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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.

Network244.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
244.0.0.0
Broadcast address
247.255.255.255
First usable
244.0.0.1
Last usable
247.255.255.254
Usable hosts
67,108,862 (67,108,864 less the network and broadcast addresses)
Subnet mask
252.0.0.0
Wildcard mask
3.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/6
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F4000000 · Integer 4093640704 to 4160749567
Reverse DNS zones
244.in-addr.arpa
245.in-addr.arpa
246.in-addr.arpa
247.in-addr.arpa
/6 is not on a 8-bit boundary, so it takes 4 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11110100.00000000.00000000.00000000244.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network11110100.00000000.00000000.00000000244.0.0.0
Broadcast11110111.11111111.11111111.11111111247.255.255.255
Split into smaller subnets/14
/7 (2)/8 (4)/9 (8)/10 (16)/11 (32)/12 (64)/13 (128)/14 (256)/15 (512)/16 (1,024)/17 (2,048)/18 (4,096)

244.0.0.0/6 makes 256 subnets of /14.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1244.0.0.0/14244.0.0.1 to 244.3.255.254244.3.255.255262,142
2244.4.0.0/14244.4.0.1 to 244.7.255.254244.7.255.255262,142
3244.8.0.0/14244.8.0.1 to 244.11.255.254244.11.255.255262,142
4244.12.0.0/14244.12.0.1 to 244.15.255.254244.15.255.255262,142
5244.16.0.0/14244.16.0.1 to 244.19.255.254244.19.255.255262,142
6244.20.0.0/14244.20.0.1 to 244.23.255.254244.23.255.255262,142
7244.24.0.0/14244.24.0.1 to 244.27.255.254244.27.255.255262,142
8244.28.0.0/14244.28.0.1 to 244.31.255.254244.31.255.255262,142
9244.32.0.0/14244.32.0.1 to 244.35.255.254244.35.255.255262,142
10244.36.0.0/14244.36.0.1 to 244.39.255.254244.39.255.255262,142
11244.40.0.0/14244.40.0.1 to 244.43.255.254244.43.255.255262,142
12244.44.0.0/14244.44.0.1 to 244.47.255.254244.47.255.255262,142
13244.48.0.0/14244.48.0.1 to 244.51.255.254244.51.255.255262,142
14244.52.0.0/14244.52.0.1 to 244.55.255.254244.55.255.255262,142
15244.56.0.0/14244.56.0.1 to 244.59.255.254244.59.255.255262,142
16244.60.0.0/14244.60.0.1 to 244.63.255.254244.63.255.255262,142
17244.64.0.0/14244.64.0.1 to 244.67.255.254244.67.255.255262,142
18244.68.0.0/14244.68.0.1 to 244.71.255.254244.71.255.255262,142
19244.72.0.0/14244.72.0.1 to 244.75.255.254244.75.255.255262,142
20244.76.0.0/14244.76.0.1 to 244.79.255.254244.79.255.255262,142
21244.80.0.0/14244.80.0.1 to 244.83.255.254244.83.255.255262,142
22244.84.0.0/14244.84.0.1 to 244.87.255.254244.87.255.255262,142
23244.88.0.0/14244.88.0.1 to 244.91.255.254244.91.255.255262,142
24244.92.0.0/14244.92.0.1 to 244.95.255.254244.95.255.255262,142
25244.96.0.0/14244.96.0.1 to 244.99.255.254244.99.255.255262,142
26244.100.0.0/14244.100.0.1 to 244.103.255.254244.103.255.255262,142
27244.104.0.0/14244.104.0.1 to 244.107.255.254244.107.255.255262,142
28244.108.0.0/14244.108.0.1 to 244.111.255.254244.111.255.255262,142
29244.112.0.0/14244.112.0.1 to 244.115.255.254244.115.255.255262,142
30244.116.0.0/14244.116.0.1 to 244.119.255.254244.119.255.255262,142
