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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.

Network250.208.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
250.208.0.0
Broadcast address
250.223.255.255
First usable
250.208.0.1
Last usable
250.223.255.254
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 FAD00000 · Integer 4207935488 to 4208984063
Reverse DNS zones
208.250.in-addr.arpa
209.250.in-addr.arpa
210.250.in-addr.arpa
211.250.in-addr.arpa
212.250.in-addr.arpa
213.250.in-addr.arpa
214.250.in-addr.arpa
215.250.in-addr.arpa
216.250.in-addr.arpa
217.250.in-addr.arpa
218.250.in-addr.arpa
219.250.in-addr.arpa
220.250.in-addr.arpa
221.250.in-addr.arpa
222.250.in-addr.arpa
223.250.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
Address11111010.11010000.00000000.00000000250.208.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11111010.11010000.00000000.00000000250.208.0.0
Broadcast11111010.11011111.11111111.11111111250.223.255.255
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)

250.208.0.0/12 makes 1,024 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1250.208.0.0/22250.208.0.1 to 250.208.3.254250.208.3.2551,022
2250.208.4.0/22250.208.4.1 to 250.208.7.254250.208.7.2551,022
3250.208.8.0/22250.208.8.1 to 250.208.11.254250.208.11.2551,022
4250.208.12.0/22250.208.12.1 to 250.208.15.254250.208.15.2551,022
5250.208.16.0/22250.208.16.1 to 250.208.19.254250.208.19.2551,022
6250.208.20.0/22250.208.20.1 to 250.208.23.254250.208.23.2551,022
7250.208.24.0/22250.208.24.1 to 250.208.27.254250.208.27.2551,022
8250.208.28.0/22250.208.28.1 to 250.208.31.254250.208.31.2551,022
9250.208.32.0/22250.208.32.1 to 250.208.35.254250.208.35.2551,022
10250.208.36.0/22250.208.36.1 to 250.208.39.254250.208.39.2551,022
11250.208.40.0/22250.208.40.1 to 250.208.43.254250.208.43.2551,022
12250.208.44.0/22250.208.44.1 to 250.208.47.254250.208.47.2551,022
13250.208.48.0/22250.208.48.1 to 250.208.51.254250.208.51.2551,022
14250.208.52.0/22250.208.52.1 to 250.208.55.254250.208.55.2551,022
15250.208.56.0/22250.208.56.1 to 250.208.59.254250.208.59.2551,022
16250.208.60.0/22250.208.60.1 to 250.208.63.254250.208.63.2551,022
17250.208.64.0/22250.208.64.1 to 250.208.67.254250.208.67.2551,022
18250.208.68.0/22250.208.68.1 to 250.208.71.254250.208.71.2551,022
19250.208.72.0/22250.208.72.1 to 250.208.75.254250.208.75.2551,022
20250.208.76.0/22250.208.76.1 to 250.208.79.254250.208.79.2551,022
21250.208.80.0/22250.208.80.1 to 250.208.83.254250.208.83.2551,022
22250.208.84.0/22250.208.84.1 to 250.208.87.254250.208.87.2551,022
23250.208.88.0/22250.208.88.1 to 250.208.91.254250.208.91.2551,022
24250.208.92.0/22250.208.92.1 to 250.208.95.254250.208.95.2551,022
25250.208.96.0/22250.208.96.1 to 250.208.99.254250.208.99.2551,022
26250.208.100.0/22250.208.100.1 to 250.208.103.254250.208.103.2551,022
27250.208.104.0/22250.208.104.1 to 250.208.107.254250.208.107.2551,022
28250.208.108.0/22250.208.108.1 to 250.208.111.254250.208.111.2551,022
29250.208.112.0/22250.208.112.1 to 250.208.115.254250.208.115.2551,022
30250.208.116.0/22250.208.116.1 to 250.208.119.254250.208.119.2551,022
31250.208.120.0/22250.208.120.1 to 250.208.123.254250.208.123.2551,022
