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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.

Network199.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
199.0.0.0
Broadcast address
199.63.255.255
First usable
199.0.0.1
Last usable
199.63.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
C (default /24)
As numbers
Hex C7000000 · Integer 3338665984 to 3342860287
Reverse DNS zones
0.199.in-addr.arpa
1.199.in-addr.arpa
2.199.in-addr.arpa
3.199.in-addr.arpa
4.199.in-addr.arpa
5.199.in-addr.arpa
6.199.in-addr.arpa
7.199.in-addr.arpa
8.199.in-addr.arpa
9.199.in-addr.arpa
10.199.in-addr.arpa
11.199.in-addr.arpa
12.199.in-addr.arpa
13.199.in-addr.arpa
14.199.in-addr.arpa
15.199.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000111.00000000.00000000.00000000199.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network11000111.00000000.00000000.00000000199.0.0.0
Broadcast11000111.00111111.11111111.11111111199.63.255.255
Split into smaller subnets/21
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

199.0.0.0/10 makes 2,048 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1199.0.0.0/21199.0.0.1 to 199.0.7.254199.0.7.2552,046
2199.0.8.0/21199.0.8.1 to 199.0.15.254199.0.15.2552,046
3199.0.16.0/21199.0.16.1 to 199.0.23.254199.0.23.2552,046
4199.0.24.0/21199.0.24.1 to 199.0.31.254199.0.31.2552,046
5199.0.32.0/21199.0.32.1 to 199.0.39.254199.0.39.2552,046
6199.0.40.0/21199.0.40.1 to 199.0.47.254199.0.47.2552,046
7199.0.48.0/21199.0.48.1 to 199.0.55.254199.0.55.2552,046
8199.0.56.0/21199.0.56.1 to 199.0.63.254199.0.63.2552,046
9199.0.64.0/21199.0.64.1 to 199.0.71.254199.0.71.2552,046
10199.0.72.0/21199.0.72.1 to 199.0.79.254199.0.79.2552,046
11199.0.80.0/21199.0.80.1 to 199.0.87.254199.0.87.2552,046
12199.0.88.0/21199.0.88.1 to 199.0.95.254199.0.95.2552,046
13199.0.96.0/21199.0.96.1 to 199.0.103.254199.0.103.2552,046
14199.0.104.0/21199.0.104.1 to 199.0.111.254199.0.111.2552,046
15199.0.112.0/21199.0.112.1 to 199.0.119.254199.0.119.2552,046
16199.0.120.0/21199.0.120.1 to 199.0.127.254199.0.127.2552,046
17199.0.128.0/21199.0.128.1 to 199.0.135.254199.0.135.2552,046
18199.0.136.0/21199.0.136.1 to 199.0.143.254199.0.143.2552,046
19199.0.144.0/21199.0.144.1 to 199.0.151.254199.0.151.2552,046
20199.0.152.0/21199.0.152.1 to 199.0.159.254199.0.159.2552,046
21199.0.160.0/21199.0.160.1 to 199.0.167.254199.0.167.2552,046
22199.0.168.0/21199.0.168.1 to 199.0.175.254199.0.175.2552,046
23199.0.176.0/21199.0.176.1 to 199.0.183.254199.0.183.2552,046
24199.0.184.0/21199.0.184.1 to 199.0.191.254199.0.191.2552,046
25199.0.192.0/21199.0.192.1 to 199.0.199.254199.0.199.2552,046
26199.0.200.0/21199.0.200.1 to 199.0.207.254199.0.207.2552,046
27199.0.208.0/21199.0.208.1 to 199.0.215.254199.0.215.2552,046
28199.0.216.0/21199.0.216.1 to 199.0.223.254199.0.223.2552,046