31244.120.0.0/14244.120.0.1 to 244.123.255.254244.123.255.255262,142
32244.124.0.0/14244.124.0.1 to 244.127.255.254244.127.255.255262,142
33244.128.0.0/14244.128.0.1 to 244.131.255.254244.131.255.255262,142
34244.132.0.0/14244.132.0.1 to 244.135.255.254244.135.255.255262,142
35244.136.0.0/14244.136.0.1 to 244.139.255.254244.139.255.255262,142
36244.140.0.0/14244.140.0.1 to 244.143.255.254244.143.255.255262,142
37244.144.0.0/14244.144.0.1 to 244.147.255.254244.147.255.255262,142
38244.148.0.0/14244.148.0.1 to 244.151.255.254244.151.255.255262,142
39244.152.0.0/14244.152.0.1 to 244.155.255.254244.155.255.255262,142
40244.156.0.0/14244.156.0.1 to 244.159.255.254244.159.255.255262,142
41244.160.0.0/14244.160.0.1 to 244.163.255.254244.163.255.255262,142
42244.164.0.0/14244.164.0.1 to 244.167.255.254244.167.255.255262,142
43244.168.0.0/14244.168.0.1 to 244.171.255.254244.171.255.255262,142
44244.172.0.0/14244.172.0.1 to 244.175.255.254244.175.255.255262,142
45244.176.0.0/14244.176.0.1 to 244.179.255.254244.179.255.255262,142
46244.180.0.0/14244.180.0.1 to 244.183.255.254244.183.255.255262,142
47244.184.0.0/14244.184.0.1 to 244.187.255.254244.187.255.255262,142
48244.188.0.0/14244.188.0.1 to 244.191.255.254244.191.255.255262,142
49244.192.0.0/14244.192.0.1 to 244.195.255.254244.195.255.255262,142
50244.196.0.0/14244.196.0.1 to 244.199.255.254244.199.255.255262,142
51244.200.0.0/14244.200.0.1 to 244.203.255.254244.203.255.255262,142
52244.204.0.0/14244.204.0.1 to 244.207.255.254244.207.255.255262,142
53244.208.0.0/14244.208.0.1 to 244.211.255.254244.211.255.255262,142
54244.212.0.0/14244.212.0.1 to 244.215.255.254244.215.255.255262,142
55244.216.0.0/14244.216.0.1 to 244.219.255.254244.219.255.255262,142
56244.220.0.0/14244.220.0.1 to 244.223.255.254244.223.255.255262,142
57244.224.0.0/14244.224.0.1 to 244.227.255.254244.227.255.255262,142
58244.228.0.0/14244.228.0.1 to 244.231.255.254244.231.255.255262,142
59244.232.0.0/14244.232.0.1 to 244.235.255.254244.235.255.255262,142
60244.236.0.0/14244.236.0.1 to 244.239.255.254244.239.255.255262,142
61244.240.0.0/14244.240.0.1 to 244.243.255.254244.243.255.255262,142
62244.244.0.0/14244.244.0.1 to 244.247.255.254244.247.255.255262,142
63244.248.0.0/14244.248.0.1 to 244.251.255.254244.251.255.255262,142
64244.252.0.0/14244.252.0.1 to 244.255.255.254244.255.255.255262,142
65245.0.0.0/14245.0.0.1 to 245.3.255.254245.3.255.255262,142
66245.4.0.0/14245.4.0.1 to 245.7.255.254245.7.255.255262,142
67245.8.0.0/14245.8.0.1 to 245.11.255.254245.11.255.255262,142
68245.12.0.0/14245.12.0.1 to 245.15.255.254245.15.255.255262,142
69245.16.0.0/14245.16.0.1 to 245.19.255.254245.19.255.255262,142
70245.20.0.0/14245.20.0.1 to 245.23.255.254245.23.255.255262,142
71245.24.0.0/14245.24.0.1 to 245.27.255.254245.27.255.255262,142
72245.28.0.0/14245.28.0.1 to 245.31.255.254245.31.255.255262,142
73245.32.0.0/14245.32.0.1 to 245.35.255.254245.35.255.255262,142
74245.36.0.0/14245.36.0.1 to 245.39.255.254245.39.255.255262,142
75245.40.0.0/14245.40.0.1 to 245.43.255.254245.43.255.255262,142
76245.44.0.0/14245.44.0.1 to 245.47.255.254245.47.255.255262,142
