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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.

Network253.176.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
253.176.0.0
Broadcast address
253.191.255.255
First usable
253.176.0.1
Last usable
253.191.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex FDB00000 · Integer 4256169984 to 4257218559
Reverse DNS zones
176.253.in-addr.arpa
177.253.in-addr.arpa
178.253.in-addr.arpa
179.253.in-addr.arpa
180.253.in-addr.arpa
181.253.in-addr.arpa
182.253.in-addr.arpa
183.253.in-addr.arpa
184.253.in-addr.arpa
185.253.in-addr.arpa
186.253.in-addr.arpa
187.253.in-addr.arpa
188.253.in-addr.arpa
189.253.in-addr.arpa
190.253.in-addr.arpa
191.253.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11111101.10110000.00000000.00000000253.176.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11111101.10110000.00000000.00000000253.176.0.0
Broadcast11111101.10111111.11111111.11111111253.191.255.255
Split into smaller subnets/22
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

253.176.0.0/12 makes 1,024 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1253.176.0.0/22253.176.0.1 to 253.176.3.254253.176.3.2551,022
2253.176.4.0/22253.176.4.1 to 253.176.7.254253.176.7.2551,022
3253.176.8.0/22253.176.8.1 to 253.176.11.254253.176.11.2551,022
4253.176.12.0/22253.176.12.1 to 253.176.15.254253.176.15.2551,022
5253.176.16.0/22253.176.16.1 to 253.176.19.254253.176.19.2551,022
6253.176.20.0/22253.176.20.1 to 253.176.23.254253.176.23.2551,022
7253.176.24.0/22253.176.24.1 to 253.176.27.254253.176.27.2551,022
8253.176.28.0/22253.176.28.1 to 253.176.31.254253.176.31.2551,022
9253.176.32.0/22253.176.32.1 to 253.176.35.254253.176.35.2551,022
10253.176.36.0/22253.176.36.1 to 253.176.39.254253.176.39.2551,022
11253.176.40.0/22253.176.40.1 to 253.176.43.254253.176.43.2551,022
12253.176.44.0/22253.176.44.1 to 253.176.47.254253.176.47.2551,022
13253.176.48.0/22253.176.48.1 to 253.176.51.254253.176.51.2551,022
14253.176.52.0/22253.176.52.1 to 253.176.55.254253.176.55.2551,022
15253.176.56.0/22253.176.56.1 to 253.176.59.254253.176.59.2551,022
16253.176.60.0/22253.176.60.1 to 253.176.63.254253.176.63.2551,022
17253.176.64.0/22253.176.64.1 to 253.176.67.254253.176.67.2551,022
18253.176.68.0/22253.176.68.1 to 253.176.71.254253.176.71.2551,022
19253.176.72.0/22253.176.72.1 to 253.176.75.254253.176.75.2551,022
20253.176.76.0/22253.176.76.1 to 253.176.79.254253.176.79.2551,022
21253.176.80.0/22253.176.80.1 to 253.176.83.254253.176.83.2551,022
22253.176.84.0/22253.176.84.1 to 253.176.87.254253.176.87.2551,022
23253.176.88.0/22253.176.88.1 to 253.176.91.254253.176.91.2551,022
24253.176.92.0/22253.176.92.1 to 253.176.95.254253.176.95.2551,022
25253.176.96.0/22253.176.96.1 to 253.176.99.254253.176.99.2551,022
26253.176.100.0/22253.176.100.1 to 253.176.103.254253.176.103.2551,022
27253.176.104.0/22253.176.104.1 to 253.176.107.254253.176.107.2551,022
28253.176.108.0/22253.176.108.1 to 253.176.111.254253.176.111.2551,022
29253.176.112.0/22253.176.112.1 to 253.176.115.254253.176.115.2551,022
30253.176.116.0/22253.176.116.1 to 253.176.119.254253.176.119.2551,022
31253.176.120.0/22253.176.120.1 to 253.176.123.254253.176.123.2551,022