29199.0.224.0/21199.0.224.1 to 199.0.231.254199.0.231.2552,046
30199.0.232.0/21199.0.232.1 to 199.0.239.254199.0.239.2552,046
31199.0.240.0/21199.0.240.1 to 199.0.247.254199.0.247.2552,046
32199.0.248.0/21199.0.248.1 to 199.0.255.254199.0.255.2552,046
33199.1.0.0/21199.1.0.1 to 199.1.7.254199.1.7.2552,046
34199.1.8.0/21199.1.8.1 to 199.1.15.254199.1.15.2552,046
35199.1.16.0/21199.1.16.1 to 199.1.23.254199.1.23.2552,046
36199.1.24.0/21199.1.24.1 to 199.1.31.254199.1.31.2552,046
37199.1.32.0/21199.1.32.1 to 199.1.39.254199.1.39.2552,046
38199.1.40.0/21199.1.40.1 to 199.1.47.254199.1.47.2552,046
39199.1.48.0/21199.1.48.1 to 199.1.55.254199.1.55.2552,046
40199.1.56.0/21199.1.56.1 to 199.1.63.254199.1.63.2552,046
41199.1.64.0/21199.1.64.1 to 199.1.71.254199.1.71.2552,046
42199.1.72.0/21199.1.72.1 to 199.1.79.254199.1.79.2552,046
43199.1.80.0/21199.1.80.1 to 199.1.87.254199.1.87.2552,046
44199.1.88.0/21199.1.88.1 to 199.1.95.254199.1.95.2552,046
45199.1.96.0/21199.1.96.1 to 199.1.103.254199.1.103.2552,046
46199.1.104.0/21199.1.104.1 to 199.1.111.254199.1.111.2552,046
47199.1.112.0/21199.1.112.1 to 199.1.119.254199.1.119.2552,046
48199.1.120.0/21199.1.120.1 to 199.1.127.254199.1.127.2552,046
49199.1.128.0/21199.1.128.1 to 199.1.135.254199.1.135.2552,046
50199.1.136.0/21199.1.136.1 to 199.1.143.254199.1.143.2552,046
51199.1.144.0/21199.1.144.1 to 199.1.151.254199.1.151.2552,046
52199.1.152.0/21199.1.152.1 to 199.1.159.254199.1.159.2552,046
53199.1.160.0/21199.1.160.1 to 199.1.167.254199.1.167.2552,046
54199.1.168.0/21199.1.168.1 to 199.1.175.254199.1.175.2552,046
55199.1.176.0/21199.1.176.1 to 199.1.183.254199.1.183.2552,046
56199.1.184.0/21199.1.184.1 to 199.1.191.254199.1.191.2552,046
57199.1.192.0/21199.1.192.1 to 199.1.199.254199.1.199.2552,046
58199.1.200.0/21199.1.200.1 to 199.1.207.254199.1.207.2552,046
59199.1.208.0/21199.1.208.1 to 199.1.215.254199.1.215.2552,046
60199.1.216.0/21199.1.216.1 to 199.1.223.254199.1.223.2552,046
61199.1.224.0/21199.1.224.1 to 199.1.231.254199.1.231.2552,046
62199.1.232.0/21199.1.232.1 to 199.1.239.254199.1.239.2552,046
63199.1.240.0/21199.1.240.1 to 199.1.247.254199.1.247.2552,046
64199.1.248.0/21199.1.248.1 to 199.1.255.254199.1.255.2552,046
65199.2.0.0/21199.2.0.1 to 199.2.7.254199.2.7.2552,046
66199.2.8.0/21199.2.8.1 to 199.2.15.254199.2.15.2552,046
67199.2.16.0/21199.2.16.1 to 199.2.23.254199.2.23.2552,046
68199.2.24.0/21199.2.24.1 to 199.2.31.254199.2.31.2552,046
69199.2.32.0/21199.2.32.1 to 199.2.39.254199.2.39.2552,046
70199.2.40.0/21199.2.40.1 to 199.2.47.254199.2.47.2552,046
71199.2.48.0/21199.2.48.1 to 199.2.55.254199.2.55.2552,046
72199.2.56.0/21199.2.56.1 to 199.2.63.254199.2.63.2552,046
73199.2.64.0/21199.2.64.1 to 199.2.71.254199.2.71.2552,046
74199.2.72.0/21199.2.72.1 to 199.2.79.254199.2.79.2552,046
75199.2.80.0/21199.2.80.1 to 199.2.87.254199.2.87.2552,046