77245.48.0.0/14245.48.0.1 to 245.51.255.254245.51.255.255262,142
78245.52.0.0/14245.52.0.1 to 245.55.255.254245.55.255.255262,142
79245.56.0.0/14245.56.0.1 to 245.59.255.254245.59.255.255262,142
80245.60.0.0/14245.60.0.1 to 245.63.255.254245.63.255.255262,142
81245.64.0.0/14245.64.0.1 to 245.67.255.254245.67.255.255262,142
82245.68.0.0/14245.68.0.1 to 245.71.255.254245.71.255.255262,142
83245.72.0.0/14245.72.0.1 to 245.75.255.254245.75.255.255262,142
84245.76.0.0/14245.76.0.1 to 245.79.255.254245.79.255.255262,142
85245.80.0.0/14245.80.0.1 to 245.83.255.254245.83.255.255262,142
86245.84.0.0/14245.84.0.1 to 245.87.255.254245.87.255.255262,142
87245.88.0.0/14245.88.0.1 to 245.91.255.254245.91.255.255262,142
88245.92.0.0/14245.92.0.1 to 245.95.255.254245.95.255.255262,142
89245.96.0.0/14245.96.0.1 to 245.99.255.254245.99.255.255262,142
90245.100.0.0/14245.100.0.1 to 245.103.255.254245.103.255.255262,142
91245.104.0.0/14245.104.0.1 to 245.107.255.254245.107.255.255262,142
92245.108.0.0/14245.108.0.1 to 245.111.255.254245.111.255.255262,142
93245.112.0.0/14245.112.0.1 to 245.115.255.254245.115.255.255262,142
94245.116.0.0/14245.116.0.1 to 245.119.255.254245.119.255.255262,142
95245.120.0.0/14245.120.0.1 to 245.123.255.254245.123.255.255262,142
96245.124.0.0/14245.124.0.1 to 245.127.255.254245.127.255.255262,142
97245.128.0.0/14245.128.0.1 to 245.131.255.254245.131.255.255262,142
98245.132.0.0/14245.132.0.1 to 245.135.255.254245.135.255.255262,142
99245.136.0.0/14245.136.0.1 to 245.139.255.254245.139.255.255262,142
100245.140.0.0/14245.140.0.1 to 245.143.255.254245.143.255.255262,142
101245.144.0.0/14245.144.0.1 to 245.147.255.254245.147.255.255262,142
102245.148.0.0/14245.148.0.1 to 245.151.255.254245.151.255.255262,142
103245.152.0.0/14245.152.0.1 to 245.155.255.254245.155.255.255262,142
104245.156.0.0/14245.156.0.1 to 245.159.255.254245.159.255.255262,142
105245.160.0.0/14245.160.0.1 to 245.163.255.254245.163.255.255262,142
106245.164.0.0/14245.164.0.1 to 245.167.255.254245.167.255.255262,142
107245.168.0.0/14245.168.0.1 to 245.171.255.254245.171.255.255262,142
108245.172.0.0/14245.172.0.1 to 245.175.255.254245.175.255.255262,142
109245.176.0.0/14245.176.0.1 to 245.179.255.254245.179.255.255262,142
110245.180.0.0/14245.180.0.1 to 245.183.255.254245.183.255.255262,142
111245.184.0.0/14245.184.0.1 to 245.187.255.254245.187.255.255262,142
112245.188.0.0/14245.188.0.1 to 245.191.255.254245.191.255.255262,142
113245.192.0.0/14245.192.0.1 to 245.195.255.254245.195.255.255262,142
114245.196.0.0/14245.196.0.1 to 245.199.255.254245.199.255.255262,142
115245.200.0.0/14245.200.0.1 to 245.203.255.254245.203.255.255262,142
116245.204.0.0/14245.204.0.1 to 245.207.255.254245.207.255.255262,142
117245.208.0.0/14245.208.0.1 to 245.211.255.254245.211.255.255262,142
118245.212.0.0/14245.212.0.1 to 245.215.255.254245.215.255.255262,142
119245.216.0.0/14245.216.0.1 to 245.219.255.254245.219.255.255262,142
120245.220.0.0/14245.220.0.1 to 245.223.255.254245.223.255.255262,142
121245.224.0.0/14245.224.0.1 to 245.227.255.254245.227.255.255262,142
