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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.

Network249.232.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
249.232.0.0
Broadcast address
249.239.255.255
First usable
249.232.0.1
Last usable
249.239.255.254
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 F9E80000 · Integer 4192731136 to 4193255423
Reverse DNS zones
232.249.in-addr.arpa
233.249.in-addr.arpa
234.249.in-addr.arpa
235.249.in-addr.arpa
236.249.in-addr.arpa
237.249.in-addr.arpa
238.249.in-addr.arpa
239.249.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
Address11111001.11101000.00000000.00000000249.232.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network11111001.11101000.00000000.00000000249.232.0.0
Broadcast11111001.11101111.11111111.11111111249.239.255.255
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)

249.232.0.0/13 makes 512 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1249.232.0.0/22249.232.0.1 to 249.232.3.254249.232.3.2551,022
2249.232.4.0/22249.232.4.1 to 249.232.7.254249.232.7.2551,022
3249.232.8.0/22249.232.8.1 to 249.232.11.254249.232.11.2551,022
4249.232.12.0/22249.232.12.1 to 249.232.15.254249.232.15.2551,022
5249.232.16.0/22249.232.16.1 to 249.232.19.254249.232.19.2551,022
6249.232.20.0/22249.232.20.1 to 249.232.23.254249.232.23.2551,022
7249.232.24.0/22249.232.24.1 to 249.232.27.254249.232.27.2551,022
8249.232.28.0/22249.232.28.1 to 249.232.31.254249.232.31.2551,022
9249.232.32.0/22249.232.32.1 to 249.232.35.254249.232.35.2551,022
10249.232.36.0/22249.232.36.1 to 249.232.39.254249.232.39.2551,022
11249.232.40.0/22249.232.40.1 to 249.232.43.254249.232.43.2551,022
12249.232.44.0/22249.232.44.1 to 249.232.47.254249.232.47.2551,022
13249.232.48.0/22249.232.48.1 to 249.232.51.254249.232.51.2551,022
14249.232.52.0/22249.232.52.1 to 249.232.55.254249.232.55.2551,022
15249.232.56.0/22249.232.56.1 to 249.232.59.254249.232.59.2551,022
16249.232.60.0/22249.232.60.1 to 249.232.63.254249.232.63.2551,022
17249.232.64.0/22249.232.64.1 to 249.232.67.254249.232.67.2551,022
18249.232.68.0/22249.232.68.1 to 249.232.71.254249.232.71.2551,022
19249.232.72.0/22249.232.72.1 to 249.232.75.254249.232.75.2551,022
20249.232.76.0/22249.232.76.1 to 249.232.79.254249.232.79.2551,022
21249.232.80.0/22249.232.80.1 to 249.232.83.254249.232.83.2551,022
22249.232.84.0/22249.232.84.1 to 249.232.87.254249.232.87.2551,022
23249.232.88.0/22249.232.88.1 to 249.232.91.254249.232.91.2551,022
24249.232.92.0/22249.232.92.1 to 249.232.95.254249.232.95.2551,022
25249.232.96.0/22249.232.96.1 to 249.232.99.254249.232.99.2551,022
26249.232.100.0/22249.232.100.1 to 249.232.103.254249.232.103.2551,022
27249.232.104.0/22249.232.104.1 to 249.232.107.254249.232.107.2551,022
28249.232.108.0/22249.232.108.1 to 249.232.111.254249.232.111.2551,022
29249.232.112.0/22249.232.112.1 to 249.232.115.254249.232.115.2551,022
30249.232.116.0/22249.232.116.1 to 249.232.119.254249.232.119.2551,022
31249.232.120.0/22249.232.120.1 to 249.232.123.254249.232.123.2551,022
32249.232.124.0/22249.232.124.1 to 249.232.127.254249.232.127.2551,022
33249.232.128.0/22249.232.128.1 to 249.232.131.254249.232.131.2551,022
