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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.

Network245.72.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
245.72.0.0
Broadcast address
245.79.255.255
First usable
245.72.0.1
Last usable
245.79.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F5480000 · Integer 4115136512 to 4115660799
Reverse DNS zones
72.245.in-addr.arpa
73.245.in-addr.arpa
74.245.in-addr.arpa
75.245.in-addr.arpa
76.245.in-addr.arpa
77.245.in-addr.arpa
78.245.in-addr.arpa
79.245.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11110101.01001000.00000000.00000000245.72.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network11110101.01001000.00000000.00000000245.72.0.0
Broadcast11110101.01001111.11111111.11111111245.79.255.255
Split into smaller subnets/22
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

245.72.0.0/13 makes 512 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1245.72.0.0/22245.72.0.1 to 245.72.3.254245.72.3.2551,022
2245.72.4.0/22245.72.4.1 to 245.72.7.254245.72.7.2551,022
3245.72.8.0/22245.72.8.1 to 245.72.11.254245.72.11.2551,022
4245.72.12.0/22245.72.12.1 to 245.72.15.254245.72.15.2551,022
5245.72.16.0/22245.72.16.1 to 245.72.19.254245.72.19.2551,022
6245.72.20.0/22245.72.20.1 to 245.72.23.254245.72.23.2551,022
7245.72.24.0/22245.72.24.1 to 245.72.27.254245.72.27.2551,022
8245.72.28.0/22245.72.28.1 to 245.72.31.254245.72.31.2551,022
9245.72.32.0/22245.72.32.1 to 245.72.35.254245.72.35.2551,022
10245.72.36.0/22245.72.36.1 to 245.72.39.254245.72.39.2551,022
11245.72.40.0/22245.72.40.1 to 245.72.43.254245.72.43.2551,022
12245.72.44.0/22245.72.44.1 to 245.72.47.254245.72.47.2551,022
13245.72.48.0/22245.72.48.1 to 245.72.51.254245.72.51.2551,022
14245.72.52.0/22245.72.52.1 to 245.72.55.254245.72.55.2551,022
15245.72.56.0/22245.72.56.1 to 245.72.59.254245.72.59.2551,022
16245.72.60.0/22245.72.60.1 to 245.72.63.254245.72.63.2551,022
17245.72.64.0/22245.72.64.1 to 245.72.67.254245.72.67.2551,022
18245.72.68.0/22245.72.68.1 to 245.72.71.254245.72.71.2551,022
19245.72.72.0/22245.72.72.1 to 245.72.75.254245.72.75.2551,022
20245.72.76.0/22245.72.76.1 to 245.72.79.254245.72.79.2551,022
21245.72.80.0/22245.72.80.1 to 245.72.83.254245.72.83.2551,022
22245.72.84.0/22245.72.84.1 to 245.72.87.254245.72.87.2551,022
23245.72.88.0/22245.72.88.1 to 245.72.91.254245.72.91.2551,022
24245.72.92.0/22245.72.92.1 to 245.72.95.254245.72.95.2551,022
25245.72.96.0/22245.72.96.1 to 245.72.99.254245.72.99.2551,022
26245.72.100.0/22245.72.100.1 to 245.72.103.254245.72.103.2551,022
27245.72.104.0/22245.72.104.1 to 245.72.107.254245.72.107.2551,022
28245.72.108.0/22245.72.108.1 to 245.72.111.254245.72.111.2551,022
29245.72.112.0/22245.72.112.1 to 245.72.115.254245.72.115.2551,022
30245.72.116.0/22245.72.116.1 to 245.72.119.254245.72.119.2551,022
31245.72.120.0/22245.72.120.1 to 245.72.123.254245.72.123.2551,022
32245.72.124.0/22245.72.124.1 to 245.72.127.254245.72.127.2551,022