122245.228.0.0/14245.228.0.1 to 245.231.255.254245.231.255.255262,142
123245.232.0.0/14245.232.0.1 to 245.235.255.254245.235.255.255262,142
124245.236.0.0/14245.236.0.1 to 245.239.255.254245.239.255.255262,142
125245.240.0.0/14245.240.0.1 to 245.243.255.254245.243.255.255262,142
126245.244.0.0/14245.244.0.1 to 245.247.255.254245.247.255.255262,142
127245.248.0.0/14245.248.0.1 to 245.251.255.254245.251.255.255262,142
128245.252.0.0/14245.252.0.1 to 245.255.255.254245.255.255.255262,142
129246.0.0.0/14246.0.0.1 to 246.3.255.254246.3.255.255262,142
130246.4.0.0/14246.4.0.1 to 246.7.255.254246.7.255.255262,142
131246.8.0.0/14246.8.0.1 to 246.11.255.254246.11.255.255262,142
132246.12.0.0/14246.12.0.1 to 246.15.255.254246.15.255.255262,142
133246.16.0.0/14246.16.0.1 to 246.19.255.254246.19.255.255262,142
134246.20.0.0/14246.20.0.1 to 246.23.255.254246.23.255.255262,142
135246.24.0.0/14246.24.0.1 to 246.27.255.254246.27.255.255262,142
136246.28.0.0/14246.28.0.1 to 246.31.255.254246.31.255.255262,142
137246.32.0.0/14246.32.0.1 to 246.35.255.254246.35.255.255262,142
138246.36.0.0/14246.36.0.1 to 246.39.255.254246.39.255.255262,142
139246.40.0.0/14246.40.0.1 to 246.43.255.254246.43.255.255262,142
140246.44.0.0/14246.44.0.1 to 246.47.255.254246.47.255.255262,142
141246.48.0.0/14246.48.0.1 to 246.51.255.254246.51.255.255262,142
142246.52.0.0/14246.52.0.1 to 246.55.255.254246.55.255.255262,142
143246.56.0.0/14246.56.0.1 to 246.59.255.254246.59.255.255262,142
144246.60.0.0/14246.60.0.1 to 246.63.255.254246.63.255.255262,142
145246.64.0.0/14246.64.0.1 to 246.67.255.254246.67.255.255262,142
146246.68.0.0/14246.68.0.1 to 246.71.255.254246.71.255.255262,142
147246.72.0.0/14246.72.0.1 to 246.75.255.254246.75.255.255262,142
148246.76.0.0/14246.76.0.1 to 246.79.255.254246.79.255.255262,142
149246.80.0.0/14246.80.0.1 to 246.83.255.254246.83.255.255262,142
150246.84.0.0/14246.84.0.1 to 246.87.255.254246.87.255.255262,142
151246.88.0.0/14246.88.0.1 to 246.91.255.254246.91.255.255262,142
152246.92.0.0/14246.92.0.1 to 246.95.255.254246.95.255.255262,142
153246.96.0.0/14246.96.0.1 to 246.99.255.254246.99.255.255262,142
154246.100.0.0/14246.100.0.1 to 246.103.255.254246.103.255.255262,142
155246.104.0.0/14246.104.0.1 to 246.107.255.254246.107.255.255262,142
156246.108.0.0/14246.108.0.1 to 246.111.255.254246.111.255.255262,142
157246.112.0.0/14246.112.0.1 to 246.115.255.254246.115.255.255262,142
158246.116.0.0/14246.116.0.1 to 246.119.255.254246.119.255.255262,142
159246.120.0.0/14246.120.0.1 to 246.123.255.254246.123.255.255262,142
160246.124.0.0/14246.124.0.1 to 246.127.255.254246.127.255.255262,142
161246.128.0.0/14246.128.0.1 to 246.131.255.254246.131.255.255262,142
162246.132.0.0/14246.132.0.1 to 246.135.255.254246.135.255.255262,142
163246.136.0.0/14246.136.0.1 to 246.139.255.254246.139.255.255262,142
164246.140.0.0/14246.140.0.1 to 246.143.255.254246.143.255.255262,142
165246.144.0.0/14246.144.0.1 to 246.147.255.254246.147.255.255262,142
166246.148.0.0/14246.148.0.1 to 246.151.255.254246.151.255.255262,142
167246.152.0.0/14246.152.0.1 to 246.155.255.254246.155.255.255262,142