32253.176.124.0/22253.176.124.1 to 253.176.127.254253.176.127.2551,022
33253.176.128.0/22253.176.128.1 to 253.176.131.254253.176.131.2551,022
34253.176.132.0/22253.176.132.1 to 253.176.135.254253.176.135.2551,022
35253.176.136.0/22253.176.136.1 to 253.176.139.254253.176.139.2551,022
36253.176.140.0/22253.176.140.1 to 253.176.143.254253.176.143.2551,022
37253.176.144.0/22253.176.144.1 to 253.176.147.254253.176.147.2551,022
38253.176.148.0/22253.176.148.1 to 253.176.151.254253.176.151.2551,022
39253.176.152.0/22253.176.152.1 to 253.176.155.254253.176.155.2551,022
40253.176.156.0/22253.176.156.1 to 253.176.159.254253.176.159.2551,022
41253.176.160.0/22253.176.160.1 to 253.176.163.254253.176.163.2551,022
42253.176.164.0/22253.176.164.1 to 253.176.167.254253.176.167.2551,022
43253.176.168.0/22253.176.168.1 to 253.176.171.254253.176.171.2551,022
44253.176.172.0/22253.176.172.1 to 253.176.175.254253.176.175.2551,022
45253.176.176.0/22253.176.176.1 to 253.176.179.254253.176.179.2551,022
46253.176.180.0/22253.176.180.1 to 253.176.183.254253.176.183.2551,022
47253.176.184.0/22253.176.184.1 to 253.176.187.254253.176.187.2551,022
48253.176.188.0/22253.176.188.1 to 253.176.191.254253.176.191.2551,022
49253.176.192.0/22253.176.192.1 to 253.176.195.254253.176.195.2551,022
50253.176.196.0/22253.176.196.1 to 253.176.199.254253.176.199.2551,022
51253.176.200.0/22253.176.200.1 to 253.176.203.254253.176.203.2551,022
52253.176.204.0/22253.176.204.1 to 253.176.207.254253.176.207.2551,022
53253.176.208.0/22253.176.208.1 to 253.176.211.254253.176.211.2551,022
54253.176.212.0/22253.176.212.1 to 253.176.215.254253.176.215.2551,022
55253.176.216.0/22253.176.216.1 to 253.176.219.254253.176.219.2551,022
56253.176.220.0/22253.176.220.1 to 253.176.223.254253.176.223.2551,022
57253.176.224.0/22253.176.224.1 to 253.176.227.254253.176.227.2551,022
58253.176.228.0/22253.176.228.1 to 253.176.231.254253.176.231.2551,022
59253.176.232.0/22253.176.232.1 to 253.176.235.254253.176.235.2551,022
60253.176.236.0/22253.176.236.1 to 253.176.239.254253.176.239.2551,022
61253.176.240.0/22253.176.240.1 to 253.176.243.254253.176.243.2551,022
62253.176.244.0/22253.176.244.1 to 253.176.247.254253.176.247.2551,022
63253.176.248.0/22253.176.248.1 to 253.176.251.254253.176.251.2551,022
64253.176.252.0/22253.176.252.1 to 253.176.255.254253.176.255.2551,022
65253.177.0.0/22253.177.0.1 to 253.177.3.254253.177.3.2551,022
66253.177.4.0/22253.177.4.1 to 253.177.7.254253.177.7.2551,022
67253.177.8.0/22253.177.8.1 to 253.177.11.254253.177.11.2551,022
68253.177.12.0/22253.177.12.1 to 253.177.15.254253.177.15.2551,022
69253.177.16.0/22253.177.16.1 to 253.177.19.254253.177.19.2551,022
70253.177.20.0/22253.177.20.1 to 253.177.23.254253.177.23.2551,022
71253.177.24.0/22253.177.24.1 to 253.177.27.254253.177.27.2551,022
72253.177.28.0/22253.177.28.1 to 253.177.31.254253.177.31.2551,022
73253.177.32.0/22253.177.32.1 to 253.177.35.254253.177.35.2551,022
74253.177.36.0/22253.177.36.1 to 253.177.39.254253.177.39.2551,022
75253.177.40.0/22253.177.40.1 to 253.177.43.254253.177.43.2551,022
76253.177.44.0/22253.177.44.1 to 253.177.47.254253.177.47.2551,022