33245.72.128.0/22245.72.128.1 to 245.72.131.254245.72.131.2551,022
34245.72.132.0/22245.72.132.1 to 245.72.135.254245.72.135.2551,022
35245.72.136.0/22245.72.136.1 to 245.72.139.254245.72.139.2551,022
36245.72.140.0/22245.72.140.1 to 245.72.143.254245.72.143.2551,022
37245.72.144.0/22245.72.144.1 to 245.72.147.254245.72.147.2551,022
38245.72.148.0/22245.72.148.1 to 245.72.151.254245.72.151.2551,022
39245.72.152.0/22245.72.152.1 to 245.72.155.254245.72.155.2551,022
40245.72.156.0/22245.72.156.1 to 245.72.159.254245.72.159.2551,022
41245.72.160.0/22245.72.160.1 to 245.72.163.254245.72.163.2551,022
42245.72.164.0/22245.72.164.1 to 245.72.167.254245.72.167.2551,022
43245.72.168.0/22245.72.168.1 to 245.72.171.254245.72.171.2551,022
44245.72.172.0/22245.72.172.1 to 245.72.175.254245.72.175.2551,022
45245.72.176.0/22245.72.176.1 to 245.72.179.254245.72.179.2551,022
46245.72.180.0/22245.72.180.1 to 245.72.183.254245.72.183.2551,022
47245.72.184.0/22245.72.184.1 to 245.72.187.254245.72.187.2551,022
48245.72.188.0/22245.72.188.1 to 245.72.191.254245.72.191.2551,022
49245.72.192.0/22245.72.192.1 to 245.72.195.254245.72.195.2551,022
50245.72.196.0/22245.72.196.1 to 245.72.199.254245.72.199.2551,022
51245.72.200.0/22245.72.200.1 to 245.72.203.254245.72.203.2551,022
52245.72.204.0/22245.72.204.1 to 245.72.207.254245.72.207.2551,022
53245.72.208.0/22245.72.208.1 to 245.72.211.254245.72.211.2551,022
54245.72.212.0/22245.72.212.1 to 245.72.215.254245.72.215.2551,022
55245.72.216.0/22245.72.216.1 to 245.72.219.254245.72.219.2551,022
56245.72.220.0/22245.72.220.1 to 245.72.223.254245.72.223.2551,022
57245.72.224.0/22245.72.224.1 to 245.72.227.254245.72.227.2551,022
58245.72.228.0/22245.72.228.1 to 245.72.231.254245.72.231.2551,022
59245.72.232.0/22245.72.232.1 to 245.72.235.254245.72.235.2551,022
60245.72.236.0/22245.72.236.1 to 245.72.239.254245.72.239.2551,022
61245.72.240.0/22245.72.240.1 to 245.72.243.254245.72.243.2551,022
62245.72.244.0/22245.72.244.1 to 245.72.247.254245.72.247.2551,022
63245.72.248.0/22245.72.248.1 to 245.72.251.254245.72.251.2551,022
64245.72.252.0/22245.72.252.1 to 245.72.255.254245.72.255.2551,022
65245.73.0.0/22245.73.0.1 to 245.73.3.254245.73.3.2551,022
66245.73.4.0/22245.73.4.1 to 245.73.7.254245.73.7.2551,022
67245.73.8.0/22245.73.8.1 to 245.73.11.254245.73.11.2551,022
68245.73.12.0/22245.73.12.1 to 245.73.15.254245.73.15.2551,022
69245.73.16.0/22245.73.16.1 to 245.73.19.254245.73.19.2551,022
70245.73.20.0/22245.73.20.1 to 245.73.23.254245.73.23.2551,022
71245.73.24.0/22245.73.24.1 to 245.73.27.254245.73.27.2551,022
72245.73.28.0/22245.73.28.1 to 245.73.31.254245.73.31.2551,022
73245.73.32.0/22245.73.32.1 to 245.73.35.254245.73.35.2551,022
74245.73.36.0/22245.73.36.1 to 245.73.39.254245.73.39.2551,022
75245.73.40.0/22245.73.40.1 to 245.73.43.254245.73.43.2551,022
76245.73.44.0/22245.73.44.1 to 245.73.47.254245.73.47.2551,022
77245.73.48.0/22245.73.48.1 to 245.73.51.254245.73.51.2551,022