168246.156.0.0/14246.156.0.1 to 246.159.255.254246.159.255.255262,142
169246.160.0.0/14246.160.0.1 to 246.163.255.254246.163.255.255262,142
170246.164.0.0/14246.164.0.1 to 246.167.255.254246.167.255.255262,142
171246.168.0.0/14246.168.0.1 to 246.171.255.254246.171.255.255262,142
172246.172.0.0/14246.172.0.1 to 246.175.255.254246.175.255.255262,142
173246.176.0.0/14246.176.0.1 to 246.179.255.254246.179.255.255262,142
174246.180.0.0/14246.180.0.1 to 246.183.255.254246.183.255.255262,142
175246.184.0.0/14246.184.0.1 to 246.187.255.254246.187.255.255262,142
176246.188.0.0/14246.188.0.1 to 246.191.255.254246.191.255.255262,142
177246.192.0.0/14246.192.0.1 to 246.195.255.254246.195.255.255262,142
178246.196.0.0/14246.196.0.1 to 246.199.255.254246.199.255.255262,142
179246.200.0.0/14246.200.0.1 to 246.203.255.254246.203.255.255262,142
180246.204.0.0/14246.204.0.1 to 246.207.255.254246.207.255.255262,142
181246.208.0.0/14246.208.0.1 to 246.211.255.254246.211.255.255262,142
182246.212.0.0/14246.212.0.1 to 246.215.255.254246.215.255.255262,142
183246.216.0.0/14246.216.0.1 to 246.219.255.254246.219.255.255262,142
184246.220.0.0/14246.220.0.1 to 246.223.255.254246.223.255.255262,142
185246.224.0.0/14246.224.0.1 to 246.227.255.254246.227.255.255262,142
186246.228.0.0/14246.228.0.1 to 246.231.255.254246.231.255.255262,142
187246.232.0.0/14246.232.0.1 to 246.235.255.254246.235.255.255262,142
188246.236.0.0/14246.236.0.1 to 246.239.255.254246.239.255.255262,142
189246.240.0.0/14246.240.0.1 to 246.243.255.254246.243.255.255262,142
190246.244.0.0/14246.244.0.1 to 246.247.255.254246.247.255.255262,142
191246.248.0.0/14246.248.0.1 to 246.251.255.254246.251.255.255262,142
192246.252.0.0/14246.252.0.1 to 246.255.255.254246.255.255.255262,142
193247.0.0.0/14247.0.0.1 to 247.3.255.254247.3.255.255262,142
194247.4.0.0/14247.4.0.1 to 247.7.255.254247.7.255.255262,142
195247.8.0.0/14247.8.0.1 to 247.11.255.254247.11.255.255262,142
196247.12.0.0/14247.12.0.1 to 247.15.255.254247.15.255.255262,142
197247.16.0.0/14247.16.0.1 to 247.19.255.254247.19.255.255262,142
198247.20.0.0/14247.20.0.1 to 247.23.255.254247.23.255.255262,142
199247.24.0.0/14247.24.0.1 to 247.27.255.254247.27.255.255262,142
200247.28.0.0/14247.28.0.1 to 247.31.255.254247.31.255.255262,142
201247.32.0.0/14247.32.0.1 to 247.35.255.254247.35.255.255262,142
202247.36.0.0/14247.36.0.1 to 247.39.255.254247.39.255.255262,142
203247.40.0.0/14247.40.0.1 to 247.43.255.254247.43.255.255262,142
204247.44.0.0/14247.44.0.1 to 247.47.255.254247.47.255.255262,142
205247.48.0.0/14247.48.0.1 to 247.51.255.254247.51.255.255262,142
206247.52.0.0/14247.52.0.1 to 247.55.255.254247.55.255.255262,142
207247.56.0.0/14247.56.0.1 to 247.59.255.254247.59.255.255262,142
208247.60.0.0/14247.60.0.1 to 247.63.255.254247.63.255.255262,142
209247.64.0.0/14247.64.0.1 to 247.67.255.254247.67.255.255262,142
210247.68.0.0/14247.68.0.1 to 247.71.255.254247.71.255.255262,142
211247.72.0.0/14247.72.0.1 to 247.75.255.254247.75.255.255262,142
212247.76.0.0/14247.76.0.1 to 247.79.255.254247.79.255.255262,142