77253.177.48.0/22253.177.48.1 to 253.177.51.254253.177.51.2551,022
78253.177.52.0/22253.177.52.1 to 253.177.55.254253.177.55.2551,022
79253.177.56.0/22253.177.56.1 to 253.177.59.254253.177.59.2551,022
80253.177.60.0/22253.177.60.1 to 253.177.63.254253.177.63.2551,022
81253.177.64.0/22253.177.64.1 to 253.177.67.254253.177.67.2551,022
82253.177.68.0/22253.177.68.1 to 253.177.71.254253.177.71.2551,022
83253.177.72.0/22253.177.72.1 to 253.177.75.254253.177.75.2551,022
84253.177.76.0/22253.177.76.1 to 253.177.79.254253.177.79.2551,022
85253.177.80.0/22253.177.80.1 to 253.177.83.254253.177.83.2551,022
86253.177.84.0/22253.177.84.1 to 253.177.87.254253.177.87.2551,022
87253.177.88.0/22253.177.88.1 to 253.177.91.254253.177.91.2551,022
88253.177.92.0/22253.177.92.1 to 253.177.95.254253.177.95.2551,022
89253.177.96.0/22253.177.96.1 to 253.177.99.254253.177.99.2551,022
90253.177.100.0/22253.177.100.1 to 253.177.103.254253.177.103.2551,022
91253.177.104.0/22253.177.104.1 to 253.177.107.254253.177.107.2551,022
92253.177.108.0/22253.177.108.1 to 253.177.111.254253.177.111.2551,022
93253.177.112.0/22253.177.112.1 to 253.177.115.254253.177.115.2551,022
94253.177.116.0/22253.177.116.1 to 253.177.119.254253.177.119.2551,022
95253.177.120.0/22253.177.120.1 to 253.177.123.254253.177.123.2551,022
96253.177.124.0/22253.177.124.1 to 253.177.127.254253.177.127.2551,022
97253.177.128.0/22253.177.128.1 to 253.177.131.254253.177.131.2551,022
98253.177.132.0/22253.177.132.1 to 253.177.135.254253.177.135.2551,022
99253.177.136.0/22253.177.136.1 to 253.177.139.254253.177.139.2551,022
100253.177.140.0/22253.177.140.1 to 253.177.143.254253.177.143.2551,022
101253.177.144.0/22253.177.144.1 to 253.177.147.254253.177.147.2551,022
102253.177.148.0/22253.177.148.1 to 253.177.151.254253.177.151.2551,022
103253.177.152.0/22253.177.152.1 to 253.177.155.254253.177.155.2551,022
104253.177.156.0/22253.177.156.1 to 253.177.159.254253.177.159.2551,022
105253.177.160.0/22253.177.160.1 to 253.177.163.254253.177.163.2551,022
106253.177.164.0/22253.177.164.1 to 253.177.167.254253.177.167.2551,022
107253.177.168.0/22253.177.168.1 to 253.177.171.254253.177.171.2551,022
108253.177.172.0/22253.177.172.1 to 253.177.175.254253.177.175.2551,022
109253.177.176.0/22253.177.176.1 to 253.177.179.254253.177.179.2551,022
110253.177.180.0/22253.177.180.1 to 253.177.183.254253.177.183.2551,022
111253.177.184.0/22253.177.184.1 to 253.177.187.254253.177.187.2551,022
112253.177.188.0/22253.177.188.1 to 253.177.191.254253.177.191.2551,022
113253.177.192.0/22253.177.192.1 to 253.177.195.254253.177.195.2551,022
114253.177.196.0/22253.177.196.1 to 253.177.199.254253.177.199.2551,022
115253.177.200.0/22253.177.200.1 to 253.177.203.254253.177.203.2551,022
116253.177.204.0/22253.177.204.1 to 253.177.207.254253.177.207.2551,022
117253.177.208.0/22253.177.208.1 to 253.177.211.254253.177.211.2551,022
118253.177.212.0/22253.177.212.1 to 253.177.215.254253.177.215.2551,022
119253.177.216.0/22253.177.216.1 to 253.177.219.254253.177.219.2551,022
120253.177.220.0/22253.177.220.1 to 253.177.223.254253.177.223.2551,022
121253.177.224.0/22253.177.224.1 to 253.177.227.254253.177.227.2551,022
