4.159.2554,094
75193.4.160.0/20193.4.160.1 to 193.4.175.254193.4.175.2554,094
76193.4.176.0/20193.4.176.1 to 193.4.191.254193.4.191.2554,094
77193.4.192.0/20193.4.192.1 to 193.4.207.254193.4.207.2554,094
78193.4.208.0/20193.4.208.1 to 193.4.223.254193.4.223.2554,094
79193.4.224.0/20193.4.224.1 to 193.4.239.254193.4.239.2554,094
80193.4.240.0/20193.4.240.1 to 193.4.255.254193.4.255.2554,094
81193.5.0.0/20193.5.0.1 to 193.5.15.254193.5.15.2554,094
82193.5.16.0/20193.5.16.1 to 193.5.31.254193.5.31.2554,094
83193.5.32.0/20193.5.32.1 to 193.5.47.254193.5.47.2554,094
84193.5.48.0/20193.5.48.1 to 193.5.63.254193.5.63.2554,094
85193.5.64.0/20193.5.64.1 to 193.5.79.254193.5.79.2554,094
86193.5.80.0/20193.5.80.1 to 193.5.95.254193.5.95.2554,094
87193.5.96.0/20193.5.96.1 to 193.5.111.254193.5.111.2554,094
88193.5.112.0/20193.5.112.1 to 193.5.127.254193.5.127.2554,094
89193.5.128.0/20193.5.128.1 to 193.5.143.254193.5.143.2554,094
90193.5.144.0/20193.5.144.1 to 193.5.159.254193.5.159.2554,094
91193.5.160.0/20193.5.160.1 to 193.5.175.254193.5.175.2554,094
92193.5.176.0/20193.5.176.1 to 193.5.191.254193.5.191.2554,094
93193.5.192.0/20193.5.192.1 to 193.5.207.254193.5.207.2554,094
94193.5.208.0/20193.5.208.1 to 193.5.223.254193.5.223.2554,094
95193.5.224.0/20193.5.224.1 to 193.5.239.254193.5.239.2554,094
96193.5.240.0/20193.5.240.1 to 193.5.255.254193.5.255.2554,094
97193.6.0.0/20193.6.0.1 to 193.6.15.254193.6.15.2554,094
98193.6.16.0/20193.6.16.1 to 193.6.31.254193.6.31.2554,094
99193.6.32.0/20193.6.32.1 to 193.6.47.254193.6.47.2554,094
100193.6.48.0/20193.6.48.1 to 193.6.63.254193.6.63.2554,094
101193.6.64.0/20193.6.64.1 to 193.6.79.254193.6.79.2554,094
102193.6.80.0/20193.6.80.1 to 193.6.95.254193.6.95.2554,094
103193.6.96.0/20193.6.96.1 to 193.6.111.254193.6.111.2554,094
104193.6.112.0/20193.6.112.1 to 193.6.127.254193.6.127.2554,094
105193.6.128.0/20193.6.128.1 to 193.6.143.254193.6.143.2554,094
106193.6.144.0/20193.6.144.1 to 193.6.159.254193.6.159.2554,094
107193.6.160.0/20193.6.160.1 to 193.6.175.254193.6.175.2554,094
108193.6.176.0/20193.6.176.1 to 193.6.191.254193.6.191.2554,094
109193.6.192.0/20193.6.192.1 to 193.6.207.254193.6.207.2554,094
110193.6.208.0/20193.6.208.1 to 193.6.223.254193.6.223.2554,094
111193.6.224.0/20193.6.224.1 to 193.6.239.254193.6.239.2554,094
112193.6.240.0/20193.6.240.1 to 193.6.255.254193.6.255.2554,094
113193.7.0.0/20193.7.0.1 to 193.7.15.254193.7.15.2554,094
114193.7.16.0/20193.7.16.1 to 193.7.31.254193.7.31.2554,094
115193.7.32.0/20193.7.32.1 to 193.7.47.254193.7.47.2554,094
116193.7.48.0/20193.7.48.1 to 193.7.63.254193.7.63.2554,094
117193.7.64.0/20193.7.64.1 to 193.7.79.254193.7.79.2554,094
118193.7.80.0/20193.7.80.1 to 193.7.95.254193.7.95.2554,094
119193.7.96.0/20193.7.96.1 to 193.7.111.254193.7.111.2554,094
120193.7.112.0/20193.7.112.1 to 193.7.127.254193.7.127.2554,094
121193.7.128.0/20193.7.128.1 to 193.7.143.254193.7.143.2554,094