32250.208.124.0/22250.208.124.1 to 250.208.127.254250.208.127.2551,022
33250.208.128.0/22250.208.128.1 to 250.208.131.254250.208.131.2551,022
34250.208.132.0/22250.208.132.1 to 250.208.135.254250.208.135.2551,022
35250.208.136.0/22250.208.136.1 to 250.208.139.254250.208.139.2551,022
36250.208.140.0/22250.208.140.1 to 250.208.143.254250.208.143.2551,022
37250.208.144.0/22250.208.144.1 to 250.208.147.254250.208.147.2551,022
38250.208.148.0/22250.208.148.1 to 250.208.151.254250.208.151.2551,022
39250.208.152.0/22250.208.152.1 to 250.208.155.254250.208.155.2551,022
40250.208.156.0/22250.208.156.1 to 250.208.159.254250.208.159.2551,022
41250.208.160.0/22250.208.160.1 to 250.208.163.254250.208.163.2551,022
42250.208.164.0/22250.208.164.1 to 250.208.167.254250.208.167.2551,022
43250.208.168.0/22250.208.168.1 to 250.208.171.254250.208.171.2551,022
44250.208.172.0/22250.208.172.1 to 250.208.175.254250.208.175.2551,022
45250.208.176.0/22250.208.176.1 to 250.208.179.254250.208.179.2551,022
46250.208.180.0/22250.208.180.1 to 250.208.183.254250.208.183.2551,022
47250.208.184.0/22250.208.184.1 to 250.208.187.254250.208.187.2551,022
48250.208.188.0/22250.208.188.1 to 250.208.191.254250.208.191.2551,022
49250.208.192.0/22250.208.192.1 to 250.208.195.254250.208.195.2551,022
50250.208.196.0/22250.208.196.1 to 250.208.199.254250.208.199.2551,022
51250.208.200.0/22250.208.200.1 to 250.208.203.254250.208.203.2551,022
52250.208.204.0/22250.208.204.1 to 250.208.207.254250.208.207.2551,022
53250.208.208.0/22250.208.208.1 to 250.208.211.254250.208.211.2551,022
54250.208.212.0/22250.208.212.1 to 250.208.215.254250.208.215.2551,022
55250.208.216.0/22250.208.216.1 to 250.208.219.254250.208.219.2551,022
56250.208.220.0/22250.208.220.1 to 250.208.223.254250.208.223.2551,022
57250.208.224.0/22250.208.224.1 to 250.208.227.254250.208.227.2551,022
58250.208.228.0/22250.208.228.1 to 250.208.231.254250.208.231.2551,022
59250.208.232.0/22250.208.232.1 to 250.208.235.254250.208.235.2551,022
60250.208.236.0/22250.208.236.1 to 250.208.239.254250.208.239.2551,022
61250.208.240.0/22250.208.240.1 to 250.208.243.254250.208.243.2551,022
62250.208.244.0/22250.208.244.1 to 250.208.247.254250.208.247.2551,022
63250.208.248.0/22250.208.248.1 to 250.208.251.254250.208.251.2551,022
64250.208.252.0/22250.208.252.1 to 250.208.255.254250.208.255.2551,022
65250.209.0.0/22250.209.0.1 to 250.209.3.254250.209.3.2551,022
66250.209.4.0/22250.209.4.1 to 250.209.7.254250.209.7.2551,022
67250.209.8.0/22250.209.8.1 to 250.209.11.254250.209.11.2551,022
68250.209.12.0/22250.209.12.1 to 250.209.15.254250.209.15.2551,022
69250.209.16.0/22250.209.16.1 to 250.209.19.254250.209.19.2551,022
70250.209.20.0/22250.209.20.1 to 250.209.23.254250.209.23.2551,022
71250.209.24.0/22250.209.24.1 to 250.209.27.254250.209.27.2551,022
72250.209.28.0/22250.209.28.1 to 250.209.31.254250.209.31.2551,022
73250.209.32.0/22250.209.32.1 to 250.209.35.254250.209.35.2551,022
74250.209.36.0/22250.209.36.1 to 250.209.39.254250.209.39.2551,022
75250.209.40.0/22250.209.40.1 to 250.209.43.254250.209.43.2551,022
76250.209.44.0/22250.209.44.1 to 250.209.47.254250.209.47.2551,022