78245.73.52.0/22245.73.52.1 to 245.73.55.254245.73.55.2551,022
79245.73.56.0/22245.73.56.1 to 245.73.59.254245.73.59.2551,022
80245.73.60.0/22245.73.60.1 to 245.73.63.254245.73.63.2551,022
81245.73.64.0/22245.73.64.1 to 245.73.67.254245.73.67.2551,022
82245.73.68.0/22245.73.68.1 to 245.73.71.254245.73.71.2551,022
83245.73.72.0/22245.73.72.1 to 245.73.75.254245.73.75.2551,022
84245.73.76.0/22245.73.76.1 to 245.73.79.254245.73.79.2551,022
85245.73.80.0/22245.73.80.1 to 245.73.83.254245.73.83.2551,022
86245.73.84.0/22245.73.84.1 to 245.73.87.254245.73.87.2551,022
87245.73.88.0/22245.73.88.1 to 245.73.91.254245.73.91.2551,022
88245.73.92.0/22245.73.92.1 to 245.73.95.254245.73.95.2551,022
89245.73.96.0/22245.73.96.1 to 245.73.99.254245.73.99.2551,022
90245.73.100.0/22245.73.100.1 to 245.73.103.254245.73.103.2551,022
91245.73.104.0/22245.73.104.1 to 245.73.107.254245.73.107.2551,022
92245.73.108.0/22245.73.108.1 to 245.73.111.254245.73.111.2551,022
93245.73.112.0/22245.73.112.1 to 245.73.115.254245.73.115.2551,022
94245.73.116.0/22245.73.116.1 to 245.73.119.254245.73.119.2551,022
95245.73.120.0/22245.73.120.1 to 245.73.123.254245.73.123.2551,022
96245.73.124.0/22245.73.124.1 to 245.73.127.254245.73.127.2551,022
97245.73.128.0/22245.73.128.1 to 245.73.131.254245.73.131.2551,022
98245.73.132.0/22245.73.132.1 to 245.73.135.254245.73.135.2551,022
99245.73.136.0/22245.73.136.1 to 245.73.139.254245.73.139.2551,022
100245.73.140.0/22245.73.140.1 to 245.73.143.254245.73.143.2551,022
101245.73.144.0/22245.73.144.1 to 245.73.147.254245.73.147.2551,022
102245.73.148.0/22245.73.148.1 to 245.73.151.254245.73.151.2551,022
103245.73.152.0/22245.73.152.1 to 245.73.155.254245.73.155.2551,022
104245.73.156.0/22245.73.156.1 to 245.73.159.254245.73.159.2551,022
105245.73.160.0/22245.73.160.1 to 245.73.163.254245.73.163.2551,022
106245.73.164.0/22245.73.164.1 to 245.73.167.254245.73.167.2551,022
107245.73.168.0/22245.73.168.1 to 245.73.171.254245.73.171.2551,022
108245.73.172.0/22245.73.172.1 to 245.73.175.254245.73.175.2551,022
109245.73.176.0/22245.73.176.1 to 245.73.179.254245.73.179.2551,022
110245.73.180.0/22245.73.180.1 to 245.73.183.254245.73.183.2551,022
111245.73.184.0/22245.73.184.1 to 245.73.187.254245.73.187.2551,022
112245.73.188.0/22245.73.188.1 to 245.73.191.254245.73.191.2551,022
113245.73.192.0/22245.73.192.1 to 245.73.195.254245.73.195.2551,022
114245.73.196.0/22245.73.196.1 to 245.73.199.254245.73.199.2551,022
115245.73.200.0/22245.73.200.1 to 245.73.203.254245.73.203.2551,022
116245.73.204.0/22245.73.204.1 to 245.73.207.254245.73.207.2551,022
117245.73.208.0/22245.73.208.1 to 245.73.211.254245.73.211.2551,022
118245.73.212.0/22245.73.212.1 to 245.73.215.254245.73.215.2551,022
119245.73.216.0/22245.73.216.1 to 245.73.219.254245.73.219.2551,022
120245.73.220.0/22245.73.220.1 to 245.73.223.254245.73.223.2551,022
121245.73.224.0/22245.73.224.1 to 245.73.227.254245.73.227.2551,022
122245.73.228.0/22245.73.228.1 to 245.73.231.254245.73.231.2551,022
