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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.

Network199.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
199.0.0.0
Broadcast address
199.255.255.255
First usable
199.0.0.1
Last usable
199.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
C (default /24)
As numbers
Hex C7000000 · Integer 3338665984 to 3355443199
Reverse DNS zone
199.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000111..00000000.00000000.00000000199.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network11000111..00000000.00000000.00000000199.0.0.0
Broadcast11000111..11111111.11111111.11111111199.255.255.255
Split into smaller subnets/20
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

199.0.0.0/8 makes 4,096 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1199.0.0.0/20199.0.0.1 to 199.0.15.254199.0.15.2554,094
2199.0.16.0/20199.0.16.1 to 199.0.31.254199.0.31.2554,094
3199.0.32.0/20199.0.32.1 to 199.0.47.254199.0.47.2554,094
4199.0.48.0/20199.0.48.1 to 199.0.63.254199.0.63.2554,094
5199.0.64.0/20199.0.64.1 to 199.0.79.254199.0.79.2554,094
6199.0.80.0/20199.0.80.1 to 199.0.95.254199.0.95.2554,094
7199.0.96.0/20199.0.96.1 to 199.0.111.254199.0.111.2554,094
8199.0.112.0/20199.0.112.1 to 199.0.127.254199.0.127.2554,094
9199.0.128.0/20199.0.128.1 to 199.0.143.254199.0.143.2554,094
10199.0.144.0/20199.0.144.1 to 199.0.159.254199.0.159.2554,094
11199.0.160.0/20199.0.160.1 to 199.0.175.254199.0.175.2554,094
12199.0.176.0/20199.0.176.1 to 199.0.191.254199.0.191.2554,094
13199.0.192.0/20199.0.192.1 to 199.0.207.254199.0.207.2554,094
14199.0.208.0/20199.0.208.1 to 199.0.223.254199.0.223.2554,094
15199.0.224.0/20199.0.224.1 to 199.0.239.254199.0.239.2554,094
16199.0.240.0/20199.0.240.1 to 199.0.255.254199.0.255.2554,094
17199.1.0.0/20199.1.0.1 to 199.1.15.254199.1.15.2554,094
18199.1.16.0/20199.1.16.1 to 199.1.31.254199.1.31.2554,094
19199.1.32.0/20199.1.32.1 to 199.1.47.254199.1.47.2554,094
20199.1.48.0/20199.1.48.1 to 199.1.63.254199.1.63.2554,094
21199.1.64.0/20199.1.64.1 to 199.1.79.254199.1.79.2554,094
22199.1.80.0/20199.1.80.1 to 199.1.95.254199.1.95.2554,094
23199.1.96.0/20199.1.96.1 to 199.1.111.254199.1.111.2554,094
24199.1.112.0/20199.1.112.1 to 199.1.127.254199.1.127.2554,094
25199.1.128.0/20199.1.128.1 to 199.1.143.254199.1.143.2554,094
26199.1.144.0/20199.1.144.1 to 199.1.159.254199.1.159.2554,094
27199.1.160.0/20199.1.160.1 to 199.1.175.254199.1.175.2554,094
28199.1.176.0/20199.1.176.1 to 199.1.191.254199.1.191.2554,094
29199.1.192.0/20199.1.192.1 to 199.1.207.254199.1.207.2554,094
30199.1.208.0/20199.1.208.1 to 199.1.223.254199.1.223.2554,094
31199.1.224.0/20199.1.224.1 to 199.1.239.254199.1.239.2554,094
32199.1.240.0/20199.1.240.1 to 199.1.255.254199.1.255.2554,094
33199.2.0.0/20199.2.0.1 to 199.2.15.254199.2.15.2554,094