77250.209.48.0/22250.209.48.1 to 250.209.51.254250.209.51.2551,022
78250.209.52.0/22250.209.52.1 to 250.209.55.254250.209.55.2551,022
79250.209.56.0/22250.209.56.1 to 250.209.59.254250.209.59.2551,022
80250.209.60.0/22250.209.60.1 to 250.209.63.254250.209.63.2551,022
81250.209.64.0/22250.209.64.1 to 250.209.67.254250.209.67.2551,022
82250.209.68.0/22250.209.68.1 to 250.209.71.254250.209.71.2551,022
83250.209.72.0/22250.209.72.1 to 250.209.75.254250.209.75.2551,022
84250.209.76.0/22250.209.76.1 to 250.209.79.254250.209.79.2551,022
85250.209.80.0/22250.209.80.1 to 250.209.83.254250.209.83.2551,022
86250.209.84.0/22250.209.84.1 to 250.209.87.254250.209.87.2551,022
87250.209.88.0/22250.209.88.1 to 250.209.91.254250.209.91.2551,022
88250.209.92.0/22250.209.92.1 to 250.209.95.254250.209.95.2551,022
89250.209.96.0/22250.209.96.1 to 250.209.99.254250.209.99.2551,022
90250.209.100.0/22250.209.100.1 to 250.209.103.254250.209.103.2551,022
91250.209.104.0/22250.209.104.1 to 250.209.107.254250.209.107.2551,022
92250.209.108.0/22250.209.108.1 to 250.209.111.254250.209.111.2551,022
93250.209.112.0/22250.209.112.1 to 250.209.115.254250.209.115.2551,022
94250.209.116.0/22250.209.116.1 to 250.209.119.254250.209.119.2551,022
95250.209.120.0/22250.209.120.1 to 250.209.123.254250.209.123.2551,022
96250.209.124.0/22250.209.124.1 to 250.209.127.254250.209.127.2551,022
97250.209.128.0/22250.209.128.1 to 250.209.131.254250.209.131.2551,022
98250.209.132.0/22250.209.132.1 to 250.209.135.254250.209.135.2551,022
99250.209.136.0/22250.209.136.1 to 250.209.139.254250.209.139.2551,022
100250.209.140.0/22250.209.140.1 to 250.209.143.254250.209.143.2551,022
101250.209.144.0/22250.209.144.1 to 250.209.147.254250.209.147.2551,022
102250.209.148.0/22250.209.148.1 to 250.209.151.254250.209.151.2551,022
103250.209.152.0/22250.209.152.1 to 250.209.155.254250.209.155.2551,022
104250.209.156.0/22250.209.156.1 to 250.209.159.254250.209.159.2551,022
105250.209.160.0/22250.209.160.1 to 250.209.163.254250.209.163.2551,022
106250.209.164.0/22250.209.164.1 to 250.209.167.254250.209.167.2551,022
107250.209.168.0/22250.209.168.1 to 250.209.171.254250.209.171.2551,022
108250.209.172.0/22250.209.172.1 to 250.209.175.254250.209.175.2551,022
109250.209.176.0/22250.209.176.1 to 250.209.179.254250.209.179.2551,022
110250.209.180.0/22250.209.180.1 to 250.209.183.254250.209.183.2551,022
111250.209.184.0/22250.209.184.1 to 250.209.187.254250.209.187.2551,022
112250.209.188.0/22250.209.188.1 to 250.209.191.254250.209.191.2551,022
113250.209.192.0/22250.209.192.1 to 250.209.195.254250.209.195.2551,022
114250.209.196.0/22250.209.196.1 to 250.209.199.254250.209.199.2551,022
115250.209.200.0/22250.209.200.1 to 250.209.203.254250.209.203.2551,022
116250.209.204.0/22250.209.204.1 to 250.209.207.254250.209.207.2551,022
117250.209.208.0/22250.209.208.1 to 250.209.211.254250.209.211.2551,022
118250.209.212.0/22250.209.212.1 to 250.209.215.254250.209.215.2551,022
119250.209.216.0/22250.209.216.1 to 250.209.219.254250.209.219.2551,022
120250.209.220.0/22250.209.220.1 to 250.209.223.254250.209.223.2551,022
121250.209.224.0/22250.209.224.1 to 250.209.227.254250.209.227.2551,022
