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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network200.0.0.0/5
Usable hosts134,217,726
Subnet mask248.0.0.0
Addresses134,217,728
Network address
200.0.0.0
Broadcast address
207.255.255.255
First usable
200.0.0.1
Last usable
207.255.255.254
Usable hosts
134,217,726 (134,217,728 less the network and broadcast addresses)
Subnet mask
248.0.0.0
Wildcard mask
7.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/5
Type
Public public
Old class
C (default /24)
As numbers
Hex C8000000 · Integer 3355443200 to 3489660927
Reverse DNS zones
200.in-addr.arpa
201.in-addr.arpa
202.in-addr.arpa
203.in-addr.arpa
204.in-addr.arpa
205.in-addr.arpa
206.in-addr.arpa
207.in-addr.arpa
/5 is not on a 8-bit boundary, so it takes 8 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11001000.00000000.00000000.00000000200.0.0.0
Subnet mask11111000.00000000.00000000.00000000248.0.0.0
Network11001000.00000000.00000000.00000000200.0.0.0
Broadcast11001111.11111111.11111111.11111111207.255.255.255
Split into smaller subnets/13
/6 (2)/7 (4)/8 (8)/9 (16)/10 (32)/11 (64)/12 (128)/13 (256)/14 (512)/15 (1,024)/16 (2,048)/17 (4,096)

200.0.0.0/5 makes 256 subnets of /13.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1200.0.0.0/13200.0.0.1 to 200.7.255.254200.7.255.255524,286
2200.8.0.0/13200.8.0.1 to 200.15.255.254200.15.255.255524,286
3200.16.0.0/13200.16.0.1 to 200.23.255.254200.23.255.255524,286
4200.24.0.0/13200.24.0.1 to 200.31.255.254200.31.255.255524,286
5200.32.0.0/13200.32.0.1 to 200.39.255.254200.39.255.255524,286
6200.40.0.0/13200.40.0.1 to 200.47.255.254200.47.255.255524,286
7200.48.0.0/13200.48.0.1 to 200.55.255.254200.55.255.255524,286
8200.56.0.0/13200.56.0.1 to 200.63.255.254200.63.255.255524,286
9200.64.0.0/13200.64.0.1 to 200.71.255.254200.71.255.255524,286
10200.72.0.0/13200.72.0.1 to 200.79.255.254200.79.255.255524,286
11200.80.0.0/13200.80.0.1 to 200.87.255.254200.87.255.255524,286
12200.88.0.0/13200.88.0.1 to 200.95.255.254200.95.255.255524,286
13200.96.0.0/13200.96.0.1 to 200.103.255.254200.103.255.255524,286
14200.104.0.0/13200.104.0.1 to 200.111.255.254200.111.255.255524,286
15200.112.0.0/13200.112.0.1 to 200.119.255.254200.119.255.255524,286
16200.120.0.0/13200.120.0.1 to 200.127.255.254200.127.255.255524,286
17200.128.0.0/13200.128.0.1 to 200.135.255.254200.135.255.255524,286
18200.136.0.0/13200.136.0.1 to 200.143.255.254200.143.255.255524,286
19200.144.0.0/13200.144.0.1 to 200.151.255.254200.151.255.255524,286
20200.152.0.0/13200.152.0.1 to 200.159.255.254200.159.255.255524,286
21200.160.0.0/13200.160.0.1 to 200.167.255.254200.167.255.255524,286
22200.168.0.0/13200.168.0.1 to 200.175.255.254200.175.255.255524,286
23200.176.0.0/13200.176.0.1 to 200.183.255.254200.183.255.255524,286
24200.184.0.0/13200.184.0.1 to 200.191.255.254200.191.255.255524,286
25200.192.0.0/13200.192.0.1 to 200.199.255.254200.199.255.255524,286
26200.200.0.0/13200.200.0.1 to 200.207.255.254200.207.255.255524,286
27200.208.0.0/13200.208.0.1 to 200.215.255.254200.215.255.255524,286
28200.216.0.0/13200.216.0.1 to 200.223.255.254200.223.255.255524,286