34249.232.132.0/22249.232.132.1 to 249.232.135.254249.232.135.2551,022
35249.232.136.0/22249.232.136.1 to 249.232.139.254249.232.139.2551,022
36249.232.140.0/22249.232.140.1 to 249.232.143.254249.232.143.2551,022
37249.232.144.0/22249.232.144.1 to 249.232.147.254249.232.147.2551,022
38249.232.148.0/22249.232.148.1 to 249.232.151.254249.232.151.2551,022
39249.232.152.0/22249.232.152.1 to 249.232.155.254249.232.155.2551,022
40249.232.156.0/22249.232.156.1 to 249.232.159.254249.232.159.2551,022
41249.232.160.0/22249.232.160.1 to 249.232.163.254249.232.163.2551,022
42249.232.164.0/22249.232.164.1 to 249.232.167.254249.232.167.2551,022
43249.232.168.0/22249.232.168.1 to 249.232.171.254249.232.171.2551,022
44249.232.172.0/22249.232.172.1 to 249.232.175.254249.232.175.2551,022
45249.232.176.0/22249.232.176.1 to 249.232.179.254249.232.179.2551,022
46249.232.180.0/22249.232.180.1 to 249.232.183.254249.232.183.2551,022
47249.232.184.0/22249.232.184.1 to 249.232.187.254249.232.187.2551,022
48249.232.188.0/22249.232.188.1 to 249.232.191.254249.232.191.2551,022
49249.232.192.0/22249.232.192.1 to 249.232.195.254249.232.195.2551,022
50249.232.196.0/22249.232.196.1 to 249.232.199.254249.232.199.2551,022
51249.232.200.0/22249.232.200.1 to 249.232.203.254249.232.203.2551,022
52249.232.204.0/22249.232.204.1 to 249.232.207.254249.232.207.2551,022
53249.232.208.0/22249.232.208.1 to 249.232.211.254249.232.211.2551,022
54249.232.212.0/22249.232.212.1 to 249.232.215.254249.232.215.2551,022
55249.232.216.0/22249.232.216.1 to 249.232.219.254249.232.219.2551,022
56249.232.220.0/22249.232.220.1 to 249.232.223.254249.232.223.2551,022
57249.232.224.0/22249.232.224.1 to 249.232.227.254249.232.227.2551,022
58249.232.228.0/22249.232.228.1 to 249.232.231.254249.232.231.2551,022
59249.232.232.0/22249.232.232.1 to 249.232.235.254249.232.235.2551,022
60249.232.236.0/22249.232.236.1 to 249.232.239.254249.232.239.2551,022
61249.232.240.0/22249.232.240.1 to 249.232.243.254249.232.243.2551,022
62249.232.244.0/22249.232.244.1 to 249.232.247.254249.232.247.2551,022
63249.232.248.0/22249.232.248.1 to 249.232.251.254249.232.251.2551,022
64249.232.252.0/22249.232.252.1 to 249.232.255.254249.232.255.2551,022
65249.233.0.0/22249.233.0.1 to 249.233.3.254249.233.3.2551,022
66249.233.4.0/22249.233.4.1 to 249.233.7.254249.233.7.2551,022
67249.233.8.0/22249.233.8.1 to 249.233.11.254249.233.11.2551,022
68249.233.12.0/22249.233.12.1 to 249.233.15.254249.233.15.2551,022
69249.233.16.0/22249.233.16.1 to 249.233.19.254249.233.19.2551,022
70249.233.20.0/22249.233.20.1 to 249.233.23.254249.233.23.2551,022
71249.233.24.0/22249.233.24.1 to 249.233.27.254249.233.27.2551,022
72249.233.28.0/22249.233.28.1 to 249.233.31.254249.233.31.2551,022
73249.233.32.0/22249.233.32.1 to 249.233.35.254249.233.35.2551,022
74249.233.36.0/22249.233.36.1 to 249.233.39.254249.233.39.2551,022
75249.233.40.0/22249.233.40.1 to 249.233.43.254249.233.43.2551,022
76249.233.44.0/22249.233.44.1 to 249.233.47.254249.233.47.2551,022
77249.233.48.0/22249.233.48.1 to 249.233.51.254249.233.51.2551,022
78249.233.52.0/22249.233.52.1 to 249.233.55.254249.233.55.2551,022