34199.2.16.0/20199.2.16.1 to 199.2.31.254199.2.31.2554,094
35199.2.32.0/20199.2.32.1 to 199.2.47.254199.2.47.2554,094
36199.2.48.0/20199.2.48.1 to 199.2.63.254199.2.63.2554,094
37199.2.64.0/20199.2.64.1 to 199.2.79.254199.2.79.2554,094
38199.2.80.0/20199.2.80.1 to 199.2.95.254199.2.95.2554,094
39199.2.96.0/20199.2.96.1 to 199.2.111.254199.2.111.2554,094
40199.2.112.0/20199.2.112.1 to 199.2.127.254199.2.127.2554,094
41199.2.128.0/20199.2.128.1 to 199.2.143.254199.2.143.2554,094
42199.2.144.0/20199.2.144.1 to 199.2.159.254199.2.159.2554,094
43199.2.160.0/20199.2.160.1 to 199.2.175.254199.2.175.2554,094
44199.2.176.0/20199.2.176.1 to 199.2.191.254199.2.191.2554,094
45199.2.192.0/20199.2.192.1 to 199.2.207.254199.2.207.2554,094
46199.2.208.0/20199.2.208.1 to 199.2.223.254199.2.223.2554,094
47199.2.224.0/20199.2.224.1 to 199.2.239.254199.2.239.2554,094
48199.2.240.0/20199.2.240.1 to 199.2.255.254199.2.255.2554,094
49199.3.0.0/20199.3.0.1 to 199.3.15.254199.3.15.2554,094
50199.3.16.0/20199.3.16.1 to 199.3.31.254199.3.31.2554,094
51199.3.32.0/20199.3.32.1 to 199.3.47.254199.3.47.2554,094
52199.3.48.0/20199.3.48.1 to 199.3.63.254199.3.63.2554,094
53199.3.64.0/20199.3.64.1 to 199.3.79.254199.3.79.2554,094
54199.3.80.0/20199.3.80.1 to 199.3.95.254199.3.95.2554,094
55199.3.96.0/20199.3.96.1 to 199.3.111.254199.3.111.2554,094
56199.3.112.0/20199.3.112.1 to 199.3.127.254199.3.127.2554,094
57199.3.128.0/20199.3.128.1 to 199.3.143.254199.3.143.2554,094
58199.3.144.0/20199.3.144.1 to 199.3.159.254199.3.159.2554,094
59199.3.160.0/20199.3.160.1 to 199.3.175.254199.3.175.2554,094
60199.3.176.0/20199.3.176.1 to 199.3.191.254199.3.191.2554,094
61199.3.192.0/20199.3.192.1 to 199.3.207.254199.3.207.2554,094
62199.3.208.0/20199.3.208.1 to 199.3.223.254199.3.223.2554,094
63199.3.224.0/20199.3.224.1 to 199.3.239.254199.3.239.2554,094
64199.3.240.0/20199.3.240.1 to 199.3.255.254199.3.255.2554,094
65199.4.0.0/20199.4.0.1 to 199.4.15.254199.4.15.2554,094
66199.4.16.0/20199.4.16.1 to 199.4.31.254199.4.31.2554,094
67199.4.32.0/20199.4.32.1 to 199.4.47.254199.4.47.2554,094
68199.4.48.0/20199.4.48.1 to 199.4.63.254199.4.63.2554,094
69199.4.64.0/20199.4.64.1 to 199.4.79.254199.4.79.2554,094
70199.4.80.0/20199.4.80.1 to 199.4.95.254199.4.95.2554,094
71199.4.96.0/20199.4.96.1 to 199.4.111.254199.4.111.2554,094
72199.4.112.0/20199.4.112.1 to 199.4.127.254199.4.127.2554,094
73199.4.128.0/20199.4.128.1 to 199.4.143.254199.4.143.2554,094
74199.4.144.0/20199.4.144.1 to 199.4.159.254199.4.159.2554,094
75199.4.160.0/20199.4.160.1 to 199.4.175.254199.4.175.2554,094
76199.4.176.0/20199.4.176.1 to 199.4.191.254199.4.191.2554,094
77199.4.192.0/20199.4.192.1 to 199.4.207.254199.4.207.2554,094
78199.4.208.0/20199.4.208.1 to 199.4.223.254199.4.223.2554,094
79199.4.224.0/20199.4.224.1 to 199.4.239.254199.4.239.2554,094
80199.4.240.0/20199.4.240.1 to 199.4.255.254199.4.255.2554,094