29200.224.0.0/13200.224.0.1 to 200.231.255.254200.231.255.255524,286
30200.232.0.0/13200.232.0.1 to 200.239.255.254200.239.255.255524,286
31200.240.0.0/13200.240.0.1 to 200.247.255.254200.247.255.255524,286
32200.248.0.0/13200.248.0.1 to 200.255.255.254200.255.255.255524,286
33201.0.0.0/13201.0.0.1 to 201.7.255.254201.7.255.255524,286
34201.8.0.0/13201.8.0.1 to 201.15.255.254201.15.255.255524,286
35201.16.0.0/13201.16.0.1 to 201.23.255.254201.23.255.255524,286
36201.24.0.0/13201.24.0.1 to 201.31.255.254201.31.255.255524,286
37201.32.0.0/13201.32.0.1 to 201.39.255.254201.39.255.255524,286
38201.40.0.0/13201.40.0.1 to 201.47.255.254201.47.255.255524,286
39201.48.0.0/13201.48.0.1 to 201.55.255.254201.55.255.255524,286
40201.56.0.0/13201.56.0.1 to 201.63.255.254201.63.255.255524,286
41201.64.0.0/13201.64.0.1 to 201.71.255.254201.71.255.255524,286
42201.72.0.0/13201.72.0.1 to 201.79.255.254201.79.255.255524,286
43201.80.0.0/13201.80.0.1 to 201.87.255.254201.87.255.255524,286
44201.88.0.0/13201.88.0.1 to 201.95.255.254201.95.255.255524,286
45201.96.0.0/13201.96.0.1 to 201.103.255.254201.103.255.255524,286
46201.104.0.0/13201.104.0.1 to 201.111.255.254201.111.255.255524,286
47201.112.0.0/13201.112.0.1 to 201.119.255.254201.119.255.255524,286
48201.120.0.0/13201.120.0.1 to 201.127.255.254201.127.255.255524,286
49201.128.0.0/13201.128.0.1 to 201.135.255.254201.135.255.255524,286
50201.136.0.0/13201.136.0.1 to 201.143.255.254201.143.255.255524,286
51201.144.0.0/13201.144.0.1 to 201.151.255.254201.151.255.255524,286
52201.152.0.0/13201.152.0.1 to 201.159.255.254201.159.255.255524,286
53201.160.0.0/13201.160.0.1 to 201.167.255.254201.167.255.255524,286
54201.168.0.0/13201.168.0.1 to 201.175.255.254201.175.255.255524,286
55201.176.0.0/13201.176.0.1 to 201.183.255.254201.183.255.255524,286
56201.184.0.0/13201.184.0.1 to 201.191.255.254201.191.255.255524,286
57201.192.0.0/13201.192.0.1 to 201.199.255.254201.199.255.255524,286
58201.200.0.0/13201.200.0.1 to 201.207.255.254201.207.255.255524,286
59201.208.0.0/13201.208.0.1 to 201.215.255.254201.215.255.255524,286
60201.216.0.0/13201.216.0.1 to 201.223.255.254201.223.255.255524,286
61201.224.0.0/13201.224.0.1 to 201.231.255.254201.231.255.255524,286
62201.232.0.0/13201.232.0.1 to 201.239.255.254201.239.255.255524,286
63201.240.0.0/13201.240.0.1 to 201.247.255.254201.247.255.255524,286
64201.248.0.0/13201.248.0.1 to 201.255.255.254201.255.255.255524,286
65202.0.0.0/13202.0.0.1 to 202.7.255.254202.7.255.255524,286
66202.8.0.0/13202.8.0.1 to 202.15.255.254202.15.255.255524,286
67202.16.0.0/13202.16.0.1 to 202.23.255.254202.23.255.255524,286
68202.24.0.0/13202.24.0.1 to 202.31.255.254202.31.255.255524,286
69202.32.0.0/13202.32.0.1 to 202.39.255.254202.39.255.255524,286
70202.40.0.0/13202.40.0.1 to 202.47.255.254202.47.255.255524,286
71202.48.0.0/13202.48.0.1 to 202.55.255.254202.55.255.255524,286
72202.56.0.0/13202.56.0.1 to 202.63.255.254202.63.255.255524,286
73202.64.0.0/13202.64.0.1 to 202.71.255.254202.71.255.255524,286
74202.72.0.0/13202.72.0.1 to 202.79.255.254202.79.255.255524,286