79249.233.56.0/22249.233.56.1 to 249.233.59.254249.233.59.2551,022
80249.233.60.0/22249.233.60.1 to 249.233.63.254249.233.63.2551,022
81249.233.64.0/22249.233.64.1 to 249.233.67.254249.233.67.2551,022
82249.233.68.0/22249.233.68.1 to 249.233.71.254249.233.71.2551,022
83249.233.72.0/22249.233.72.1 to 249.233.75.254249.233.75.2551,022
84249.233.76.0/22249.233.76.1 to 249.233.79.254249.233.79.2551,022
85249.233.80.0/22249.233.80.1 to 249.233.83.254249.233.83.2551,022
86249.233.84.0/22249.233.84.1 to 249.233.87.254249.233.87.2551,022
87249.233.88.0/22249.233.88.1 to 249.233.91.254249.233.91.2551,022
88249.233.92.0/22249.233.92.1 to 249.233.95.254249.233.95.2551,022
89249.233.96.0/22249.233.96.1 to 249.233.99.254249.233.99.2551,022
90249.233.100.0/22249.233.100.1 to 249.233.103.254249.233.103.2551,022
91249.233.104.0/22249.233.104.1 to 249.233.107.254249.233.107.2551,022
92249.233.108.0/22249.233.108.1 to 249.233.111.254249.233.111.2551,022
93249.233.112.0/22249.233.112.1 to 249.233.115.254249.233.115.2551,022
94249.233.116.0/22249.233.116.1 to 249.233.119.254249.233.119.2551,022
95249.233.120.0/22249.233.120.1 to 249.233.123.254249.233.123.2551,022
96249.233.124.0/22249.233.124.1 to 249.233.127.254249.233.127.2551,022
97249.233.128.0/22249.233.128.1 to 249.233.131.254249.233.131.2551,022
98249.233.132.0/22249.233.132.1 to 249.233.135.254249.233.135.2551,022
99249.233.136.0/22249.233.136.1 to 249.233.139.254249.233.139.2551,022
100249.233.140.0/22249.233.140.1 to 249.233.143.254249.233.143.2551,022
101249.233.144.0/22249.233.144.1 to 249.233.147.254249.233.147.2551,022
102249.233.148.0/22249.233.148.1 to 249.233.151.254249.233.151.2551,022
103249.233.152.0/22249.233.152.1 to 249.233.155.254249.233.155.2551,022
104249.233.156.0/22249.233.156.1 to 249.233.159.254249.233.159.2551,022
105249.233.160.0/22249.233.160.1 to 249.233.163.254249.233.163.2551,022
106249.233.164.0/22249.233.164.1 to 249.233.167.254249.233.167.2551,022
107249.233.168.0/22249.233.168.1 to 249.233.171.254249.233.171.2551,022
108249.233.172.0/22249.233.172.1 to 249.233.175.254249.233.175.2551,022
109249.233.176.0/22249.233.176.1 to 249.233.179.254249.233.179.2551,022
110249.233.180.0/22249.233.180.1 to 249.233.183.254249.233.183.2551,022
111249.233.184.0/22249.233.184.1 to 249.233.187.254249.233.187.2551,022
112249.233.188.0/22249.233.188.1 to 249.233.191.254249.233.191.2551,022
113249.233.192.0/22249.233.192.1 to 249.233.195.254249.233.195.2551,022
114249.233.196.0/22249.233.196.1 to 249.233.199.254249.233.199.2551,022
115249.233.200.0/22249.233.200.1 to 249.233.203.254249.233.203.2551,022
116249.233.204.0/22249.233.204.1 to 249.233.207.254249.233.207.2551,022
117249.233.208.0/22249.233.208.1 to 249.233.211.254249.233.211.2551,022
118249.233.212.0/22249.233.212.1 to 249.233.215.254249.233.215.2551,022
119249.233.216.0/22249.233.216.1 to 249.233.219.254249.233.219.2551,022
120249.233.220.0/22249.233.220.1 to 249.233.223.254249.233.223.2551,022
121249.233.224.0/22249.233.224.1 to 249.233.227.254249.233.227.2551,022
122249.233.228.0/22249.233.228.1 to 249.233.231.254249.233.231.2551,022
123249.233.232.0/22249.233.232.1 to 249.233.235.254249.233.235.2551,022