213247.80.0.0/14247.80.0.1 to 247.83.255.254247.83.255.255262,142
214247.84.0.0/14247.84.0.1 to 247.87.255.254247.87.255.255262,142
215247.88.0.0/14247.88.0.1 to 247.91.255.254247.91.255.255262,142
216247.92.0.0/14247.92.0.1 to 247.95.255.254247.95.255.255262,142
217247.96.0.0/14247.96.0.1 to 247.99.255.254247.99.255.255262,142
218247.100.0.0/14247.100.0.1 to 247.103.255.254247.103.255.255262,142
219247.104.0.0/14247.104.0.1 to 247.107.255.254247.107.255.255262,142
220247.108.0.0/14247.108.0.1 to 247.111.255.254247.111.255.255262,142
221247.112.0.0/14247.112.0.1 to 247.115.255.254247.115.255.255262,142
222247.116.0.0/14247.116.0.1 to 247.119.255.254247.119.255.255262,142
223247.120.0.0/14247.120.0.1 to 247.123.255.254247.123.255.255262,142
224247.124.0.0/14247.124.0.1 to 247.127.255.254247.127.255.255262,142
225247.128.0.0/14247.128.0.1 to 247.131.255.254247.131.255.255262,142
226247.132.0.0/14247.132.0.1 to 247.135.255.254247.135.255.255262,142
227247.136.0.0/14247.136.0.1 to 247.139.255.254247.139.255.255262,142
228247.140.0.0/14247.140.0.1 to 247.143.255.254247.143.255.255262,142
229247.144.0.0/14247.144.0.1 to 247.147.255.254247.147.255.255262,142
230247.148.0.0/14247.148.0.1 to 247.151.255.254247.151.255.255262,142
231247.152.0.0/14247.152.0.1 to 247.155.255.254247.155.255.255262,142
232247.156.0.0/14247.156.0.1 to 247.159.255.254247.159.255.255262,142
233247.160.0.0/14247.160.0.1 to 247.163.255.254247.163.255.255262,142
234247.164.0.0/14247.164.0.1 to 247.167.255.254247.167.255.255262,142
235247.168.0.0/14247.168.0.1 to 247.171.255.254247.171.255.255262,142
236247.172.0.0/14247.172.0.1 to 247.175.255.254247.175.255.255262,142
237247.176.0.0/14247.176.0.1 to 247.179.255.254247.179.255.255262,142
238247.180.0.0/14247.180.0.1 to 247.183.255.254247.183.255.255262,142
239247.184.0.0/14247.184.0.1 to 247.187.255.254247.187.255.255262,142
240247.188.0.0/14247.188.0.1 to 247.191.255.254247.191.255.255262,142
241247.192.0.0/14247.192.0.1 to 247.195.255.254247.195.255.255262,142
242247.196.0.0/14247.196.0.1 to 247.199.255.254247.199.255.255262,142
243247.200.0.0/14247.200.0.1 to 247.203.255.254247.203.255.255262,142
244247.204.0.0/14247.204.0.1 to 247.207.255.254247.207.255.255262,142
245247.208.0.0/14247.208.0.1 to 247.211.255.254247.211.255.255262,142
246247.212.0.0/14247.212.0.1 to 247.215.255.254247.215.255.255262,142
247247.216.0.0/14247.216.0.1 to 247.219.255.254247.219.255.255262,142
248247.220.0.0/14247.220.0.1 to 247.223.255.254247.223.255.255262,142
249247.224.0.0/14247.224.0.1 to 247.227.255.254247.227.255.255262,142
250247.228.0.0/14247.228.0.1 to 247.231.255.254247.231.255.255262,142
251247.232.0.0/14247.232.0.1 to 247.235.255.254247.235.255.255262,142
252247.236.0.0/14247.236.0.1 to 247.239.255.254247.239.255.255262,142
253247.240.0.0/14247.240.0.1 to 247.243.255.254247.243.255.255262,142
254247.244.0.0/14247.244.0.1 to 247.247.255.254247.247.255.255262,142
255247.248.0.0/14247.248.0.1 to 247.251.255.254247.251.255.255262,142
256247.252.0.0/14247.252.0.1 to 247.255.255.254247.255.255.255262,142

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.