75202.80.0.0/13202.80.0.1 to 202.87.255.254202.87.255.255524,286
76202.88.0.0/13202.88.0.1 to 202.95.255.254202.95.255.255524,286
77202.96.0.0/13202.96.0.1 to 202.103.255.254202.103.255.255524,286
78202.104.0.0/13202.104.0.1 to 202.111.255.254202.111.255.255524,286
79202.112.0.0/13202.112.0.1 to 202.119.255.254202.119.255.255524,286
80202.120.0.0/13202.120.0.1 to 202.127.255.254202.127.255.255524,286
81202.128.0.0/13202.128.0.1 to 202.135.255.254202.135.255.255524,286
82202.136.0.0/13202.136.0.1 to 202.143.255.254202.143.255.255524,286
83202.144.0.0/13202.144.0.1 to 202.151.255.254202.151.255.255524,286
84202.152.0.0/13202.152.0.1 to 202.159.255.254202.159.255.255524,286
85202.160.0.0/13202.160.0.1 to 202.167.255.254202.167.255.255524,286
86202.168.0.0/13202.168.0.1 to 202.175.255.254202.175.255.255524,286
87202.176.0.0/13202.176.0.1 to 202.183.255.254202.183.255.255524,286
88202.184.0.0/13202.184.0.1 to 202.191.255.254202.191.255.255524,286
89202.192.0.0/13202.192.0.1 to 202.199.255.254202.199.255.255524,286
90202.200.0.0/13202.200.0.1 to 202.207.255.254202.207.255.255524,286
91202.208.0.0/13202.208.0.1 to 202.215.255.254202.215.255.255524,286
92202.216.0.0/13202.216.0.1 to 202.223.255.254202.223.255.255524,286
93202.224.0.0/13202.224.0.1 to 202.231.255.254202.231.255.255524,286
94202.232.0.0/13202.232.0.1 to 202.239.255.254202.239.255.255524,286
95202.240.0.0/13202.240.0.1 to 202.247.255.254202.247.255.255524,286
96202.248.0.0/13202.248.0.1 to 202.255.255.254202.255.255.255524,286
97203.0.0.0/13203.0.0.1 to 203.7.255.254203.7.255.255524,286
98203.8.0.0/13203.8.0.1 to 203.15.255.254203.15.255.255524,286
99203.16.0.0/13203.16.0.1 to 203.23.255.254203.23.255.255524,286
100203.24.0.0/13203.24.0.1 to 203.31.255.254203.31.255.255524,286
101203.32.0.0/13203.32.0.1 to 203.39.255.254203.39.255.255524,286
102203.40.0.0/13203.40.0.1 to 203.47.255.254203.47.255.255524,286
103203.48.0.0/13203.48.0.1 to 203.55.255.254203.55.255.255524,286
104203.56.0.0/13203.56.0.1 to 203.63.255.254203.63.255.255524,286
105203.64.0.0/13203.64.0.1 to 203.71.255.254203.71.255.255524,286
106203.72.0.0/13203.72.0.1 to 203.79.255.254203.79.255.255524,286
107203.80.0.0/13203.80.0.1 to 203.87.255.254203.87.255.255524,286
108203.88.0.0/13203.88.0.1 to 203.95.255.254203.95.255.255524,286
109203.96.0.0/13203.96.0.1 to 203.103.255.254203.103.255.255524,286
110203.104.0.0/13203.104.0.1 to 203.111.255.254203.111.255.255524,286
111203.112.0.0/13203.112.0.1 to 203.119.255.254203.119.255.255524,286
112203.120.0.0/13203.120.0.1 to 203.127.255.254203.127.255.255524,286
113203.128.0.0/13203.128.0.1 to 203.135.255.254203.135.255.255524,286
114203.136.0.0/13203.136.0.1 to 203.143.255.254203.143.255.255524,286
115203.144.0.0/13203.144.0.1 to 203.151.255.254203.151.255.255524,286
116203.152.0.0/13203.152.0.1 to 203.159.255.254203.159.255.255524,286
117203.160.0.0/13203.160.0.1 to 203.167.255.254203.167.255.255524,286
118203.168.0.0/13203.168.0.1 to 203.175.255.254203.175.255.255524,286
119203.176.0.0/13203.176.0.1 to 203.183.255.254203.183.255.255524,286
120203.184.0.0/13203.184.0.1 to 203.191.255.254203.191.255.255524,286