124249.233.236.0/22249.233.236.1 to 249.233.239.254249.233.239.2551,022
125249.233.240.0/22249.233.240.1 to 249.233.243.254249.233.243.2551,022
126249.233.244.0/22249.233.244.1 to 249.233.247.254249.233.247.2551,022
127249.233.248.0/22249.233.248.1 to 249.233.251.254249.233.251.2551,022
128249.233.252.0/22249.233.252.1 to 249.233.255.254249.233.255.2551,022
129249.234.0.0/22249.234.0.1 to 249.234.3.254249.234.3.2551,022
130249.234.4.0/22249.234.4.1 to 249.234.7.254249.234.7.2551,022
131249.234.8.0/22249.234.8.1 to 249.234.11.254249.234.11.2551,022
132249.234.12.0/22249.234.12.1 to 249.234.15.254249.234.15.2551,022
133249.234.16.0/22249.234.16.1 to 249.234.19.254249.234.19.2551,022
134249.234.20.0/22249.234.20.1 to 249.234.23.254249.234.23.2551,022
135249.234.24.0/22249.234.24.1 to 249.234.27.254249.234.27.2551,022
136249.234.28.0/22249.234.28.1 to 249.234.31.254249.234.31.2551,022
137249.234.32.0/22249.234.32.1 to 249.234.35.254249.234.35.2551,022
138249.234.36.0/22249.234.36.1 to 249.234.39.254249.234.39.2551,022
139249.234.40.0/22249.234.40.1 to 249.234.43.254249.234.43.2551,022
140249.234.44.0/22249.234.44.1 to 249.234.47.254249.234.47.2551,022
141249.234.48.0/22249.234.48.1 to 249.234.51.254249.234.51.2551,022
142249.234.52.0/22249.234.52.1 to 249.234.55.254249.234.55.2551,022
143249.234.56.0/22249.234.56.1 to 249.234.59.254249.234.59.2551,022
144249.234.60.0/22249.234.60.1 to 249.234.63.254249.234.63.2551,022
145249.234.64.0/22249.234.64.1 to 249.234.67.254249.234.67.2551,022
146249.234.68.0/22249.234.68.1 to 249.234.71.254249.234.71.2551,022
147249.234.72.0/22249.234.72.1 to 249.234.75.254249.234.75.2551,022
148249.234.76.0/22249.234.76.1 to 249.234.79.254249.234.79.2551,022
149249.234.80.0/22249.234.80.1 to 249.234.83.254249.234.83.2551,022
150249.234.84.0/22249.234.84.1 to 249.234.87.254249.234.87.2551,022
151249.234.88.0/22249.234.88.1 to 249.234.91.254249.234.91.2551,022
152249.234.92.0/22249.234.92.1 to 249.234.95.254249.234.95.2551,022
153249.234.96.0/22249.234.96.1 to 249.234.99.254249.234.99.2551,022
154249.234.100.0/22249.234.100.1 to 249.234.103.254249.234.103.2551,022
155249.234.104.0/22249.234.104.1 to 249.234.107.254249.234.107.2551,022
156249.234.108.0/22249.234.108.1 to 249.234.111.254249.234.111.2551,022
157249.234.112.0/22249.234.112.1 to 249.234.115.254249.234.115.2551,022
158249.234.116.0/22249.234.116.1 to 249.234.119.254249.234.119.2551,022
159249.234.120.0/22249.234.120.1 to 249.234.123.254249.234.123.2551,022
160249.234.124.0/22249.234.124.1 to 249.234.127.254249.234.127.2551,022
161249.234.128.0/22249.234.128.1 to 249.234.131.254249.234.131.2551,022
162249.234.132.0/22249.234.132.1 to 249.234.135.254249.234.135.2551,022
163249.234.136.0/22249.234.136.1 to 249.234.139.254249.234.139.2551,022
164249.234.140.0/22249.234.140.1 to 249.234.143.254249.234.143.2551,022
165249.234.144.0/22249.234.144.1 to 249.234.147.254249.234.147.2551,022
166249.234.148.0/22249.234.148.1 to 249.234.151.254249.234.151.2551,022
167249.234.152.0/22249.234.152.1 to 249.234.155.254249.234.155.2551,022
168249.234.156.0/22249.234.156.1 to 249.234.159.254249.234.159.2551,022