81199.5.0.0/20199.5.0.1 to 199.5.15.254199.5.15.2554,094
82199.5.16.0/20199.5.16.1 to 199.5.31.254199.5.31.2554,094
83199.5.32.0/20199.5.32.1 to 199.5.47.254199.5.47.2554,094
84199.5.48.0/20199.5.48.1 to 199.5.63.254199.5.63.2554,094
85199.5.64.0/20199.5.64.1 to 199.5.79.254199.5.79.2554,094
86199.5.80.0/20199.5.80.1 to 199.5.95.254199.5.95.2554,094
87199.5.96.0/20199.5.96.1 to 199.5.111.254199.5.111.2554,094
88199.5.112.0/20199.5.112.1 to 199.5.127.254199.5.127.2554,094
89199.5.128.0/20199.5.128.1 to 199.5.143.254199.5.143.2554,094
90199.5.144.0/20199.5.144.1 to 199.5.159.254199.5.159.2554,094
91199.5.160.0/20199.5.160.1 to 199.5.175.254199.5.175.2554,094
92199.5.176.0/20199.5.176.1 to 199.5.191.254199.5.191.2554,094
93199.5.192.0/20199.5.192.1 to 199.5.207.254199.5.207.2554,094
94199.5.208.0/20199.5.208.1 to 199.5.223.254199.5.223.2554,094
95199.5.224.0/20199.5.224.1 to 199.5.239.254199.5.239.2554,094
96199.5.240.0/20199.5.240.1 to 199.5.255.254199.5.255.2554,094
97199.6.0.0/20199.6.0.1 to 199.6.15.254199.6.15.2554,094
98199.6.16.0/20199.6.16.1 to 199.6.31.254199.6.31.2554,094
99199.6.32.0/20199.6.32.1 to 199.6.47.254199.6.47.2554,094
100199.6.48.0/20199.6.48.1 to 199.6.63.254199.6.63.2554,094
101199.6.64.0/20199.6.64.1 to 199.6.79.254199.6.79.2554,094
102199.6.80.0/20199.6.80.1 to 199.6.95.254199.6.95.2554,094
103199.6.96.0/20199.6.96.1 to 199.6.111.254199.6.111.2554,094
104199.6.112.0/20199.6.112.1 to 199.6.127.254199.6.127.2554,094
105199.6.128.0/20199.6.128.1 to 199.6.143.254199.6.143.2554,094
106199.6.144.0/20199.6.144.1 to 199.6.159.254199.6.159.2554,094
107199.6.160.0/20199.6.160.1 to 199.6.175.254199.6.175.2554,094
108199.6.176.0/20199.6.176.1 to 199.6.191.254199.6.191.2554,094
109199.6.192.0/20199.6.192.1 to 199.6.207.254199.6.207.2554,094
110199.6.208.0/20199.6.208.1 to 199.6.223.254199.6.223.2554,094
111199.6.224.0/20199.6.224.1 to 199.6.239.254199.6.239.2554,094
112199.6.240.0/20199.6.240.1 to 199.6.255.254199.6.255.2554,094
113199.7.0.0/20199.7.0.1 to 199.7.15.254199.7.15.2554,094
114199.7.16.0/20199.7.16.1 to 199.7.31.254199.7.31.2554,094
115199.7.32.0/20199.7.32.1 to 199.7.47.254199.7.47.2554,094
116199.7.48.0/20199.7.48.1 to 199.7.63.254199.7.63.2554,094
117199.7.64.0/20199.7.64.1 to 199.7.79.254199.7.79.2554,094
118199.7.80.0/20199.7.80.1 to 199.7.95.254199.7.95.2554,094
119199.7.96.0/20199.7.96.1 to 199.7.111.254199.7.111.2554,094
120199.7.112.0/20199.7.112.1 to 199.7.127.254199.7.127.2554,094
121199.7.128.0/20199.7.128.1 to 199.7.143.254199.7.143.2554,094
122199.7.144.0/20199.7.144.1 to 199.7.159.254199.7.159.2554,094
123199.7.160.0/20199.7.160.1 to 199.7.175.254199.7.175.2554,094
124199.7.176.0/20199.7.176.1 to 199.7.191.254199.7.191.2554,094
125199.7.192.0/20199.7.192.1 to 199.7.207.254199.7.207.2554,094
126199.7.208.0/20199.7.208.1 to 199.7.223.254199.7.223.2554,094