122250.209.228.0/22250.209.228.1 to 250.209.231.254250.209.231.2551,022
123250.209.232.0/22250.209.232.1 to 250.209.235.254250.209.235.2551,022
124250.209.236.0/22250.209.236.1 to 250.209.239.254250.209.239.2551,022
125250.209.240.0/22250.209.240.1 to 250.209.243.254250.209.243.2551,022
126250.209.244.0/22250.209.244.1 to 250.209.247.254250.209.247.2551,022
127250.209.248.0/22250.209.248.1 to 250.209.251.254250.209.251.2551,022
128250.209.252.0/22250.209.252.1 to 250.209.255.254250.209.255.2551,022
129250.210.0.0/22250.210.0.1 to 250.210.3.254250.210.3.2551,022
130250.210.4.0/22250.210.4.1 to 250.210.7.254250.210.7.2551,022
131250.210.8.0/22250.210.8.1 to 250.210.11.254250.210.11.2551,022
132250.210.12.0/22250.210.12.1 to 250.210.15.254250.210.15.2551,022
133250.210.16.0/22250.210.16.1 to 250.210.19.254250.210.19.2551,022
134250.210.20.0/22250.210.20.1 to 250.210.23.254250.210.23.2551,022
135250.210.24.0/22250.210.24.1 to 250.210.27.254250.210.27.2551,022
136250.210.28.0/22250.210.28.1 to 250.210.31.254250.210.31.2551,022
137250.210.32.0/22250.210.32.1 to 250.210.35.254250.210.35.2551,022
138250.210.36.0/22250.210.36.1 to 250.210.39.254250.210.39.2551,022
139250.210.40.0/22250.210.40.1 to 250.210.43.254250.210.43.2551,022
140250.210.44.0/22250.210.44.1 to 250.210.47.254250.210.47.2551,022
141250.210.48.0/22250.210.48.1 to 250.210.51.254250.210.51.2551,022
142250.210.52.0/22250.210.52.1 to 250.210.55.254250.210.55.2551,022
143250.210.56.0/22250.210.56.1 to 250.210.59.254250.210.59.2551,022
144250.210.60.0/22250.210.60.1 to 250.210.63.254250.210.63.2551,022
145250.210.64.0/22250.210.64.1 to 250.210.67.254250.210.67.2551,022
146250.210.68.0/22250.210.68.1 to 250.210.71.254250.210.71.2551,022
147250.210.72.0/22250.210.72.1 to 250.210.75.254250.210.75.2551,022
148250.210.76.0/22250.210.76.1 to 250.210.79.254250.210.79.2551,022
149250.210.80.0/22250.210.80.1 to 250.210.83.254250.210.83.2551,022
150250.210.84.0/22250.210.84.1 to 250.210.87.254250.210.87.2551,022
151250.210.88.0/22250.210.88.1 to 250.210.91.254250.210.91.2551,022
152250.210.92.0/22250.210.92.1 to 250.210.95.254250.210.95.2551,022
153250.210.96.0/22250.210.96.1 to 250.210.99.254250.210.99.2551,022
154250.210.100.0/22250.210.100.1 to 250.210.103.254250.210.103.2551,022
155250.210.104.0/22250.210.104.1 to 250.210.107.254250.210.107.2551,022
156250.210.108.0/22250.210.108.1 to 250.210.111.254250.210.111.2551,022
157250.210.112.0/22250.210.112.1 to 250.210.115.254250.210.115.2551,022
158250.210.116.0/22250.210.116.1 to 250.210.119.254250.210.119.2551,022
159250.210.120.0/22250.210.120.1 to 250.210.123.254250.210.123.2551,022
160250.210.124.0/22250.210.124.1 to 250.210.127.254250.210.127.2551,022
161250.210.128.0/22250.210.128.1 to 250.210.131.254250.210.131.2551,022
162250.210.132.0/22250.210.132.1 to 250.210.135.254250.210.135.2551,022
163250.210.136.0/22250.210.136.1 to 250.210.139.254250.210.139.2551,022
164250.210.140.0/22250.210.140.1 to 250.210.143.254250.210.143.2551,022
165250.210.144.0/22250.210.144.1 to 250.210.147.254250.210.147.2551,022
166250.210.148.0/22250.210.148.1 to 250.210.151.254250.210.151.2551,022
167250.210.152.0/22250.210.152.1 to 250.210.155.254250.210.155.2551,022