121203.192.0.0/13203.192.0.1 to 203.199.255.254203.199.255.255524,286
122203.200.0.0/13203.200.0.1 to 203.207.255.254203.207.255.255524,286
123203.208.0.0/13203.208.0.1 to 203.215.255.254203.215.255.255524,286
124203.216.0.0/13203.216.0.1 to 203.223.255.254203.223.255.255524,286
125203.224.0.0/13203.224.0.1 to 203.231.255.254203.231.255.255524,286
126203.232.0.0/13203.232.0.1 to 203.239.255.254203.239.255.255524,286
127203.240.0.0/13203.240.0.1 to 203.247.255.254203.247.255.255524,286
128203.248.0.0/13203.248.0.1 to 203.255.255.254203.255.255.255524,286
129204.0.0.0/13204.0.0.1 to 204.7.255.254204.7.255.255524,286
130204.8.0.0/13204.8.0.1 to 204.15.255.254204.15.255.255524,286
131204.16.0.0/13204.16.0.1 to 204.23.255.254204.23.255.255524,286
132204.24.0.0/13204.24.0.1 to 204.31.255.254204.31.255.255524,286
133204.32.0.0/13204.32.0.1 to 204.39.255.254204.39.255.255524,286
134204.40.0.0/13204.40.0.1 to 204.47.255.254204.47.255.255524,286
135204.48.0.0/13204.48.0.1 to 204.55.255.254204.55.255.255524,286
136204.56.0.0/13204.56.0.1 to 204.63.255.254204.63.255.255524,286
137204.64.0.0/13204.64.0.1 to 204.71.255.254204.71.255.255524,286
138204.72.0.0/13204.72.0.1 to 204.79.255.254204.79.255.255524,286
139204.80.0.0/13204.80.0.1 to 204.87.255.254204.87.255.255524,286
140204.88.0.0/13204.88.0.1 to 204.95.255.254204.95.255.255524,286
141204.96.0.0/13204.96.0.1 to 204.103.255.254204.103.255.255524,286
142204.104.0.0/13204.104.0.1 to 204.111.255.254204.111.255.255524,286
143204.112.0.0/13204.112.0.1 to 204.119.255.254204.119.255.255524,286
144204.120.0.0/13204.120.0.1 to 204.127.255.254204.127.255.255524,286
145204.128.0.0/13204.128.0.1 to 204.135.255.254204.135.255.255524,286
146204.136.0.0/13204.136.0.1 to 204.143.255.254204.143.255.255524,286
147204.144.0.0/13204.144.0.1 to 204.151.255.254204.151.255.255524,286
148204.152.0.0/13204.152.0.1 to 204.159.255.254204.159.255.255524,286
149204.160.0.0/13204.160.0.1 to 204.167.255.254204.167.255.255524,286
150204.168.0.0/13204.168.0.1 to 204.175.255.254204.175.255.255524,286
151204.176.0.0/13204.176.0.1 to 204.183.255.254204.183.255.255524,286
152204.184.0.0/13204.184.0.1 to 204.191.255.254204.191.255.255524,286
153204.192.0.0/13204.192.0.1 to 204.199.255.254204.199.255.255524,286
154204.200.0.0/13204.200.0.1 to 204.207.255.254204.207.255.255524,286
155204.208.0.0/13204.208.0.1 to 204.215.255.254204.215.255.255524,286
156204.216.0.0/13204.216.0.1 to 204.223.255.254204.223.255.255524,286
157204.224.0.0/13204.224.0.1 to 204.231.255.254204.231.255.255524,286
158204.232.0.0/13204.232.0.1 to 204.239.255.254204.239.255.255524,286
159204.240.0.0/13204.240.0.1 to 204.247.255.254204.247.255.255524,286
160204.248.0.0/13204.248.0.1 to 204.255.255.254204.255.255.255524,286
161205.0.0.0/13205.0.0.1 to 205.7.255.254205.7.255.255524,286
162205.8.0.0/13205.8.0.1 to 205.15.255.254205.15.255.255524,286
163205.16.0.0/13205.16.0.1 to 205.23.255.254205.23.255.255524,286
164205.24.0.0/13205.24.0.1 to 205.31.255.254205.31.255.255524,286
165205.32.0.0/13205.32.0.1 to 205.39.255.254205.39.255.255524,286
166205.40.0.0/13205.40.0.1 to 205.47.255.254205.47.255.255524,286