123245.73.232.0/22245.73.232.1 to 245.73.235.254245.73.235.2551,022
124245.73.236.0/22245.73.236.1 to 245.73.239.254245.73.239.2551,022
125245.73.240.0/22245.73.240.1 to 245.73.243.254245.73.243.2551,022
126245.73.244.0/22245.73.244.1 to 245.73.247.254245.73.247.2551,022
127245.73.248.0/22245.73.248.1 to 245.73.251.254245.73.251.2551,022
128245.73.252.0/22245.73.252.1 to 245.73.255.254245.73.255.2551,022
129245.74.0.0/22245.74.0.1 to 245.74.3.254245.74.3.2551,022
130245.74.4.0/22245.74.4.1 to 245.74.7.254245.74.7.2551,022
131245.74.8.0/22245.74.8.1 to 245.74.11.254245.74.11.2551,022
132245.74.12.0/22245.74.12.1 to 245.74.15.254245.74.15.2551,022
133245.74.16.0/22245.74.16.1 to 245.74.19.254245.74.19.2551,022
134245.74.20.0/22245.74.20.1 to 245.74.23.254245.74.23.2551,022
135245.74.24.0/22245.74.24.1 to 245.74.27.254245.74.27.2551,022
136245.74.28.0/22245.74.28.1 to 245.74.31.254245.74.31.2551,022
137245.74.32.0/22245.74.32.1 to 245.74.35.254245.74.35.2551,022
138245.74.36.0/22245.74.36.1 to 245.74.39.254245.74.39.2551,022
139245.74.40.0/22245.74.40.1 to 245.74.43.254245.74.43.2551,022
140245.74.44.0/22245.74.44.1 to 245.74.47.254245.74.47.2551,022
141245.74.48.0/22245.74.48.1 to 245.74.51.254245.74.51.2551,022
142245.74.52.0/22245.74.52.1 to 245.74.55.254245.74.55.2551,022
143245.74.56.0/22245.74.56.1 to 245.74.59.254245.74.59.2551,022
144245.74.60.0/22245.74.60.1 to 245.74.63.254245.74.63.2551,022
145245.74.64.0/22245.74.64.1 to 245.74.67.254245.74.67.2551,022
146245.74.68.0/22245.74.68.1 to 245.74.71.254245.74.71.2551,022
147245.74.72.0/22245.74.72.1 to 245.74.75.254245.74.75.2551,022
148245.74.76.0/22245.74.76.1 to 245.74.79.254245.74.79.2551,022
149245.74.80.0/22245.74.80.1 to 245.74.83.254245.74.83.2551,022
150245.74.84.0/22245.74.84.1 to 245.74.87.254245.74.87.2551,022
151245.74.88.0/22245.74.88.1 to 245.74.91.254245.74.91.2551,022
152245.74.92.0/22245.74.92.1 to 245.74.95.254245.74.95.2551,022
153245.74.96.0/22245.74.96.1 to 245.74.99.254245.74.99.2551,022
154245.74.100.0/22245.74.100.1 to 245.74.103.254245.74.103.2551,022
155245.74.104.0/22245.74.104.1 to 245.74.107.254245.74.107.2551,022
156245.74.108.0/22245.74.108.1 to 245.74.111.254245.74.111.2551,022
157245.74.112.0/22245.74.112.1 to 245.74.115.254245.74.115.2551,022
158245.74.116.0/22245.74.116.1 to 245.74.119.254245.74.119.2551,022
159245.74.120.0/22245.74.120.1 to 245.74.123.254245.74.123.2551,022
160245.74.124.0/22245.74.124.1 to 245.74.127.254245.74.127.2551,022
161245.74.128.0/22245.74.128.1 to 245.74.131.254245.74.131.2551,022
162245.74.132.0/22245.74.132.1 to 245.74.135.254245.74.135.2551,022
163245.74.136.0/22245.74.136.1 to 245.74.139.254245.74.139.2551,022
164245.74.140.0/22245.74.140.1 to 245.74.143.254245.74.143.2551,022
165245.74.144.0/22245.74.144.1 to 245.74.147.254245.74.147.2551,022
166245.74.148.0/22245.74.148.1 to 245.74.151.254245.74.151.2551,022
167245.74.152.0/22245.74.152.1 to 245.74.155.254245.74.155.2551,022
168245.74.156.0/22245.74.156.1 to 245.74.159.254245.74.159.2551,022