127199.7.224.0/20199.7.224.1 to 199.7.239.254199.7.239.2554,094
128199.7.240.0/20199.7.240.1 to 199.7.255.254199.7.255.2554,094
129199.8.0.0/20199.8.0.1 to 199.8.15.254199.8.15.2554,094
130199.8.16.0/20199.8.16.1 to 199.8.31.254199.8.31.2554,094
131199.8.32.0/20199.8.32.1 to 199.8.47.254199.8.47.2554,094
132199.8.48.0/20199.8.48.1 to 199.8.63.254199.8.63.2554,094
133199.8.64.0/20199.8.64.1 to 199.8.79.254199.8.79.2554,094
134199.8.80.0/20199.8.80.1 to 199.8.95.254199.8.95.2554,094
135199.8.96.0/20199.8.96.1 to 199.8.111.254199.8.111.2554,094
136199.8.112.0/20199.8.112.1 to 199.8.127.254199.8.127.2554,094
137199.8.128.0/20199.8.128.1 to 199.8.143.254199.8.143.2554,094
138199.8.144.0/20199.8.144.1 to 199.8.159.254199.8.159.2554,094
139199.8.160.0/20199.8.160.1 to 199.8.175.254199.8.175.2554,094
140199.8.176.0/20199.8.176.1 to 199.8.191.254199.8.191.2554,094
141199.8.192.0/20199.8.192.1 to 199.8.207.254199.8.207.2554,094
142199.8.208.0/20199.8.208.1 to 199.8.223.254199.8.223.2554,094
143199.8.224.0/20199.8.224.1 to 199.8.239.254199.8.239.2554,094
144199.8.240.0/20199.8.240.1 to 199.8.255.254199.8.255.2554,094
145199.9.0.0/20199.9.0.1 to 199.9.15.254199.9.15.2554,094
146199.9.16.0/20199.9.16.1 to 199.9.31.254199.9.31.2554,094
147199.9.32.0/20199.9.32.1 to 199.9.47.254199.9.47.2554,094
148199.9.48.0/20199.9.48.1 to 199.9.63.254199.9.63.2554,094
149199.9.64.0/20199.9.64.1 to 199.9.79.254199.9.79.2554,094
150199.9.80.0/20199.9.80.1 to 199.9.95.254199.9.95.2554,094
151199.9.96.0/20199.9.96.1 to 199.9.111.254199.9.111.2554,094
152199.9.112.0/20199.9.112.1 to 199.9.127.254199.9.127.2554,094
153199.9.128.0/20199.9.128.1 to 199.9.143.254199.9.143.2554,094
154199.9.144.0/20199.9.144.1 to 199.9.159.254199.9.159.2554,094
155199.9.160.0/20199.9.160.1 to 199.9.175.254199.9.175.2554,094
156199.9.176.0/20199.9.176.1 to 199.9.191.254199.9.191.2554,094
157199.9.192.0/20199.9.192.1 to 199.9.207.254199.9.207.2554,094
158199.9.208.0/20199.9.208.1 to 199.9.223.254199.9.223.2554,094
159199.9.224.0/20199.9.224.1 to 199.9.239.254199.9.239.2554,094
160199.9.240.0/20199.9.240.1 to 199.9.255.254199.9.255.2554,094
161199.10.0.0/20199.10.0.1 to 199.10.15.254199.10.15.2554,094
162199.10.16.0/20199.10.16.1 to 199.10.31.254199.10.31.2554,094
163199.10.32.0/20199.10.32.1 to 199.10.47.254199.10.47.2554,094
164199.10.48.0/20199.10.48.1 to 199.10.63.254199.10.63.2554,094
165199.10.64.0/20199.10.64.1 to 199.10.79.254199.10.79.2554,094
166199.10.80.0/20199.10.80.1 to 199.10.95.254199.10.95.2554,094
167199.10.96.0/20199.10.96.1 to 199.10.111.254199.10.111.2554,094
168199.10.112.0/20199.10.112.1 to 199.10.127.254199.10.127.2554,094
169199.10.128.0/20199.10.128.1 to 199.10.143.254199.10.143.2554,094
170199.10.144.0/20199.10.144.1 to 199.10.159.254199.10.159.2554,094
171199.10.160.0/20199.10.160.1 to 199.10.175.254199.10.175.2554,094