122193.7.144.0/20193.7.144.1 to 193.7.159.254193.7.159.2554,094
123193.7.160.0/20193.7.160.1 to 193.7.175.254193.7.175.2554,094
124193.7.176.0/20193.7.176.1 to 193.7.191.254193.7.191.2554,094
125193.7.192.0/20193.7.192.1 to 193.7.207.254193.7.207.2554,094
126193.7.208.0/20193.7.208.1 to 193.7.223.254193.7.223.2554,094
127193.7.224.0/20193.7.224.1 to 193.7.239.254193.7.239.2554,094
128193.7.240.0/20193.7.240.1 to 193.7.255.254193.7.255.2554,094
129193.8.0.0/20193.8.0.1 to 193.8.15.254193.8.15.2554,094
130193.8.16.0/20193.8.16.1 to 193.8.31.254193.8.31.2554,094
131193.8.32.0/20193.8.32.1 to 193.8.47.254193.8.47.2554,094
132193.8.48.0/20193.8.48.1 to 193.8.63.254193.8.63.2554,094
133193.8.64.0/20193.8.64.1 to 193.8.79.254193.8.79.2554,094
134193.8.80.0/20193.8.80.1 to 193.8.95.254193.8.95.2554,094
135193.8.96.0/20193.8.96.1 to 193.8.111.254193.8.111.2554,094
136193.8.112.0/20193.8.112.1 to 193.8.127.254193.8.127.2554,094
137193.8.128.0/20193.8.128.1 to 193.8.143.254193.8.143.2554,094
138193.8.144.0/20193.8.144.1 to 193.8.159.254193.8.159.2554,094
139193.8.160.0/20193.8.160.1 to 193.8.175.254193.8.175.2554,094
140193.8.176.0/20193.8.176.1 to 193.8.191.254193.8.191.2554,094
141193.8.192.0/20193.8.192.1 to 193.8.207.254193.8.207.2554,094
142193.8.208.0/20193.8.208.1 to 193.8.223.254193.8.223.2554,094
143193.8.224.0/20193.8.224.1 to 193.8.239.254193.8.239.2554,094
144193.8.240.0/20193.8.240.1 to 193.8.255.254193.8.255.2554,094
145193.9.0.0/20193.9.0.1 to 193.9.15.254193.9.15.2554,094
146193.9.16.0/20193.9.16.1 to 193.9.31.254193.9.31.2554,094
147193.9.32.0/20193.9.32.1 to 193.9.47.254193.9.47.2554,094
148193.9.48.0/20193.9.48.1 to 193.9.63.254193.9.63.2554,094
149193.9.64.0/20193.9.64.1 to 193.9.79.254193.9.79.2554,094
150193.9.80.0/20193.9.80.1 to 193.9.95.254193.9.95.2554,094
151193.9.96.0/20193.9.96.1 to 193.9.111.254193.9.111.2554,094
152193.9.112.0/20193.9.112.1 to 193.9.127.254193.9.127.2554,094
153193.9.128.0/20193.9.128.1 to 193.9.143.254193.9.143.2554,094
154193.9.144.0/20193.9.144.1 to 193.9.159.254193.9.159.2554,094
155193.9.160.0/20193.9.160.1 to 193.9.175.254193.9.175.2554,094
156193.9.176.0/20193.9.176.1 to 193.9.191.254193.9.191.2554,094
157193.9.192.0/20193.9.192.1 to 193.9.207.254193.9.207.2554,094
158193.9.208.0/20193.9.208.1 to 193.9.223.254193.9.223.2554,094
159193.9.224.0/20193.9.224.1 to 193.9.239.254193.9.239.2554,094
160193.9.240.0/20193.9.240.1 to 193.9.255.254193.9.255.2554,094
161193.10.0.0/20193.10.0.1 to 193.10.15.254193.10.15.2554,094
162193.10.16.0/20193.10.16.1 to 193.10.31.254193.10.31.2554,094
163193.10.32.0/20193.10.32.1 to 193.10.47.254193.10.47.2554,094
164193.10.48.0/20193.10.48.1 to 193.10.63.254193.10.63.2554,094
165193.10.64.0/20193.10.64.1 to 193.10.79.254193.10.79.2554,094
166193.10.80.0/20193.10.80.1 to 193.10.95.254193.10.95.2554,094
167193.10.96.0/20193.10.96.1 to 193.10.111.254193.10.111.2554,094
168193.10.112.0/20193.10.112.1 to 193.10.127.254193.10.127.2554,094