76199.2.88.0/21199.2.88.1 to 199.2.95.254199.2.95.2552,046
77199.2.96.0/21199.2.96.1 to 199.2.103.254199.2.103.2552,046
78199.2.104.0/21199.2.104.1 to 199.2.111.254199.2.111.2552,046
79199.2.112.0/21199.2.112.1 to 199.2.119.254199.2.119.2552,046
80199.2.120.0/21199.2.120.1 to 199.2.127.254199.2.127.2552,046
81199.2.128.0/21199.2.128.1 to 199.2.135.254199.2.135.2552,046
82199.2.136.0/21199.2.136.1 to 199.2.143.254199.2.143.2552,046
83199.2.144.0/21199.2.144.1 to 199.2.151.254199.2.151.2552,046
84199.2.152.0/21199.2.152.1 to 199.2.159.254199.2.159.2552,046
85199.2.160.0/21199.2.160.1 to 199.2.167.254199.2.167.2552,046
86199.2.168.0/21199.2.168.1 to 199.2.175.254199.2.175.2552,046
87199.2.176.0/21199.2.176.1 to 199.2.183.254199.2.183.2552,046
88199.2.184.0/21199.2.184.1 to 199.2.191.254199.2.191.2552,046
89199.2.192.0/21199.2.192.1 to 199.2.199.254199.2.199.2552,046
90199.2.200.0/21199.2.200.1 to 199.2.207.254199.2.207.2552,046
91199.2.208.0/21199.2.208.1 to 199.2.215.254199.2.215.2552,046
92199.2.216.0/21199.2.216.1 to 199.2.223.254199.2.223.2552,046
93199.2.224.0/21199.2.224.1 to 199.2.231.254199.2.231.2552,046
94199.2.232.0/21199.2.232.1 to 199.2.239.254199.2.239.2552,046
95199.2.240.0/21199.2.240.1 to 199.2.247.254199.2.247.2552,046
96199.2.248.0/21199.2.248.1 to 199.2.255.254199.2.255.2552,046
97199.3.0.0/21199.3.0.1 to 199.3.7.254199.3.7.2552,046
98199.3.8.0/21199.3.8.1 to 199.3.15.254199.3.15.2552,046
99199.3.16.0/21199.3.16.1 to 199.3.23.254199.3.23.2552,046
100199.3.24.0/21199.3.24.1 to 199.3.31.254199.3.31.2552,046
101199.3.32.0/21199.3.32.1 to 199.3.39.254199.3.39.2552,046
102199.3.40.0/21199.3.40.1 to 199.3.47.254199.3.47.2552,046
103199.3.48.0/21199.3.48.1 to 199.3.55.254199.3.55.2552,046
104199.3.56.0/21199.3.56.1 to 199.3.63.254199.3.63.2552,046
105199.3.64.0/21199.3.64.1 to 199.3.71.254199.3.71.2552,046
106199.3.72.0/21199.3.72.1 to 199.3.79.254199.3.79.2552,046
107199.3.80.0/21199.3.80.1 to 199.3.87.254199.3.87.2552,046
108199.3.88.0/21199.3.88.1 to 199.3.95.254199.3.95.2552,046
109199.3.96.0/21199.3.96.1 to 199.3.103.254199.3.103.2552,046
110199.3.104.0/21199.3.104.1 to 199.3.111.254199.3.111.2552,046
111199.3.112.0/21199.3.112.1 to 199.3.119.254199.3.119.2552,046
112199.3.120.0/21199.3.120.1 to 199.3.127.254199.3.127.2552,046
113199.3.128.0/21199.3.128.1 to 199.3.135.254199.3.135.2552,046
114199.3.136.0/21199.3.136.1 to 199.3.143.254199.3.143.2552,046
115199.3.144.0/21199.3.144.1 to 199.3.151.254199.3.151.2552,046
116199.3.152.0/21199.3.152.1 to 199.3.159.254199.3.159.2552,046
117199.3.160.0/21199.3.160.1 to 199.3.167.254199.3.167.2552,046
118199.3.168.0/21199.3.168.1 to 199.3.175.254199.3.175.2552,046
119199.3.176.0/21199.3.176.1 to 199.3.183.254199.3.183.2552,046
120199.3.184.0/21199.3.184.1 to 199.3.191.254199.3.191.2552,046
121199.3.192.0/21199.3.192.1 to 199.3.199.254199.3.199.2552,046