122253.177.228.0/22253.177.228.1 to 253.177.231.254253.177.231.2551,022
123253.177.232.0/22253.177.232.1 to 253.177.235.254253.177.235.2551,022
124253.177.236.0/22253.177.236.1 to 253.177.239.254253.177.239.2551,022
125253.177.240.0/22253.177.240.1 to 253.177.243.254253.177.243.2551,022
126253.177.244.0/22253.177.244.1 to 253.177.247.254253.177.247.2551,022
127253.177.248.0/22253.177.248.1 to 253.177.251.254253.177.251.2551,022
128253.177.252.0/22253.177.252.1 to 253.177.255.254253.177.255.2551,022
129253.178.0.0/22253.178.0.1 to 253.178.3.254253.178.3.2551,022
130253.178.4.0/22253.178.4.1 to 253.178.7.254253.178.7.2551,022
131253.178.8.0/22253.178.8.1 to 253.178.11.254253.178.11.2551,022
132253.178.12.0/22253.178.12.1 to 253.178.15.254253.178.15.2551,022
133253.178.16.0/22253.178.16.1 to 253.178.19.254253.178.19.2551,022
134253.178.20.0/22253.178.20.1 to 253.178.23.254253.178.23.2551,022
135253.178.24.0/22253.178.24.1 to 253.178.27.254253.178.27.2551,022
136253.178.28.0/22253.178.28.1 to 253.178.31.254253.178.31.2551,022
137253.178.32.0/22253.178.32.1 to 253.178.35.254253.178.35.2551,022
138253.178.36.0/22253.178.36.1 to 253.178.39.254253.178.39.2551,022
139253.178.40.0/22253.178.40.1 to 253.178.43.254253.178.43.2551,022
140253.178.44.0/22253.178.44.1 to 253.178.47.254253.178.47.2551,022
141253.178.48.0/22253.178.48.1 to 253.178.51.254253.178.51.2551,022
142253.178.52.0/22253.178.52.1 to 253.178.55.254253.178.55.2551,022
143253.178.56.0/22253.178.56.1 to 253.178.59.254253.178.59.2551,022
144253.178.60.0/22253.178.60.1 to 253.178.63.254253.178.63.2551,022
145253.178.64.0/22253.178.64.1 to 253.178.67.254253.178.67.2551,022
146253.178.68.0/22253.178.68.1 to 253.178.71.254253.178.71.2551,022
147253.178.72.0/22253.178.72.1 to 253.178.75.254253.178.75.2551,022
148253.178.76.0/22253.178.76.1 to 253.178.79.254253.178.79.2551,022
149253.178.80.0/22253.178.80.1 to 253.178.83.254253.178.83.2551,022
150253.178.84.0/22253.178.84.1 to 253.178.87.254253.178.87.2551,022
151253.178.88.0/22253.178.88.1 to 253.178.91.254253.178.91.2551,022
152253.178.92.0/22253.178.92.1 to 253.178.95.254253.178.95.2551,022
153253.178.96.0/22253.178.96.1 to 253.178.99.254253.178.99.2551,022
154253.178.100.0/22253.178.100.1 to 253.178.103.254253.178.103.2551,022
155253.178.104.0/22253.178.104.1 to 253.178.107.254253.178.107.2551,022
156253.178.108.0/22253.178.108.1 to 253.178.111.254253.178.111.2551,022
157253.178.112.0/22253.178.112.1 to 253.178.115.254253.178.115.2551,022
158253.178.116.0/22253.178.116.1 to 253.178.119.254253.178.119.2551,022
159253.178.120.0/22253.178.120.1 to 253.178.123.254253.178.123.2551,022
160253.178.124.0/22253.178.124.1 to 253.178.127.254253.178.127.2551,022
161253.178.128.0/22253.178.128.1 to 253.178.131.254253.178.131.2551,022
162253.178.132.0/22253.178.132.1 to 253.178.135.254253.178.135.2551,022
163253.178.136.0/22253.178.136.1 to 253.178.139.254253.178.139.2551,022
164253.178.140.0/22253.178.140.1 to 253.178.143.254253.178.143.2551,022
165253.178.144.0/22253.178.144.1 to 253.178.147.254253.178.147.2551,022
166253.178.148.0/22253.178.148.1 to 253.178.151.254253.178.151.2551,022
167253.178.152.0/22253.178.152.1 to 253.178.155.254253.178.155.2551,022