169249.234.160.0/22249.234.160.1 to 249.234.163.254249.234.163.2551,022
170249.234.164.0/22249.234.164.1 to 249.234.167.254249.234.167.2551,022
171249.234.168.0/22249.234.168.1 to 249.234.171.254249.234.171.2551,022
172249.234.172.0/22249.234.172.1 to 249.234.175.254249.234.175.2551,022
173249.234.176.0/22249.234.176.1 to 249.234.179.254249.234.179.2551,022
174249.234.180.0/22249.234.180.1 to 249.234.183.254249.234.183.2551,022
175249.234.184.0/22249.234.184.1 to 249.234.187.254249.234.187.2551,022
176249.234.188.0/22249.234.188.1 to 249.234.191.254249.234.191.2551,022
177249.234.192.0/22249.234.192.1 to 249.234.195.254249.234.195.2551,022
178249.234.196.0/22249.234.196.1 to 249.234.199.254249.234.199.2551,022
179249.234.200.0/22249.234.200.1 to 249.234.203.254249.234.203.2551,022
180249.234.204.0/22249.234.204.1 to 249.234.207.254249.234.207.2551,022
181249.234.208.0/22249.234.208.1 to 249.234.211.254249.234.211.2551,022
182249.234.212.0/22249.234.212.1 to 249.234.215.254249.234.215.2551,022
183249.234.216.0/22249.234.216.1 to 249.234.219.254249.234.219.2551,022
184249.234.220.0/22249.234.220.1 to 249.234.223.254249.234.223.2551,022
185249.234.224.0/22249.234.224.1 to 249.234.227.254249.234.227.2551,022
186249.234.228.0/22249.234.228.1 to 249.234.231.254249.234.231.2551,022
187249.234.232.0/22249.234.232.1 to 249.234.235.254249.234.235.2551,022
188249.234.236.0/22249.234.236.1 to 249.234.239.254249.234.239.2551,022
189249.234.240.0/22249.234.240.1 to 249.234.243.254249.234.243.2551,022
190249.234.244.0/22249.234.244.1 to 249.234.247.254249.234.247.2551,022
191249.234.248.0/22249.234.248.1 to 249.234.251.254249.234.251.2551,022
192249.234.252.0/22249.234.252.1 to 249.234.255.254249.234.255.2551,022
193249.235.0.0/22249.235.0.1 to 249.235.3.254249.235.3.2551,022
194249.235.4.0/22249.235.4.1 to 249.235.7.254249.235.7.2551,022
195249.235.8.0/22249.235.8.1 to 249.235.11.254249.235.11.2551,022
196249.235.12.0/22249.235.12.1 to 249.235.15.254249.235.15.2551,022
197249.235.16.0/22249.235.16.1 to 249.235.19.254249.235.19.2551,022
198249.235.20.0/22249.235.20.1 to 249.235.23.254249.235.23.2551,022
199249.235.24.0/22249.235.24.1 to 249.235.27.254249.235.27.2551,022
200249.235.28.0/22249.235.28.1 to 249.235.31.254249.235.31.2551,022
201249.235.32.0/22249.235.32.1 to 249.235.35.254249.235.35.2551,022
202249.235.36.0/22249.235.36.1 to 249.235.39.254249.235.39.2551,022
203249.235.40.0/22249.235.40.1 to 249.235.43.254249.235.43.2551,022
204249.235.44.0/22249.235.44.1 to 249.235.47.254249.235.47.2551,022
205249.235.48.0/22249.235.48.1 to 249.235.51.254249.235.51.2551,022
206249.235.52.0/22249.235.52.1 to 249.235.55.254249.235.55.2551,022
207249.235.56.0/22249.235.56.1 to 249.235.59.254249.235.59.2551,022
208249.235.60.0/22249.235.60.1 to 249.235.63.254249.235.63.2551,022
209249.235.64.0/22249.235.64.1 to 249.235.67.254249.235.67.2551,022
210249.235.68.0/22249.235.68.1 to 249.235.71.254249.235.71.2551,022
211249.235.72.0/22249.235.72.1 to 249.235.75.254249.235.75.2551,022
212249.235.76.0/22249.235.76.1 to 249.235.79.254249.235.79.2551,022
213249.235.80.0/22249.235.80.1 to 249.235.83.254249.235.83.2551,022