122199.3.200.0/21199.3.200.1 to 199.3.207.254199.3.207.2552,046
123199.3.208.0/21199.3.208.1 to 199.3.215.254199.3.215.2552,046
124199.3.216.0/21199.3.216.1 to 199.3.223.254199.3.223.2552,046
125199.3.224.0/21199.3.224.1 to 199.3.231.254199.3.231.2552,046
126199.3.232.0/21199.3.232.1 to 199.3.239.254199.3.239.2552,046
127199.3.240.0/21199.3.240.1 to 199.3.247.254199.3.247.2552,046
128199.3.248.0/21199.3.248.1 to 199.3.255.254199.3.255.2552,046
129199.4.0.0/21199.4.0.1 to 199.4.7.254199.4.7.2552,046
130199.4.8.0/21199.4.8.1 to 199.4.15.254199.4.15.2552,046
131199.4.16.0/21199.4.16.1 to 199.4.23.254199.4.23.2552,046
132199.4.24.0/21199.4.24.1 to 199.4.31.254199.4.31.2552,046
133199.4.32.0/21199.4.32.1 to 199.4.39.254199.4.39.2552,046
134199.4.40.0/21199.4.40.1 to 199.4.47.254199.4.47.2552,046
135199.4.48.0/21199.4.48.1 to 199.4.55.254199.4.55.2552,046
136199.4.56.0/21199.4.56.1 to 199.4.63.254199.4.63.2552,046
137199.4.64.0/21199.4.64.1 to 199.4.71.254199.4.71.2552,046
138199.4.72.0/21199.4.72.1 to 199.4.79.254199.4.79.2552,046
139199.4.80.0/21199.4.80.1 to 199.4.87.254199.4.87.2552,046
140199.4.88.0/21199.4.88.1 to 199.4.95.254199.4.95.2552,046
141199.4.96.0/21199.4.96.1 to 199.4.103.254199.4.103.2552,046
142199.4.104.0/21199.4.104.1 to 199.4.111.254199.4.111.2552,046
143199.4.112.0/21199.4.112.1 to 199.4.119.254199.4.119.2552,046
144199.4.120.0/21199.4.120.1 to 199.4.127.254199.4.127.2552,046
145199.4.128.0/21199.4.128.1 to 199.4.135.254199.4.135.2552,046
146199.4.136.0/21199.4.136.1 to 199.4.143.254199.4.143.2552,046
147199.4.144.0/21199.4.144.1 to 199.4.151.254199.4.151.2552,046
148199.4.152.0/21199.4.152.1 to 199.4.159.254199.4.159.2552,046
149199.4.160.0/21199.4.160.1 to 199.4.167.254199.4.167.2552,046
150199.4.168.0/21199.4.168.1 to 199.4.175.254199.4.175.2552,046
151199.4.176.0/21199.4.176.1 to 199.4.183.254199.4.183.2552,046
152199.4.184.0/21199.4.184.1 to 199.4.191.254199.4.191.2552,046
153199.4.192.0/21199.4.192.1 to 199.4.199.254199.4.199.2552,046
154199.4.200.0/21199.4.200.1 to 199.4.207.254199.4.207.2552,046
155199.4.208.0/21199.4.208.1 to 199.4.215.254199.4.215.2552,046
156199.4.216.0/21199.4.216.1 to 199.4.223.254199.4.223.2552,046
157199.4.224.0/21199.4.224.1 to 199.4.231.254199.4.231.2552,046
158199.4.232.0/21199.4.232.1 to 199.4.239.254199.4.239.2552,046
159199.4.240.0/21199.4.240.1 to 199.4.247.254199.4.247.2552,046
160199.4.248.0/21199.4.248.1 to 199.4.255.254199.4.255.2552,046
161199.5.0.0/21199.5.0.1 to 199.5.7.254199.5.7.2552,046
162199.5.8.0/21199.5.8.1 to 199.5.15.254199.5.15.2552,046
163199.5.16.0/21199.5.16.1 to 199.5.23.254199.5.23.2552,046
164199.5.24.0/21199.5.24.1 to 199.5.31.254199.5.31.2552,046
165199.5.32.0/21199.5.32.1 to 199.5.39.254199.5.39.2552,046
166199.5.40.0/21199.5.40.1 to 199.5.47.254199.5.47.2552,046