168253.178.156.0/22253.178.156.1 to 253.178.159.254253.178.159.2551,022
169253.178.160.0/22253.178.160.1 to 253.178.163.254253.178.163.2551,022
170253.178.164.0/22253.178.164.1 to 253.178.167.254253.178.167.2551,022
171253.178.168.0/22253.178.168.1 to 253.178.171.254253.178.171.2551,022
172253.178.172.0/22253.178.172.1 to 253.178.175.254253.178.175.2551,022
173253.178.176.0/22253.178.176.1 to 253.178.179.254253.178.179.2551,022
174253.178.180.0/22253.178.180.1 to 253.178.183.254253.178.183.2551,022
175253.178.184.0/22253.178.184.1 to 253.178.187.254253.178.187.2551,022
176253.178.188.0/22253.178.188.1 to 253.178.191.254253.178.191.2551,022
177253.178.192.0/22253.178.192.1 to 253.178.195.254253.178.195.2551,022
178253.178.196.0/22253.178.196.1 to 253.178.199.254253.178.199.2551,022
179253.178.200.0/22253.178.200.1 to 253.178.203.254253.178.203.2551,022
180253.178.204.0/22253.178.204.1 to 253.178.207.254253.178.207.2551,022
181253.178.208.0/22253.178.208.1 to 253.178.211.254253.178.211.2551,022
182253.178.212.0/22253.178.212.1 to 253.178.215.254253.178.215.2551,022
183253.178.216.0/22253.178.216.1 to 253.178.219.254253.178.219.2551,022
184253.178.220.0/22253.178.220.1 to 253.178.223.254253.178.223.2551,022
185253.178.224.0/22253.178.224.1 to 253.178.227.254253.178.227.2551,022
186253.178.228.0/22253.178.228.1 to 253.178.231.254253.178.231.2551,022
187253.178.232.0/22253.178.232.1 to 253.178.235.254253.178.235.2551,022
188253.178.236.0/22253.178.236.1 to 253.178.239.254253.178.239.2551,022
189253.178.240.0/22253.178.240.1 to 253.178.243.254253.178.243.2551,022
190253.178.244.0/22253.178.244.1 to 253.178.247.254253.178.247.2551,022
191253.178.248.0/22253.178.248.1 to 253.178.251.254253.178.251.2551,022
192253.178.252.0/22253.178.252.1 to 253.178.255.254253.178.255.2551,022
193253.179.0.0/22253.179.0.1 to 253.179.3.254253.179.3.2551,022
194253.179.4.0/22253.179.4.1 to 253.179.7.254253.179.7.2551,022
195253.179.8.0/22253.179.8.1 to 253.179.11.254253.179.11.2551,022
196253.179.12.0/22253.179.12.1 to 253.179.15.254253.179.15.2551,022
197253.179.16.0/22253.179.16.1 to 253.179.19.254253.179.19.2551,022
198253.179.20.0/22253.179.20.1 to 253.179.23.254253.179.23.2551,022
199253.179.24.0/22253.179.24.1 to 253.179.27.254253.179.27.2551,022
200253.179.28.0/22253.179.28.1 to 253.179.31.254253.179.31.2551,022
201253.179.32.0/22253.179.32.1 to 253.179.35.254253.179.35.2551,022
202253.179.36.0/22253.179.36.1 to 253.179.39.254253.179.39.2551,022
203253.179.40.0/22253.179.40.1 to 253.179.43.254253.179.43.2551,022
204253.179.44.0/22253.179.44.1 to 253.179.47.254253.179.47.2551,022
205253.179.48.0/22253.179.48.1 to 253.179.51.254253.179.51.2551,022
206253.179.52.0/22253.179.52.1 to 253.179.55.254253.179.55.2551,022
207253.179.56.0/22253.179.56.1 to 253.179.59.254253.179.59.2551,022
208253.179.60.0/22253.179.60.1 to 253.179.63.254253.179.63.2551,022
209253.179.64.0/22253.179.64.1 to 253.179.67.254253.179.67.2551,022
210253.179.68.0/22253.179.68.1 to 253.179.71.254253.179.71.2551,022
211253.179.72.0/22253.179.72.1 to 253.179.75.254253.179.75.2551,022
212253.179.76.0/22253.179.76.1 to 253.179.79.254253.179.79.2551,022