167205.48.0.0/13205.48.0.1 to 205.55.255.254205.55.255.255524,286
168205.56.0.0/13205.56.0.1 to 205.63.255.254205.63.255.255524,286
169205.64.0.0/13205.64.0.1 to 205.71.255.254205.71.255.255524,286
170205.72.0.0/13205.72.0.1 to 205.79.255.254205.79.255.255524,286
171205.80.0.0/13205.80.0.1 to 205.87.255.254205.87.255.255524,286
172205.88.0.0/13205.88.0.1 to 205.95.255.254205.95.255.255524,286
173205.96.0.0/13205.96.0.1 to 205.103.255.254205.103.255.255524,286
174205.104.0.0/13205.104.0.1 to 205.111.255.254205.111.255.255524,286
175205.112.0.0/13205.112.0.1 to 205.119.255.254205.119.255.255524,286
176205.120.0.0/13205.120.0.1 to 205.127.255.254205.127.255.255524,286
177205.128.0.0/13205.128.0.1 to 205.135.255.254205.135.255.255524,286
178205.136.0.0/13205.136.0.1 to 205.143.255.254205.143.255.255524,286
179205.144.0.0/13205.144.0.1 to 205.151.255.254205.151.255.255524,286
180205.152.0.0/13205.152.0.1 to 205.159.255.254205.159.255.255524,286
181205.160.0.0/13205.160.0.1 to 205.167.255.254205.167.255.255524,286
182205.168.0.0/13205.168.0.1 to 205.175.255.254205.175.255.255524,286
183205.176.0.0/13205.176.0.1 to 205.183.255.254205.183.255.255524,286
184205.184.0.0/13205.184.0.1 to 205.191.255.254205.191.255.255524,286
185205.192.0.0/13205.192.0.1 to 205.199.255.254205.199.255.255524,286
186205.200.0.0/13205.200.0.1 to 205.207.255.254205.207.255.255524,286
187205.208.0.0/13205.208.0.1 to 205.215.255.254205.215.255.255524,286
188205.216.0.0/13205.216.0.1 to 205.223.255.254205.223.255.255524,286
189205.224.0.0/13205.224.0.1 to 205.231.255.254205.231.255.255524,286
190205.232.0.0/13205.232.0.1 to 205.239.255.254205.239.255.255524,286
191205.240.0.0/13205.240.0.1 to 205.247.255.254205.247.255.255524,286
192205.248.0.0/13205.248.0.1 to 205.255.255.254205.255.255.255524,286
193206.0.0.0/13206.0.0.1 to 206.7.255.254206.7.255.255524,286
194206.8.0.0/13206.8.0.1 to 206.15.255.254206.15.255.255524,286
195206.16.0.0/13206.16.0.1 to 206.23.255.254206.23.255.255524,286
196206.24.0.0/13206.24.0.1 to 206.31.255.254206.31.255.255524,286
197206.32.0.0/13206.32.0.1 to 206.39.255.254206.39.255.255524,286
198206.40.0.0/13206.40.0.1 to 206.47.255.254206.47.255.255524,286
199206.48.0.0/13206.48.0.1 to 206.55.255.254206.55.255.255524,286
200206.56.0.0/13206.56.0.1 to 206.63.255.254206.63.255.255524,286
201206.64.0.0/13206.64.0.1 to 206.71.255.254206.71.255.255524,286
202206.72.0.0/13206.72.0.1 to 206.79.255.254206.79.255.255524,286
203206.80.0.0/13206.80.0.1 to 206.87.255.254206.87.255.255524,286
204206.88.0.0/13206.88.0.1 to 206.95.255.254206.95.255.255524,286
205206.96.0.0/13206.96.0.1 to 206.103.255.254206.103.255.255524,286
206206.104.0.0/13206.104.0.1 to 206.111.255.254206.111.255.255524,286
207206.112.0.0/13206.112.0.1 to 206.119.255.254206.119.255.255524,286
208206.120.0.0/13206.120.0.1 to 206.127.255.254206.127.255.255524,286
209206.128.0.0/13206.128.0.1 to 206.135.255.254206.135.255.255524,286
210206.136.0.0/13206.136.0.1 to 206.143.255.254206.143.255.255524,286
211206.144.0.0/13206.144.0.1 to 206.151.255.254206.151.255.255524,286