167199.5.48.0/21199.5.48.1 to 199.5.55.254199.5.55.2552,046
168199.5.56.0/21199.5.56.1 to 199.5.63.254199.5.63.2552,046
169199.5.64.0/21199.5.64.1 to 199.5.71.254199.5.71.2552,046
170199.5.72.0/21199.5.72.1 to 199.5.79.254199.5.79.2552,046
171199.5.80.0/21199.5.80.1 to 199.5.87.254199.5.87.2552,046
172199.5.88.0/21199.5.88.1 to 199.5.95.254199.5.95.2552,046
173199.5.96.0/21199.5.96.1 to 199.5.103.254199.5.103.2552,046
174199.5.104.0/21199.5.104.1 to 199.5.111.254199.5.111.2552,046
175199.5.112.0/21199.5.112.1 to 199.5.119.254199.5.119.2552,046
176199.5.120.0/21199.5.120.1 to 199.5.127.254199.5.127.2552,046
177199.5.128.0/21199.5.128.1 to 199.5.135.254199.5.135.2552,046
178199.5.136.0/21199.5.136.1 to 199.5.143.254199.5.143.2552,046
179199.5.144.0/21199.5.144.1 to 199.5.151.254199.5.151.2552,046
180199.5.152.0/21199.5.152.1 to 199.5.159.254199.5.159.2552,046
181199.5.160.0/21199.5.160.1 to 199.5.167.254199.5.167.2552,046
182199.5.168.0/21199.5.168.1 to 199.5.175.254199.5.175.2552,046
183199.5.176.0/21199.5.176.1 to 199.5.183.254199.5.183.2552,046
184199.5.184.0/21199.5.184.1 to 199.5.191.254199.5.191.2552,046
185199.5.192.0/21199.5.192.1 to 199.5.199.254199.5.199.2552,046
186199.5.200.0/21199.5.200.1 to 199.5.207.254199.5.207.2552,046
187199.5.208.0/21199.5.208.1 to 199.5.215.254199.5.215.2552,046
188199.5.216.0/21199.5.216.1 to 199.5.223.254199.5.223.2552,046
189199.5.224.0/21199.5.224.1 to 199.5.231.254199.5.231.2552,046
190199.5.232.0/21199.5.232.1 to 199.5.239.254199.5.239.2552,046
191199.5.240.0/21199.5.240.1 to 199.5.247.254199.5.247.2552,046
192199.5.248.0/21199.5.248.1 to 199.5.255.254199.5.255.2552,046
193199.6.0.0/21199.6.0.1 to 199.6.7.254199.6.7.2552,046
194199.6.8.0/21199.6.8.1 to 199.6.15.254199.6.15.2552,046
195199.6.16.0/21199.6.16.1 to 199.6.23.254199.6.23.2552,046
196199.6.24.0/21199.6.24.1 to 199.6.31.254199.6.31.2552,046
197199.6.32.0/21199.6.32.1 to 199.6.39.254199.6.39.2552,046
198199.6.40.0/21199.6.40.1 to 199.6.47.254199.6.47.2552,046
199199.6.48.0/21199.6.48.1 to 199.6.55.254199.6.55.2552,046
200199.6.56.0/21199.6.56.1 to 199.6.63.254199.6.63.2552,046
201199.6.64.0/21199.6.64.1 to 199.6.71.254199.6.71.2552,046
202199.6.72.0/21199.6.72.1 to 199.6.79.254199.6.79.2552,046
203199.6.80.0/21199.6.80.1 to 199.6.87.254199.6.87.2552,046
204199.6.88.0/21199.6.88.1 to 199.6.95.254199.6.95.2552,046
205199.6.96.0/21199.6.96.1 to 199.6.103.254199.6.103.2552,046
206199.6.104.0/21199.6.104.1 to 199.6.111.254199.6.111.2552,046
207199.6.112.0/21199.6.112.1 to 199.6.119.254199.6.119.2552,046
208199.6.120.0/21199.6.120.1 to 199.6.127.254199.6.127.2552,046
209199.6.128.0/21199.6.128.1 to 199.6.135.254199.6.135.2552,046
210199.6.136.0/21199.6.136.1 to 199.6.143.254199.6.143.2552,046
211199.6.144.0/21199.6.144.1 to 199.6.151.254199.6.151.2552,046
212199.6.152.0/21199.6.152.1 to 199.6.159.254199.6.159.2552,046