169193.10.128.0/20193.10.128.1 to 193.10.143.254193.10.143.2554,094
170193.10.144.0/20193.10.144.1 to 193.10.159.254193.10.159.2554,094
171193.10.160.0/20193.10.160.1 to 193.10.175.254193.10.175.2554,094
172193.10.176.0/20193.10.176.1 to 193.10.191.254193.10.191.2554,094
173193.10.192.0/20193.10.192.1 to 193.10.207.254193.10.207.2554,094
174193.10.208.0/20193.10.208.1 to 193.10.223.254193.10.223.2554,094
175193.10.224.0/20193.10.224.1 to 193.10.239.254193.10.239.2554,094
176193.10.240.0/20193.10.240.1 to 193.10.255.254193.10.255.2554,094
177193.11.0.0/20193.11.0.1 to 193.11.15.254193.11.15.2554,094
178193.11.16.0/20193.11.16.1 to 193.11.31.254193.11.31.2554,094
179193.11.32.0/20193.11.32.1 to 193.11.47.254193.11.47.2554,094
180193.11.48.0/20193.11.48.1 to 193.11.63.254193.11.63.2554,094
181193.11.64.0/20193.11.64.1 to 193.11.79.254193.11.79.2554,094
182193.11.80.0/20193.11.80.1 to 193.11.95.254193.11.95.2554,094
183193.11.96.0/20193.11.96.1 to 193.11.111.254193.11.111.2554,094
184193.11.112.0/20193.11.112.1 to 193.11.127.254193.11.127.2554,094
185193.11.128.0/20193.11.128.1 to 193.11.143.254193.11.143.2554,094
186193.11.144.0/20193.11.144.1 to 193.11.159.254193.11.159.2554,094
187193.11.160.0/20193.11.160.1 to 193.11.175.254193.11.175.2554,094
188193.11.176.0/20193.11.176.1 to 193.11.191.254193.11.191.2554,094
189193.11.192.0/20193.11.192.1 to 193.11.207.254193.11.207.2554,094
190193.11.208.0/20193.11.208.1 to 193.11.223.254193.11.223.2554,094
191193.11.224.0/20193.11.224.1 to 193.11.239.254193.11.239.2554,094
192193.11.240.0/20193.11.240.1 to 193.11.255.254193.11.255.2554,094
193193.12.0.0/20193.12.0.1 to 193.12.15.254193.12.15.2554,094
194193.12.16.0/20193.12.16.1 to 193.12.31.254193.12.31.2554,094
195193.12.32.0/20193.12.32.1 to 193.12.47.254193.12.47.2554,094
196193.12.48.0/20193.12.48.1 to 193.12.63.254193.12.63.2554,094
197193.12.64.0/20193.12.64.1 to 193.12.79.254193.12.79.2554,094
198193.12.80.0/20193.12.80.1 to 193.12.95.254193.12.95.2554,094
199193.12.96.0/20193.12.96.1 to 193.12.111.254193.12.111.2554,094
200193.12.112.0/20193.12.112.1 to 193.12.127.254193.12.127.2554,094
201193.12.128.0/20193.12.128.1 to 193.12.143.254193.12.143.2554,094
202193.12.144.0/20193.12.144.1 to 193.12.159.254193.12.159.2554,094
203193.12.160.0/20193.12.160.1 to 193.12.175.254193.12.175.2554,094
204193.12.176.0/20193.12.176.1 to 193.12.191.254193.12.191.2554,094
205193.12.192.0/20193.12.192.1 to 193.12.207.254193.12.207.2554,094
206193.12.208.0/20193.12.208.1 to 193.12.223.254193.12.223.2554,094
207193.12.224.0/20193.12.224.1 to 193.12.239.254193.12.239.2554,094
208193.12.240.0/20193.12.240.1 to 193.12.255.254193.12.255.2554,094
209193.13.0.0/20193.13.0.1 to 193.13.15.254193.13.15.2554,094
210193.13.16.0/20193.13.16.1 to 193.13.31.254193.13.31.2554,094
211193.13.32.0/20193.13.32.1 to 193.13.47.254193.13.47.2554,094
212193.13.48.0/20193.13.48.1 to 193.13.63.254193.13.63.2554,094
213193.13.64.0/20193.13.64.1 to 193.13.79.254193.13.79.2554,094