172199.10.176.0/20199.10.176.1 to 199.10.191.254199.10.191.2554,094
173199.10.192.0/20199.10.192.1 to 199.10.207.254199.10.207.2554,094
174199.10.208.0/20199.10.208.1 to 199.10.223.254199.10.223.2554,094
175199.10.224.0/20199.10.224.1 to 199.10.239.254199.10.239.2554,094
176199.10.240.0/20199.10.240.1 to 199.10.255.254199.10.255.2554,094
177199.11.0.0/20199.11.0.1 to 199.11.15.254199.11.15.2554,094
178199.11.16.0/20199.11.16.1 to 199.11.31.254199.11.31.2554,094
179199.11.32.0/20199.11.32.1 to 199.11.47.254199.11.47.2554,094
180199.11.48.0/20199.11.48.1 to 199.11.63.254199.11.63.2554,094
181199.11.64.0/20199.11.64.1 to 199.11.79.254199.11.79.2554,094
182199.11.80.0/20199.11.80.1 to 199.11.95.254199.11.95.2554,094
183199.11.96.0/20199.11.96.1 to 199.11.111.254199.11.111.2554,094
184199.11.112.0/20199.11.112.1 to 199.11.127.254199.11.127.2554,094
185199.11.128.0/20199.11.128.1 to 199.11.143.254199.11.143.2554,094
186199.11.144.0/20199.11.144.1 to 199.11.159.254199.11.159.2554,094
187199.11.160.0/20199.11.160.1 to 199.11.175.254199.11.175.2554,094
188199.11.176.0/20199.11.176.1 to 199.11.191.254199.11.191.2554,094
189199.11.192.0/20199.11.192.1 to 199.11.207.254199.11.207.2554,094
190199.11.208.0/20199.11.208.1 to 199.11.223.254199.11.223.2554,094
191199.11.224.0/20199.11.224.1 to 199.11.239.254199.11.239.2554,094
192199.11.240.0/20199.11.240.1 to 199.11.255.254199.11.255.2554,094
193199.12.0.0/20199.12.0.1 to 199.12.15.254199.12.15.2554,094
194199.12.16.0/20199.12.16.1 to 199.12.31.254199.12.31.2554,094
195199.12.32.0/20199.12.32.1 to 199.12.47.254199.12.47.2554,094
196199.12.48.0/20199.12.48.1 to 199.12.63.254199.12.63.2554,094
197199.12.64.0/20199.12.64.1 to 199.12.79.254199.12.79.2554,094
198199.12.80.0/20199.12.80.1 to 199.12.95.254199.12.95.2554,094
199199.12.96.0/20199.12.96.1 to 199.12.111.254199.12.111.2554,094
200199.12.112.0/20199.12.112.1 to 199.12.127.254199.12.127.2554,094
201199.12.128.0/20199.12.128.1 to 199.12.143.254199.12.143.2554,094
202199.12.144.0/20199.12.144.1 to 199.12.159.254199.12.159.2554,094
203199.12.160.0/20199.12.160.1 to 199.12.175.254199.12.175.2554,094
204199.12.176.0/20199.12.176.1 to 199.12.191.254199.12.191.2554,094
205199.12.192.0/20199.12.192.1 to 199.12.207.254199.12.207.2554,094
206199.12.208.0/20199.12.208.1 to 199.12.223.254199.12.223.2554,094
207199.12.224.0/20199.12.224.1 to 199.12.239.254199.12.239.2554,094
208199.12.240.0/20199.12.240.1 to 199.12.255.254199.12.255.2554,094
209199.13.0.0/20199.13.0.1 to 199.13.15.254199.13.15.2554,094
210199.13.16.0/20199.13.16.1 to 199.13.31.254199.13.31.2554,094
211199.13.32.0/20199.13.32.1 to 199.13.47.254199.13.47.2554,094
212199.13.48.0/20199.13.48.1 to 199.13.63.254199.13.63.2554,094
213199.13.64.0/20199.13.64.1 to 199.13.79.254199.13.79.2554,094
214199.13.80.0/20199.13.80.1 to 199.13.95.254199.13.95.2554,094