168250.210.156.0/22250.210.156.1 to 250.210.159.254250.210.159.2551,022
169250.210.160.0/22250.210.160.1 to 250.210.163.254250.210.163.2551,022
170250.210.164.0/22250.210.164.1 to 250.210.167.254250.210.167.2551,022
171250.210.168.0/22250.210.168.1 to 250.210.171.254250.210.171.2551,022
172250.210.172.0/22250.210.172.1 to 250.210.175.254250.210.175.2551,022
173250.210.176.0/22250.210.176.1 to 250.210.179.254250.210.179.2551,022
174250.210.180.0/22250.210.180.1 to 250.210.183.254250.210.183.2551,022
175250.210.184.0/22250.210.184.1 to 250.210.187.254250.210.187.2551,022
176250.210.188.0/22250.210.188.1 to 250.210.191.254250.210.191.2551,022
177250.210.192.0/22250.210.192.1 to 250.210.195.254250.210.195.2551,022
178250.210.196.0/22250.210.196.1 to 250.210.199.254250.210.199.2551,022
179250.210.200.0/22250.210.200.1 to 250.210.203.254250.210.203.2551,022
180250.210.204.0/22250.210.204.1 to 250.210.207.254250.210.207.2551,022
181250.210.208.0/22250.210.208.1 to 250.210.211.254250.210.211.2551,022
182250.210.212.0/22250.210.212.1 to 250.210.215.254250.210.215.2551,022
183250.210.216.0/22250.210.216.1 to 250.210.219.254250.210.219.2551,022
184250.210.220.0/22250.210.220.1 to 250.210.223.254250.210.223.2551,022
185250.210.224.0/22250.210.224.1 to 250.210.227.254250.210.227.2551,022
186250.210.228.0/22250.210.228.1 to 250.210.231.254250.210.231.2551,022
187250.210.232.0/22250.210.232.1 to 250.210.235.254250.210.235.2551,022
188250.210.236.0/22250.210.236.1 to 250.210.239.254250.210.239.2551,022
189250.210.240.0/22250.210.240.1 to 250.210.243.254250.210.243.2551,022
190250.210.244.0/22250.210.244.1 to 250.210.247.254250.210.247.2551,022
191250.210.248.0/22250.210.248.1 to 250.210.251.254250.210.251.2551,022
192250.210.252.0/22250.210.252.1 to 250.210.255.254250.210.255.2551,022
193250.211.0.0/22250.211.0.1 to 250.211.3.254250.211.3.2551,022
194250.211.4.0/22250.211.4.1 to 250.211.7.254250.211.7.2551,022
195250.211.8.0/22250.211.8.1 to 250.211.11.254250.211.11.2551,022
196250.211.12.0/22250.211.12.1 to 250.211.15.254250.211.15.2551,022
197250.211.16.0/22250.211.16.1 to 250.211.19.254250.211.19.2551,022
198250.211.20.0/22250.211.20.1 to 250.211.23.254250.211.23.2551,022
199250.211.24.0/22250.211.24.1 to 250.211.27.254250.211.27.2551,022
200250.211.28.0/22250.211.28.1 to 250.211.31.254250.211.31.2551,022
201250.211.32.0/22250.211.32.1 to 250.211.35.254250.211.35.2551,022
202250.211.36.0/22250.211.36.1 to 250.211.39.254250.211.39.2551,022
203250.211.40.0/22250.211.40.1 to 250.211.43.254250.211.43.2551,022
204250.211.44.0/22250.211.44.1 to 250.211.47.254250.211.47.2551,022
205250.211.48.0/22250.211.48.1 to 250.211.51.254250.211.51.2551,022
206250.211.52.0/22250.211.52.1 to 250.211.55.254250.211.55.2551,022
207250.211.56.0/22250.211.56.1 to 250.211.59.254250.211.59.2551,022
208250.211.60.0/22250.211.60.1 to 250.211.63.254250.211.63.2551,022
209250.211.64.0/22250.211.64.1 to 250.211.67.254250.211.67.2551,022
210250.211.68.0/22250.211.68.1 to 250.211.71.254250.211.71.2551,022
211250.211.72.0/22250.211.72.1 to 250.211.75.254250.211.75.2551,022
212250.211.76.0/22250.211.76.1 to 250.211.79.254250.211.79.2551,022