214193.13.80.0/20193.13.80.1 to 193.13.95.254193.13.95.2554,094
215193.13.96.0/20193.13.96.1 to 193.13.111.254193.13.111.2554,094
216193.13.112.0/20193.13.112.1 to 193.13.127.254193.13.127.2554,094
217193.13.128.0/20193.13.128.1 to 193.13.143.254193.13.143.2554,094
218193.13.144.0/20193.13.144.1 to 193.13.159.254193.13.159.2554,094
219193.13.160.0/20193.13.160.1 to 193.13.175.254193.13.175.2554,094
220193.13.176.0/20193.13.176.1 to 193.13.191.254193.13.191.2554,094
221193.13.192.0/20193.13.192.1 to 193.13.207.254193.13.207.2554,094
222193.13.208.0/20193.13.208.1 to 193.13.223.254193.13.223.2554,094
223193.13.224.0/20193.13.224.1 to 193.13.239.254193.13.239.2554,094
224193.13.240.0/20193.13.240.1 to 193.13.255.254193.13.255.2554,094
225193.14.0.0/20193.14.0.1 to 193.14.15.254193.14.15.2554,094
226193.14.16.0/20193.14.16.1 to 193.14.31.254193.14.31.2554,094
227193.14.32.0/20193.14.32.1 to 193.14.47.254193.14.47.2554,094
228193.14.48.0/20193.14.48.1 to 193.14.63.254193.14.63.2554,094
229193.14.64.0/20193.14.64.1 to 193.14.79.254193.14.79.2554,094
230193.14.80.0/20193.14.80.1 to 193.14.95.254193.14.95.2554,094
231193.14.96.0/20193.14.96.1 to 193.14.111.254193.14.111.2554,094
232193.14.112.0/20193.14.112.1 to 193.14.127.254193.14.127.2554,094
233193.14.128.0/20193.14.128.1 to 193.14.143.254193.14.143.2554,094
234193.14.144.0/20193.14.144.1 to 193.14.159.254193.14.159.2554,094
235193.14.160.0/20193.14.160.1 to 193.14.175.254193.14.175.2554,094
236193.14.176.0/20193.14.176.1 to 193.14.191.254193.14.191.2554,094
237193.14.192.0/20193.14.192.1 to 193.14.207.254193.14.207.2554,094
238193.14.208.0/20193.14.208.1 to 193.14.223.254193.14.223.2554,094
239193.14.224.0/20193.14.224.1 to 193.14.239.254193.14.239.2554,094
240193.14.240.0/20193.14.240.1 to 193.14.255.254193.14.255.2554,094
241193.15.0.0/20193.15.0.1 to 193.15.15.254193.15.15.2554,094
242193.15.16.0/20193.15.16.1 to 193.15.31.254193.15.31.2554,094
243193.15.32.0/20193.15.32.1 to 193.15.47.254193.15.47.2554,094
244193.15.48.0/20193.15.48.1 to 193.15.63.254193.15.63.2554,094
245193.15.64.0/20193.15.64.1 to 193.15.79.254193.15.79.2554,094
246193.15.80.0/20193.15.80.1 to 193.15.95.254193.15.95.2554,094
247193.15.96.0/20193.15.96.1 to 193.15.111.254193.15.111.2554,094
248193.15.112.0/20193.15.112.1 to 193.15.127.254193.15.127.2554,094
249193.15.128.0/20193.15.128.1 to 193.15.143.254193.15.143.2554,094
250193.15.144.0/20193.15.144.1 to 193.15.159.254193.15.159.2554,094
251193.15.160.0/20193.15.160.1 to 193.15.175.254193.15.175.2554,094
252193.15.176.0/20193.15.176.1 to 193.15.191.254193.15.191.2554,094
253193.15.192.0/20193.15.192.1 to 193.15.207.254193.15.207.2554,094
254193.15.208.0/20193.15.208.1 to 193.15.223.254193.15.223.2554,094
255193.15.224.0/20193.15.224.1 to 193.15.239.254193.15.239.2554,094
256193.15.240.0/20193.15.240.1 to 193.15.255.254193.15.255.2554,094

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.