212206.152.0.0/13206.152.0.1 to 206.159.255.254206.159.255.255524,286
213206.160.0.0/13206.160.0.1 to 206.167.255.254206.167.255.255524,286
214206.168.0.0/13206.168.0.1 to 206.175.255.254206.175.255.255524,286
215206.176.0.0/13206.176.0.1 to 206.183.255.254206.183.255.255524,286
216206.184.0.0/13206.184.0.1 to 206.191.255.254206.191.255.255524,286
217206.192.0.0/13206.192.0.1 to 206.199.255.254206.199.255.255524,286
218206.200.0.0/13206.200.0.1 to 206.207.255.254206.207.255.255524,286
219206.208.0.0/13206.208.0.1 to 206.215.255.254206.215.255.255524,286
220206.216.0.0/13206.216.0.1 to 206.223.255.254206.223.255.255524,286
221206.224.0.0/13206.224.0.1 to 206.231.255.254206.231.255.255524,286
222206.232.0.0/13206.232.0.1 to 206.239.255.254206.239.255.255524,286
223206.240.0.0/13206.240.0.1 to 206.247.255.254206.247.255.255524,286
224206.248.0.0/13206.248.0.1 to 206.255.255.254206.255.255.255524,286
225207.0.0.0/13207.0.0.1 to 207.7.255.254207.7.255.255524,286
226207.8.0.0/13207.8.0.1 to 207.15.255.254207.15.255.255524,286
227207.16.0.0/13207.16.0.1 to 207.23.255.254207.23.255.255524,286
228207.24.0.0/13207.24.0.1 to 207.31.255.254207.31.255.255524,286
229207.32.0.0/13207.32.0.1 to 207.39.255.254207.39.255.255524,286
230207.40.0.0/13207.40.0.1 to 207.47.255.254207.47.255.255524,286
231207.48.0.0/13207.48.0.1 to 207.55.255.254207.55.255.255524,286
232207.56.0.0/13207.56.0.1 to 207.63.255.254207.63.255.255524,286
233207.64.0.0/13207.64.0.1 to 207.71.255.254207.71.255.255524,286
234207.72.0.0/13207.72.0.1 to 207.79.255.254207.79.255.255524,286
235207.80.0.0/13207.80.0.1 to 207.87.255.254207.87.255.255524,286
236207.88.0.0/13207.88.0.1 to 207.95.255.254207.95.255.255524,286
237207.96.0.0/13207.96.0.1 to 207.103.255.254207.103.255.255524,286
238207.104.0.0/13207.104.0.1 to 207.111.255.254207.111.255.255524,286
239207.112.0.0/13207.112.0.1 to 207.119.255.254207.119.255.255524,286
240207.120.0.0/13207.120.0.1 to 207.127.255.254207.127.255.255524,286
241207.128.0.0/13207.128.0.1 to 207.135.255.254207.135.255.255524,286
242207.136.0.0/13207.136.0.1 to 207.143.255.254207.143.255.255524,286
243207.144.0.0/13207.144.0.1 to 207.151.255.254207.151.255.255524,286
244207.152.0.0/13207.152.0.1 to 207.159.255.254207.159.255.255524,286
245207.160.0.0/13207.160.0.1 to 207.167.255.254207.167.255.255524,286
246207.168.0.0/13207.168.0.1 to 207.175.255.254207.175.255.255524,286
247207.176.0.0/13207.176.0.1 to 207.183.255.254207.183.255.255524,286
248207.184.0.0/13207.184.0.1 to 207.191.255.254207.191.255.255524,286
249207.192.0.0/13207.192.0.1 to 207.199.255.254207.199.255.255524,286
250207.200.0.0/13207.200.0.1 to 207.207.255.254207.207.255.255524,286
251207.208.0.0/13207.208.0.1 to 207.215.255.254207.215.255.255524,286
252207.216.0.0/13207.216.0.1 to 207.223.255.254207.223.255.255524,286
253207.224.0.0/13207.224.0.1 to 207.231.255.254207.231.255.255524,286
254207.232.0.0/13207.232.0.1 to 207.239.255.254207.239.255.255524,286
255207.240.0.0/13207.240.0.1 to 207.247.255.254207.247.255.255524,286
256207.248.0.0/13207.248.0.1 to 207.255.255.254207.255.255.255524,286

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.