169245.74.160.0/22245.74.160.1 to 245.74.163.254245.74.163.2551,022
170245.74.164.0/22245.74.164.1 to 245.74.167.254245.74.167.2551,022
171245.74.168.0/22245.74.168.1 to 245.74.171.254245.74.171.2551,022
172245.74.172.0/22245.74.172.1 to 245.74.175.254245.74.175.2551,022
173245.74.176.0/22245.74.176.1 to 245.74.179.254245.74.179.2551,022
174245.74.180.0/22245.74.180.1 to 245.74.183.254245.74.183.2551,022
175245.74.184.0/22245.74.184.1 to 245.74.187.254245.74.187.2551,022
176245.74.188.0/22245.74.188.1 to 245.74.191.254245.74.191.2551,022
177245.74.192.0/22245.74.192.1 to 245.74.195.254245.74.195.2551,022
178245.74.196.0/22245.74.196.1 to 245.74.199.254245.74.199.2551,022
179245.74.200.0/22245.74.200.1 to 245.74.203.254245.74.203.2551,022
180245.74.204.0/22245.74.204.1 to 245.74.207.254245.74.207.2551,022
181245.74.208.0/22245.74.208.1 to 245.74.211.254245.74.211.2551,022
182245.74.212.0/22245.74.212.1 to 245.74.215.254245.74.215.2551,022
183245.74.216.0/22245.74.216.1 to 245.74.219.254245.74.219.2551,022
184245.74.220.0/22245.74.220.1 to 245.74.223.254245.74.223.2551,022
185245.74.224.0/22245.74.224.1 to 245.74.227.254245.74.227.2551,022
186245.74.228.0/22245.74.228.1 to 245.74.231.254245.74.231.2551,022
187245.74.232.0/22245.74.232.1 to 245.74.235.254245.74.235.2551,022
188245.74.236.0/22245.74.236.1 to 245.74.239.254245.74.239.2551,022
189245.74.240.0/22245.74.240.1 to 245.74.243.254245.74.243.2551,022
190245.74.244.0/22245.74.244.1 to 245.74.247.254245.74.247.2551,022
191245.74.248.0/22245.74.248.1 to 245.74.251.254245.74.251.2551,022
192245.74.252.0/22245.74.252.1 to 245.74.255.254245.74.255.2551,022
193245.75.0.0/22245.75.0.1 to 245.75.3.254245.75.3.2551,022
194245.75.4.0/22245.75.4.1 to 245.75.7.254245.75.7.2551,022
195245.75.8.0/22245.75.8.1 to 245.75.11.254245.75.11.2551,022
196245.75.12.0/22245.75.12.1 to 245.75.15.254245.75.15.2551,022
197245.75.16.0/22245.75.16.1 to 245.75.19.254245.75.19.2551,022
198245.75.20.0/22245.75.20.1 to 245.75.23.254245.75.23.2551,022
199245.75.24.0/22245.75.24.1 to 245.75.27.254245.75.27.2551,022
200245.75.28.0/22245.75.28.1 to 245.75.31.254245.75.31.2551,022
201245.75.32.0/22245.75.32.1 to 245.75.35.254245.75.35.2551,022
202245.75.36.0/22245.75.36.1 to 245.75.39.254245.75.39.2551,022
203245.75.40.0/22245.75.40.1 to 245.75.43.254245.75.43.2551,022
204245.75.44.0/22245.75.44.1 to 245.75.47.254245.75.47.2551,022
205245.75.48.0/22245.75.48.1 to 245.75.51.254245.75.51.2551,022
206245.75.52.0/22245.75.52.1 to 245.75.55.254245.75.55.2551,022
207245.75.56.0/22245.75.56.1 to 245.75.59.254245.75.59.2551,022
208245.75.60.0/22245.75.60.1 to 245.75.63.254245.75.63.2551,022
209245.75.64.0/22245.75.64.1 to 245.75.67.254245.75.67.2551,022
210245.75.68.0/22245.75.68.1 to 245.75.71.254245.75.71.2551,022
211245.75.72.0/22245.75.72.1 to 245.75.75.254245.75.75.2551,022
212245.75.76.0/22245.75.76.1 to 245.75.79.254245.75.79.2551,022
213245.75.80.0/22245.75.80.1 to 245.75.83.254245.75.83.2551,022