213253.179.80.0/22253.179.80.1 to 253.179.83.254253.179.83.2551,022
214253.179.84.0/22253.179.84.1 to 253.179.87.254253.179.87.2551,022
215253.179.88.0/22253.179.88.1 to 253.179.91.254253.179.91.2551,022
216253.179.92.0/22253.179.92.1 to 253.179.95.254253.179.95.2551,022
217253.179.96.0/22253.179.96.1 to 253.179.99.254253.179.99.2551,022
218253.179.100.0/22253.179.100.1 to 253.179.103.254253.179.103.2551,022
219253.179.104.0/22253.179.104.1 to 253.179.107.254253.179.107.2551,022
220253.179.108.0/22253.179.108.1 to 253.179.111.254253.179.111.2551,022
221253.179.112.0/22253.179.112.1 to 253.179.115.254253.179.115.2551,022
222253.179.116.0/22253.179.116.1 to 253.179.119.254253.179.119.2551,022
223253.179.120.0/22253.179.120.1 to 253.179.123.254253.179.123.2551,022
224253.179.124.0/22253.179.124.1 to 253.179.127.254253.179.127.2551,022
225253.179.128.0/22253.179.128.1 to 253.179.131.254253.179.131.2551,022
226253.179.132.0/22253.179.132.1 to 253.179.135.254253.179.135.2551,022
227253.179.136.0/22253.179.136.1 to 253.179.139.254253.179.139.2551,022
228253.179.140.0/22253.179.140.1 to 253.179.143.254253.179.143.2551,022
229253.179.144.0/22253.179.144.1 to 253.179.147.254253.179.147.2551,022
230253.179.148.0/22253.179.148.1 to 253.179.151.254253.179.151.2551,022
231253.179.152.0/22253.179.152.1 to 253.179.155.254253.179.155.2551,022
232253.179.156.0/22253.179.156.1 to 253.179.159.254253.179.159.2551,022
233253.179.160.0/22253.179.160.1 to 253.179.163.254253.179.163.2551,022
234253.179.164.0/22253.179.164.1 to 253.179.167.254253.179.167.2551,022
235253.179.168.0/22253.179.168.1 to 253.179.171.254253.179.171.2551,022
236253.179.172.0/22253.179.172.1 to 253.179.175.254253.179.175.2551,022
237253.179.176.0/22253.179.176.1 to 253.179.179.254253.179.179.2551,022
238253.179.180.0/22253.179.180.1 to 253.179.183.254253.179.183.2551,022
239253.179.184.0/22253.179.184.1 to 253.179.187.254253.179.187.2551,022
240253.179.188.0/22253.179.188.1 to 253.179.191.254253.179.191.2551,022
241253.179.192.0/22253.179.192.1 to 253.179.195.254253.179.195.2551,022
242253.179.196.0/22253.179.196.1 to 253.179.199.254253.179.199.2551,022
243253.179.200.0/22253.179.200.1 to 253.179.203.254253.179.203.2551,022
244253.179.204.0/22253.179.204.1 to 253.179.207.254253.179.207.2551,022
245253.179.208.0/22253.179.208.1 to 253.179.211.254253.179.211.2551,022
246253.179.212.0/22253.179.212.1 to 253.179.215.254253.179.215.2551,022
247253.179.216.0/22253.179.216.1 to 253.179.219.254253.179.219.2551,022
248253.179.220.0/22253.179.220.1 to 253.179.223.254253.179.223.2551,022
249253.179.224.0/22253.179.224.1 to 253.179.227.254253.179.227.2551,022
250253.179.228.0/22253.179.228.1 to 253.179.231.254253.179.231.2551,022
251253.179.232.0/22253.179.232.1 to 253.179.235.254253.179.235.2551,022
252253.179.236.0/22253.179.236.1 to 253.179.239.254253.179.239.2551,022
253253.179.240.0/22253.179.240.1 to 253.179.243.254253.179.243.2551,022
254253.179.244.0/22253.179.244.1 to 253.179.247.254253.179.247.2551,022
255253.179.248.0/22253.179.248.1 to 253.179.251.254253.179.251.2551,022
256253.179.252.0/22253.179.252.1 to 253.179.255.254253.179.255.2551,022

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.