213250.211.80.0/22250.211.80.1 to 250.211.83.254250.211.83.2551,022
214250.211.84.0/22250.211.84.1 to 250.211.87.254250.211.87.2551,022
215250.211.88.0/22250.211.88.1 to 250.211.91.254250.211.91.2551,022
216250.211.92.0/22250.211.92.1 to 250.211.95.254250.211.95.2551,022
217250.211.96.0/22250.211.96.1 to 250.211.99.254250.211.99.2551,022
218250.211.100.0/22250.211.100.1 to 250.211.103.254250.211.103.2551,022
219250.211.104.0/22250.211.104.1 to 250.211.107.254250.211.107.2551,022
220250.211.108.0/22250.211.108.1 to 250.211.111.254250.211.111.2551,022
221250.211.112.0/22250.211.112.1 to 250.211.115.254250.211.115.2551,022
222250.211.116.0/22250.211.116.1 to 250.211.119.254250.211.119.2551,022
223250.211.120.0/22250.211.120.1 to 250.211.123.254250.211.123.2551,022
224250.211.124.0/22250.211.124.1 to 250.211.127.254250.211.127.2551,022
225250.211.128.0/22250.211.128.1 to 250.211.131.254250.211.131.2551,022
226250.211.132.0/22250.211.132.1 to 250.211.135.254250.211.135.2551,022
227250.211.136.0/22250.211.136.1 to 250.211.139.254250.211.139.2551,022
228250.211.140.0/22250.211.140.1 to 250.211.143.254250.211.143.2551,022
229250.211.144.0/22250.211.144.1 to 250.211.147.254250.211.147.2551,022
230250.211.148.0/22250.211.148.1 to 250.211.151.254250.211.151.2551,022
231250.211.152.0/22250.211.152.1 to 250.211.155.254250.211.155.2551,022
232250.211.156.0/22250.211.156.1 to 250.211.159.254250.211.159.2551,022
233250.211.160.0/22250.211.160.1 to 250.211.163.254250.211.163.2551,022
234250.211.164.0/22250.211.164.1 to 250.211.167.254250.211.167.2551,022
235250.211.168.0/22250.211.168.1 to 250.211.171.254250.211.171.2551,022
236250.211.172.0/22250.211.172.1 to 250.211.175.254250.211.175.2551,022
237250.211.176.0/22250.211.176.1 to 250.211.179.254250.211.179.2551,022
238250.211.180.0/22250.211.180.1 to 250.211.183.254250.211.183.2551,022
239250.211.184.0/22250.211.184.1 to 250.211.187.254250.211.187.2551,022
240250.211.188.0/22250.211.188.1 to 250.211.191.254250.211.191.2551,022
241250.211.192.0/22250.211.192.1 to 250.211.195.254250.211.195.2551,022
242250.211.196.0/22250.211.196.1 to 250.211.199.254250.211.199.2551,022
243250.211.200.0/22250.211.200.1 to 250.211.203.254250.211.203.2551,022
244250.211.204.0/22250.211.204.1 to 250.211.207.254250.211.207.2551,022
245250.211.208.0/22250.211.208.1 to 250.211.211.254250.211.211.2551,022
246250.211.212.0/22250.211.212.1 to 250.211.215.254250.211.215.2551,022
247250.211.216.0/22250.211.216.1 to 250.211.219.254250.211.219.2551,022
248250.211.220.0/22250.211.220.1 to 250.211.223.254250.211.223.2551,022
249250.211.224.0/22250.211.224.1 to 250.211.227.254250.211.227.2551,022
250250.211.228.0/22250.211.228.1 to 250.211.231.254250.211.231.2551,022
251250.211.232.0/22250.211.232.1 to 250.211.235.254250.211.235.2551,022
252250.211.236.0/22250.211.236.1 to 250.211.239.254250.211.239.2551,022
253250.211.240.0/22250.211.240.1 to 250.211.243.254250.211.243.2551,022
254250.211.244.0/22250.211.244.1 to 250.211.247.254250.211.247.2551,022
255250.211.248.0/22250.211.248.1 to 250.211.251.254250.211.251.2551,022
256250.211.252.0/22250.211.252.1 to 250.211.255.254250.211.255.2551,022

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.