214245.75.84.0/22245.75.84.1 to 245.75.87.254245.75.87.2551,022
215245.75.88.0/22245.75.88.1 to 245.75.91.254245.75.91.2551,022
216245.75.92.0/22245.75.92.1 to 245.75.95.254245.75.95.2551,022
217245.75.96.0/22245.75.96.1 to 245.75.99.254245.75.99.2551,022
218245.75.100.0/22245.75.100.1 to 245.75.103.254245.75.103.2551,022
219245.75.104.0/22245.75.104.1 to 245.75.107.254245.75.107.2551,022
220245.75.108.0/22245.75.108.1 to 245.75.111.254245.75.111.2551,022
221245.75.112.0/22245.75.112.1 to 245.75.115.254245.75.115.2551,022
222245.75.116.0/22245.75.116.1 to 245.75.119.254245.75.119.2551,022
223245.75.120.0/22245.75.120.1 to 245.75.123.254245.75.123.2551,022
224245.75.124.0/22245.75.124.1 to 245.75.127.254245.75.127.2551,022
225245.75.128.0/22245.75.128.1 to 245.75.131.254245.75.131.2551,022
226245.75.132.0/22245.75.132.1 to 245.75.135.254245.75.135.2551,022
227245.75.136.0/22245.75.136.1 to 245.75.139.254245.75.139.2551,022
228245.75.140.0/22245.75.140.1 to 245.75.143.254245.75.143.2551,022
229245.75.144.0/22245.75.144.1 to 245.75.147.254245.75.147.2551,022
230245.75.148.0/22245.75.148.1 to 245.75.151.254245.75.151.2551,022
231245.75.152.0/22245.75.152.1 to 245.75.155.254245.75.155.2551,022
232245.75.156.0/22245.75.156.1 to 245.75.159.254245.75.159.2551,022
233245.75.160.0/22245.75.160.1 to 245.75.163.254245.75.163.2551,022
234245.75.164.0/22245.75.164.1 to 245.75.167.254245.75.167.2551,022
235245.75.168.0/22245.75.168.1 to 245.75.171.254245.75.171.2551,022
236245.75.172.0/22245.75.172.1 to 245.75.175.254245.75.175.2551,022
237245.75.176.0/22245.75.176.1 to 245.75.179.254245.75.179.2551,022
238245.75.180.0/22245.75.180.1 to 245.75.183.254245.75.183.2551,022
239245.75.184.0/22245.75.184.1 to 245.75.187.254245.75.187.2551,022
240245.75.188.0/22245.75.188.1 to 245.75.191.254245.75.191.2551,022
241245.75.192.0/22245.75.192.1 to 245.75.195.254245.75.195.2551,022
242245.75.196.0/22245.75.196.1 to 245.75.199.254245.75.199.2551,022
243245.75.200.0/22245.75.200.1 to 245.75.203.254245.75.203.2551,022
244245.75.204.0/22245.75.204.1 to 245.75.207.254245.75.207.2551,022
245245.75.208.0/22245.75.208.1 to 245.75.211.254245.75.211.2551,022
246245.75.212.0/22245.75.212.1 to 245.75.215.254245.75.215.2551,022
247245.75.216.0/22245.75.216.1 to 245.75.219.254245.75.219.2551,022
248245.75.220.0/22245.75.220.1 to 245.75.223.254245.75.223.2551,022
249245.75.224.0/22245.75.224.1 to 245.75.227.254245.75.227.2551,022
250245.75.228.0/22245.75.228.1 to 245.75.231.254245.75.231.2551,022
251245.75.232.0/22245.75.232.1 to 245.75.235.254245.75.235.2551,022
252245.75.236.0/22245.75.236.1 to 245.75.239.254245.75.239.2551,022
253245.75.240.0/22245.75.240.1 to 245.75.243.254245.75.243.2551,022
254245.75.244.0/22245.75.244.1 to 245.75.247.254245.75.247.2551,022
255245.75.248.0/22245.75.248.1 to 245.75.251.254245.75.251.2551,022
256245.75.252.0/22245.75.252.1 to 245.75.255.254245.75.255.2551,022

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.