215199.13.96.0/20199.13.96.1 to 199.13.111.254199.13.111.2554,094
216199.13.112.0/20199.13.112.1 to 199.13.127.254199.13.127.2554,094
217199.13.128.0/20199.13.128.1 to 199.13.143.254199.13.143.2554,094
218199.13.144.0/20199.13.144.1 to 199.13.159.254199.13.159.2554,094
219199.13.160.0/20199.13.160.1 to 199.13.175.254199.13.175.2554,094
220199.13.176.0/20199.13.176.1 to 199.13.191.254199.13.191.2554,094
221199.13.192.0/20199.13.192.1 to 199.13.207.254199.13.207.2554,094
222199.13.208.0/20199.13.208.1 to 199.13.223.254199.13.223.2554,094
223199.13.224.0/20199.13.224.1 to 199.13.239.254199.13.239.2554,094
224199.13.240.0/20199.13.240.1 to 199.13.255.254199.13.255.2554,094
225199.14.0.0/20199.14.0.1 to 199.14.15.254199.14.15.2554,094
226199.14.16.0/20199.14.16.1 to 199.14.31.254199.14.31.2554,094
227199.14.32.0/20199.14.32.1 to 199.14.47.254199.14.47.2554,094
228199.14.48.0/20199.14.48.1 to 199.14.63.254199.14.63.2554,094
229199.14.64.0/20199.14.64.1 to 199.14.79.254199.14.79.2554,094
230199.14.80.0/20199.14.80.1 to 199.14.95.254199.14.95.2554,094
231199.14.96.0/20199.14.96.1 to 199.14.111.254199.14.111.2554,094
232199.14.112.0/20199.14.112.1 to 199.14.127.254199.14.127.2554,094
233199.14.128.0/20199.14.128.1 to 199.14.143.254199.14.143.2554,094
234199.14.144.0/20199.14.144.1 to 199.14.159.254199.14.159.2554,094
235199.14.160.0/20199.14.160.1 to 199.14.175.254199.14.175.2554,094
236199.14.176.0/20199.14.176.1 to 199.14.191.254199.14.191.2554,094
237199.14.192.0/20199.14.192.1 to 199.14.207.254199.14.207.2554,094
238199.14.208.0/20199.14.208.1 to 199.14.223.254199.14.223.2554,094
239199.14.224.0/20199.14.224.1 to 199.14.239.254199.14.239.2554,094
240199.14.240.0/20199.14.240.1 to 199.14.255.254199.14.255.2554,094
241199.15.0.0/20199.15.0.1 to 199.15.15.254199.15.15.2554,094
242199.15.16.0/20199.15.16.1 to 199.15.31.254199.15.31.2554,094
243199.15.32.0/20199.15.32.1 to 199.15.47.254199.15.47.2554,094
244199.15.48.0/20199.15.48.1 to 199.15.63.254199.15.63.2554,094
245199.15.64.0/20199.15.64.1 to 199.15.79.254199.15.79.2554,094
246199.15.80.0/20199.15.80.1 to 199.15.95.254199.15.95.2554,094
247199.15.96.0/20199.15.96.1 to 199.15.111.254199.15.111.2554,094
248199.15.112.0/20199.15.112.1 to 199.15.127.254199.15.127.2554,094
249199.15.128.0/20199.15.128.1 to 199.15.143.254199.15.143.2554,094
250199.15.144.0/20199.15.144.1 to 199.15.159.254199.15.159.2554,094
251199.15.160.0/20199.15.160.1 to 199.15.175.254199.15.175.2554,094
252199.15.176.0/20199.15.176.1 to 199.15.191.254199.15.191.2554,094
253199.15.192.0/20199.15.192.1 to 199.15.207.254199.15.207.2554,094
254199.15.208.0/20199.15.208.1 to 199.15.223.254199.15.223.2554,094
255199.15.224.0/20199.15.224.1 to 199.15.239.254199.15.239.2554,094
256199.15.240.0/20199.15.240.1 to 199.15.255.254199.15.255.2554,094

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.