214249.235.84.0/22249.235.84.1 to 249.235.87.254249.235.87.2551,022
215249.235.88.0/22249.235.88.1 to 249.235.91.254249.235.91.2551,022
216249.235.92.0/22249.235.92.1 to 249.235.95.254249.235.95.2551,022
217249.235.96.0/22249.235.96.1 to 249.235.99.254249.235.99.2551,022
218249.235.100.0/22249.235.100.1 to 249.235.103.254249.235.103.2551,022
219249.235.104.0/22249.235.104.1 to 249.235.107.254249.235.107.2551,022
220249.235.108.0/22249.235.108.1 to 249.235.111.254249.235.111.2551,022
221249.235.112.0/22249.235.112.1 to 249.235.115.254249.235.115.2551,022
222249.235.116.0/22249.235.116.1 to 249.235.119.254249.235.119.2551,022
223249.235.120.0/22249.235.120.1 to 249.235.123.254249.235.123.2551,022
224249.235.124.0/22249.235.124.1 to 249.235.127.254249.235.127.2551,022
225249.235.128.0/22249.235.128.1 to 249.235.131.254249.235.131.2551,022
226249.235.132.0/22249.235.132.1 to 249.235.135.254249.235.135.2551,022
227249.235.136.0/22249.235.136.1 to 249.235.139.254249.235.139.2551,022
228249.235.140.0/22249.235.140.1 to 249.235.143.254249.235.143.2551,022
229249.235.144.0/22249.235.144.1 to 249.235.147.254249.235.147.2551,022
230249.235.148.0/22249.235.148.1 to 249.235.151.254249.235.151.2551,022
231249.235.152.0/22249.235.152.1 to 249.235.155.254249.235.155.2551,022
232249.235.156.0/22249.235.156.1 to 249.235.159.254249.235.159.2551,022
233249.235.160.0/22249.235.160.1 to 249.235.163.254249.235.163.2551,022
234249.235.164.0/22249.235.164.1 to 249.235.167.254249.235.167.2551,022
235249.235.168.0/22249.235.168.1 to 249.235.171.254249.235.171.2551,022
236249.235.172.0/22249.235.172.1 to 249.235.175.254249.235.175.2551,022
237249.235.176.0/22249.235.176.1 to 249.235.179.254249.235.179.2551,022
238249.235.180.0/22249.235.180.1 to 249.235.183.254249.235.183.2551,022
239249.235.184.0/22249.235.184.1 to 249.235.187.254249.235.187.2551,022
240249.235.188.0/22249.235.188.1 to 249.235.191.254249.235.191.2551,022
241249.235.192.0/22249.235.192.1 to 249.235.195.254249.235.195.2551,022
242249.235.196.0/22249.235.196.1 to 249.235.199.254249.235.199.2551,022
243249.235.200.0/22249.235.200.1 to 249.235.203.254249.235.203.2551,022
244249.235.204.0/22249.235.204.1 to 249.235.207.254249.235.207.2551,022
245249.235.208.0/22249.235.208.1 to 249.235.211.254249.235.211.2551,022
246249.235.212.0/22249.235.212.1 to 249.235.215.254249.235.215.2551,022
247249.235.216.0/22249.235.216.1 to 249.235.219.254249.235.219.2551,022
248249.235.220.0/22249.235.220.1 to 249.235.223.254249.235.223.2551,022
249249.235.224.0/22249.235.224.1 to 249.235.227.254249.235.227.2551,022
250249.235.228.0/22249.235.228.1 to 249.235.231.254249.235.231.2551,022
251249.235.232.0/22249.235.232.1 to 249.235.235.254249.235.235.2551,022
252249.235.236.0/22249.235.236.1 to 249.235.239.254249.235.239.2551,022
253249.235.240.0/22249.235.240.1 to 249.235.243.254249.235.243.2551,022
254249.235.244.0/22249.235.244.1 to 249.235.247.254249.235.247.2551,022
255249.235.248.0/22249.235.248.1 to 249.235.251.254249.235.251.2551,022
256249.235.252.0/22249.235.252.1 to 249.235.255.254249.235.255.2551,022

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.