213199.6.160.0/21199.6.160.1 to 199.6.167.254199.6.167.2552,046
214199.6.168.0/21199.6.168.1 to 199.6.175.254199.6.175.2552,046
215199.6.176.0/21199.6.176.1 to 199.6.183.254199.6.183.2552,046
216199.6.184.0/21199.6.184.1 to 199.6.191.254199.6.191.2552,046
217199.6.192.0/21199.6.192.1 to 199.6.199.254199.6.199.2552,046
218199.6.200.0/21199.6.200.1 to 199.6.207.254199.6.207.2552,046
219199.6.208.0/21199.6.208.1 to 199.6.215.254199.6.215.2552,046
220199.6.216.0/21199.6.216.1 to 199.6.223.254199.6.223.2552,046
221199.6.224.0/21199.6.224.1 to 199.6.231.254199.6.231.2552,046
222199.6.232.0/21199.6.232.1 to 199.6.239.254199.6.239.2552,046
223199.6.240.0/21199.6.240.1 to 199.6.247.254199.6.247.2552,046
224199.6.248.0/21199.6.248.1 to 199.6.255.254199.6.255.2552,046
225199.7.0.0/21199.7.0.1 to 199.7.7.254199.7.7.2552,046
226199.7.8.0/21199.7.8.1 to 199.7.15.254199.7.15.2552,046
227199.7.16.0/21199.7.16.1 to 199.7.23.254199.7.23.2552,046
228199.7.24.0/21199.7.24.1 to 199.7.31.254199.7.31.2552,046
229199.7.32.0/21199.7.32.1 to 199.7.39.254199.7.39.2552,046
230199.7.40.0/21199.7.40.1 to 199.7.47.254199.7.47.2552,046
231199.7.48.0/21199.7.48.1 to 199.7.55.254199.7.55.2552,046
232199.7.56.0/21199.7.56.1 to 199.7.63.254199.7.63.2552,046
233199.7.64.0/21199.7.64.1 to 199.7.71.254199.7.71.2552,046
234199.7.72.0/21199.7.72.1 to 199.7.79.254199.7.79.2552,046
235199.7.80.0/21199.7.80.1 to 199.7.87.254199.7.87.2552,046
236199.7.88.0/21199.7.88.1 to 199.7.95.254199.7.95.2552,046
237199.7.96.0/21199.7.96.1 to 199.7.103.254199.7.103.2552,046
238199.7.104.0/21199.7.104.1 to 199.7.111.254199.7.111.2552,046
239199.7.112.0/21199.7.112.1 to 199.7.119.254199.7.119.2552,046
240199.7.120.0/21199.7.120.1 to 199.7.127.254199.7.127.2552,046
241199.7.128.0/21199.7.128.1 to 199.7.135.254199.7.135.2552,046
242199.7.136.0/21199.7.136.1 to 199.7.143.254199.7.143.2552,046
243199.7.144.0/21199.7.144.1 to 199.7.151.254199.7.151.2552,046
244199.7.152.0/21199.7.152.1 to 199.7.159.254199.7.159.2552,046
245199.7.160.0/21199.7.160.1 to 199.7.167.254199.7.167.2552,046
246199.7.168.0/21199.7.168.1 to 199.7.175.254199.7.175.2552,046
247199.7.176.0/21199.7.176.1 to 199.7.183.254199.7.183.2552,046
248199.7.184.0/21199.7.184.1 to 199.7.191.254199.7.191.2552,046
249199.7.192.0/21199.7.192.1 to 199.7.199.254199.7.199.2552,046
250199.7.200.0/21199.7.200.1 to 199.7.207.254199.7.207.2552,046
251199.7.208.0/21199.7.208.1 to 199.7.215.254199.7.215.2552,046
252199.7.216.0/21199.7.216.1 to 199.7.223.254199.7.223.2552,046
253199.7.224.0/21199.7.224.1 to 199.7.231.254199.7.231.2552,046
254199.7.232.0/21199.7.232.1 to 199.7.239.254199.7.239.2552,046
255199.7.240.0/21199.7.240.1 to 199.7.247.254199.7.247.2552,046
256199.7.248.0/21199.7.248.1 to 199.7.255.254199.7.255.2552,046

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.